Amniotic fluid embolism

Learning objectives

Basic Knobology Useful for the BLUE-Protocol (Lung and Venous Assessment) and Derived Protocols

Notions of the physical properties of ultrasound are not indispensable for the user (as we wrote in our 1992, 2002, 2005, 2010, and 2011 editions). Interested readers will find them in any ultrasound textbook. We will discuss here the notions useful for understanding critical ultrasound. Every maneuver which favors simplicity will be exploited. Space will be used for explaining why only one setting is used; why, at the lung or venous area, only one probe orientation is favored; and how to easily improve the image quality.

PLAPS and Pleural Effusion

In the usual work of a physician, knowing how to detect a pleural effusion is a conclusion. The interest of the BLUE-protocol is to specify…

Interstitial Syndrome in the Critically Ill: The B-Profile and the B’-Profile

This chapter will probably be the shortest. It was necessary to understand quietly, step-by-step, the elementary sign, the developed sign of interstitial syndrome, and the phenomenon of lung sliding. Lung ultrasound is a dynamic tool investigating a dynamic organ, using a sign, lung sliding, with no equivalent using traditional tools (X-rays and CT mainly). This allows to define two opposing kinds of interstitial syndrome, the transudative and the exudative interstitial syndrome.

The A-Profile (Normal Lung Surface): 2) Lung Sliding

In workshops, the lung sliding of healthy models is rather easy to study. In the critically ill, because either exacerbated but parasited by severe dyspneas or made too subtle by deep sedations, its study needs the consideration of adapted signs.

The A-Profile (Normal Lung Surface): 1) The A-Line

We now describe the 5th principle of LUCI. It should be understood that the A-profile is defined by both lung sliding and the A-line. Note that a Lung sliding associated to one, or even 2 B-lines, is still in the definition of an A-profile (3 B-lines would change it into a B-profile. We do not use transversal scans. This would make lung ultrasound more difficult. Slight movements (of the physician or patient) would deeply change the image. Our 5 MHz microconvex probe is perfect for this part of lung investigation.

An Introduction to the Signatures of Lung Ultrasound

For performing lung ultrasound in the critically ill, we have counted 12 main signs. Only the first ten are used in the BLUE- protocol (the two others are the dynamic air bronchogram and the lung pulse).

The BLUE-Points: Three Points Allowing Standardization of a BLUE-Protocol

For exploring the most voluminous organ, three points allow standardized protocols, expedite the investigation of critically ill patients, and warrant the accuracy published in the BLUE-protocol native article.

The Pleural Line

The previous chapters detailed the first three of the seven main principles of lung ultrasound, just evoking the four last. Now it is time to…

The Seven Principles of Lung Ultrasound

Lung ultrasound is a standardized domain. Each of its components is based upon pathophysiological realities. As for any novelty, a new terminology had to be…

How We Conduct a BLUE-Protocol (And Any Critical Ultrasound): Practical Aspects

What happens when a BLUE-protocol is performed or when any ultrasound test is done on a critically ill patient?

Ultrasound-guided IV access technique

Patient preparation

Transducer-needle orientation for US-guided IV access

Two views are typically used in ultrasound-guided peripheral venous cannulation: in-plane and out-of-plane. The orientation of the needle with respect to the ultrasound transducer determines whether the needle is in-plane or out-of-plane.

Indications for US-guided peripheral IV cannulation

In IV therapy, ultrasound-guided peripheral IV cannulation has emerged as an important technique, enhancing the success rates of venous access, especially in patients with difficult venous anatomy. Ultrasound guidance for peripheral IV cannulation represents a significant advancement in venous access. It provides real-time visualization of veins, surrounding tissues, and the needle path. It is particularly beneficial for patients with difficult access due to obesity, chronic illness, or depleted venous reserves. This technique enhances the accuracy of needle insertion, minimizes the number of attempts required for successful cannulation, and increases patient comfort and satisfaction.

IV access in emergency settings

Emergency situations demand swift action; obtaining IV access can be the difference between life and death. However, the process is fraught with difficulty, especially in patients with compromised vascular access due to dehydration, trauma, shock, obesity, or IV drug use. We introduce a practical algorithm specifically designed for IV access in emergency settings to streamline the decision-making process and enhance clinical outcomes. These algorithms are step-by-step guides that address initial site selection, techniques for difficult IV access, use of ultrasound-guided venipuncture, and alternative access methods such as IO infusion. It is intended to serve as a practical tool for clinicians, reducing the time to achieve access and improving patient care.

IV access in patients with a history of cancer or chemotherapy treatment

Patients with a history of cancer, especially those who have received chemotherapy, often experience venous changes that make IV access difficult. Chemotherapy agents can cause venous damage, leading to sclerosis, reduced elasticity, and increased fragility of the veins. Additionally, repeated venipunctures throughout the treatment can further compromise venous integrity, resulting in limited or difficult-to-access venous sites.

IV access in patients with a history of IV drug use

Patients with a history of IV drug use often present unique challenges when establishing IV access. Adopt an empathetic approach and utilize technical solutions to establish IV access in these patients. 

IV access in patients with diabetes

Patients with diabetes often have complications such as peripheral vascular disease, changes in skin texture, and susceptibility to infection, all of which can complicate the process of obtaining and maintaining reliable IV access.

IV access in patients with burns

Depending on their severity and location, burns can significantly alter the anatomy of the skin and underlying tissues, complicating the identification and cannulation of peripheral veins.

IV access in obese patients

Securing IV access in obese patients presents a unique set of challenges for healthcare professionals. The increasing prevalence of obesity worldwide has made this a common issue in clinical settings, necessitating a deeper understanding and specialized approaches to ensure effective venous cannulation. In obese individuals, the excessive adipose tissue can obscure superficial veins, making them difficult to palpate and visualize. This complicates the identification of suitable veins for cannulation and increases the risk of multiple cannulation attempts, leading to patient discomfort and potential complications such as hematoma, infection, or thrombophlebitis.

IV access in underweight patients

IV access in patients with low body weight or a low body mass index (BMI) presents unique challenges for healthcare professionals. These individuals often have less subcutaneous fat and smaller, more fragile veins, making traditional IV insertion more difficult and increasing the risk of complications such as vein damage or infiltration. The reduced vein visibility and palpability require a higher level of skill and sometimes necessitate the use of ultrasound-guided techniques to achieve successful venipuncture. Additionally, these patients may have a higher risk of adverse reactions from fluid overload or medication toxicity, necessitating careful monitoring and adjustment of IV fluid and medication dosages. 

IV access in elderly patients

Thinner skin and fragile veins

IV access in pediatric patients

Securing venous access in infants and children presents unique challenges due to the delicate nature of their veins, potential dehydration, and anxiety about the procedure. This manual focuses primarily on IV access in adults. However, here are essential points to consider when attempting vein access in pediatric patients.

Algorithms