High-dose vecuronium may be an alternative to suxamethonium for rapid-sequence intubation

Endotracheal intubation conditions 60 s after intravenous administration of either high-dose vecuronium (0.3 mg kg^-1; n = 25) or suxamethonium (1.0 mg kg^-1; n = 25) were compared in a blind, randomised study. No significant differences were found between the two drugs. In 96% of the patients intubation conditions were characterized as excellent or good. In only one patient (4%) in each group were intubation conditions unsatisfactory. According to our findings, high-dose vecuronium provides satisfactory intubation conditions after 60 s and may be used instead of suxamethonium for rapid sequence intubation when a long duration of neuromuscular blockade is acceptable.     

Tracheal intubation after induction of anaesthesia with propofol,alfentanil and lidocaine without neuromuscular blocking drugs in children

In a double-blind study, intubating conditions and haemodynamic responses were assessed in two age-groups of 45 ASA I-II children, with mean ages of 2.4 and 6.3 years, premedicated with oral midazolam and atropine. The children were randomly allocated to one of three groups: aifentanil 20 μg · kg^-1 + lidocaine 1 mg · kg^-1 (AIRO + Lign); alfentanil 20 μg μ kg^-1 (Alf20); or alfentanil 40 μg · kg^-1 (Alf40), followed by propofol 3.5 mg · kg^-1 in the children aged 1–3 years and 3.0 mg · kg^-1 in the older children. Intubating conditions, 40 s after the administration of propofol, were assessed as good, moderate or impossible on the basis of jaw relaxation, ease of insertion of the endotracheal tube and coughing during intubation. In the younger age group the frequencies of good, moderate or impossible intubating conditions were 87, 13 and 0% in the Alf40, 40, 60 and 0% in the Alf20 (P < 0.05 compared to the Alf40 group) and 53, 47 and 0% in the Alf20 + Lign group. In the older age group the corresponding frequencies were 60, 33 and 7% in the Alf20 + Lign, 47, 53 and 0% in the Alf20 and 47, 40 and 13% in the Alf40 group. All the drugs prevented any increase in arterial pressure and heart rate after tracheal intubation. The QTc interval of the EGG was always in the normal range. Clinically important bradycardia did not occur. In conclusion, the best intubating conditions occurred after propofol 3.5 mg · kg^-1 and alfentanil 40 μg · kg^-1 in the younger age group. In the other children good or moderate intubating conditions occurred in 87–100% after all the drugs used in the present study.     

Excellent intubating conditions with remifentanil–propofol and either low-dose rocuronium or succinylcholine

Purpose

The shortest time to tracheal intubation, the best intubating conditions, and the shortest duration of muscle paralysis are achieved with succinylcholine. During a lidocaine–remifentanil–propofol induction of anesthesia, we compared intubating conditions 90 s after administering low-dose rocuronium (0.3 mg · kg^?1) with intubating conditions 60 s after administering succinylcholine 1.5 mg · kg^?1.

Methods

The randomized double-blind study included 184 healthy adult patients scheduled for elective surgery. Anesthesia was induced in all patients with lidocaine 1.5 mg · kg^?1, remifentanil 2 μg · kg^?1, and propofol 2 mg · kg^?1 administered over 30 s. In one group, rocuronium 0.3 mg · kg^?1 was administered before the induction sequence, and in the other group, succinylcholine 1.5 mg · kg^?1 was administered after the induction sequence. Laryngoscopy was attempted 90 s after rocuronium administration and 60 s after succinylcholine administration. Intubating conditions were assessed as excellent, good, or poor on the basis of ease of laryngoscopy, position of the vocal cords, and reaction to insertion of the tracheal tube and cuff inflation.

Results

There were 92 patients per group. In the rocuronium group, intubating conditions were excellent in 83 patients (90%), good in 8 (9%), and poor in 1 (1%), not significantly different from the intubating conditions in the succinylcholine group, which were excellent in 88 patients (96%), good in 3 (3%), and poor in 1 (1%) (P = 0.3).

Conclusion

During a lidocaine–remifentanil–propofol induction of anesthesia, rocuronium 0.3 mg · kg^?1 administered before the induction sequence provides intubating conditions comparable to those achieved with succinylcholine 1.5 mg · kg^?1 administered after the induction sequence.     

