Background and Objective To investigate the response to general anaesthetics of different sodium channel subtypes, we examined the effects of pentobarbital, a close thiopental analogue, on single sodium channels from human ventricular muscle and compared them with existing data from human brain channels.

Methods Sodium channels from preparations of human ventricular muscle were incorporated into planar lipid bilayers in the presence of batrachotoxin, a sodium channel activator. Single channel currents were recorded in symmetrical 100mmolL−1 and 500mmolL−1 NaCl before and after the addition of the anaesthetic pentobarbital (0.34–1.34mmolL−1).

Results The blocking effect of pentobarbital on the fractional open time had an IC50 of 690 μmol L−1 in 500 mmolL−1 NaCl, whereas it had a significantly lower IC50 of 400 μmol L−1 in 100 mmolL−1 NaCl. Pentobarbital caused a significant shift of steady-state activation to hyperpolarized potentials (fmax = −42 mV, IC50=2 mmolL−1). This effect was independent of NaCl concentration.

Conclusion Despite pharmacological and electrophysiological differences between human cardiac and human brain sodium channels their responses to pentobarbital are similar. The finding of channel block being dependent on the electrolyte concentration is novel for sodium channels.

Background and objective Minimal- and low-flow anaesthesia (fresh gas flow below 1 L min−1) provide many advantages, including reduced cost, conservation of body heat and airway humidity. An airtight seal is essential between the airway device and the airway of the patient. Therefore, we investigated whether the airtight seal created by a laryngeal mask airway allows controlled ventilation of the lungs when the fresh gas flow is reduced to 0.5 L min−1 and compared this with an endotracheal tube.

Methods In a prospective clinical study, 207 patients were managed using a laryngeal mask or an endotracheal tube. After intravenous induction of anaesthesia and 15 min of high fresh gas flow, the flow was reduced to 0.5 L min−1. The breathing system was monitored for airway leaks, and the patients were assessed for complications after airway removal and postoperative discomfort.

Results Both the laryngeal mask and endotracheal tube allowed fresh gas flow reduction to 0.5 L min−1 in 84.7% and 98.3% of cases respectively (small leaks: 12% laryngeal mask, 1.7% endotracheal tube). Three patients with the laryngeal mask (3.3%l) had airway leaks that were too large to permit any reduction in the fresh gas flow.

Conclusions The use of the laryngeal mask airway was more likely to be associated with a gas leak than use of an endotracheal tube; however, if modern anaesthesia machines and monitors are used, in 96.7% of the patients managed with a laryngeal mask a reduction in the fresh gas flow to 0.5 L min−1 was possible. The incidence of coughing and postoperative complaints (sore throat, swallowing problems) was higher after use of an endotracheal tube.

Background and objective We investigated whether glibenclamide (glyburide) affects myocardial metabolism and hydroxyl radical formation in the rat heart–lung preparation with or without inhalation anaesthetics.

Methods Thirty-seven male Wistar rats were allocated to four groups: (a) control group (C), received vehicle only; (b) group G, received glibenclamide 10 μM L−1; (c) group I, received glibenclamide 10 μM L−1 and 1.4% isoflurane during perfusion; (d) group S, received glibenclamide 10 μM L−1 and 2.7% sevoflurane during perfusion. Glibenclamide was administered 7 min after the start of perfusion. Ten minutes later, the heart was rendered globally ischaemic for 10 min by reducing the preload and afterload to zero, and then the heart was reperfused for 10 min. The formation of hydroxyl radicals in perfusate blood and heart was measured with high performance liquid chromatography using salicylic acid. Hydroxyl radicals react with salicylic acid, yielding dihydroxybenzoic acids.

Results The recovery time from ischaemia in group G was significantly longer than the other groups. However, there were no differences in myocardial metabolites and dihydroxybenzoic acids concentrations in the perfusate and heart among the four groups.

Conclusions Glibenclamide prolonged recovery time from ischaemia, but did not affect hydroxyl radical formation in the postischaemic reperfused heart. In addition, isoflurane and sevoflurane shortened this time. These facts suggest that mechanisms other than effects of volatile anaesthetics on hydroxyl radical formation are responsible for their protective effects in this model.

Background and aim Infusion of ketamine and midazolam can maintain prolonged anaesthesia, but delayed recovery is a limitation. We aimed to develop an approximation regimen for the infusion of ketamine and midazolam to obtain steady-state anaesthesia with acceptable recovery.

