Regional and Topical Anesthesia for Awake Endotracheal Intubation
Based on Hadzic’s Textbook of RAPM 2nd Ed 2017Artwork by Vali Lancea
Awake endotracheal intubation can be achieved using a variety of equipment, such as video laryngoscopes, optical stylets, and fiber-optic scopes. Appropriate anesthesia of the airway and sedation can enable any of these techniques to be used successfully
The commonest method used to perform an awake endotracheal intubation is with a flexible fiberscope, and an awake fiber-optic intubation is regarded as the gold standard for the endotracheal intubation of patients with an anticipated difficult airway. This procedure requires skills and knowledge that should be familiar to all anesthesiologists.
Recently, there have been many advances in regional anesthesia, allowing for more complicated and innovative procedures to be done under regional block techniques; however, not all of these cases can be done solely under regional anesthesia. Often, a combination of regional and general anesthesia is required; therefore, all anesthesiologists must be familiar with awake intubation techniques, especially if the patient has an anticipated difficult airway. Anesthetizing patients with an anticipated difficult airway is often a source of anxiety and trepidation, but appropriate airway topicalization and sedation techniques can create the appropriate conditions for a safe and stress-free procedure for both the patient and the anesthesiologist
It is difficult to give precise figures on the incidence of difficult airways due to a variety of reasons, including population differences, operator skill variation, operator reporting, and an inconsistency in the definition of a difficult airway. In the general population, the approximate figures for the incidence of
Cormack and Lehane laryngoscopy grades 3 and 4 is 10%, difficult intubation is 1%, and difficult bag mask ventilation is 0.08%–5%.1–4.
Endotracheal intubation is usually performed under general anesthesia, but if a difficult airway is anticipated, then this should ideally be done under regional anesthesia (with or without sedation) as this allows the patient to breathe spontaneously, maintain airway patency, and cooperate with the operator. If any untoward difficulties are experienced, then the procedure can be abandoned with minimum risk to the patient. There are obvious exceptions to performing an awake intubation, such as patient refusal, young children, and uncooperative patients (due to confusion or learning disabilities).
To successfully perform an awake endotracheal intubation, one should be familiar with the following:
- Sensory innervation of the upper airway
- Agents available for topicalization
- Application techniques available to topicalize the airway
- Regional anesthesia techniques, landmark or ultrasound guided
- Safe sedation techniques
SENSORY INNERVATION OF THE AIRWAY
The upper airway is divided into the nasal and oral cavities, the pharynx, and the larynx. The sensory innervation to the upper airway is supplied by the trigeminal, glossopharyngeal, and vagus nerves (Figure 1).
The nose is entirely innervated by branches of the trigeminal nerve. Septum and anterior parts of the nasal cavity are affected by the anterior ethmoidal nerve (a branch of the ophthalmic nerve). The rest of the nasal cavity is innervated by the greater and lesser palatine nerves (branches of the maxillary nerve).
Figure-1 Innervation of the upper airway
The palatine nerves are relayed through the pterygopalatine ganglion, found in the pterygopalatine fossa, which is situated close to the sphenopalatine fossa, located just posterior to the middle turbinate.
The pharynx is largely innervated by the glossopharyngeal nerve. Innervation of the whole pharynx, posterior third of tongue, the fauces, tonsils, and epiglottis is from the glossopharyngeal nerve.
The oropharynx is innervated by branches of the vagus, trigeminal, and glossopharyngeal nerves. The posterior third of the tongue, vallecula, and anterior surface of the epiglottis are innervated by the tonsillar nerve (a branch of the glossopharyngeal nerve). The posterior and lateral wall of the pharynx are innervated by the pharyngeal nerve (a branch of the vagus nerve). The tonsillar nerve affects the tonsils. The anterior twothirds of the tongue are innervated by the lingual nerve (branch of the mandibular division of the trigeminal nerve).
The larynx is innervated by the vagus nerve (Figure 2). Above the vocal cords (base of tongue, posterior epiglottis, aryepiglottic folds, and arytenoids), the internal branch of the superior laryngeal nerve (a branch of the vagus nerve) supplies innervation. For the vocal cords and below the vocal cords, the recurrent laryngeal nerve (a branch of the vagus nerve) is the supplier.
- The greater and lesser palatine nerves provide sensation to the nasal turbinates and posterior two thirds of the nasal septum.
- The anterior ethmoid nerve innervates the remainder of the nasal passage.
- The glossopharyngeal nerve provides sensory innervation to the posterior third of the tongue, the vallecula, the anterior surface of the epiglottis (lingual branch), the walls of the pharynx (pharyngeal branch), and the tonsils (tonsillar branch).
- The superior laryngeal nerve innervates the base of the tongue, posterior surface of the epiglottis, aryepiglottic fold, and the arytenoids.
- The recurrent laryngeal nerve provides sensory innervation to the trachea and vocal folds.
Cocaine is the only local anesthetic with vasoconstrictor properties; therefore, it is particularly useful for topical anesthesia of the nasopharynx, which is highly vascular. Cocaine is available as a 5% or 10% solution and in paste form; the maximum recommended dose is 1.5 mg/kg. It should be used with caution in patients with coronary artery disease, hypertension, and pseudocholinesterase deficiency.
The mixture of 2 mL of 10% cocaine, 1 mL 1:1000 adrenaline, 2 mL sodium bicarbonate, and 5 mL sodium chloride
makes 10 mL of Moffett’s solution.5 This is commonly used in rhinological procedures to provide local anesthesia, vasoconstriction, and decongestion. It is also used to topicalize the nasal mucosa to provide the optimal conditions for nasal intubations.
Lidocaine is the most commonly used local anesthetic for airway topicalization. The 4% solution and 10% spray are most often used (Figure 3). Systemic absorption from topical application to the upper airways is lower than
expected, so in practice higher doses can be used than the recommended 2 mg/kg.3,6
Vasoconstrictors should be used when the nasal mucosa is being anesthetized; this is because the mucosa is highly vascular, and bleeding can readily occur on instrumentation, which can obscure the view seen on the fiberscope.
As mentioned, cocaine has inherent vasoconstrictor properties, so it is a suitable agent to use for the nasal mucosa. Vasoconstrictor agents such as xylometazoline and phenylephrine are prepared with lidocaine to produce local anesthesia and vasoconstriction. These mixtures are also suitable agents for preparation of the nasal mucosa.6
- The use of vasoconstrictors reduces the bleeding “shrinks” the nasal mucosa resulting in better surgical exposure.
- Shrinking of the nasal mucosa increases the size of the nasal airway passages, creating more space for the fiberscope and endotracheal tube.