Intubating conditions and neuromuscular block after divided dose mivacurium or single dose rocuronium

Purpose

To evaluate the tracheal intubating conditions and neuromuscular blocking charactenstics of divided dose mivacurium or single dose rocuronium.

Methods

Thirty-two patients undergoing elective surgery were studied. Anaesthesia was with propofol 2 mg · kg^?1, followed by an infusion of l50 μg · kg^?1 · min^?1. Patients were randomized to receive either mivacurium-0.15 mg · kg^?1 followed 30 sec later by 0.1 mg · kg^?1, or rocuronium-0.9 mg · kg^?1, followed 30 sec later by placebo. Tracheal intubating conditions were assessed 90 sec after the initial dose of relaxant by an anaesthetist who was unaware of patient group. The electromyographic (EMG) response of the first dorsal interosseus muscle to ulnar nerve train-of-four was measured.

Results

Successful tracheal intubation was performed in all patients after both mivacurium and rocuronium. Intubating conditions (jaw relaxation, open visible vocal cords) were judged to be good-excellent in all but one patient before insertion of the tracheal tube. However, patients receiving mivacunum were more likely to experience coughing and bucking after tracheal tube insertion (10/16 patients) than those receiving rocuronium (3/16 patients, P < 0.05). No patient in the rocuronium group experienced moderately vigorous coughing and bucking after insertion of the tracheal tube vs six patients in the mivacurium group (P < 0.05). Time to 10 and 25% recovery of neuromuscular function was faster (P < 0.05) after divided dose mivacunum (20 ± 1 and 23 ± 1 min, respectively) than after rocuronium (45 ± 5 and 57 ± 8 min, respectively).

Conclusion

The results suggest that, during conditions of the study, divided dose mivacurium is not recommended for a 90-sec tracheal intubation in patients where moderate coughing and bucking is deemed unacceptable.     

Dose of propofol required to insert the laryngeal mask airway in children

We have assessed the ease of insertion of the Brain Laryngeal Mask Airway (LMA) after induction of anaesthesia with propofol in 60 healthy unpremedicated children aged between four and nine years. Patients were randomly allocated into three groups: group A = propofol 2.5 mg·kg^?1; group B = propofol 3 mg·kg^?1 and group C = propofol 3.5 mg·kg^?1. Propofol was mixed with lignocaine 0.5 mg·kg^?1. Insertion conditions were assessed subjectively as good, acceptable, unacceptable or impossible. Insertion of the LMA was possible in all patients. Good and acceptable conditions were obtained in 35%, 70% and 95% in groups A, B, and C respectively (P < 0.0001). There was no statistically significant inter group variation in systolic and diastolic arterial pressure or in heart rate for five min after induction. All measured cardiovascular changes were considered to be clinically insignificant in healthy children. We conclude it is safe and effective to insert a LMA immediately after induction of anaesthesia with propofol 3.5 mg·kg^?1.     

Propofol for tracheal intubation in children anesthetized with sevoflurane: a dose–response study

Background: Tracheal intubation during sevoflurane induction is frequently facilitated with i.v. propofol. We designed a dose–response study to evaluate the intubating conditions, and the incidence and duration of apnea after i.v. propofol in children. Methods/Materials: Sixty healthy children were randomly assigned to 0, 0.5, 1, 2 or 3 mg·kg^?1 i.v. propofol during sevoflurane/nitrous oxide anesthesia. Tracheal intubation was performed approximately 30 s after propofol by an anesthesiologist who was blind to the treatment. The anesthesiologist assessed the responses to laryngoscopy and intubation using a standardized scale. Incidence and duration of apnea after propofol as well as heart rate, and systolic blood pressure before and after laryngoscopy were recorded. Data were analyzed using one‐way and repeated measures anova , the Jonckheere–Terpstra test, and logistic regression, with P < 0.05 accepted. Results: The laryngoscopy score after 3 mg·kg^?1 propofol was less than that after 0 mg·kg^?1 (P < 0.01) and 0.5 mg·kg^?1 (P < 0.05). Incidence of apnea after propofol 3 mg·kg^?1, 8/10, was greater than after 0 mg·kg^?1, 3/14 (P < 0.011) and 0.5 mg·kg^?1, 3/12 (P < 0.03). Duration of apnea after 3 mg·kg^?1 was greater than after 0 and 0.5 mg·kg^?1 (P < 0.01). The risk of apnea increased 1.83 fold for each 1 mg·kg^?1 dose increase in propofol (P < 0.01). Mean heart rate and systolic pressure decreased with the main effect, time. Conclusion: During sevoflurane/nitrous oxide anesthesia, propofol 3 mg·kg^?1 provides superior intubating conditions with an increased incidence of and prolonged apnea compared with 0 and 0.5 mg·kg^?1.     

