A t~t i~~r t / 2 c~i i c~. c , wkirilc: cnflurane. 8r.eiiii; blood flow, glucose, lactate. oxygenation.Therc arc only few studies on the effect of propofol (24-diisopropylphcnol) on cerebral blood flow and metabolism in man. Stephen and co-workers' found a 51 YO decrease of cerebral blood flow in patients scheduled for coronary artery bypass surgery after a bolus injection of propofol 2 mg:'kg followed by an infusion of 0.2 nigjkginiinute. They noted a proportional decrease of 36% in cerebral oxygen consumption which was associated with a decrease in electroencephalographic (EEC) activity.We compared ccrcbral blood flow under stable and coiiipmiblc conditions o f Ptrco2 and niciin blood pressure ~ iri patients of AS.4 grade I w h o underwcnt 35% oxygen in riitrou5 owidc anaesthesia with cnfluranc 0.59,;1 before and during ii proporol infusion to ucliicvc stcady-state anaesthcaia. MethodsThirtecn paticnts ( 2 fcmalc) aged from 22 62 years schcdulcd Ihr intervertebral disc surgery were included in the ~t u d y after informed consent and approval by the hospital cthica! committee. N o preinedicatiori was given. Anaes- Monitoring consisted of lead I I ECG. I-pl T5 and Fp2 Th EEG recording, continuous blood pressure measurement via a radial artery cannula. jugular bulb pressure ria ii percutaneous catheter (Lcdcrcath 17-gauge), arterial and jugular bulb blood gas. glucosc and lactate analysis.A first CBF measurement was pcrformed when stable conditions were acheived. at least one hour after thiopentone induction. using the xenon 133 inhalation technique. Cerebral radioactivity decay and the expired xenon 133 were recorded by gamma camera (Elscint Apex 21 S) and cerebral blood flow was calculated using the initial slope index.An infusion of propofol (three-step infusion technique) was started a t H rate of 0.35 mgikgiminute (21 nigikgihour) [or 5 minute\ alier the first CBF inexurement. then at 0.2 iiig k p m i n u t e (12 mg k g ' h o u r ) I'or a furthcr 10 tninutcs and then at 0. I mg3 kg minute ( 6 m g ' k g . h o u r ) for tlic last 25 minutes. This scheme of propofol infusion was based on data collected l'rcmi ii previous personal ctiidy of 1 h patients wlicrc ii stable blood concentration 01'4 /1y.iiil w a s achicvsd after-30 minutes of infusion.Blood samples were drawn one minute before the $tart of the infusion and at 1. 2. 3. 4. 5. 7. 9, 1 1 . 13. IS. 20. 25. 30 and 40 minutes from the jugular bulb. and at 20. 30 and 40 minutes liom a periphcral vcin. Blood pressure WBS

Postoperative residual paralysis is an important complication of the use of neuromuscular blocking drugs. In this prospective study, the incidence of residual paralysis detected as a train-of-four response <90% was less frequent in surgical outpatients (38%) than inpatients (47%) (P = 0.001). This might have been the result of the more frequent use of mivacurium for outpatients. Before undertaking tracheal extubation, the anesthesiologists had applied clinical criteria (outpatients, 49%; inpatients, 45%), pharmacological reversal (26%, 25%), neuromuscular transmission monitoring (12%, 11%), or a combination of these. None of these measures seemed to reduce the incidence of residual paralysis except for quantitative train-of-four monitoring. Postoperatively, eight individual clinical tests or a sum of these tests were also unable to predict residual paralysis by train-of-four. Although the incidence of residual paralysis was less frequent in surgical outpatients, predictive criteria were not evident.

Tramadol has weak opioid properties, and an analgesic effect that is mediated mainly by inhibition of the reuptake of norepinephrine and serotonin (5-hydroxytryptamine [5-HT]) and facilitation of 5-HT release (1,2) at the spinal cord. Because 5-HT3 receptors play a key role in pain transmission at the spinal level (3), the 5-HT3 antagonist ondansetron may decrease the efficacy of tramadol, as suggested in an abstract by Maroof et al. In that study, a small dose of 1 mg/kg tramadol was administered along with ondansetron 0.1 mg/kg or placebo, 15 min before the induction of anesthesia. Early postoperative pain scored differed significantly between the test groups. We therefore tested the hypothesis that the tramadol requirement by patient-controlled analgesia (PCA) may be increased when ondansetron is administered for antiemetic prophylaxis.

Tramadol's distinct features in the treatment of shivering reside in its high safety profile and weak sedative properties, particularly in patients with poor cardiorespiratory reserve, in outpatients and on recurrence of shivering.

Reliability of auscultation in positioning of double-lumen endobronchial tubes Auscultation is a well-established technique to confirm the position of double-lumen endobronchial tubes (DLTs

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We investigated the effects of nitroprusside and isoflurane on multipoint pulmonary arterial pressure (PAP)/cardiac index (Q) plots in pentobarbital sodium-anesthetized dogs ventilated alternatively in hyperoxia (fraction of inspired O2, FIO2, 0.4) and hypoxia (FIO2 0.1). Over the entire range of Q studied, 2-5 l.min-1.m-2, hypoxia increased PAP in 16 dogs ("responders") and did not affect PAP in 16 other dogs ("nonresponders"). A hypoxic pulmonary vasoconstriction (HPV) was restored in the nonresponders by intravenous administration of 1 g of acetylsalicylic acid (ASA). Nitroprusside (5 micrograms.kg-1.min-1) inhibited HPV in responders (n = 8) and nonresponders treated with ASA (n = 8). End-tidal 1.41% isoflurane (a minimal alveolar concentration equal to one for dogs) did not affect HPV in responders (n = 8) and nonresponders treated with ASA (n = 8). In the latter group isoflurane increased PAP at the highest Q studied (3-5 l.min-1.m-2) in hyperoxia and hypoxia. In a final group of eight dogs with Q kept constant, PAP remained unchanged during two consecutive sequences of alternated 30-min periods (maximum time to generate a PAP/Q plot) successively at FIO2 0.4 and 0.1, and the hypoxia-induced increase in PAP was reproducible. Thus the present experimental model appeared suitable for the study of the effects of hypoxia and drugs on pulmonary vascular tone of intact dogs. At the given doses HPV was inhibited by nitroprusside and not affected by isoflurane. Products of arachidonic acid metabolism possibly could be implicated in the pulmonary vascular effects of isoflurane.

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