Methods Thirty-one patients undergoing radical cystect-omy were studied. The initial regimen was calculated from drug pharmacokinetic variables and tailored in a pilot study (15 patients) to develop the approximation regimen dosage. Anaesthesia was induced with midazolam (150μgkg−1) and ketamine (2mgkg−1). Tracheal intubation and ventilation with oxygen enriched air (FiO2 = 0.35) were facilitated by muscle relaxants. Anaesthesia was maintained by the approximation regimen doses. Routine monitoring was used for all patients, but pulmonary artery catheters were inserted in 11 patients, to obtain haemo-dynamic and oxygenation variables.

Results Steady-state anaesthesia was obtained with minimal deviations in the regimen in some patients followed by reasonable recovery.

Conclusion It is concluded that infusion of ketamine and midazolam in the approximation regimen doses can be used to maintain anaesthesia for prolonged abdominal surgery.

Background and objective Ischaemic colitis can be a serious complication after aortic surgery. The paucity of clinical symptoms makes its diagnosis particularly difficult and often delayed. Automated on-line tonometry is now proposed to monitor intestinal perfusion. This study was designed to assess the use of semi-continuous sigmoid-to-arterial [P(r-a)CO2] PCO2 gap monitoring in aortic surgery to detect colonic ischaemia.

Methods This prospective clinical study was realized at the University Hospital of Lille, France, including eight males scheduled for abdominal aortic aneurysm surgery. Intraoperative and postoperative P(r-a)CO2 values were compared with conventional monitoring and colonic mucosa aspect performed by sigmoidoscopy 48 h after surgery. Haemodynamic variables, O2 delivery (DO2), O2 consumption (VO2), O2 extraction (ERO2), lactate, P(v-a)CO2, P(r-a)CO2 were measured peroperatively and every 4 h during a 48-h postoperative period.

Results Intraoperative P(r-a)CO2 values increased significantly with the highest value (4.36 ± 3.42 kPa) observed during aortic clamping when DO2 was the most altered. P(r-a)CO2 continued to deteriorate after surgery with the maximal values between 8 (4.79 ± 3.85 kPa) and 12 (4.68 ± 3.26 kPa) h after surgery. This peak was associated with a significant ERO2 increase counterbalancing an increase of VO2 whereas DO2 tended to decrease. P(r-a)CO2 values began to decrease only at the end of the study. The highest values of P(r-a)CO2 were registered in patients with the most altered haemodynamic variables, severe ischaemic colitis along with higher hospital lengths of stay.

Conclusion Taken together, these data suggest that regional and automated capnometry may be easily used non-invasively to detect peroperative intestinal ischaemia in aortic surgery.

Backgound and objective A postal survey was conducted in order to investigate current practice in airway management amongst Dutch anaesthetists and to investigate the role of recent training and the role of an ‘Access to the Airway’ airway management course.

Methods A questionnaire containing 27 questions was sent to all practising anaesthetists in The Netherlands. Questionnaires were returned anonymously and were analysed using the Pearson χ2-test (P < 0.05) with the SPSS® version 8.0 statistical software program.

Results The response rate was 42%. Of the respondents, 78% claim often or always to assess the expected degree of difficulty in tracheal intubation as part of routine preoperative assessment. The American Society of Anesthesiologist’s Difficult Airway Algorithm was used by 19% of respondents. A wide variety of airway management techniques is being used. In 36% of all general anaesthetics a laryngeal mask airway is used. In 1.1% of all general anaesthetics tracheal intubation is performed with the flexible fibrescope.

Conclusions Dutch anaesthetists, who commenced anaesthetic training after 1988, and those who attended the airway management course ‘Access to the Airway’ are significantly more likely to follow the American Society of Anesthesiologist’s Difficult Airway Algorithm and to use adjunctive techniques for airway management.

Background and aim The effects of analgesic drugs on sleep are poorly understood. We investigated short- and medium-term effects of tramadol on sleep structure.