- Appropriate time should be allowed for the vasoconstrictor to take effect before commencing fiberoscopy
There are various techniques available to topicalize the upper airway in preparation for awake intubation.7,8 The nasopharynx and oropharynx can be sprayed directly from the container of local anesthetic preparations, sprayed using the McKenzie technique, or sprayed via a mucosal atomization device (MAD). The McKenzie technique uses a 20-gauge cannula attached to oxygen bubble tubing via a three-way tap. The other end of bubble tubing is then attached to an oxygen source, which is turned on to deliver a flow of 2–4 L/min. As the local anesthetic is slowly administered via a 5-mL syringe attached to the top port of the cannula, a jetlike spray effect is seen, which greatly increases the surface area of the local anesthetic and allows directed topicalization of the nasal and oral mucosa (Figure 4).
- Maintain a tight seal between the tubing and the cannula to prevent leakage of local anesthetic from these areas.
- Slow, continuous pressure on the 5-mL syringe containing local anesthesia will result in a “hissing” sound as a fine mist is sprayed out of the cannula.
Commercially available mucosal atomizers allow a similar mistlike effect as seen with the McKenzie technique by just attaching them to the end of a syringe (Figure 5). These devices are available for nasal and oral applications.6
Adding approximately 5 mL of 4% lidocaine to a nebulizer, then delivering it with oxygen for up to 30 minutes is a safe and noninvasive way to topicalize the airway all the way down to the trachea (Figure 6). It is well tolerated and is a useful technique to topicalize the whole airway. It also allows the topicalization of patients with limited mouth opening, where atomizers cannot be passed into the mouth to topicalize the oropharynx.6
The vocal cords can also be sprayed directly with local anesthetic using the spray-as-you-go (SAYGO) technique.9 Here, the distal end of a 16-gauge epidural catheter is cut 3 cm from the end and then fed through the working channel of a fiberscope. The Luer lock connector is connected to the proximal end of the catheter and then attached to a 5-mL syringe prepared with 4% lidocaine. The distal end should protrude out of the fiberscope, so that the tip is just visible. The local anesthetic is then dripped onto the vocal cords prior to the fiberscope being introduced into the trachea. This reduces patient discomfort and coughing when the fiberscope and endotracheal tube are introduced into the trachea Usually, a combination of techniques (Table 1) is used to deliver local anesthetic to the airway mucosa in preparation for awake intubation.
Figure-5 Mucosal atomization device (MAD).
For example, to prepare the nasopharynx, preprepared local anesthetic solution can be sprayed into the nasal mucosa using the nozzle from the container. The oropharynx could be prepared using local anesthetic sprayed using the McKenzie technique, and the vocal cords could be sprayed using the SAYGO method. Alternatively, the MADs can be used to spray the nasal and oral mucosa. Whichever technique or combination of techniques is used, the aim should be to have an airway adequately anesthetized in preparation for instrumentation.
- Sitting the patient in an upright position will help with oxygenation and topicalization.
- Always administer supplementary oxygen.
- Start and establish the sedation before commencing the topicalization process, which can be uncomfortable.
- Asking the patient to “sniff” while spraying the nasopharynx can aid in the distribution of local anesthetic.
Figure-6 Administration of nebulized lidocaine.
|TABLE 1. Application techniques.|
|Spray from container|
|Local anesthetic soaked in ribbon gauze|
|Mucosal atomization device|
|Inhalation of nebulized lidocaine|
|“Spray as you go” via epidural catheter|
REGIONAL ANESTHESIA TECHNIQUES
Nerve blocks can provide anesthesia for awake intubation but can be technically more challenging to perform than topical anesthesia of the airway. They do carry a higher risk of complications, such as intravascular injection and nerve damage, and more than one nerve needs to be blocked. These are the glossopharyngeal, superior laryngeal, and recurrent laryngeal nerves, as they supply the innervation to the oropharynx and larynx. Therefore, the nerve blocks required to anesthetize the airway are the glossopharyngeal, superior laryngeal, and translaryngeal blocks.
The nasal passages are supplied by the palatine nerves and anterior ethmoidal nerve. These nerves need to be blocked to allow for awake nasal fiber-optic intubation. These nerves are usually blocked by the topical application of local anesthetic to the nasal passages, usually by inhalation, spray topicalization, or the application of cotton applicators soaked in anesthetic.
Landmark Technique Glossopharyngeal Nerve Block
The glossopharyngeal nerve provides sensation to the posterior third of the tongue and the vallecula and provides the sensory limb for the gag reflex; therefore, this block is particularly useful in abolishing this reflex. There are two approaches described for this block: intraoral and peristyloid.
For the intraoral approach, the patient requires sufficient mouth opening to allow adequate visualization and access to the base of the posterior tonsillar pillars (palatopharyngeal arch) (Figure 7). After adequate topical anesthesia (lidocaine spray) has been applied, the tongue is retracted medially with a laryngoscope blade or a tongue depressor, allowing access to the posterior tonsillar pillar. Then, using a 22- or 25-gauge needle, 2–5 mL of 2% lidocaine are injected submucosally, after negative aspiration. The point of injection is at the caudal aspect of the posterior tonsillar pillar (approximately 0.5 cm lateral to the lateral edge of the tongue where it joins the floor of the mouth; (Figure 8). This is then repeated on the other side.
Alternatively, a gauze soaked in local anesthetic (Figure 13) can be firmly applied to this region for a few minutes. This method avoids the risk of intravascular injection but is not as successful as when the local anesthetic is injected.
The peristyloid approach aims to infiltrate local anesthetic just posterior to the styloid process where the glossopharyngeal nerve lies. In close proximity to this is the internal carotid artery, so care must be taken when using this approach.
Figure-7 Palatopharyngeal arch.
The patient should be placed in a supine position with the head placed neutrally. The styloid process is located at the midpoint of a line drawn from the angle of the jaw to the tip of the mastoid process. It can be palpated using deep pressure, but this may be uncomfortable for the patient; a needle is inserted perpendicular to the skin, aiming to hit the styloid process. Once contact has been made (usually 1–2 cm deep), the needle should be reangled posteriorly and walked off the styloid process until contact is lost, then 5–7 mL of 2% lidocaine can be injected after negative aspiration. This is then repeated on the other side.
- The glossopharyngeal nerve is most easily blocked where it crosses the palatoglossal arch.
- It can be blocked by spraying local anesthetic, by applying gauze or pledgets soaked in local anesthetic directly over the nerve, or by direct injection of local anesthetic around the nerve
- This helps to abolish the gag reflex, but this block on its own will not provide adequate conditions for an awake fiber-optic intubation.
Superior Laryngeal Nerve Block
The superior laryngeal nerve provides sensation to the laryngeal structures above the vocal cords and lies inferior to the greater cornu of the hyoid bone; here, it splits into the internal and external branches. The internal branch then penetrates the thyrohyoid membrane about 2–4 mm inferior to the greater cornu, continuing submucosally in the piriform recess (Figure 9) and (Figure 10). The external branch does not penetrate the thyrohyoid membrane; it descends on the larynx deep to the sternothyroid muscle. The superior laryngeal nerve can be blocked using the external or internal approach.
