CORRESPONDENCE 137 extensive block cannot be excluded when such large activity .7 The role of rapid injection of the solvent vehicle volumes of local anaesthetic solution are employed. is also possible, in experimental fat embolism, bradycar- Again, this has not been a problem and we believe that it is dia and even atriso-ventricular block were observed and the probable malplacement of the catheter in the antero- associated with right coronary ischaemia. 8 Severe intra- lateral space and resultant poor block that provides some lipid-induced transient sinus bradycardia has been ob- protection against such extensive blocks. Finally, we served. 9 Furthermore, in a dog model of ischaemia, would caution against the use of this technique in patients induced by partial occlusion of the left inter-ventricular who have experienced accidental dural puncture during coronary artery, IV intralipid decreased regional myo- the placement of the epidural catheter. There is the cardial blood flow in the subendocardial and subepicardial potential for transdural passage of the injected chloro- layers,~~ perhaps because of increased blood viscosity. procaine and decreased neurotoxicity of the new prepara- tions has not yet been affirmed. Marc Freysz, MD PhD D6partement d'Anesth6sie-R6animation Edward Crosby asc MD FRCPC H6pital G6n6ral, CHRU Dijon, Universit6 de Bourgogne Dennis Read MB FFARCSFRCPC 21033 Dijon C6dex France Ottawa General Hospital Quadiri Timour PhD Lucien Bertrix MD PhD REFERENCES Georges Faucon MD PhD I Shnider SM. Levinson G. Anaesthetic for Caesarean Sec- Laboratoire de Pharmacologie M6dicale tion. In: Shnidcr SM, Lcvinson G (Eds.). Anesthesia for Facult6 de M6decine CI. Bernard obstetrics, 2nd Ed. Baltimore: Williams and Wilkins, Universit6 Lyon l 1987; 159-78. 69006 Lyon C6dex 08 France 2 Foldes FF, McNall PG. 2-Chloroprocaine: a new local anesthetic agent. Anesthesiology 1952;13: 287-96. REFERENCES 1 Doyle DJ, Mark PWS Reflex bradycardia during sur- gery. Can J Anaesth 1990; 37" 219-22. 2 Cullen PM, Turtle M, Prys-Roberts C, Way WL, Dye J. Propofol bradycardia Effect of propofol anesthesia on barorcflex activity in hu- mans. Anesth Analg 1987; 66: I 115-20. To the Editor: 3 Baraka A. Severe bradycardia following propofol-sux- We read with interest the recently published review of amethonium sequence. Br J Anaesth 1988; 61: 482-3. reflex bradycardia during surgery. ~ Recent reports impli- 4 Ganansia MF, Francois TP, Ormezzano X, Pinaud ML, cating propofol with bradycardia suggested to us the Lepage JY. Atrioventricular Mobitz I block during pro- following comments. pofol anesthesia for laparoscopic tubal ligation. Anesth Propofol is a new alkyl phenol intravenous anaesthetic Anal 1989; 69" 524-5. agent now available in an aqueous solution of ten per cent 5 Thirion B, Haberer JP. Arr~t circulatoire Iors d'une anes- soybean oil, 2.25 per cent glycerol and 1.2 per cent th6sie par propofol. Ann Fr Anesth R6anim 1989', 8: purified egg phosphatide. In contrast to other IV 386-7. anaesthetics, propofol does not depress baroreflex sensi- 6 James MFM, Reyneke C J, Whiffler K. Heart block follow- tivity directly but may produce an increase in vagal tone ing propofoi" a case report. Br J Anaesth 1989; 62: and/or a decrease in sympathetic tone by central mechan- 213-5. isms. 2 Severe bradycardia and arrhythm~as have been 7 Colson P, Barlet H, Roquefeuil B, Eledjam JJ. Mechan- described after propofol, 3-6 either with fentanyl and its ism of propofol bradycardia. Anesth Anal 1988; 67: congeners, 4"5 or with succinylcholine, 3 vecuronium 4"5 or 906-7. neostigmine. 6 All these drugs may be responsible for 8 Kaulbach W, Benninger K. Experimentelle fettembolie cholinergic effects and it would seem advisable to mit electrokardiographischen und histologischen untersu- recommend that an anticholinergic drug be administered chungen. Langenbecks Arch Chir 1962; 300: 48-70. whenever propofol is given in combination with potential 9 Sternberg A, Gruenevald T., Deutsch AA, Reiss R. lntra- cholinergic agents or betablocking drugs. 6 Mechanisms lipid induced transient sinus bradycardia. N Engl J Med of the bradycardia with propofol remain obscure. They 1981; 304: 422-3. may be produced by a decrease in sensitivity of the baro- 10 Prinzen FW, Van Der Vusse GJ, Coumans WA, Reneman reflex control of the heart or by a direct effect on sinus RS. The effect of intralipid/heparin administration on 138 CANADIAN JOURNAl. OF ANAESTHESIA