Methods Eight healthy volunteers received a placebo (predrug placebo-night), then, in a randomized, double-blind, cross-over fashion a single oral dose of tramadol 50 mg or 100mg (drug-night), and finally, again a placebo (postdrug placebo-night). Standardized polysomnography (electroencephalogram, electro-oculogram, submental electromyogram) was continuously recorded during placebo- and drug-nights

Results During drug-nights both doses of tramadol significantly increased the duration of stage 2 sleep, and significantly decreased the duration of slow-wave sleep (stage 4). Tramadol 100mg but not 50 mg significantly decreased the duration of paradoxical (rapid eye movement) sleep. In the placebo-night after tramadol 100mg (but not after 50 mg) duration of stage 2 sleep was significantly shorter, and duration of stage 4 sleep was significantly longer compared with the predrug placebo-night. Conclusion In healthy volunteers, a single dose of tramadol 50 mg disturbs sleep in the night of drug application. With 100mg, sleep is disturbed in both the night of drug application and in the subsequent night.

Background and objective The endovascular treatment of abdominal aortic aneurysms has raised great interest amongst vascular surgeons. The aim of this study was to com pare the postoperative morbidity and mortality rates of endovascular treatment with those of open surgery, from the anaesthesiologist's standpoint.

Methods From January 1997 to June 2000, 425 consecutive patients with abdominal aortic aneurysms were referred for regular surgery. Thirty-nine patients who needed a visceral or renal artery revasculariza-tion, or a nephrectomy were excluded. The remaining 386 patients were studied in a prospective manner. Aneurysms were evaluated with spiral computerized tomography scanning and calibrated aortography. After informed consent, only those patients with a suitable vascular anatomy underwent endovascular treatment (n = 193). All other patients underwent open surgery and are considered as a control group n= 193). Endovascular treatment was performed by a femoral or an iliac retroperitoneal route. All stent-grafts were made to measure using auto-expandable stainless-steel stents covered with a standard polyester prosthetic graft.

Results Six patients in the endovascular treatment group needed to be converted to the open surgical technique (during the same operation) because of rupture of the iliac bifurcation (1 patient), a large en-doleak (2 patients), or technical problems (3 patients).

Conclusion The amount of bleeding and the need for blood products were significantly lower in the endovascular treatment group. Despite the absence of significant differences regarding cardiac complications and mortality, there was a lesser incidence of pneumonia, acute respiratory and renal failure. Patients in the endovascular treatment group spent less time in the intensive care unit and in the Hospital.

Background and objective In the present study, we investigated the combination of etomidate and s-ketamine with regard to its suitability for modified rapid-sequence induction using rocuronium for muscle relaxation.

Methods In a prospective, randomized and double-blinded study, 90 patients were assigned to one of three groups for induction of anaesthesia in combination with etomidate (0.3 mg kg−1) and muscle relaxation with rocuronium (0.6 mg kg−1). The groups were as follows: (a) control, i.e. placebo; (b) fentanyl, fentanyl (1.5 μg kg−1); (c) ketamine, s-ketamine (0.5 mg kg−1). Tracheal-intubating conditions after 1 min were classified as excellent, good or poor. During the induction of anaesthesia, arterial pressure and heart rate were measured every 60 s.

Results Intubating conditions were best using etomidate and s-ketamine (23 excellent, 7 good, 0 poor) compared with the control (8, 16, 6 respectively) and fentanyl groups (7, 21, 2 respectively) (P < 0.01). While heart rate and arterial pressure remained stable in the control and fentanyl groups during induction, both significantly increased in the ketamine group (P < 0.01).

Conclusions The combination of etomidate and s-ketamine for anaesthesia induction produces mostly excellent intubating conditions after 60 s using only 0.6 mg kg−1 of rocuronium. This combination of drugs may be a useful alternative, if succinylcholine needs to be avoided, for modified rapid-sequence induction.

Background and objective Patients with end-stage chronic renal failure are at risk of developing several serious postanaesthetic complications. Many anaes-thesiologists perform brachial plexus anaesthesia with high doses of local anaesthetic in order to achieve an extensive blockade of the upper limb. Brachial plexus block is a suitable technique for anaesthesia for creation, repair or removal of vascular access for haemo-dialysis. The aim of this study was to measure mepivacaine plasma concentrations after axillary block with 650 mg plain mepivacaine in patients with end-stage chronic renal failure.

Methods Mepivacaine plasma concentrations were assessed throughout a 150-min period, in 10 patients after axillary block with 650 mg plain mepivacaine (600 mg for axillary block and 50 mg for supplementation).

