The Institute of Medicine Ethics and Law, Hadassah University Medical Center, The Hebrew University of Jerusalem, Jerusalem, Israel. Supported, in part, by the Walter S. and Alice Gorham Foundation. The authors thank Mrs. Barbara Piperno for her technical assistance. Address requests for reprints to: Charles L. Sprung, MD, JD, Department of Anesthesiology and Critical Care Medicine, Hadassah University Hospital, POB 12000, Jerusalem, Israel 91120.

Department of Anesthesia and Critical Care Medicine, Hadassah Hebrew University Medical Center, P.O. Box 12000, Jerusalem, 91120, Israel.galo@netvision.net.il.To the Editor:-We read with great interest the article by Kalfon et al., [1]which demonstrated the efficacy of tracheal gas insufflation (TGI) during expiration (expiratory washout) in reducing PaCO2without increasing the prescribed tidal volume. The authors presented an effective method of enhancing mechanical ventilation in patients with severe respiratory failure. The use of distal airway pressure monitoring, as used by the authors, is of clinical importance during TGI administration because it provides accurate airway pressure measurement.There are, however, certain comments we would like to make. Although gas insufflation was synchronized with expiration, it resulted in a significant increase in peak, plateau, and mean airway pressures, signifying an increase in end-expiratory lung volume and possibly in minute ventilation as well. The measurement of respiratory volumes and auto-PEEP during TGI is problematic and, at present, not feasible at bedside. The assessment of tidal volume during TGI is problematic because it is difficult to say whether the gas entering the trachea and the smaller airways adds to the tidal ventilation or participates only in airway flushing during expiration. The measurement of auto-PEEP is problematic because it requires accurate timing of the closure of the inspiratory and the expiratory valves and the cessation of TGI flow. For these reasons, it is difficult to draw conclusions about the efficacy of the ventilatory mode when improvement in ventilation is associated with a significant increase in airway pressure.To resolve similar problems encountered when trying to compare TGI with two different gases, helium and oxygen, we devised a “coefficient of efficiency” to assess the efficacy of TGI at different flow rates and with different gases [2]: The change in PaCO2divided by the change in peak airway pressure. This coefficient, with its easily measured variables (PaCO2and peak airway pressure), helped us to compare different strategies of ventilation according to their ability to clear CO2with minimal lung distention.In addition, we would like to suggest that the term TGI be used in the future to describe all modes of ventilation in which CO2clearance is enhanced by intratracheal gas flow during part or all of the respiratory cycle.Arieh Oppenheim, M.D.Reuven Pizov, M.D.Department of Anesthesia and Critical Care Medicine; Hadassah Hebrew University Medical Center; P.O. Box 12000; Jerusalem, 91120; Israelgalo@netvision.net.il(Accepted for publication November 18, 1997.)

Tension pneumoperitoneum is a known although rare complication of barotrauma, which can accompany blast injury. We report two patients who suffered from severe pulmonary blast injury, accompanied by tension pneumoperitoneum, and who were severely hypoxemic, hypercarbic, and in shock. After surgical decompression of their pneumoperitoneum, respiratory and hemodynamic functions improved dramatically. Several mechanisms to explain this improvement are suggested. In such cases the release of the tension pneumoperitoneum is mandatory, and laparotomy with delayed closure can be contemplated.

Tension pneumoperitoneum is a known although rare complication of barotrauma, which can accompany blast injury. We report two patients who suffered from severe pulmonary blast injury, accompanied by tension pneumoperitoneum, and who were severely hypoxemic, hypercarbic, and in shock. After surgical decompression of their pneumoperitoneum, respiratory and hemodynamic functions improved dramatically. Several mechanisms to explain this improvement are suggested. In such cases the release of the tension pneumoperitoneum is mandatory, and laparotomy with delayed closure can he contemplated.

Septic encephalopathy is a reversible dysfunction of the central nervous system (CNS) that develops in seriously ill patients with sepsis. Conditions in which altered mental status results from localized infections of the CNS, such as meningitis, encephalitis and brain abscess, are not considered septic encephalopathy, and so are beyond the scope of this chapter. We will review the manifestations, incidence, etiology, and treatment of septic encephalopathy. In addition, we will review the spectrum of the systemic inflammatory response syndrome (SIRS) and sepsis, based on the American College of Chest Physicians and the Society of Critical Care Medicine (ACCP/SCCM) Consensus Conference Committee statement [1]. This statement came in response to the need for guidelines for sepsis studies and the knowledge that as long as definitions remained ambiguous and controversial, it would be impossible to compare incidence of sepsis, outcome and effect of new therapies in different studies [1–3].

Oppenheim, Arieh MD; Pizov, Reuven MD; Eidelman, Leonid A MD; Sprung, Charles L MD; Cotev, Shamay MD. Author Information