The use of demineralized laminar bone sheets in guided bone regeneration procedures: report of three cases

We have studied the time course of recovery after administration of edrophonium during intense mivacurium block in children aged 2-10 yr, using thumb acceleration in response to train-of-four (TOF) stimulation. Forty-three children receiving alfentanil, propofol, nitrous oxide, isoflurane anaesthesia and mivacurium 0.2 mg kg-1 were allocated randomly to one of three groups. Patients in group 1 (n = 15) received edrophonium 1 mg kg-1, 2 min after maximum block (intense block group). At the time of administration of edrophonium in this group, there was no response to TOF stimulation (100% block) and the post-tetanic count was 10.7 (range 0-20). Patients in group 2 received the same dose of edrophonium after 10% recovery of the first twitch (T1) in the TOF (conventional reversal). Patients in group 3 (n = 13) recovered spontaneously. All patients developed complete suppression of twitch height in response to the bolus dose of mivacurium. All recovery times were measured from the point of maximum block after mivacurium. Mean time for 25% recovery of T1 (clinical duration) was 3.8 (SD 1.1) min in the intense block group. This was significantly shorter than the conventional reversal (8.3 (2.4) min) and spontaneous recovery (9.2 (3.5) min) groups (P < 0.001). The times for 75% and 90% recovery of T1 were shorter in the intense block group (9.4 (2.8), 12.3 (4.2) min) compared with the conventional (13.1 (3.8), 17.3 (4.8) min) and spontaneous recovery (14.9 (4.5), 17.9 (5.2) min) groups (P < 0.01). Total recovery time required for 70% recovery of the TOF ratio (T4/T1) was 8.8 (2.4) min in the intense block group. This was significantly shorter than the conventional reversal (11.9 (3.2) min) (P < 0.05) and spontaneous recovery (17.1 (4.0) min) groups (P < 0.001). Conventional reversal was associated with a shorter total recovery time compared with spontaneous recovery (P < 0.01). The recovery index (time interval between T1 25% and 75%) was comparable in groups 1-3 (5.5 (2.0), 4.8 (2.1) and 5.7 (1.4) min respectively). Ten minutes after development of maximum block, the numbers of patients who recovered adequately (TOF ratio 70% or more) were, respectively, 12 (80%), 8 (53%) and 1 (8%) in groups 1-3. We conclude that edrophonium antagonized intense (no response to TOF stimulation) mivacurium-induced block in children, with significant reduction in the recovery times of T1 and TOF ratio compared with conventional reversal and spontaneous recovery.     

Monitoring orbicularis oculi predicts good intubating conditions after vecuronium in children

PURPOSE: The aim of the study was to compare visual estimation of onset of neuromuscular blockade at both the adductor pollicis (AP) and the orbicularis oculi (OO) in children and to determine if monitoring the OO could predict good intubating conditions during vecuronium-induced neuromuscular blockade. METHODS: Thirty ASAI--II children (1.5-9 yr) were studied. Anaesthesia was induced with 6-8 mg.kg-1 thiopentone. The ulnar nerve at the wrist and the temporal branch of the facial nerve were stimulated every 10 sec using train-of-four (TOF) stimuli. Vecuronium, 0.15 mg.kg-1, was administered as a bolus. The responses at both the OO and the AP were evaluated visually. Patients were randomly divided into two groups. In the AP group (n = 15), the trachea was intubated when the AP was completely blocked. In the OO group (n = 15), intubation was performed when the OO was completely blocked. Intubating conditions were scored on a scale of 1 to 4. RESULTS: All the patients had complete blockade at both the orbicularis oculi and the adductor pollicis. In the two group, time from injection of vecuronium to complete neuromuscular blockade was shorter at the orbicularis oculi than at the adductor pollicis, 1.5 +/- 0.5 min vs 2.3 +/- 0.7 min, respectively, (P < 0.05; mean +/- SD) in the AP group, 1.7 +/- 0.3 min vs 2.3 +/- 0.8 min, respectively in the OO group (P < 0.05). Intubating conditions were excellent in all patient except one, where it was rated as good. They did not differ between groups. CONCLUSION: Following administration of 0.15 mg.kg-1 vecuronium in children, monitoring of the OO can detect good intubating conditions 0.7 min earlier than with monitoring of the AP.     

Reduced neuromuscular blocking potency of atracurium in patients with purulent intrathoracic diseases

OBJECTIVE: Based on personal observations the neuromuscular blocking potency of atracurium was supposed to be diminished in purulent intrathoracic diseases. This hypothesis was tested in a prospective clinical trial. METHODS: 52 adult patients undergoing general anaesthesia (methohexitone, sufentanil, flunitrazepam, N2O, enflurane) for elective thoracic surgery were investigated. After the intubation dose of 0.6 mg/kg atracurium was applied continuously to maintain a 90% suppression of the evoked compound electromyogram. According to the intraoperatively established diagnosis patients were allocated to three categories: 1) non-malignant tumor as the control group (n = 15), 2) lung cancer (n = 22), 3) purulent intrathoracic process without tumor (n = 15). The groups were compared regarding onset time, DUR 10% and maintenance dose of atracurium. RESULTS: Patients with lung cancer did not differ significantly from the controls regarding efficiency of atracurium. In contrast, patients with a purulent intrathoracic process showed a significantly longer onset time (6.3 +/- 2.5 vs. 2.9 +/- 0.8 min, p < 0.001), and a significantly shorter DUR 10% (23 +/- 6 vs. 36 +/- 10 min, p < 0.001) compared to the control group. Mean infusion rate of atracurium to maintain a 90% suppression of the evoked compound electromyogram was significantly higher in patients with a purulent process compared to the controls (10.5 +/- 3.2 vs. 6.0 +/- 1.2 micrograms/kg.min, p < 0.001). CONCLUSION: Our results support the hypothesis that patients with a purulent intrathoracic disease show a clear reduction in neuromuscular blocking potency of atracurium.     