Results Mepivacaine plasma concentrations expressed in μg mL−1 as medians and their ranges were: 1.69 (1.23–7.78) at 5min, 5.61 (4.36–8.19) at 30min, 8.28 (3.83–11.21) at 60min, 7.93 (5.63–11.1) at 90min and 6.49 (5.56–8.35) at 150 min without any symptoms of toxicity.

Conclusions Brachial plexus anaesthesia with 650 mg plain mepivacaine did not result in serious systemic toxicity in these patients despite the high mepivacaine plasma concentrations found.

Background and objective Imbalance between cerebral oxygen supply and demand is thought to play an important role in the development of cerebral injury during cardiac surgery with cardiopulmonary bypass.

Methods We studied jugular bulb oxygen saturation, jugular bulb oxygen tension, arterial–jugular bulb oxygen content difference and oxygen extraction ratio in 20 patients undergoing warm coronary artery bypass surgery (34–37°C) with pH-stat blood gas management.

Results Only two patients showed desaturation (jugular bulb oxygen saturation <50%) at 5 min on bypass, and none from 20 min onwards. Multiple regression models were performed after using bypass temperature, mean arterial pressure, cerebral perfusion pressure, haemoglobin concentration and arterial carbon dioxide tension as independent variables, and arterial–jugular bulb oxygen content difference, jugular bulb oxygen saturation, oxygen extraction ratio and jugular bulb oxygen tension as individual dependent variables.

Conclusions We found that jugular bulb oxygen saturation, jugular bulb oxygen tension and oxygen extraction ratio are mainly dependent on arterial carbon dioxide tension, and arterial–jugular bulb oxygen content difference is dependent on arterial carbon dioxide tension and the bypass temperature. Our results suggest jugular bulb oxygenation is mainly dependent on arterial carbon dioxide tension during warm cardiopulmonary bypass.

Background and objective The intubating laryngeal mask is designed to act as a ventilatory device and as an aid to blind tracheal intubation in adults. The aim of this study was to evaluate the efficacy of the intubating laryngeal mask for ventilation of the lungs and tracheal intubation in children using video-endoscopic control.

Methods The handling and efficacy of the size 3 intubating laryngeal mask for tracheal intubation in 80 children weighing ≥ 25 kg were assessed under video-endoscopic control. Ease of intubating laryngeal mask insertion, adequacy of lung ventilation through the intubating laryngeal mask and airway sealing pressures were recorded. Tracheal intubation was performed blindly by the intubator, while the supervisor observed the procedure on the video display. If blind intubation failed at the first attempt, the monitor view was used to guide the tracheal tube into the trachea. The success rate and time required for successfully placing the tracheal tube were recorded.

Results Insertion of the intubating laryngeal mask was easy in all children. Lung ventilation through the intubating laryngeal mask was uniformly excellent. Blind tracheal intubation at the first attempt was successful in 53 children (66%) within 18.8 ± 4.1 s. Twenty-four of the 27 failed blind intubation attempts were successfully intubated with video-endoscopic guidance within 28.6 ± 9.4 s. Two children required replacing the intubating laryngeal mask, one child had to be intubated conventionally.

Conclusions The size 3 intubating laryngeal mask provides an airway that is easy to establish in children ≥ 25 kg with excellent ventilation conditions and allows blind tracheal intubation at the first attempt with a high success rate. Endoscopic monitoring improves its safety and intubation success rate.

Background and objective Factors which lead to prolonged stay in the day–care unit and unplanned admission after day-case surgery are poorly understood.

Methods Data sets of 3152 day-case patients were collected with a computerized online record keeping system (NarkoData). Predictors of prolonged postoperative stay including unanticipated admission were identified using univariate analysis. Charts of patients, who needed admission, were reviewed.

Results 13.2% of day–case patients had a postoperative stay ≤3 h, 55.3% 3–6 h and 26.2%≥6h. The rate of unanticipated admission was 5.4%. Intraoperative haemoglobin concentration and blood loss were the best predictors of a prolonged postoperative stay. Other significant predictors were female gender, advanced age, longer duration of surgery, larger volume of infusions, intubation, spinal anaesthesia, intraoperative use of opioids and non–depolarizing muscle relaxants, high pain score, nausea and vomiting and prolonged preoperative waiting time. Chart review of patients admitted to hospital confirmed the validity of the statistically significant predictors.