To perform the block using the external approach, the patient is placed in the supine position and will need a degree of neck extension to facilitate identification of the hyoid bone. Once identified, the hyoid bone is gently displaced to the side where the block is to be performed and a 25-gauge needle is
Figure-8 Glossopharyngeal nerve block.
inserted from the lateral side of the neck, aiming toward the greater cornu.10 Once contact has been made, the needle is walked off the bone inferiorly, and injecting 2 mL of 2% lidocaine here will block both the internal and the external branches of the superior laryngeal nerve (Figure 11). If the
Figure-9 Surface anatomy of hyoid bone, thyroid, and cricoid cartilages.
Figure-10 Surface anatomy of superior laryngeal nerve and branches.
needle is advanced a few millimeters, it will pierce the thyrohyoid membrane, and a “give” is felt. Injecting local anesthetic here will result in only the internal branch of the superior laryngeal nerve being blocked. As with all blocks, careful aspiration must be performed prior to injection, especially as the carotid artery is in close proximity
If it is difficult to identify the hyoid bone, the superior cornu of the thyroid cartilage can be identified instead. This is located by identifying the thyroid notch, tracing the upper edge posteriorly until the superior cornu can be palpated as a small round structure. This lies just inferior to the greater cornu of the hyoid bone. The needle can be inserted, aiming for the superior cornu of the thyroid cartilage, then walked cephalad, then local anesthetic is injected once the needle loses contact with the superior cornu. If the thyrohyoid membrane is pierced, then inject 2 mL of local anesthetic here and a further 2 mL as the needle is withdrawn; this will increase the chances of both the internal and external branches of the superior laryngeal nerve being blocked.11
The internal approach uses gauze or pledgets soaked in local anesthetic and placed in the piriform fossae using Krause’s forceps. These need to be kept in place for 5-10 minutes to allow sufficient time for the local anesthetic to take effect.12
Figure-11 Superior laryngeal nerve block.
Recurrent Laryngeal Nerve Block
The sensory innervation of the vocal cords and trachea is supplied by the recurrent laryngeal nerves. These ascend along the tracheoesophageal groove and also provide the motor supply to all the intrinsic muscles of the larynx except the cricothyroid muscle. Direct recurrent laryngeal nerve blocks are not performed as they can result in bilateral vocal cord paralysis and airway obstruction, as both the motor and the sensory fibers run together. Therefore, this nerve is blocked using the translaryngeal block.13
To perform this, the patient should be supine, with the neck extended be identified in the midline, then the palpating finger should be moved in a caudad direction until the cricoid cartilage is palpated. The cricothyroid membrane lies between these two structures, immediately above the cricoid cartilage. The thumb and third digit of one hand should stabilize the trachea at the level of the thyroid cartilage, then a 22 or 20 gauge needle should be inserted perpendicular to the skin with the aim to penetrate the cricothyroid membrane (above the cricoid cartilage) (Figure 12). This should be done with continuous aspiration of the syringe, as the appearance of bubbles will indicate that the needle tip is now in the trachea. At this point, immediately stop advancing the needle; otherwise, the posterior laryngeal wall can be punctured. Rapid injection (and then removal of the needle) of 5 mL of 4% lidocaine will result in coughing, which will help to disperse the local anesthetic and blockade of the recurrent laryngeal nerve.
- Appropriate position of the patient will aid in the correct identification of the cricoid and thyroid cartilages and the cricothyroid membrane.
- The neck should be extended, which makes these structures more prominent.
- Placing a liter bag of infusion fluids between the shoulder blades can help achieve this position.
Figure-12 Translaryngeal block.
|Structures that can be identified on ultrasound.|
|Superior laryngeal artery|
|Superior laryngeal nerve|
Ultrasound can be used to help increase the success rate of performing some of the blocks described (Table 2). Ultrasound can increase the accuracy of the deposition of local anesthetic around the greater cornu of the hyoid bone for the superior laryngeal nerve block and can be used to identify the cricothyroid membrane for translaryngeal blocks.14–16
Superior Laryngeal Nerve Block
Sometimes, it can be difficult to identify the landmarks (eg, in obese patients) when trying to perform this block. Ultrasound can therefore be used to facilitate the deposition of local anesthetic to the correct place. The hyoid bone can be visualized on ultrasound (Figure 13), and an in-plane technique can be used to deposit local anesthetic around the surface of the greater cornu of the hyoid bone to achieve the block.17
Place the transducer probe in the sagittal plane to identify the greater cornu of the hyoid bone; the transducer is then rotated transversely to identify the superior lateral aspect of the thyrohyoid membrane. The superior laryngeal nerve can be seen superficial to the thyrohyoid membrane when the medial aspect of the probe is rotated cephalad. The internal branch of the superior laryngeal nerve runs along with the superior laryngeal artery, just below the greater cornu of the hyoid bone.
An alternative approach is to identify the hyoid bone, which appears as a hyperechoic curved bright structure on ultrasound in the midline. If the probe is moved laterally, the greater cornu of the hyoid bone can be seen as a bright structure medial to the superior laryngeal artery. The internal branch of the superior laryngeal nerve runs with the superior laryngeal artery just below the level of the greater cornu of the hyoid bone. Using an in-plane technique, a needle is passed perpendicular to the skin, aiming just below the greater cornu of the hyoid bone. Then, 1–2 mL of local anesthetic can be injected here after negative aspiration18 (Figure 14).
This technique has been shown to have a success rate of over 90%. Failure is thought to be due to variations in the anatomical position of the superior laryngeal nerve in relation to the hyoid bone.
Sometimes, the correct location of the cricothyroid membrane is difficult to identify by palpation only. Ultrasound can be used to identify the thyroid and cricoid cartilages and the cricothyroid membrane (Table 3), ensuring that the local anesthetic is deposited correctly and a successful translaryngeal block is achieved19 (Figure 15).
Figure-13 Ultrasound images of hyoid bone.
Figure-14 Ultrasound-guided superior laryngeal nerve block.
If the probe is placed longitudinally in the midline of the neck, the tracheal rings can be seen. If the probe is then advanced cranially, the cricoid cartilage can be seen next; this is a slightly elongated structure that is larger and more superficial than the tracheal rings. If the probe is further advanced cranially, the thyroid cartilage can be seen. The cricothyroid membrane lies between the caudal border of the thyroid cartilage and the cephalad border of the cricoid cartilage. Keep the probe in the midline with the cricothyroid membrane in the middle of the image seen on the monitor; then, the exact location on the patient’s neck can be marked using a marker pen. Now that the position of the cricothyroid membrane has been located, the translaryngeal block can be performed.
The block can also be performed under real-time sonography by simply tilting the probe from the midline to a parasagittal position, keeping the cricoid cartilage in view. The needle entry point should be just cranial to the cricoid cartilage and can be seen on the ultrasound monitor (Figure 16). Once air is aspirated, this confirms that the needle is through the membrane and in the trachea.
|Readily identifiable structures.|
Figure-15 Ultrasound image of cricoid cartilage, thyroid cartilage, saggital plane, and cricothyroid membrane.
Figure-16 Ultrasound-guided translaryngeal block.