Bone resorption measurement with unusual bone markers: Critical evaluation of the method in phosphorus-deficient and calcium-deficient growing rats

An in vivo method to evaluate bone resorption in rats, by using unusual bone seekers not dependent on renal tubular transfer, is described and a critical evaluation of the method is made. In our experimental conditions,⁸⁵Sr and¹⁷⁷Lu are virtually exclusively localized in bone whereas²³⁷Np remains unchanged in different soft organs, so that the concomitant use of these markers can be used for measuring bone resorption. If osteolysis occurs 21 days after the injection of these markers, under our experimental conditions, any increase in the urinary excretion of¹⁷⁷Lu and²³⁷Np represents a rise in bone resorption, whereas an increase in Sr excretion reflects both bone and renal tubular events. According to our bone localization studies, the enhancement of Lu and Np excretion reflects primarily an increase in cortical bone resorption localized at the endosteal (Lu) and at the periosteal (Np) surfaces respectively. In addition, strontium is considered to be the marker of mineral resorption whereas Lu and Np, under our experimental conditions, would reflect the organic bone resorption. This method is tested in phosphorus-deficient rats and in calcium-deficient rats which exhibit disturbances of calcium metabolism at both the bone and kidney levels. In agreement with previous investigations, the use of these bone markers to evaluate osteolysis shows: (a) after a 1-week phosphorus deficiency, a slight increase in cortical bone resorption with a simultaneous fall in calcium and strontium renal tubular reabsorption, and (b) after a 1-week calcium deficiency, a high rise in cortical bone resorption with a simultaneous increase in the renal tubular reabsorption of calcium and strontium.     

Bone resorption measurement with unusual bone markers: Critical evaluation of the method in phosphorus-deficient and calcium-deficient growing rats

An in vivo method to evaluate bone resorption in rats, by using unusual bone seekers not dependent on renal tubular transfer, is described and a critical evaluation of the method is made. In our experimental conditions,⁸⁵Sr and¹⁷⁷Lu are virtually exclusively localized in bone whereas²³⁷Np remains unchanged in different soft organs, so that the concomitant use of these markers can be used for measuring bone resorption. If osteolysis occurs 21 days after the injection of these markers, under our experimental conditions, any increase in the urinary excretion of¹⁷⁷Lu and²³⁷Np represents a rise in bone resorption, whereas an increase in Sr excretion reflects both bone and renal tubular events. According to our bone localization studies, the enhancement of Lu and Np excretion reflects primarily an increase in cortical bone resorption localized at the endosteal (Lu) and at the periosteal (Np) surfaces respectively. In addition, strontium is considered to be the marker of mineral resorption whereas Lu and Np, under our experimental conditions, would reflect the organic bone resorption. This method is tested in phosphorus-deficient rats and in calcium-deficient rats which exhibit disturbances of calcium metabolism at both the bone and kidney levels. In agreement with previous investigations, the use of these bone markers to evaluate osteolysis shows: (a) after a 1-week phosphorus deficiency, a slight increase in cortical bone resorption with a simultaneous fall in calcium and strontium renal tubular reabsorption, and (b) after a 1-week calcium deficiency, a high rise in cortical bone resorption with a simultaneous increase in the renal tubular reabsorption of calcium and strontium.     

