Chollet-Rivier, M.

Perruchoud, C.

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Narcotrend-assisted propofol/remifentanilanaesthesia for prevention of awarenessEditor—I read with interest about the comparison of theuse of Narcotrend and clinical assessment in judging thedepth of anaesthesia while using total i.v. anaesthesia(TIVA).1 I fully agree with the authors that the use ofclinical assessment alone would lead to a greater deviationfrom a defined target while running TIVA. TheNarcotrend, a computer-based EEG programme, is easy touse and has low running costs, besides in terms of predic-tion probability, the performance of the Narcotrend indexand the bispectral index to predict propofol effect-site con-centrations was comparable. I recently conducted a smallstudy to evaluate the number of cases who developedawareness under anaesthesia, out of the 25 anaesthetistswho replied, five had cases of awareness under anaesthe-sia, and out of these five, four were under TIVA. The mostsignificant of these cases was a 52-yr-old lady having anabdominal hysterectomy, anaesthetized by myself usingtarget-controlled infusion (TCI) with propofol and remi-fentanil. Despite using a 1 mg kg21 bolus of remifentanilfollowed by an infusion of 0.2 mg kg21 h21and runningpropofol at a target-controlled level of 6 mg ml21, clini-cally evaluating that the patient is asleep such as loss ofeyelash reflex, at induction, fall in arterial pressure andheart rate, during maintenance of anaesthesia, the patientcomplained about awareness under anaesthesia for a shortwhile after induction. Since awareness under anaesthesia isindeed a serious issue, I would indeed welcome the use ofNarcotrend if indeed it could decrease the incidence ofawareness, and decrease incidence of nausea and vomitingas stated by the authors.O. D’MelloBury St Edmonds, UKE-mail: oswald20577@yahoo.co.ukEditor—I thank Dr D’Mello for his interesting comment.With respect to the case of awareness he mentioned, onemay speculate that the patient experienced a period ofwakefulness shortly after induction because propofol infu-sion was stopped due to the automatic lockout interval ofthe TCI device. This lockout mechanism is automaticallyactivated, when the plasma target concentration is reduced.As it was mentioned, propofol anaesthesia was inducedrapidly by achieving a plasma target of 6 mg ml21. It isknown from the literature that this results in adequatehypnosis after about 60 s. I guess a lower target plasmaconcentration was used after intubation; thereby, the auto-matic lockout interval was activated.We agree with Dr D’Mello that most probably measur-ing the cerebral pharmacodynamics of propofol by theNarcotrend (or even any other device using theelectroencephalogram) would have resulted in indicating alow level of hypnosis during this time. However, it isknown that especially during the transition from con-sciousness to unconsciousness, the range of the Narcotrendlevel differs markedly inter-individually.2 Therefore, it isdifficult to define a threshold level differentiating the con-scious and the unconscious state precisely in the individualpatient. This holds true for all the other monitors of ‘depthof anaesthesia’, too.3 Therefore, it remains a challenge toclearly identify periods of wakefulness during generalanaesthesia. However, I am sure using an EEG monitor,using TCI devices which include the effect-site concen-tration rather than the plasma concentration and carefulclinical observation of the patient together will help toavoid periods of awareness.4I. RundshagenBerlin, GermanyE-mail: ingrid.rundshagen@charite.de1 Rundshagen I, Hardt T, Cortina K, Pragst F, Fritzsche T, Spies C.Narcotrend-assisted propofol/remifentanil anaesthesia vs clinicalpractice: does it make a difference? Br J Anaesth 2007; 99:686–932 Schneider G, Kochs EF, Horn B, Kreuzer M, Ningler M.Narcotrend does not adequately detect the transition betweenawareness and unconsciousness in surgical patients. Anaesthesiology2004; 101: 1105–113 Bruhn J, Myles PS, Sneyd R, Struys MMRF. Depth of anaesthesiamonitoring: what’s available, what’s validated and what’s next? Br JAnaesth 2006; 97: 85–944 Triem JG, Ro¨hm KD, Boldt J, Piper SN. Comparison of a propfol-based anaesthesia regimen using optimated-target-controlled-infusion (OTCI) and manually-controlled infusion (MCI) technique.Anaesthesiol Intensivmed Notfallmed Schmerzther 2006; 41: 150–5doi:10.1093/bja/aen011Cardiac arrest during induction ofanaesthesia in a child on long-termamphetamine therapyEditor—The number of children on chronic amphetaminetreatment for attention deficit hyperactivity disorder(ADHD) has dramatically increased during the lastdecade. Although several previous case reports1 havedescribed serious adverse reactions during general anaes-thesia in adult patients on chronic amphetamine, very littleis known about perioperative problems with paediatricpatients. We report a case in which a 10-yr-old child onlong-term methyphenidate (MPH) therapy presented acardiac arrest during induction of general anaesthesia.A 10-yr-old male child was undergoing an ambulatorylaser therapy of a haemangioma on the face. The patientCorrespondence421had been taking MPH daily for 4 yr because of ADHD.Anaesthesia was induced by mask with sevoflurane.Arterial pressure and heart rate remained stable andoxygen saturation was 100%. After i.v. access