Blood transfusions during major abdominal surgery

Elective major abdominal surgery (EMAS) is a cornerstone of modern surgical care, offering curative potential for cancers and other complex diseases of the gastrointestinal, reproductive, and genitourinary systems. However, these procedures frequently involve significant blood loss, leading clinicians to rely on perioperative red blood cell (RBC) transfusions to support hemodynamic stability and tissue oxygenation. While lifesaving in some cases, a comprehensive new analysis raises urgent concerns about the widespread and often routine use of this intervention.

A systematic review and meta-analysis published in the British Journal of Anaesthesia (Morris et al., 2023) synthesized data from more than 191,000 patients and found that perioperative RBC transfusions are not only associated with increased short- and long-term mortality but also with higher risks of infectious complications, postoperative morbidity, and cancer recurrence. The findings challenge longstanding assumptions and underscore the critical need for standardized, evidence-based transfusion strategies, especially in elective settings.

Key findings at a glance

From the 39 observational studies included (37 in meta-analysis), the pooled results are eye-opening:

• Short-term mortality: 2.72× higher risk (30-day or in-hospital mortality)
• Long-term mortality: 1.35× higher hazard ratio
• Overall morbidity: 2.18× higher odds
• Infectious complications: 1.90× higher odds
• Cancer outcomes:
  • Decreased overall survival
  • Increased cancer recurrence

Importantly, these associations remained significant even when accounting for preoperative anemia, a common confounder. A sensitivity analysis excluding studies that didn’t control for anemia still showed a 2.27× increase in short-term mortality.

What was studied?

• Design: Systematic review and meta-analysis (no RCTs found)
• Timeframe: Data from 2000 to 2020
• Patients: Adults (≥18 years) undergoing elective major abdominal surgeries, including:
  • Gastrointestinal (e.g., colorectal, gastric, hepatobiliary)
  • Reproductive (e.g., gynecologic oncology)
  • Genitourinary procedures

The vast scope of this analysis offers an unprecedented look at the potential risks tied to perioperative transfusion across multiple surgical domains.

What are the risks?

Let’s break down the core outcomes:

1. Short-term mortality

• Transfused patients had nearly three times the risk of dying within 30 days or during hospitalization. This finding was robust across studies and remained significant even after adjusting for anemia and other variables like comorbidity, blood loss, and surgical complexity.

2. Long-term mortality

• Beyond the hospital stay, transfused patients had a modest but statistically significant increase in long-term death rates. This raises questions about the long-term physiological consequences of transfusion and underscores the need for judicious use.

3. Postoperative morbidity

Patients receiving RBCs were more than twice as likely to experience complications of any kind. Common issues included:

• Surgical site infections
• Pneumonia
• Sepsis
• Thromboembolic events

4. Infectious complications

Odds of infection were nearly doubled in transfused patients. This is likely mediated by immune system changes known collectively as transfusion-related immunomodulation (TRIM).

5. Cancer-Specific Outcomes

Among patients undergoing cancer surgeries, RBC transfusion was associated with:

• Reduced overall survival
• Higher recurrence rates

The authors speculate this may also be linked to immune suppression caused by transfusion or to delayed systemic recovery postoperatively.

Why are these outcomes occurring?

• Storage lesion: As RBCs sit in storage, they undergo biochemical degradation, releasing cytokines and bioactive agents that can alter immune responses and contribute to systemic inflammation or infection.
• Transfusion-related Immunomodulation (TRIM): Transfused RBCs, especially allogeneic units,  can alter the recipient’s immune system, reducing the ability to fight infection and possibly facilitating cancer progression.
• Patient selection bias: It’s true: patients who are transfused tend to be sicker. They are often older, have more comorbidities, lose more blood, and undergo longer surgeries. But even when studies adjusted for these factors, the negative association remained, indicating a likely independent effect of transfusion.
  

What is Patient Blood Management (PBM)?

PBM is a proactive, evidence-based approach to minimize the need for transfusion by:

• Managing anemia before surgery (e.g., iron supplementation, erythropoietin)
• Minimizing intraoperative blood loss (e.g., surgical techniques, antifibrinolytics)
• Enhancing anemia tolerance with careful fluid and oxygen management

The 3-pillar PBM model emphasizes keeping the patient’s own blood circulating longer and healthier.

Yet, in this review, PBM was notably underutilized:

• Only 6 studies even mentioned PBM.
• No study demonstrated standardized PBM protocols.

Clinical implications

• Transfusion thresholds vary significantly across hospitals and even between clinicians, with hemoglobin triggers ranging from 7.0 to 10.0 g/dL.
• Lack of standardized transfusion protocols likely contributes to the inconsistencies in outcomes.

When to transfuse?

Step 1: Assess Hemoglobin (Hb)

• Hb < 7 g/dL:
  → Transfuse if symptomatic.
• Hb 7–8 g/dL:
  → Transfuse only if the patient is high-risk.
• Hb > 8 g/dL:
  → Avoid transfusion unless the patient has severe symptoms.

Step 2: Evaluate Bleeding

• Massive bleeding (> 30% blood loss):
  → Transfuse.
• Minor/moderate bleeding:
  → Consider blood conservation strategies.

Step 3: Assess Patient Condition

• Stable with no hypoxia:
  → Delay transfusion and monitor.
• Unstable with low oxygenation:
  → Consider transfusion.

Implement Patient Blood Management (PBM) Strategies

Preoperative Optimization

• Identify and correct anemia early (iron, folate, vitamin B12, erythropoietin).
• Screen for coagulopathies and manage accordingly.
• Consider preoperative autologous blood donation, if feasible.

Intraoperative Blood Conservation

• Use cell salvage and autotransfusion where applicable.
• Administer tranexamic acid or other antifibrinolytics.
• Restrict IV fluids to prevent dilutional anemia.

Postoperative Strategies

• Minimize blood draws (e.g., use pediatric tubes).
• Encourage early patient mobilization.
• Monitor closely for delayed bleeding or signs of coagulopathy.

Final thoughts

The findings from Morris et al. (2023) deliver a stark warning: Red blood cell transfusions during elective abdominal surgery may be more harmful than previously appreciated. This isn’t just a statistical observation—it’s a call to action.

Clinicians, hospitals, and healthcare systems must:

• Reevaluate transfusion triggers.
• Implement PBM protocols.
• Invest in staff education and data monitoring.
• Shift from reactive to proactive perioperative care.

As the evidence mounts, one message is clear: fewer transfusions, done more thoughtfully, could save lives and enhance recovery for thousands of surgical patients each year.

For more information, refer to the full article in BJA.

Reference: Morris FJD et al. Outcomes following perioperative red blood cell transfusion in patients undergoing elective major abdominal surgery, Br J Anaesth. 2023;131:1002-1013.

Read more about this topic in NYSORA’s Anesthesia Updates.