Awake endotracheal intubation can be an unpleasant experience for the patient, even if thorough topicalization of the airway has been done. The aim of conscious sedation is not only to allow the patient to tolerate the procedure but also to provide optimal intubating conditions. There are various techniques available to achieve the desired level of sedation; whichever is used, the priority is to avoid oversedation of the patient. Oversedation could lead to an unresponsive patient with loss of airway, which could result in serious consequences.
The ideal sedation conditions would involve a comfortable patient responsive to commands with a maintained airway, spontaneous breathing, and a degree of amnesia (Table 4).20.
|Ideal sedation conditions.|
|Minimal respiratory side effects|
Two drugs are becoming increasingly popular and have growing evidence to support their use for conscious sedation: remifentanil and dexmedetomidine.20 Remifentanil is an ultrashort-acting opioid, and dexmedetomidine is a highly selective α2 agonist (Table 5).
|Examples of sedation techniques.|
|Boluses of benzodiazepines (eg, diazepam, midazolam)|
|Boluses of opioids (eg, fentanyl, alfentanyl, morphine)|
|Boluses of α2 agonists (eg, clonidine, dexmedetomidine)|
|Boluses of anesthetic agents (propofol, ketamine)|
|Combination of agents (eg, benzodiazepines and opioids)|
|Intravenous infusion (propofol, remifentanil, dexmedetomidine)|
|Combination of intravenous infusions (propofol and remifentanil)|
Remifentanil has been found to provide good intubating conditions, is well tolerated, and has high patient satisfaction scores, although there is a high incidence of recall when used as a solo agent. Best results are seen when a target controlled infusion (TCI) technique is used.21–23
The advantage of dexmedetomidine is that a state of cooperative sedation is achieved; it also has antisialagogue effects. There is level 1 evidence to support its use for good intubating conditions, patient tolerance, and patient satisfaction. It is usually administered as a slow bolus over 120 minutes followed by an infusion.24–26
Benzodiazepines are usually administered in combination with an opioid as intermittent boluses and have been used as a sedative for awake fiber-optic intubation. The disadvantage of using boluses of benzodiazepines is that intermittent boluses are
associated with overshooting; therefore, there is a risk of oversedation
Propofol can be administered as intermittent boluses or as an infusion. Both techniques have been shown to be safe and well tolerated by patients. There is now increasing popularity of administering propofol as a TCI, either as a sole agent or in combination with remifentanil. Whichever technique is used, it is important to maintain a balance of an appropriate level of sedation and avoidance of underdosing or overdosing.29
The combination of propofol and remifentanil TCI has proven to be a safe technique for fiber-optic intubation with consistent pharmacodynamic effects and allows for a more predictable level of sedation.29
- Safe sedation can be achieved by slowly administering the sedative drugs and continually communicating with the patient.
- Bispectral Index (BIS) monitoring can also be used to aid and guide sedation level.
AUTHOR’S PREFERRED TECHNIQUE FOR PERFORMING AN AWAKE FIBER-OPTIC INTUBATION
There are numerous techniques available for performing an awake fiber-optic intubation. Next is described a well-accepted and successful technique I use on a regular basis:
- Sit patient as upright as tolerable.
- Administer supplemental oxygen (via Hudson mask or nasal cannulae).
- Attach full monitoring.
- Start remifentanil (1–3 ng/mL) and propofol (0.5–1 μg/mL) TCI infusion. Do not give a bolus dose. Titrate the dose according to the patient’s level of sedation.
- Start to topicalize the nasopharynx with Moffett’s solution sprayed via MAD.
- Topicalize the oropharynx with 4% lidocaine using a MAD.
- After topicalization, suction any secretions using a soft suction catheter; this also tests the effectiveness of the local anesthetic.
- If patient does not tolerate the suction catheter, spray oropharynx with 2–4 sprays of 10% lidocaine.
- Preload the fiberscope with a nasal endotracheal tube (ETT) (size 6/6.5 outer diameter [OD]).
- Start fiberoscopy via the nasopharynx and visualize the vocal cords.
- Pass the fiberscope into the trachea.
- “Railroad” the lubricated ETT over the scope gently into the trachea, trying not to touch the carina with the fiberscope.
- Confirm correct placement of the ETT by visualizing the carina and ETT.
- Connect the ETT to the anesthetic circuit and capnography.
- Gently inflate the cuff of the ETT.
- Keep hold of the ETT until it has been safely secured.
- Patient is now safe to anesthetize.
To successfully perform awake intubation in a patient with an anticipated difficult airway, it is important that you have an understanding of and are competent in all of the following:
- Innervation of the upper airway
- Knowledge of appropriate local anesthetic techniques and vasoconstrictor drugs
- Techniques available to topicalize/anesthetize the upper airway
- Prudent sedation techniques
- Oxygenation techniques during the procedure
- Techniques used for the correct placement of the endotracheal tube
This will enable a safe, stress-free, and successful awake intubation with high levels of patient satisfaction.
1 Van Zundert AAJ, Reina MA, Lee RA. Prevention of post-dural puncture headache (PDPH) in parturients. Contributions from experimental research. Acta Anaesthesiol Scand. 2013;57:947–9.
2 Reina MA, Prats-Galino A, Sola RG, Puigdellívol-Sánchez A, Arriazu Navarro R, De Andrés JA. Structure of the arachnoid layer of the human spinal meninges: a barrier that regulates dural sac permeability. Rev Esp Anestesiol Reanim. 2010;57:486–92. Spanish.
3 Reina MA, López A, Badorrey V, De Andrés JA, Martín S. Duraarachnoid lesions produced by 22 gauge Quincke spinal needles during a lumbar puncture. J Neurol Neurosurg Psychiatry. 2004;75893–7.
4 Reina MA, de Leon-Casasola OA, Lopez A, De Andres J, Martin S, Mora M. An in vitro study of dural lesions produced by 25-gauge Quincke and Whitacre needles evaluated by scanning electron microscopy. Reg Anesth Pain Med. 2000;25:393–402.
5 Dittmann M, Reina MA, López García A. New results in the visualization of the spinal dura mater with scanning electron microscopy. Anaesthesist. 1998;47:409–13. German.
6 Reina MA, Dittmann M, López Garcia A, van Zundert A. New
perspectives in the microscopic structure of human dura mater in the dorsolumbar region. Reg Anesth. 1997;22:161–6.
7 Reina MA, López-García A, de Andrés-Ibáñez JA, Dittmann M, Cascales MR, del Caño MC, Daneri J, Zambrano O. Electron microscopy of the lesions produced in the human dura mater by Quincke beveled and Whitacre needles. Rev Esp Anestesiol Reanim. 1997;44:56–61. Spanish.
8 Reina MA, López A, van Zundert A, De Andrés JA. Ultrastructure of dural lesions produced in lumbar punctures. In: Reina MA. Atlas of functional anatomy of regional anesthesia and pain medicine. New York: Springer; 2015. p.767–794.
9 Reina MA, Castedo J, López A. Postdural puncture headache. Ultrastructure of dural lesions and spinal needles used in lumbar punctures. Rev Arg Anestesiol 2008;66:6–26.