Alterations of Calcium/Calmodulin-Dependent Protein Kinase II Activity in Ischaemia-Induced Neuronal Death and Neuronal Protection Against Ischaemia in the Gerbil Hippocampus

Summary  To clarify the relation between neuronal protection against ischaemia and calcium/calmodulin-dependent protein kinase II (CaM kinase II) activity, we investigated temporal alterations of the kinase activity in the hippocampus after transient forebrain ischaemia under neuroprotective conditions, employing the gerbil bilateral carotid artery occlusion model.  The hippocampal CA1 neuronal density at 2 hours after 5 minutes of forebrain ischaemia was 214.7±25.8 /mm (mean±S.D.), and did not differ from the control significantly; however, it decreased to 11.7±4.2 /mm at 7 days after the ischaemia. The neuronal density at 7 days after the ischaemia was 185.1±18.5 under the hypothermic conditions, 128.7±19.6 with the brief ischaemic pretreatment, 65.0±13.4 with administration of MK-801, and 20.5±4.2 with the repetitive hyperthermic pretreatment, respectively.  The Ca²⁺/calmodulin-dependent activity of CaM kinase II in the hippocampal cytosolic fraction was decreased to 47.5% of the control value at 2 hours after the ischaemia, when CA1 neuronal death was not observed. In contrast, the activity was 98.8% of the control under the hypothermic conditions, 91.4% with the brief ischaemic pretreatment, 71.2% with administration of MK-801, and 47.9% with the repetitive hyperthermic pretreatment, respectively.  These results indicated that the preservation of the Ca²⁺/calmodulin-dependent activity of cytosolic CaM kinase II after ischaemia parallelled the neuroprotective effect in the gerbil hippocampus. Thus, it is suggested that the preservation of the activity may be involved in the mechanism of neuronal protection against ischaemia.     

Different priming techniques,including mivacurium,accelerate the onset of rocuronium

Different priming sequences of equipotent doses of rocuronium and mivacurium on the onset of maximum neuromuscular block and intubating conditions were compared with those obtained after succinylcholine. During thiopentone-fentanylnitrous oxide anaesthesia, 70 patients were randomly assigned into seven groups. Group I received mivacurium 0.15 mg · kg^?1 as a single bolus dose. Group II received a priming dose of mivacurium 0.015 mg · kg^?1 followed three minutes later by mivacurium 0.135 mg · kg^?1. Group III received rocuronium 0.6 mg · kg^?1 as a single bolus dose, and Group IV received an initial dose of rocuronium 0.06 mg · kg^?1 followed by rocuronium 0.54 mg · kg^?1. Group V received a priming dose of mivacurium 0.015 mg · kg^?1 followed by rocuronium 0.54 mg · kg^?1. Group VI received an initial dose of rocuronium 0.06 mg · kg^?1 followed by mivacurium 0.135 mg · kg^?1. Group VII received succinykholine 1.0 mg · kg^?1. Groups I, III, and VII received a placebo injection before the administration of the neuromuscular blocking drug. Additional thiopentone 2 mg · kg^?1 iv was given 30 sec before intubation. Onset times (mean (95% confidence interval)) after priming a rocuronium block with either rocuronium (73 (57–90) sec) or mivacurium (58 (47–69) sec) were similar to those after succinykholine (54 (40–68) sec), and were shorter (P < 0.01) than that observed in other groups. Intubating conditions were not different between the groups. The duration of neuromuscular block was shortest with succinykholine. It is concluded that priming a rocuronium block with either mivacurium or rocuronium resulted in a neuromuscular block comparable to that of succinykholine in both the onset of action and intubating conditions.     

Facilitated tracheal intubation in infants: is propofol a safe alternative to atracurium?

The conditions for intubation were studied in 28 infants (age 1–14 months, ASA I/II) after intravenous administration of propofol or atracurium. Anaesthesia was induced via mask with halothane and N₂O/O₂. The study propofol group (GrP, n= 14) received a bolus of propofol 3.0 mg·kg^?1, whilst the control atracurium group (GrA, n= 14) received atracurium 0.4 mg·kg^?1. Intubation conditions were listed as excellent, moderate or impossible in GrP 79%–14%?7% and in GrA 72%–14%–14% respectively. A decrease of mean arterial pressure (GrP–9.17 ± 10.8 mmHg, ?13% GrA–9.67 ± 15.2 mmHg, ?12%) and heart rate (GrP–18 ± 21 bpm; GrA–14 ± 23 bpm) were seen after induction with halothane. After intubation the mean arterial pressure increased. The increase of heart rate observed after intubation was higher in GrA (GrP +6 ± 8 bpm; GrA +17 ± 19 bpm). The same intubation scores found with propofol in comparison with atracurium may be due to the reflex-suppressive and stress-inhibitory effect of propofol. Since excellent conditions for intubation were found with comparable smaller effects on measured haemodynamic parameters, propofol is regarded as a safe alternative to atracurium to facilitate intubation.     