was estab-lished, propofol 2 mg kg21 and alfentanil 10 mg kg21 wereadministered. Immediately after, the child developed asevere bradycardia followed by asystole. I.V. atropine0.5 mg was given twice and external chest massage wasperformed. Normal cardiac rhythm with correct haemo-dynamic measures was restored 30 s after the start of thecardiopulmonary resuscitation. The planned operation wascontinued. Operation and emergence were uneventful. Thepatient was taken to the post-anaesthesia care unit wherehis heart rate remained stable at 90 beats min21. He wasdischarged home on the same day.Amphetamines are indirect sympathetic amines withpowerful central nervous system stimulation activity andperipheral a and b actions. Chronic administration canresult in depletion of norepinephrine and dopaminestorage. This decreased reserve of endogenous catechol-amine can contribute to a blunted sympathetic responsewhich can lead to bradycardia and refractory hypotensionduring anaesthesia. In our case, the patient did not take hismedication on the morning of surgery, but it has beenshown that intraneuronal catecholamine levels may notreturn to normal for days to weeks after cessation ofamphetamine use.2Perioperative cardiac arrest in children has multiple cau-sations.3 Propofol has been associated with bradycardiaand asystole4 and the decrease in heart rate is more pro-nounced when propofol is combined with alfentanil.5We found in the patient’s medical files several previousuneventful general anaesthetics for the same procedure,before the patient was on amphetamine therapy. However,a severe bradycardia responding to atropine was notedduring induction of a general anaesthesia several monthsearlier when the child was on amphetamine treatment. Webelieve that a blunted sympathetic response due to achronic amphetamine exposition associated to the cardiaceffects of propofol and alfentanil may have transformed atrivial bradycardia in a life-threatening asystole.Therefore, the management of children on chronicamphetamine therapy should include avoidance or carefultitration of cardiac depressor anaesthetic drugs. Directacting vasopressors such as epinephrine or phenylephrineare preferable because of possible cross-tolerance to otherindirect vasopressors such as ephedrine.6 Premedication orpre-treatment with atropine may also be useful.In conclusion, we have observed a severe cardiovascularcomplication during induction of anaesthesia, possibly inrelation to chronic amphetamine treatment. In view of theincreasing number of children on such treatment, furtherstudies on the anaesthetic implications of this are requiredto determine if a specialized anaesthetic approach isappropriate in this group.C. Perruchoud*M. Chollet-RivierLausanne, Switzerland*E-mail: christophe.perruchoud@chuv.ch1 Samuels SI, Maze A, Albright G. Cardiac arrest during caesareansection in a chronic amphetamine abuser. Anesth Analg 1979; 58:528–302 Healzer JM, Fischer SP, Brook MW, Brock-Utne JG. Generalanesthesia in a patient on long-term amphetamine therapy: is therecause for concern? Anesth Analg 2000; 91: 759–93 Flick RP, Sprung J, Harrison TE, et al. Perioperative cardiac arrestsin children between 1988 and 2005 at a tertiary referral center: astudy of 92,881 patients. Anesthesiology 2007; 106: 226–374 Tramer MR, Moore RA, McQuay HJ. Propofol and bradycardia:causation, frequency and severity. Br J Anaesth 1997; 78: 642–515 Hiller A, Saarnivaara L. Injection pain, cardiovascular changes andrecovery following induction of anaesthesia with propofol in com-bination with alfentanil or lignocaine in children. Acta AnaesthesScand 1992; 36: 564–86 Johnston RR, Way WL, Miller RD. Alteration of anesthetic require-ments by amphetamine. Anesthesiology 1972; 36: 357–63doi:10.1093/bja/aen012What can you do in 12 weeks as a houseofficer in anaesthesia at a District GeneralHospital?Editor—A house officer in anaesthetics and intensivecare? It must be a holiday! Do you feel like a medicalstudent again? Are you allowed to do anything? These aresome of the comments I repeatedly heard throughout my 3month placement from doctors in other specialities outsideanaesthesia and intensive care (ITU). However, contrary tocommon belief, doing house jobs in anaesthetics and ITUis not just being an observer. It is a unique opportunity forjunior doctors, who are less exposed to practical clinicalskills, especially with the pressures of the EuropeanWorking Time Directive, to acquire competences in per-forming essential and advanced clinical skills and to buildtheir confidence in managing critically ill patients. Here, Iexplain how much I was able to do as a house officer injust 12 weeks.The first thing someone learns at medical school is A BC. Although this is a simple principle known to everyjunior doctor, it is often not followed properly in practice.My hands-on experience in the anaesthetic room underdirect supervision, mostly by a consultant, taught me howto approach a patient who suddenly stops breathing, howto use simple manoeuvres to maintain the airways, andmore interestingly how to obtain definitive airways. I wasable to perform 35 intubations and 42 LMAs during mytime in anaesthetics, which enhanced my confidence inCorrespondence422

Cardiac arrest during induction of anaesthesia in a child on long-term amphetamine therapy

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