10 Tourtellotte WW, Haerer AF, Heller GL, Somers JE: Post-Lumbar Puncture Headaches. Thomas, 1964.
11 Moore DC: Headache. In Complications of Regional Anesthesia. Thomas, 1955, pp 177–196.
12 Gormley JB: Treatment of postspinal headache. Anesthesiology 1960; 21:565–566.
13 DiGiovanni AJ, Dunbar BS: Epidural injections of autologous blood for postlumbar-puncture headache. Anesth Analg 1970;49:268–271.
14 Crawford JS: Experiences with epidural blood patch. Anaesthesia 1980;35:513–515.
15 Harrington BE, Schmitt AM: Meningeal (postdural) puncture headache, unintentional dural puncture, and the epidural blood patch. A national survey of United States practice. Reg Anesth Pain Med 2009;34:430–437.
16 Choi PT, Galinski SE, Takeuchi L, et al: PDPH is a common complication of neuraxial blockade in parturients: A meta-analysis of obstetrical studies. Can J Anesth 2003;50:460–469.
17 Paech M, Banks S, Gurrin L: An audit of accidental dural puncture during epidural insertion of a Tuohy needle in obstetric patients. Int J Obstet Anesth 2001;10:162–167.
18 Webb CA, Weyker PD, Zhang L, et al: Unintentional dural puncture with a Tuohy needle increases risk of chronic headache. Anesth Analg 2012;115:124–132.
19 Stendell L, Fomsgaard JS, Olsen KS: There is room for improvement in the prevention and treatment of headache after lumbar puncture. Dan Med J 2012;59:1–5.
20 Vercauteren MP, Hoffmann VH, Mertens E, et al: Seven-year review of requests for epidural blood patches for headache after dural puncture: referral patterns and the effectiveness of blood patches. Eur J Anaesth 1999;16:298–303.
21 Davies JM, Posner KL, Lee LA, et al: Liability associated with obstetric anesthesia. A closed claims analysis. Anesthesiology 2009;110:131–139.
22 Lee LA, Posner KL, Domino KB, et al: Injuries associated with regional anesthesia in the 1980s and 1990s: A closed claims analysis. Anesthesiology 2004;101:143–152.
23 Fitzgibbon DR, Posner KL, Domino KB, et al: Chronic pain management: American Society of Anesthesiologists Closed Claims Project. Anesthesiology 2004;100:98–105.
24 Brull R, McCartney CJL, Chan VWS, et al: Disclosure of risks associated with regional anesthesia: A survey of academic regional anesthesiologists.
Reg Anesth Pain Med 2007;32:7–11.
25 Levine DN, Rapalino O: The pathophysiology of lumbar puncture headache. J Neurol Sci 2001;192:1–8.
26 Kunkle EC, Ray BS, Wolff HG: Experimental studies on headache. Analysis of the headache associated with changes in intracranial pressure. Arch Neurol Psychiatry 1943;49:323–358.
27 Larrier D, Lee A: Anatomy of headache and facial pain. Otolaryngol Clin N Am 2003;36:1041–1053.
28 Day CJE, Shutt LE: Auditory, ocular, and facial complications of central neural block. A review of possible mechanisms. Reg Anesth 1996; 21:197–201.
29 Pogodzinski MS, Shallop JK, Sprung J, et al: Hearing loss and cerebrospinal fluid pressure: Case report and review of the literature. Ear Nose Throat J 2009;87:144–147.
30 Nishio I, Williams BA, Williams JP: Diplopia. A complication of dural puncture. Anesthesiology 2004;100:158–164.
31 Yaman ME, Ayberk G, Eylen A, et al: Isolated abducens nerve palsy following lumbar puncture: Case report and review of the mechanism of action. J Neurosurg Sci 2010;54:119–123.
32 Fang JY, Lin JW, Li Q, et al: Trigeminal nerve and facial nerve palsy after combined spinal-epidural anesthesia for cesarean section. J Clin Anesth 2010;22:56–58.
33 Lybecker H, Djernes M, Schmidt JF: Postdural puncture headache (PDPH): Onset, duration, severity, and associated symptoms. An analysis of 75 consecutive patients with PDPH. Acta Anaesthesiol Scand 1995;39:605–612.
34 Aida S, Taga K, Yamakura T, et al: Headache after attempted epidural block: The role of intrathecal air. Anesthesiology 1998;88:76–81.
35 Reamy BV: Post-epidural headache: how late can it occur? J Am Board Fam Med 2009;22:202–205.
36 Amorim JA, Gomes de Barros MV, Valenca MM: Post-dural (post-lumbar) puncture headache: Risk factors and clinical features. Cephalalgia 2012;32:916–923.
37 Chan TM, Ahmed E, Yentis SM, et al: Postpartum headaches: Summary report of the National Obstetric Anaesthetic Database (NOAD) 1999. Int J Obstet Anesth 2003;12:107–112.
38 Sprung J, Bourke BA, Contreras MG, et al: Perioperative hearing impairment. Anesthesiology 2003;98:241–257.
39 Lybecker H, Moller JT, May O, et al: Incidence and prediction of postdural puncture headache: A prospective study of 1021 spinal anesthesias. Anesth Analg 1990;70:389–394.
40 Wu CL, Rowlingson AJ, Cohen SR, et al: Gender and post-dural puncture headache. Anesthesiology 2006;105:613–618.
41 Angle P, Thompson D, Halpern S, et al: Second stage pushing correlates with headache after unintentional dural puncture in parturients. Can J Anesth 1999;46:861–866.
42 Vallejo MC: Anesthetic management of the morbidly obese parturient. Curr Opin Anaesthesiol 2007;20:175–180.
43 Kuntz KM, Kokmen E, Stevens JC, et al: Post-lumbar puncture headaches: Experience in 501 consecutive procedures. Neurology 1992; 42:1884–1887.
44 Faure E, Moreno R, Thisted R: Incidence of postdural puncture headache in morbidly obese parturients. Reg Anesth 1994;19:361–363.
45 Dodge HS, Ekhator NN, Jefferson-Wilson L, et al: Cigarette smokers have reduced risk for post-dural puncture headache. Pain Physician 2013;16:e25–e30.
46 Hannerz J: Postlumbar puncture headache and its relation to chronic tension-type headache. Headache 1997;37:659–662.
47 van Oosterhout WPJ, van der Plas AA, van Zwet EW, et al: Postdural puncture headache in migraineurs and nonheadache subjects. A prospective study. Neurology 2013;80:941–948.
48 Echevarria M, Caba F, Rodriguez R: The influence of the menstrual cycle in postdural puncture headache. Reg Anesth Pain Med 1998;23: 485–490.
49 Blanche R, Eisenach JC, Tuttle R, et al: Previous wet tap does not reduce success rate of labor epidural analgesia. Anesth Analg 1994;79: 291–294.
50 Halpern S, Preston R: Postdural puncture headache and spinal needle design. Metaanalysis. Anesthesiology 1994;81:1376–1383.