Topical lidocaine improves conditions for laryngeal mask airway insertion

Purpose

We hypothesized that optimal laryngeal mask airway (LMA?) insertion conditions might be achieved with topical lidocaine and a smaller dose of propofol. In this study, insertion conditions after topical lidocaine 40 mg followed by propofol 2 mg·kg^?1 were compared with propofol 2 mg·kg^?1 or propofol 3 mg·kg^?1 alone.

Methods

Ninety patients were recruited for this randomized prospective double-blind study. One group received four sprays of topical lidocaine (40 mg) over the posterior pharyngeal wall followed by propofol 2 mg·kg^?1 (Group 2PL; n = 30). The other two groups received four sprays of 0.9% normal saline followed by propofol 2 mg·kg^?1 (Group 2P; n = 30) or by propofol 3 mg·kg^?1 (Group 3P; n = 30). The frequency of optimal insertion conditions (successful insertion at the first attempt without adverse responses) and side effects were recorded.

Results

The frequency of optimal insertion conditions was greater in Group 2PL (20/30, 67%) and Group 3P (22/30, 73%) than in Group 2P (11/20, 37%) (P = 0.009). In Group 3P, the mean blood pressure was lower than in the other groups prior to LMA-Classic? insertion (P = 0.003) but was similar after insertion. The incidence of apnea was greater in Group 3P patients (17/30, 57%) than in Group 2P (2/30, 7%) or Group 2PL patients (1/30, 3%) (P < 0.001).

Conclusion

Topical lidocaine 40 mg followed by propofol 2 mg·kg^?1 can provide optimal insertion conditions of the LMA-Classic comparable to those of propofol 3 mg·kg^?1, with fewer hemodynamic changes and a lower incidence of apnea.     

Prophylaxis against the systemic hypotension induced by propofol during rapid-sequence intubation

The objective of this study was to determine the effectiveness of two prophylactic approaches against the anticipated hypotension induced by propofol during rapid-sequence intubation. Thirty-six male or female nonpremedicated ASA class I-II patients aged 21– 60 yr undergoing elective outpatient surgery were included in the study. Patients were randomly allocated to receive pre-induction ephedrine sulphate (70 μg · kg^{? 1} iv), preinduction volume loading (12 ml · kg^{? 1} Ringer’s lactate) or no treatment. Rapid-sequence intubation with cricoid pressure was then performed with propofol (2.5 mg · kg^{? 1}) and succinylcholine (1.5 mg · kg^{? 1}). The lungs were subsequently ventilated with 0.25– 0.5% isoflurane in a 2:1 N₂O/O₂ mixture. Vecuronium was given once neuromuscular function had recovered from the succinylcholine. Heart rate and systemic arterial blood pressure were measured non-invasively before induction, after propofol administration and every minute for ten minutes after intubation. Pre-induction volume loading prevented the hypotension observed before surgical stimulation in control and ephedrine groups. Moreover, pre-induction volume loading was not associated with increases in heart rate after intubation as was ephedrine administration. The intubating conditions were excellent to satisfactory in most patients and the overall incidence of adverse events during induction was mainly due to pain during injection of propofol. The present study showed that preoperative volume loading is more efficacious than preinduction administration of ephedrine sulphate in maintaining haemodynamic stability during rapid-sequence induction with propofol and succinylcholine. In addition, propofol in combination with succinylcholine provides excellent conditions for rapid-sequence intubation.     

Bilateral Capitellum Humeri Fracture; a Case Report

This is the report of a 33-year-old female patient who was admitted to the Emergency Department with bilateral capitellum humerus fracture after a fall from a height. The patient was surgically treated with open reduction and internal fixation for both elbows, with 3 Kirschner wires on the right elbow and one mini-fragment screw on the left. Surgical intervention was carried out in emergency conditions. Following an early physical rehabilitation programme at the end of the 1^st week, the roentgenograms in the 9^th week showed acceptable bone union. However, in the 2^nd year of follow-up the patient had consistent pain and 35 degrees of flexion loss in her right elbow due to degenerative change. The literature reveals only two reports of such cases. Thus, this rare case of bilateral capitellum humerus showed that early mobilisation after anatomic reduction and stable fixation with a mini-screw provided the optimal outcome.     