Conclusions In day-case surgery, the predictors of prolonged stay in the day-care unit and unplanned Hospital admission are mainly related to the surgical procedure.

Background and objective The effects of sepsis on gut mucosal blood flow have not been fully clarified. We designed an experiment to explicitly describe the effects of sepsis on gut mucosal blood flow in rats using an advanced intravital microscopy technique.

Methods This work was performed as a prospective, controlled laboratory experiment. Twenty-four hours after sham laparotomy or laparotomy and caecal ligation and perforation to create sepsis, rats were anaesthetized and their lungs mechanically ventilated (n = 7 per group). Intravital videomicroscopy was performed on 6–12 villi of ileum mucosa. Video recordings were analysed off-line using computerized image analysis.

Results Intercapillary area size (inversely related to capillary density) was increased in sepsis as compared with the control group (941 ± 92 vs. 669 ± 79 μm2, P < 0.05). In the central villus arteriole, blood flow was similar between groups (control: 3.5 ± 0.4 nL min−1; caecal ligation and perforation group: 3.6 ± 0.5 nL min−1). There were no relevant changes in arteriolar red cell velocity and diameter.

Conclusions In the gut mucosa of rats, sepsis resulting from caecal ligation and perforation depressed the perfused capillary density without affecting blood flow in the central villus arteriole. Mucosal hypoperfusion at the level of the capillary networks may occur in the presence of precapillary shunting in the villus microcirculation.

Background and objective To investigate the ability of lidocaine to inhibit reactive oxygen and/or nitrogen species generation by either human leukocytes or cell-free systems via luminol- and lucigenin-enhanced chemiluminescence.

Methods Venous blood was obtained from healthy volunteers and leukocytes were isolated, from which chemiluminescence was generated. Also, chemiluminescence, induced by H2O2, HOCl, peroxynitrite or ferrous iron, was generated in cell-free systems.

Results Lidocaine produced a concentration-dependent inhibition in chemiluminescence generated by leukocytes (92 ± 1%, 1 mM). In cell-free experiments, lidocaine (1 mM) markedly inhibited chemiluminescence of xanthine-xanthine oxidase (24 ± 3%), while it slightly suppressed hypochlorous acid-induced chemiluminescence (9 ± 2%). Peroxynitrite-induced luminol- and lucigenin-enhanced chemiluminescence were also inhibited by lidocaine at 1 mM (19 ± 3% and 48 ± 8%, respectively). Lidocaine did not affect chemiluminescence generated by FeSO4. However, lidocaine produced a biphasic effect on H2O2-induced chemiluminescence (37 ± 5% inhibition at 0.01 mM and 61 ± 17% activation at 1 mM).

Conclusions Lidocaine can elicit direct scavenging activity at high concentrations that might be important at or near the site of injection in local anaesthetic use.

Anaesthesiologists administer a wide variety of drugs, including benzodiazepines, opioids, intravenous anaesthetic agents, volatile anaesthetic agents, muscle relaxants, local anaesthetics, and other drugs, especially those influencing the cardiovascular system. Sometimes a drug is chosen because of its better effect and/or side-effect profile. However, many of the drugs within each group have similar effect and/or side-effect profiles and differ mainly in their pharmacokinetics. The choice of one drug over another may then need to be based on differences in their pharmacokinetic profiles. Traditional predictors of onset of drug effect, such as time to a specified effect, are dose-dependent. Traditional predictors of offset of drug effect, such as ‘terminal half-life’, often have little clinical relevance. Newer descriptors offer significant advantages. The time to peak effect-site concentration is an informative dose-independent descriptor of the onset of drug effect following an intravenous bolus dose. The relevant decrement time (for continuous measures of drug effect) and mean effect time (for binary measures of drug effect) build upon the context-sensitive half-time concept, by considering the time required for the concentrations to decrease from one clinically relevant level of drug effect to another.

Background and objective Perioperative hypothermia has been found to impair the coagulation cascade and to increase blood loss and transfusion requirements. The effect of concomitant in vitro heparinization on coagulation during hypo- and hyperthermic conditions has not been well defined.

Methods In the present study, activated partial thromboplastin time was examined in vitro at 33°C, 35°C, 37°C, 39°C and 41°C in normal human plasma in response to unfractionated heparin.