51 Kovanen J, Sulkava R: Duration of postural headache after lumbar puncture: Effect of needle size. Headache 1986;26:224–226.
52 Lambert DH, Hurley RJ, Hertwig L, et al: Role of needle gauge and tip configuration in the production of lumbar puncture headache. Reg Anesth 1997;22:66–72.
53 Reina MA, de Leon-Casasola OA, Lopez A, et al: An in vitro study of dural lesions produced by 25-gauge Quincke and Whitacre needles evaluated by scanning electron microscopy. Reg Anesth Pain Med 2000; 25:393–402.
54 Richman J, Joe E, Cohen S, et al: Bevel direction and postdural puncture headache. A meta-analysis. Neurologist 2006;12:224–228.
55 Reina MA, Dittmann M, Garcia AL, et al: New perspectives in the microscopic structure of human dura mater in the dorsolumbar region. Reg Anesth 1997;22:161–166.
56 Seeberger MD, Kaufmann M, Staender S, et al: Repeated dural punctures increase the incidence of postdural puncture headache. Anesth Analg 1996;82:302–305.
57 De Almeida SM, Shumaker SD, LeBlanc SK, et al: Incidence of postdural puncture headache in research volunteers. Headache 2011;51:1503–1510.
58 Singh S, Chaudry SY, Phelps AL, et al: A 5-year audit of accidental dural punctures, postdural puncture headaches, and failed regional anesthetics at a tertiary-care medical center. TheScientificWorldJournal 2009;9: 715–722.
59 Goldszmidt E, Kern R, Chaput A, et al: The incidence and etiology of postpartum headaches: A prospective cohort study. Can J Anesth 2005; 52:971–977.
60 Aya AGM, Manguin R, Robert C, et al: Increased risk of unintentional dural puncture in night-time obstetric epidural anaesthesia. Can J Anesth 1999;46:665–669.
61 Paech MJ, Whybrow T: The prevention and treatment of post dural puncture headache. ASEAN J Anaesthesiol 2007;8:86–95.
62 Warwick WI, Neal JM: Beyond spinal headache: Prophylaxis and treatment of low-pressure headache syndromes. Reg Anesth Pain Med 2007;32:455–461.
63 Apfel CC, Saxena OS, Cakmakkaya OS, et al: Prevention of postdural puncture headache after accidental dural puncture: A quantitative systematic review. Br J Anaesth 2010;105:255–263.
64 Perlas A: Evidence for the use of ultrasound in neuraxial blocks. Reg Anesth Pain Med 2010;35 (Suppl. 1):S43–S46.
65 Hamzei A, Basiri-Moghadam M, Pasban-Noghabi S: Effect of dexamethasone on incidence of headache after spinal anesthesia in cesarean section. A single blind randomized controlled trial. Saudi Med J 2012;33:948–953.
66 Doroudian MR, Norouzi M, Esmailie M, et al: Dexamethasone in preventing post-dural puncture headache: A randomized, double-blind, placebo-controlled trial. Acta Anaesth Belg 2011;62:143–146.
67 Yousefshahi F, Dahmardeh AR, Khajavi M, et al: Effect of dexamethasone on the frequency of postdural puncture headache after spinal anesthesia for cesarean section: A double-blind randomized clinical trial. Acta Neurol Belg 2012;112:345–350.
68 Basurto Ona X, Uriona Tuma SM, Martinez Garcia L, et al: Drug therapy for preventing post-dural puncture headache. Cochrane Database Syst Rev 2013;(2):CD001792.
69 Al-metwalli RR: Epidural morphine injections for prevention of post dural puncture headache. Anaesthesia 2008;63:847–850.
70 Hakim SM: Cosyntropin for prophylaxis against postdural puncture headache after accidental dural puncture. Anesthesiology 2010;113:413–420.
71 Sadeghi SE, Abdollahifard G, Nasabi NA, et al: Effectiveness of single dose aminopylline administration on prevention of post dural puncture headache in patients who received spinal anesthesia for elective cesarean section. World J Med Sci 2012;7:13–16.
72 Jacobus CH: Does bed rest prevent post-lumbar puncture headache? Ann Emerg Med 2012;59:139–140.
73 Baraz R, Collis R: The management of accidental dural puncture during labor epidural analgesia: A survey of UK practice. Anaesthesia 2005;60: 673–679.
74 Sudlow C, Warlow C: Posture and fluids for preventing postdural puncture headache. Cochrane Database Syst Rev 2002;(2):CD001790.
75 Dakka Y, Warra N, Albadareen RJ, et al: Headache rate and cost of care following lumbar puncture at a single tertiary care hospital. Neurology 2011;77:71–74.
76 Strupp M, Brandt T, Muller A: Incidence of post-lumbar puncture syndrome reduced by reinserting the stylet: A randomized prospective study of 600 patients. J Neurol 1998;245:589–592.
77 Sinikoglu NS, Yeter H, Gumus F, et al: Reinsertion of the stylet does not affect incidence of post dural puncture headaches (PDPH) after spinal anesthesia. Rev Bras Anestesiol 2013;63:188–192.
78 Moore JM: Continuous spinal anesthesia. Am J Ther 2009;16: 289–294.
79 Sadashivaiah J, McClure H: 18-g Tuohy needle can reduce the incidence of severe post dural puncture headache. Anaesthesia 2009;64: 1379–1380.
80 Schier R, Guerra D, Aguilar J, et al: Epidural space identification: A meta-analysis of complications after air versus liquid as the medium for loss of resistance. Anesth Analg 2009;109:2012–2021.
81 Segal S, Arendt KW: A retrospective effectiveness study of loss of resistance to air or saline for identification of the epidural space. Anesth Analg 2010;110:558–563.
82 Norris MC, Leighton BL, DeSimone CA: Needle bevel direction and headache after inadvertent dural puncture. Anesthesiology 1989;70:729–731.
83 Duffy B: Don’t turn the needle! Anaesth Intensive Care 1993; 21:328–330.
84 Simmons SW, Cyna AM, Dennis AT, et al: Combined spinal-epidural versus epidural analgesia in labour. Cochrane Database Syst Rev 2009;(1):CD003401.
85 Kuczkowski KM, Benumof JL: Decrease in the incidence of post-dural puncture headache: Maintaining CSF volume. Acta Anaesthesiol Scand 2003;47:98–100.
86 Charsley MM, Abram SE: The injection of intrathecal normal saline reduces the severity of postdural puncture headache. Reg Anesth Pain Med 2001;26:301–305.
87 Carter BL, Pasupuleti R: Use of intravenous cosyntropin in the treatment of postdural puncture headache. Anesthesiology 2000;92:272–274.
88 Russell IF: A prospective controlled study of continuous spinal anesthesia versus repeat epidural analgesia after accidental dural puncture in labour. Int J Obstet Anesth 2012;21:7–16.
89 Ayad S, Bemian Y, Narouze S, et al: Subarachnoid catheter placement after wet tap for analgesia in labor: Influence on the risk of headache in obstetric patients. Reg Anesth Pain Med 2003;28:512–515.