A comparison of the effects of hyperbaric oxygen culture on survival of murine and canine thyroid gland grafts

Canine thyroid tissue (CTy) was subjected to hyperbaric oxygen culture (HOC) under conditions that affect immunoalteration in murine thyroid tissue (MTy). Survival of autografts and allografts implanted under the kidney capsule was determined after 21 days by ¹²⁵I uptake and histology. Unlike MTy, autograft CTy subjected to normothermic HOC (95% O₂, 5% CO₂; 1.76kg/cm²) for 48 h did not survive (0/8) whereas decrease of culture duration to 24 h resulted in autograft CTy survival (3/3). Under hypothermia (5°C), HOC could be extended to 7 days with autograft CTy survival (3/3 after 4 days and 3/3 after 7 days). Allograft CTy after 24 h of normothermic HOC and 7 days of hypothermic HOC was rejected. Indicators of oxygen free radical injury were determined: catalase activity was comparable in MTy and CTy (means 14.82 and 6.3–10.8 mm/mg protein, respectively) but superoxide dismutase activity was low in CTy (means 0.01–0.29 and 4.75 U/mg protein, respectively). Malondialdehyde content after 48 h of normothermic HOC was higher in CTy than in MTy (means 2215 and 1275 nmol/g, respectively). The results show that CTy is injured by HOC under conditions tolerated by MTy, and that this difference is related to the greater sensitivity of CTy to oxygen free radical injury.     

Tissue distribution of a new photosensitizer ATX-S10Na(II) and effect of a diode laser (670 nm) in photodynamic therapy

The aims of the present study were to analyse the quantitative tissue distribution of ATX-S10Na(II) and to investigate the maximal effect of a diode laser and the irradiation conditions required to obtain this effect in photodynamic therapy (PDT) with ATX-S10Na(II). Spectrofluorometry was used to obtain quantitative tissue distribution of ATX-S10Na(II) in Colon 26 carcinoma-bearing mice as a function of time following administration. Next, transplanted tumours of mice with or without ATX-S10Na(II) were treated with the diode laser under conditions in which power density and irradiation time were varied. Tumour tissue concentrations of ATX-S10Na(II) were higher than in all tissues at all intervals following administration. The uptake of ATX-S10Na(II) by most tissues was rapid, with maximal concentrations occurring 1 h after i.v. injection, and ATX-S10Na(II) was almost excreted within 24 h after administration. The maximal depth of necrosis induced by PDT in the treated tumour was 7.9 mm under conditions in which power density was 160 mW/cm² and total dose was above 100 J/cm². PDT with ATX-S10Na(II) and the diode laser is useful for the treatment of superficial cancers.     

Evaluation of parenchymal and nonparenchymal cell injury after different conditions of storage and reperfusion

We used the isolated perfused rat liver model (IPRL) to assess parenchymal and nonparenchymal cell integrity after different conditions of storage and reperfusion. Two studies were performed. In study 1, the IPRL was applied to evaluate the effects of 30 min of normothermic reperfusion with Elohes solution, enriched William's medium (Wif), or Carolina rinse solution (CRS) following 24 h of cold preservation in high-K⁺ or high-Na⁺ UW solution. As indicated by creatine kinase-BB (CK-BB) release, reperfusion with CRS provided greater protection of endothelial cells after storage in high-K⁺ UW solution than after storage in high-Na⁺ UW solution. In study 2, livers were cold-preserved (24 h, 4 °C) in either high-K⁺ or high-Na⁺ UW solution, then flushed with either CRS or Wif solution at room temperature before reperfusion (120 min, 37 °C) with 5 % albumin-William's medium E. There was no statistical difference between the rinse solutions for bile flow and transaminases release. However, CRS improved bile indocyanine green excretion, which is known to be a marker of parenchymal and nonparenchymal cell integrity. Therefore, we can assume that this rinse solution protects rat liver grafts from reperfusion-induced microvascular damage. Received: 29 December 1997 Received after revision: 31 March 1998 Accepted: 15 April 1998     