some hemodynamic variables, myocardial metabolism and no improvement. Verapamil 1 mg diluted in 3 ml normal regional myocardial blood flow during ischcmia. J Mol saline was flushed through the arterial-catheter. Within Cell Cardiol 1979; I1: 47. five minutes, reactive hyperaemia was noted which correlated with concommitant increases in arterial satura- tion of the involved digits. It was concluded that arterial REPLY spasm was the likely cause of the ischaemia in view of the Dr. Freysz et al. rightly point out that propofol (Diprivan ~) may history of Raynaud's phenomena. This case demonstrates be added to the list of anaesthetic drugs which max: result in the effectiveness of intra-arterial verapamil in the treat- bradyarrhythmias, particularly when used in association with cholinergic stimulating drugs like succinylcholine or neostig- ment of acute arterial ischaemia of the hand secondary to mine. Baraka j has suggested that propofol may lack the central Raynaud's phenomena. It also demonstrates the ability of vagolytic properties which the barbiturates possess. Based on the PORCH test in detecting but not predicting ischaemia. the study of a pharmacologically denervated dog. Colson et al. 2 make the stronger suggestion that propofol may slow the heart B.P. Gallacher MD FRCP directly. The occasional bradyarrhythmias experienced with propofol suggest that it would generally be wise to use King Fahad Hospital anticholinergic premedication where fast heart rates are not Riyadh, Saudi Arabia problematic, especially in vagally stimulating procedures such as laparoscopy.~ REFERENCES I Vaghadia H, Schecter M, Sheps, Jenkins L. Evaluation D.J. Doyle MO PhO FRCPC Toronto of a postocclusive reactive circulatory hyperemia (PORCH) test for the assessment of ulnar collateral circulation. Can J REFERENCES Anaesth 1988; 35: 591-8. 1 Baraka A. Severe bradycardia following propofol-sux- 2 Wong W. PORCH test. Can J Anaesth 1989; 36: 483-4. amethonium sequence. Br J Anaesth 1988; 61: 482-3. 3 Nowak GS, Moorthy SS, McNiece WL. Use of pulse oxim- 2 Colson P, Barlet H, Roquefeuil B, Eledjam JJ. Mechan- ism of propofol bradycardia. Anesth Analg 1988; 67: etry for assessment of collateral arterial flow. Anesthe- 906-7. siology 1986; 64: 527. 3 Doyle D J, Mark P. Vagally-mediated cardiac arrest during laparoscopy. Anaesthesia 1989, 44: 448-9. Eligibility of Canadians for the lntra-arterial verapamil to ASA overseas teaching program

reverse acute ischaemia of the To the Editor: hand after radial artery When the Overseas Teaching Program (OTP) sponsored by The American Society of Anesthesiologists (ASA) and cannulation the Foundation for Anesthesia Education and Research (FAER) was inaugurated in January, 1990,1 criteria of To the Editor: eligibility for those wishing to serve as volunteers A 67-yr-old male presented for left lower lobectomy for teaching anaesthesia in an undeveloped country were lung cancer after a history of progressive dyspnoea, cough described as including membership in the ASA, certifica- and haemoptysis of six months' duration. Premorbid tion by the American Board of Anesthesiology (ABA), history noted heavy cigarette and alcohol use as well as and residence in the USA. These criteria need amplifica- Raynaud's phenomena involving both hands. Preopera- tion. Applicants do have to be members of the ASA, but tive evaluation included a modified Allen's test and Porch that includes affiliate members. Also, certification as a test I using pulse oximetry to assess the collateral circula- qualified specialist in anaesthesia can be either by the tion of the hand. Both tests were negative, lntraoperative- ABA or by an equivalent certifying body. Finally, ly, an Arrow #22 percutaneous catheter was inserted into residence must be in North America, not just in the USA. the left radial artery atraumatically. Upon arrival in the Many Canadian anaesthetists are thus eligible to serve as ICU postoperatively, the patient developed acute is- OTP volunteers. chaemia of the left hand shown by decreased arterial The what, why, how and where of OTP are described in saturation involving all digits. The radial arterial line was the 1990 announcement of the program, i Suffice it to say aspirated and no air or clot was noted. Heparin 100 U that OTP's objective is to contribute to the quality of was initially flushed through the radial arterial line with patient care in developing countries by increasing the