90 Heesen M, Klohr S, Rossaint R, et al: Insertion of an intrathecal catheter following accidental dural puncture: A meta-analysis. Int J Obstet Anesth 2013;22:26–30.
91 Newman M, Cyna A: Immediate management of inadvertent dural puncture during insertion of a labour epidural: A survey of Australian obstetric anaesthetists. Anaesth Intensive Care 2008;36:96–101.
92 Stride PC, Cooper GM: Dural taps revisited: A 20-year survey from Birmingham Maternity Hospital. Anaesthesia 1993;48:247–255.
93 Trivedi NS, Eddi D, Shevde K: Headache prevention following accidental dural puncture in obstetric patients. J Clin Anesth 1993;5:42–45.
94 Scavone BM, Wong CA, Sullivan JT, et al: Efficacy of a prophylactic epidural blood patch in preventing post dural puncture headache in parturients after inadvertent dural puncture. Anesthesiology
95 Bradbury CL, Singh SI, Badder SR, et al: Prevention of post-dural puncture headache in parturients: A systematic review and meta-analysis. Acta Anaesthesiol Scand 2013;57:417–430.
96 Agerson AN, Scavone BM: Prophylactic epidural blood patch after unintentional dural puncture for the prevention of postdural puncture headache in parturients. Anesth Analg 2012;115:133–136.
97 Boonmak P, Boonmak S: Epidural blood patching for preventing and treating post-dural puncture headache. Cochrane Database Syst Rev 2010;(1):CD001791.
98 Baysinger CL, Pope JE, Lockhart EM, et al: The management of accidental dural puncture and postdural puncture headache: A North American survey. J Clin Anesth 2011;23:349–360.
99 Leivers D: Total spinal anesthesia following early prophylactic epidural blood patch. Anesthesiology 1990;73:1287–1289.
100 Tobias MD, Pilla MA, Rogers C, et al: Lidocaine inhibits blood coagulation: implications for epidural blood patch. Anesth Analg 1996; 82:766–769.
101 Gutsche BB: Lumbar epidural analgesia in obstetrics: Taps and patches. In: Reynolds F (ed): Epidural and Spinal Blockade in Obstetrics. Balliere Tindall, 1990, pp 75–106.
102 Naulty JS, Hertwig L, Hunt CO, et al: Influence of local anesthetic solution on postdural puncture headache. Anesthesiology 1990;72:450–454.
103 Santanen U, Rautoma P, Luurila H, et al: Comparison of 27-gauge (0.41-mm) Whitacre and Quincke spinal needles with respect to postdural puncture headache and non-dural puncture headache. Acta Anaesthesiol Scand 2004;48:474–479.
104 Stella CL, Jodicke CD, How HY, et al: Postpartum headache: is your work-up complete? Am J Obstet Gynecol 2007;196:318.e1–318.e7.
105 Somri M, Teszler CB, Vaida SJ, et al: Postdural puncture headache: An imaging-guided management protocol. Anesth Analg 2003;96:1809–1812.
106 Sharma R, Panda A: Ondansetron-induced headache in a parturient mimicking postdural puncture headache. Can J Anesth 2010;57:187–188.
107 Hurlburt L, Lay C, Fehlings MG, et al: Postpartum workup of postdural puncture headache leads to diagnosis and surgical treatment of thoracic pseudomeningocele: A case report. Can J Anesth 2013;60:294–298.
108 National Institute of Neurological Disorders and Stroke. Meningitis and encephalitis fact sheet. http://www.ninds.nih.gov/disorders/encephalitis_meningitis/detail_encephalitis_meningitis.htm. Accessed June 28, 2013.
109 Machurot PY, Vergnion M, Fraipont V, et al: Intracranial subdural hematoma following spinal anesthesia: Case report and review of the literature. Acta Anaesth Belg 2010;61:63–66.
110 Bleeker CP, Hendriks IM, Booij LHDJ: Postpartum post-dural puncture headache: Is your differential diagnosis complete? Br J Anaesth 2004;93:461–464.
111 Matthys LA, Coppage KH, Lambers DS, et al: Delayed postpartum preeclampsia: An experience of 151 cases. Am J Obstet Gynecol 2004;190:1464–1466.
112 Lockhart EM, Baysinger CL: Intracranial venous thrombosis in the parturient. Anesthesiology 2007;107:652–658.
113 Wittmann M, Dewald D, Urbach H, et al: Sinus venous thrombosis: A differential diagnosis of postpartum headache. Arch Gynecol Obstet 2012;285:93–97.
114 Vanden Eede H, Hoffmann VLH, Vercauteren MP: Post-delivery postural headache: Not always a classical post-dural puncture headache. Acta Anaesthesiol Scand 2007;51:763–765.
115 van Kooten F, Oedit R, Bakker SLM, et al: Epidural blood patch in post dural puncture headache: A randomized, observer-blind, controlled clinical trial. J Neurol Neurosurg Psychiatry 2008;79:553–558.
116 Sharma A, Cheam E: Acupuncture in the management of post-partum headache following neuraxial analgesia. Int J Obstet Anesth 2009;18:417–419.
117 Takmaz SA, Kantekin CU, Kaymak C, et al: Treatment of post-dural puncture headache with bilateral greater occipital nerve block. Headache 2010;50:869–872.
118 Cohen S, Ramos D, Grubb W, et al. Reg Anesth Pain Med 2014;39:563.
119 Basurto Ona X, Martinez Garcia L, Sola I, et al: Drug therapy for treating post-dural puncture headache. Cochrane Database Syst Rev 2011;(8):CD007887.
120 Choi A, Laurito CE, Cummingham FE: Pharmacologic management of postdural puncture headache. Ann Pharmacother 1996;30:831–839.
121 Camann WR, Murray RS, Mushlin PS, et al: Effects of oral caffeine on postdural puncture headache. A double-blind, placebo-controlled trial. Anesth Analg 1990;70:181–184.
122 Halker RB, Demaerschalk BM, Wellik KE, et al: Caffeine for the prevention and treatment of postdural puncture headache: debunking the myth. Neurologist 2007;13:323–327.
123 Connelly NR, Parker RK, Rahimi A, et al: Sumatriptan in patients with postdural puncture headache. Headache 2000;40:316–319.
124 Hakim S, Khan RM, Maroof M, et al: Methylergonovine maleate (methergine) relieves postdural puncture headache in obstetric patients. Acta Obstet Gynecol Scand 2005;84:100.
125 Rucklidge MWM, Yentis SM, Paech MJ, et al: Synacthen Depot for the treatment of postdural puncture headache. Anaesthesia 2004;59: 138–141.
126 Noyan Ashraf MA, Sadeghi A, Azarbakht Z, et al: Hydrocortisone in post-dural puncture headache. Middle East J Anesthesiol 2007;19:415–422.
127 Rabiul A, Aminur R, Reza E: Role of very short-term intravenous hydrocortisone in reducing postdural puncture headache. J Anaesthesiol Clin Pharmacol 2012;28:190–193.