Intubation endotrachéale sous propofol avec ou sans vécuronium

• Objective :In order to test the hypothesis that under the association propofol-alfentanil-IV lidocaine the trachea could be intubated easily without an additional muscle relaxant, this study compared the intubation conditions when this association was combined or not with vecuronium.• Study design :Randomized comparative trial.• Patients :The study included 152 young adults classified as ASA physical class I and Mallampati presentation grade 1, randomly allocated either into Vecu+ group or Vécu0 group, depending on whether vecuronium was coadministered or not.• Methods :All patients received midazolam 0.05 mg·kg⁻¹ i.v., one minute before induction. Those of group Vecu0 were given successively within two minutes : alfentanil 0.03 mg·kg⁻¹, lidocaine 1.5 mg·kg⁻¹ i.v. and propofol 2.5 mg·kg⁻¹. Patients of group Vecu+ received similar doses of alfentanil and propofol as well as vecuronium 0.08 mg·kg⁻¹. The endotracheal tube was inserted one minute after induction in the patients of Vecu0 group, and after three minutes in those of the Vecu+ group. During intubation, scores of mouth opening, glottis opening and coughing were established, in order to assess intubation conditions.• Results :Similar convenient intubating conditions were obtained in both groups (in 97 % of patients in Vecu+ group vs 95 % of those in Vecu0 group). In the latter, the glottis opening was less pronounced.• Conclusions :In young healthy adults, without anaesthetic risk (emergency, full stomach) and without foreseen difficult intubation, the endotracheal tube can be inserted in convenient conditions without a muscle relaxant, under the association propofol-alfentanil-lidocaine iv.     

A new valve for draw‐over anaesthesia*

The Diamedica non‐rebreathing valve has been developed for use in draw‐over anaesthesia and can be positioned at the common gas outlet. Its performance was evaluated against the Laerdal, Ruben and Ambu® valves under laboratory conditions. Valve resistance during inspiration and expiration was simulated over a range of constant flow conditions. During flows ranging from 5 to 45 l.min^?1, the Diamedica and Ruben valves exhibited a negligible resistance of < 150 Pa, with the Laerdal and Ambu valves achieving resistance of < 200 Pa. To assess the effects of sterilisation, this procedure was repeated following autoclaving, after which the Diamedica valve exhibited resistance to flow of < 150 Pa at 25 l.min^?1 for inlet resistance and 35 l.min^?1 for outlet resistance. The Diamedica, Ambu and Laerdal valves demonstrated resistance of < 100 Pa when saturated with water, while the Ruben valve exhibited resistance > 500 Pa.     

Mood Disturbance During Cycling Performance at Extreme Conditions

The purpose of the study was to investigate the effects of extreme environments on mood state changes in hypoxic conditions and cold conditions in comparison to baseline conditions. The research design involved participants completing a two-hour stationary cycle ergometer ride at a simulated altitude of 2,500 metres, O°C, and normal laboratory conditions at a pace equivalent of lactate threshold. Eight male elite cyclists (Age: M = 26.23 yrs., SD = 6.74) completed the hypoxia- normal cycling trials. Ten male highly trained cyclists (Age: M = 23.34 yrs., SD = 5.45) participated in the cold-normal trials. Mood was assessed before, after one hour, and after two hours using the 24-item Brunel Mood Scale. MANOVA results indicated no significant interaction effect for mood changes over time by environment condition (Wilks’ Lambda = .73, p = .32, Eta² = .05), a significant main effect for mood changes over time (Wilks’ Lambda = .61. p < .001, Partial Eta² = .15) and a significant main effect for differences in mood by condition (Wilks’ Lambda = .72, p < .000, Partial Eta² = .15). Results indicated that increased anger, depression and fatigue were associated with performing at altitude, particularly after two hours of exercise. Collectively, results lend support to the notion that altitude is associated with negative mood states, although it should be noted that environment conditions did not affect the change in mood states over time. We suggest that further research is needed to explore mechanisms that individuals use to regulate negative mood during strenuous exercise.

Key Points

• The present study found that mood state changes were more pronounced when performing at a simulated altitude of 2,500 metres than performing in the cold and normal laboratory conditions at a pace equivalent of lactate threshold.
• Findings from the present study indicate that that altitude is associated with negative mood states,
• Results show that mood states change during extreme exercise with increases most notably in fatigue and reductions in vigor. It should be noted that environment conditions did not affect the change in mood states over time.
• We suggest that further research is needed to explore mechanisms that individuals use to regulate negative mood during strenuous exercise.

Key words: Mood, coping, environment, altitude, cold, performance