letters to the Editor

Porphyria, Cardiopulmonary Bypass, and heart with additional hemorrhage into the pericardial sac (5). Peri- cardiocentesis, however, can be a temporizing measure in the se- Volatile Anesthetics verely compromised patient (4,7,8) until definitive surgical estab- lishment of a pericardial window. A pericardial window can be To the Editor: established under local (9) via the subxiphoid or lateral We take issue with Stevens et al’s contentious statements in their thoracotomy approach (1,2,5,8,9). The subxiphoid approach is less discussion of volatile anesthetics in the patient with acute intermit- useful for trauma because limited surgical exposure may preclude tent porphyria undergoing mitral valve replacement (1). repair of cardiac wounds (2). However, a pericardial window dur- In the “pre-propofol” era, the safe and appropriate use of halo- ing awake lateral thoracotomy may be both poorly tolerated and thane and isoflurane in porphyric patients was established (2). dangerous in the distressed, moving patient (7). Recent reports of the successful use of isoflurane in porphyric A blunt trauma victim (2) recently presented for an emergent patients undergoing cardiac also exist (3,4). As the authors surgical pericardial window for recurrent acute pericardial tampon- themselves allude to a report of elevated porphyrins after propofol ade. Although the patient was not hypotensive, jugular venous anesthesia in acute intermittent porphyria, favoring propofol over distention, pulsus paradoxus (1,3,7), patient distress (4), and echo- inhaled anesthetics because of the latter’s implied lack of a “safety cardiographic signs were present. As an alternative to endotracheal record” cannot be supported. after induction of anesthesia with cardiovascular depres- The authors also infer that volatile anesthetics have a deleterious sant anesthetics, we considered awake intubation of the trachea effect on myocardial stunning. However, experimental data support without sedation; we found no reports of this technique in the the premise that volatile anesthetics afford protection from the reper- literature. With persuasive explanation of the procedure to the fusion injury that results in myocardial stunning after cardiopulmo- patient (but without sedation) (9), along with lidocaine topical an- nary bypass (CPB) (5). esthesia to the pharynx, larynx, and trachea, we placed an orotra- Thus, while the authors have successfully managed a porphyric cheal tube over a bronchoscope in a few minutes without patient patient undergoing CPB with intravenous anesthesia, we cannot reaction. Then, anesthesia was gently induced (N,O, isoflurane, and condone, on the basis of a single report, the abandonment of volatile fentanyl) without cardiovascular depression. The flexible broncho- anesthetics in either porphyria or CPB. scope was chosen as the least stimulating technique for awake intubation. In the trauma patient, awake fiberoptic intubation may Evan G. Bivalizza, MBChB, FFASA also be the ideal intubation technique if a full stomach and a cervical David C. Abramson, MBChB, FFASA spine injury coexist. We further speculate that awake fiberoptic Lewis I. Gottschalk, MBchB, FFASA intubation, which avoids depressant anesthetics, could be consid- Department of Anesthesiology ered in other conditions of decreased cardiovascular reserve, such University of Texas Medical School as ischemic heart disease. Houston, TX 77030 Peter H. Breen, MD, FRCPC References Mark A. MacVay, MD 1. Stevens JJWM, Kneeshaw JD. Mitral valve replacement in a patient with acute inter- mittent oorohvria. Anesth Anale 1996:82:416-8. Department of Anesthesiology 2. Harris&G& &issner PN, HiftkJ. Anaesthesia for the porphyric patient. Anaesthesia University of California at Irvine 1993;48:417-21. UC1 Medical Center 3. Campos JH, Stein DK, Michel MK, Moyers JR. Anesthesia for aortic valve replacement Orange, CA 92613 in a patient with acute intermittent porphyria. J Cardiothorac Vast Anesth 1991;5: 258-61. References 4. Sneyd JR, Kreimer-Birnbaum M, Lust MR, H&n J. Use of sufentanil and atracurium 1. Stoelting RK, Dierdorf SF, McCammon RL. Diseases of the pericardium. In: Anesthesia anesthesia in a patient with acute porphyria undergoing coronary artery bypass and co-existine disease. New York: Churchill Livinastone, 1988:161-S. surgery. J Cardiothorac Vast An&h 1995;9:75-8. 2. Callaham ML-Pericardiocentesis in traumatic and &ntraumatic cardiac . 5. Warltier DC, Mahmood H, Kampine Jl’, Schmeling WT. Recovery of contractile func- Ann Emerg Med 1984;13:924-45. tion of stunned myocardium in chronically instrumented dogs is enhanced by halo- 3. Lake CL. Anesthesia and pericardial disease. Anesth Analg 1983;62:431-3. thaw or isoflurane. Anesthesiology 1988;69:552-65. 4. Stein L, Shubin H, Weil MH. Recognition and management of pericardial tamponade. JAMA 1973;225:503-6. 5. Spodick DH. Pericarditis, pericardial effusion, , and constriction. Crit Care Clin 1989;5:455-76. 6. MGller CT, Schoonbee CG, Rosendorff C. Haemodynamics of cardiac tamponade Pericardial Tamponade: A Case for Awake during various modes of ventilation. Br J Anaesth 1979;51:409-15. 7. Finucane BT. Thoracic trauma. In: Kaplan JA, ed. Thoracic anesthesia. New York: Endotracheal Intubation Churchill Livingstone, 1991:472-4. 8. Kaplan JA, Bland JW, Dunbar RW. The perioperative management of pericardial tamponade. South Med J 1976;69:417-9. To the Editor: 9. Stanley TH, Weidauer HE. Anesthesia for the patient with cardiac tamponade. Anesth Pericardial tamponade restricts diastolic filling of the heart (l-5). Analg 1973;52:110-4. Then, high intravascular volume and preload are required for ade- quate and end-diastolic volume and stroke volume. Increased heart This work was supported in part by National Heart, Lung, and Blood Institute Grant HL-42637. rate and contractility and peripheral vasoconstriction help maintain blood pressure in the face of decreased stroke volume (l-4). Any anesthetic (including ketamine and etomidate) or even positive pressure ventilation (6) can decrease preload, afterload, contractil- Intraoperative Hemodialysis During ity, or heart rate and precipitate cardiovascular collapse (1,3,7-9). Accordingly, removal of fluid from the pericardial sac should Emergency Intracranial Surgery always be considered before anesthesia induction for pericardial tamponade. Percutaneous pericardiocentesis is often not helpful in To the Editor: traumatic pericardial tamponade (2,7) because clots may prevent We present a case in which intraoperative hemodialysis was used to aspiration of blood (2), continued hemorrhaging rapidly refills the correct hyperkalemia unresponsive to less invasive treatment dur- pericardial sac with blood (2,6,7), and the needle can traumatize the ing emergency surgery to evacuate an intracranial hematoma.

658 Anesth Analg 1996;83:658-67 01996 by the International Anesthesia Research Society