128 Wagner Y, Storr F, Cope S: Gabapentin in the treatment of post-dural puncture headache: A case series. Anaesth Intensive Care 2012;40:714–718.
129 Huseyinoglu U, Huseyinoglu N, Hamurtekin E, et al: Efect of pregabalin on post-dural-puncture headache following spinal anesthesia and lumbar puncture. J Clin Neurosci 2011;18:1365–1368.
130 Kroin JS, Nagalla SKS, Buvanendran, et al: The mechanisms of intracranial pressure modulation by epidural blood and other injectates in a postdural puncture rat model. Anesth Analg 2002;95:423–429.
131 Bart AJ, Wheeler AS: Comparison of epidural saline placement and epidural blood placement in the treatment of post-lumbar-puncture headache. Anesthesiology 1978;48:221–223.
132 Liu SK, Chen KB, Wu RSC, et al: Management of postdural puncture headache by epidural saline delivered with a patient-controlled pump—A case report. Acta Anaesthesiol Taiwan 2006;44:227–230.
133 Kara I, Ciftci I, Apiliogullari S, et al: Management of postdural puncture headache with epidural saline patch in a 10-year-old child after inguinal hernia repair: A case report. J Pediatr Surg 2012;47:E55–E57.
134 Vakharia SB, Thomas PS, Rosenbaum AE, et al: Magnetic resonance imaging of cerebrospinal fluid leak and tamponade effect of blood patch in postdural puncture headache. Anesth Analg 1997;84:585–590.
135 Serpell MG, Haldane GJ, Jamieson DR, et al: Prevention of headache after lumbar puncture: Questionnaire survey of neurologists and neurosurgeons in United Kingdom. Br Med J 1998;316:1709–1710.
136 Darvish B, Gupta A, Alahuhta S, et al: Management of accidental dural puncture and post-dural puncture headache after labour: A Nordic survey. Acta Anaesthesiol Scand 2011;55:46–53.
137 Banks S, Paech M, Gurrin L: An audit of epidural blood patch after accidental dural puncture with a Tuohy needle in obstetric patients. Int J Obstet Anesth 2001;10:172–176.
138 Safa-Tisseront V, Thormann F, Malassine P, et al: Effectiveness of epidural blood patch in the management of post-dural puncture headache. Anesthesiology 2001;95:334–339.
139 Sandesc D, Lupei MI, Sirbu C, et al: Conventional treatment or epidural blood patch for the treatment of different etiologies of post dural puncture headache. Acta Anaesth Belg 2005;56:265–269.
140 Vilming ST, Kloster R, Sandvik L: When should an epidural blood patch be performed in postlumbar puncture headache? A theoretical approach based on a cohort of 79 patients. Cephalalgia 2005;25:523–527.
141 Chen LK, Huang CH, Jean WH, et al: Effective epidural blood patch volumes for postdural puncture headache in Taiwanese women. J Formos Med Assoc 2007;106:134–140.
142 Paech MJ, Doherty DA, Christmas T, et al: The volume of blood for epidural blood patch in obstetrics: A randomized, blinded clinical trial. Anesth Analg 2011;113:126–133.
143 Schievink WI: Spontaneous spinal cerebrospinal fluid leaks and intracranial hypotension. JAMA 2006;295:2286–2296.
144 Riley CA, Spiegel JE: Complications following large-volume epidural blood patches for postdural puncture headaches. Lumbar subdural hematoma and arachnoiditis: Initial cause or final effect? J Clin Anesth 2009;21:355–359.
145 Desai MJ, Dave AP, Martin MB: Delayed radicular pain following two large volume epidural blood patches for post-lumbar puncture headache: A case report. Pain Physician 2010;13:257–262.
146 Martin R, Jourdain S, Clairoux M, et al: Duration of decubitus position after epidural blood patch. Can J Anaesth 1994;41:23–25.
147 Jagannathan N, Tetzlaff JE: Epidural blood patch in a Jehovah’s Witness patient with post-dural puncture cephalgia. Can J Anaesth 2005;52:113.
148 Janssens E, Aerssens P, Alliet P, et al: Post-dural puncture headaches in children: A literature review. Eur J Pediatr 2003;162:117–121.
149 Kokki M, Sjovall S, Kokki H: Epidural blood patches are effective for postdural puncture headache in pediatrics—A 10-year experience. Pediatr Anesth 2012;22:1205–1210.
150 Waldman SD, Feldstein GS, Allen ML: Cervical epidural blood patch: A safe effective treatment for cervical post-dural puncture headache. Anesth Rev 1987;14:23–24.
151 Bucklin BA, Tinker JH, Smith CV: Clinical dilemma: A patient with postdural puncture headache and acute leukemia. Anesth Analg 1999;88:166–167.
152 Koeva V, Bar-Or A, Gendron D, et al: Epidural blood patch in a patient with multiple sclerosis: Is it safe? Can J Anaesth 2013;60:479–483.
153 Tom DJ, Gulevich SJ, Shapiro HM, et al: Epidural blood patch in the HIV-positive patient. Anesthesiology 1992;76:943–947.
154 Martin DP, Bergman BD, Berger IH: Epidural blood patch and acute varicella. Anesth Analg 2004;99:1760–1762.
155 Abouleish E, de la Vega S, Blendinger I, et al: Long-term follow-up of epidural blood patch. Anesth Analg 1975;54:459–463.
156 Andrews PJD, Ackerman WE, Juneja M, et al: Transient bradycardia associated with extradural blood patch after inadvertent dural puncture in parturients. Br J Anaesth 1992;69:401–403.
157 Hebl JR, Horlocker TT, Chantigian RC, et al: Epidural anesthesia and analgesia are not impaired after dural puncture with or without epidural blood patch. Anesth Analg 1999;89:390–394.
158 Collier CB: Blood patches may cause scarring in the epidural space: Two case reports. Int J Obstet Anesth 2011;20:347–351.
159 Vassal O, Baud MC, Bolandard F, et al: Epidural injection of hydroxyethyl starch in the management of postdural puncture headache. Int J Obstet Anesth 2013;22:153–155.
160 Williams EJ, Beaulieu P, Fawcett WJ, et al: Efficacy of epidural blood patch in the obstetric population. Int J Obstet Anesth 1999;8: 105–109.
161 Sadashivaiah J: 18-G Tuohy needle can reduce the incidence of severe post dural puncture headache. Anaesthesia 2009;64:1379–1380.
162 Ho KY, Gan TJ: Management of persistent post-dural puncture headache after repeated epidural blood patch. Acta Anaesthesiol Scand 2007;51:633–636.
163 Sullivan FM, Swan IRC, Donnan PT, et al: Early treatment with prednisone or acyclovir in Bell’s palsy. N Engl J Med 2007;357: 1598–1607.
164 Choi PTL, Galinski SE, Lucas S, et al: Examining the evidence in anesthesia literature: A survey and evaluation of obstetrical post-dural puncture headache reports. Can J Anaesth 2002;49:49–56.