Results Hypothermia ≤ 35°C prolonged activated partial thromboplastin time by 10% compared with test temperatures at 37°C (P < 0.05). Hyperthermia alone had no effect. Unfractionated heparin (0.1–0.4 IU mL−1) increased activated partial thromboplastin time in a dose-dependent manner (by 189% at 0.4 IU mL−1, P < 0.05). Test temperatures of 33°C and 41°C increased heparin-induced prolongation of activated partial thromboplastin time. At a heparin concentration of 0.4 IU mL−1, hypothermia (33°C) and hyperthermia (41°C) prolonged partial thromboplastin time by 12% and 22%, respectively, compared with normothermic test temperature of 37°C within the heparin group (P < 0.05).

Conclusions These observations suggest that both hypo- and hyperthermia increase the response to heparin in vitro. Further studies are needed to identify the effect of patient’s body temperature on heparin activity and bleeding tendency in vivo.

Background and objective Situations may occur in anaesthetic practice where the use of neuromuscular blocking drugs is unsuitable or contraindicated. We investigated the use of propofol given 5 min after fentanyl to permit endotracheal intubation in children. Methods We studied the intubating conditions and cardiovascular parameters in 60 ASA I and II children. Intravenous midazolam (0.1mgkg−1) was given as premedication 5 min before the induction of anaesthesia. The children received different doses of propofol (group I, 2.5mgkg−1; group II, 3.0mgkg−1; group III, 3.5mgkg−1) preceded by fentanyl (3.0 μgkg−1) given 5 min earlier. No neuromuscular blocking agents were administered. The intubating conditionswere assessed using a four-point scoring system based on the degree of difficulty of laryngoscopy, the position of vocal cords and the intensity of coughing.

Results Tracheal intubating conditions were adequate in 20% of the patients in group I, in 75% of the patients in group II and in 80% of the patients in group III (P < 0.05 for group I vs. groups II and III). Haemodynamic changes were not significantly different between the groups.

Conclusions Propofol (3.0mgkg−1) preceded by fentanyl (3.0 μgkg−1) was adequate for the induction of anaesthesia in children and provided adequate tracheal intubating conditions without significant haemodynamic changes. This method represents a useful alternative technique for tracheal intubation when neuromuscular blocking drugs are contraindicated or should be avoided.

Background and objective The laryngeal tube is a variant of the oesophageal obturator airway. The manufacturer claims that it is an alternative to ventilation with a facemask, laryngeal mask or endotracheal tube. To date, published studies have only involved controlled ventilation. We wished to find out if its use in spontaneous ventilation was equivalent to using the laryngeal mask airway.

Methods We have compared the laryngeal tube with the laryngeal mask in a randomized prospective study involving patients breathing spontaneously under general anaesthesia. Criteria and a scoring system were used for the comparison. A sequential analysis chart with P=0.01 was chosen for each of two anaesthetists.

Results Only seven and 10 pairs of patients were required to indicate that the laryngeal tube was poorer at airway maintenance than the laryngeal mask. Of the 17 patients who had received the laryngeal tube, successful airway maintenance was only possible in seven. In the remaining 10 patients, the laryngeal tube was abandoned and the rescue airway was the laryngeal mask in all cases. All 17 patients randomized to the laryngeal mask were successfully managed.

Conclusions We conclude that the laryngeal tube is not a satisfactory device for management of the airway during spontaneous ventilation.

Background and objective The intubating laryngeal mask (intubating laryngeal mask airway) was designed to facilitate blind intubation. Its value as an adjunct to fibreoptic laryngoscopy has not been evaluated. This study compares the intubating laryngeal mask airway with the standard laryngeal mask airway as conduits for fibreoptic laryngoscopy.

Methods The fibreoptic view of the laryngeal inlet was graded via both devices in 60 anaesthetized patients. The fibreoptic view through the intubating laryngeal mask airway was assessed after the central epiglottic elevator bar had been lifted out of the field of vision by an 8-mm Euromedical® tracheal tube, which was inserted to a depth of 18 cm. The fibreoptic view from the aperture bars of the laryngeal mask was recorded.

Results The vocal cords were viewed less frequently through the intubating laryngeal mask airway (52%) than through the laryngeal mask airway (92%) [difference = 40% (95% CI = 26% to 54%), P < 0.0001].

Conclusion The view of the laryngeal inlet is better through the laryngeal mask airway than through a tracheal tube inserted to 18 cm in the intubating laryngeal mask.