Zdravka D. Zafirova, M.D.

Gerald A. Maccioli, M.D., F.C.C.M., President
American Society of Critical Care Anesthesiologists

ecent developments in the field of critical care continue to refine our understanding of pathophysiology, mechanisms and treatment of critically ill patients.

The Ongoing Controversy Regarding Blood Transfusion: More Answers and Questions
The liberal utilization of transfusion of blood products has been challenged in the past decade. Transfusion of blood products in the intensive care unit (ICU) — and operating room — remains a topic of controversy despite years of research. Our understanding of the association between patient comorbidities and outcomes related to hemoglobin (Hgb) level continues to evolve. The dissociation between theory and practice in the transfusion arena persists, and the optimal value of Hgb for critically ill patients remains elusive.

Evaluation of disability and mortality in patients with subarachnoid hemorrhage reveals that lower mean and nadir Hgb and higher transfusion rate are associated with worse outcomes.¹ Mounting evidence weakens support for the benefits of transfusion, and the risks are less clearly justified. Studies support association between transfusion and infectious complications. Transfusion of leuco-reduced red blood cells in patients undergoing cardiac surgery is associated with lower incidence of infection and lower mortality with infection, while mortality without infection is unchanged.²

Transfusion-related acute lung injury (TRALI) is a significant cause of transfusion-related morbidity and mortality and remains under-recognized. The incidence of TRALI is increased with transfusion of high plasma components (platelets and fresh frozen plasma) and from alloimmunized donors such as female, multiparous individuals. TRALI is more likely to develop in recipients with sepsis.³

Interdisciplinary intervention aimed at prevention of acute lung injury (ALI) in ICU patients by protocol-guided utilization of low tidal volumes and restrictive transfusion practices has been studied in a tertiary care center. This intervention has resulted in lower incidence of ALI and fewer days in the ICU and on mechanical ventilation as well as reduced mortality.⁴

Anesthesiology-Based Advanced Cardiac Life Support (ACLS): Guidance on Management of Perioperative Cardiopulmonary Events
Cardiopulmonary arrest during anesthesia is a distinct entity.^5-6 The event is often foreseeable and typically witnessed, and extensive monitoring of vital signs is usually in progress. The evaluation of the arrest is facilitated by the pre-existing knowledge of the patient’s history and the circumstances under which it has occurred. The etiology is frequently readily identifiable and can be linked to specific anesthesia- or procedure-related factors as well as patient comorbidities. Therefore, the response is prompt, focused and may require specific measures addressing the intraoperative situation. The current ACLS guidelines may not provide adequate guidance in the management of these incidents. The ASA Committee on Critical Care Medicine and the American Society of Critical Care Anesthesiologists (ASCCA) have developed anesthesia/perioperative ACLS guidelines to address the distinct situations of perioperative cardiopulmonary events. This document has gone through the process of ASA administrative review and has been approved as a committee work product. Our ASA liaison to the American Heart Association will now coordinate to begin a dialogue on (hopefully) making this an ACLS educational module. Our committee is doing a final review before ASA makes this available as a monograph download on its Web site for our membership.

Tight Glycemic Control: How Tight Does It Need to Be?
Tight glycemic control has been associated with improved outcomes in critically ill patients in several studies and has become prevalent in the contemporary ICU.⁷ However, results from recent trials have raised questions about the safety of this intervention. The incidence of hypoglycemia and the associated morbidity and mortality have challenged the stringent glucose goals utilized in the published protocols. Increased severity of illness, renal failure and sepsis have been identified as risk factors for hypoglycemia.⁸ Severe hyperglycemia adversely affects patient outcomes, and the benefits of tight glucose control outweigh the risks. The glucose values at which these benefits are realized while avoiding hypoglycemia-related complications remain uncertain.

Burgeoning Opportunities for Intensivists
As outpatient care and day-case surgery continue to grow, all in-patient services are becoming more “ICU-like” in nature. Health care systems and administrators are realizing the clinical and economic value of intensivists clearly espoused by the Leapfrog Group. As such, the marketplace for specialists in critical care medicine is enormous.⁹ As a hospital-based medical specialty, many anesthesiology groups are being approached to assume broader clinical responsibilities, principally in the ICU. For both the individual intensivist and groups, this represents a golden opportunity. In response, the residency program at Oregon Health & Science University has pioneered a unique combined four-year program, which upon completion allows taking both the anesthesiology and critical care medicine American Board of Anesthesiology examinations. Other residency programs are watching the results of this educational change, and it may become more broadly adopted.

Physician Performance Measures
The ASA Committee on Critical Care Medicine, in collaboration with ASCCA, authored the ASA-sponsored physician performance measures on catheter-related bloodstream infection and ventilator-associated pneumonia. These measures have been approved by the AMA Physician Consortium for Performance Improvement www.ama-assn.org/ama/pub/category/2946.html and AQA (formerly the Ambulatory Care Quality Alliance). Both are expected to be part of Medicare’s Physician Quality Reporting Initiative in 2008. Anesthesiologists place the majority of central vascular catheters, and ASA leadership on this matter demonstrates our specialty’s continuing leadership in critical care and patient safety.

References:
1. Naidech AM, Jovanovic B, Wartenberg KE, et al. Higher hemoglobin is associated with improved outcome after subarachnoid hemorrhage. Crit Care Med. 2007; 35:2383-2389.
2. Bilgin YM, van de Watering LMG, Eijsman L, et al. Is increased mortality associated with post-operative infections after leukocytes containing red blood cell transfusions in cardiac surgery? Transfusion Med. 2007; 17:304-311.
3. Gajic O, Rana R, Winters J, et al. Transfusion-related acute lung injury in the critically ill. Am J Respir Crit Care Med. 2007; 176:886-891.
4. Yilmaz M, Keegan MT, Iscimen R, et al. Toward the prevention of acute lung injury: Protocol-guided limitation of large tidal volume ventilation and inappropriate transfusion. Crit Care Med. 2007; 35:1660-1666.
5. Biboulet P, Aubas P, Dubourdieu J, et al. Fatal and nonfatal cardiac arrests related to anesthesia. Can J Anesth. 2001; 48:326-332.
6. Olsson GL, Hallen B. Cardiac arrest during anaesthesia. A computer-aided study in 250,543 anaesthetics. Acta Anaesthesiol Scand. 1988; 32:653-664.
7. Van den Berghe G, Wilmer A, Hermans G, et al. Intensive insulin therapy in the medical ICU. N Engl J Med. 2006; 354:449-461.
8. Krinsley J, Grover A. Severe hypoglycemia in critically ill patients: Risk factors and outcomes. Crit Care Med. 2007; 35:2262-2267.
9. Recent Studies and Reports on Physician Shortages in the U.S. Center for Workforce Studies. Association of American Medical Colleges. August 2007.

Zdravka D. Zafirova, M.D., is Associate Director, Anesthesia Perioperative Medicine Clinic and Assistant Professor, Department of Anesthesia and Critical Care, University of Chicago.

Gerald A. Maccioli, M.D., F.C.C.M., is Director of Critical Care Medicine, Critical Health Systems of North Carolina, Raleigh Practice Center, Raleigh, North Carolina. He is ASA Director for North Carolina and Chair, ASA Committee on Critical Care Medicine.