Potency and time course of action of rocuronium during desflurane and isoflurane anaesthesia

We have studied the potency and onset and duration of action of rocuronium in patients anaesthetized with 1 MAC of desflurane or isoflurane (in 66% nitrous oxide). Potency was estimated using the single bolus dose technique. Neuromuscular block was measured by stimulation of the ulnar nerve and recording the force of contraction of the adductor pollicis muscle. The ED50 and ED95 of rocuronium were estimated as 138 (95% confidence limits 117-162) micrograms kg-1 and 281 (241-328) micrograms kg-1, and 126 (105-151) micrograms kg-1 and 283 (236-339) micrograms kg-1 during desflurane and isoflurane anaesthesia, respectively. The mean times to onset of maximum block after rocuronium 0.6 mg kg-1 were 1.0 (SD 0.10) min and 1.1 (0.15) min, respectively, during anaesthesia with desflurane and isoflurane. The respective times to recovery of T1 (the first response in the train-of-four (TOF) stimulation) to 25% and 90% were 36 (8.3) min and 54 (15.4) min during desflurane anaesthesia and 31 (8.2) min and 45 (12.7) min during isoflurane anaesthesia. The times to recovery of the TOF ratio to 0.7 were 66 (13.4) min and 52 (16.3) min and the 25-75% recovery indices 14 (5.3) min and 10 (3.2) min, respectively, in the desflurane and isoflurane groups. There were no differences in the estimated potency or onset of action of rocuronium during desflurane and isoflurane anaesthesia. However, duration of action tended to be longer curing desflurane anaesthesia although only the differences in times to TOF ratio of 0.7 and the recovery indices were close to being significantly different (P = 0.0503 and 0.0560).     

Recovery of post-tetanic and train-of-four responses at the first dorsal interosseous and adductor pollicis muscles in patients receiving vecuronium

PURPOSE: To compare recovery of accelographical responses to post-tetanic twitch (PTT) and train-of-four (TOF) stimuli obtained at the first dorsal interosseous muscle (DI) with those at the adductor pollicis muscle (AP) after administration of vecuronium 70 micrograms.kg-1. METHODS: Sixty adult patients were randomly assigned to one of four groups: PTT-DI (n = 15), PTT-AP (n = 15), TOF-DI (n = 15), or TOF-AP (n = 15) group. In PTT-DI and PTT-AP groups, responses to PTT were measured accelographically at the DI and at the AP, respectively. In TOF-DI and TOF-AP groups, responses to TOF were measured at the DI and at the AP, respectively. RESULTS: The T1/T0 (T0 = control) was greater in the TOF-DI than in TOF-AP group throughout recovery (P < 0.05), and the T4/T1 was greater in the TOF-DI than in TOF-AP group during the 30-40 min after vecuronium injection (P < 0.05). Time to the return of the first response to PTT (post-tetanic count(1), PTC1) was less in the PTT-DI than in the PTT-AP group (17.7 +/- 4.2 vs 21.7 +/- 5.6 min, mean +/- SD, P = 0.0341). The post-tetanic count PTC (number of single twitch stimuli in response to PTT) was greater in the PTT-DI than in the PTT-AP group during the 10-30 min after vecuronium (P < 0.05). Time to the return of T1 was less in the TOF-DI than in the TOF-AP group (23.1 +/- 6.0 vs 27.6 +/- 4.9 min, P = 0.0334). CONCLUSION: Recovery of responses to PTT and TOF stimuli occurred earlier at the DI than at the AP.     

Delay of clinical recovery from paralysis induced by atracurium: comparison between orbicularis oculi and adductor pollicis

OBJECTIVE: To compare with train-of-four stimulation the delays of the beginning of the spontaneous recovery of the orbicularis oculi and of the adductor pollicis after profound neuromuscular blockade with atracurium. STUDY DESIGN: Prospective, comparative open study. PATIENTS AND METHODS: Twenty-eight physical class ASA 1 and 2 patients under general anaesthesia (propofol, N2O, fentanyl) and profound neuromuscular blockade with atracurium. Train-of-four stimulation, every 10 s, of the ulnar nerve at the wrist (for assessing by tactile means the response of the adductor pollicis) and of the temporal branch of the facial nerve (for assessing visually the response of the orbicularis oculi). On each site, measurement of the delay between the end of the maintenance of deep neuromuscular blockade (last dose of atracurium) and the beginning of the recovery (first response to train-of-four stimulation). RESULTS: In each case, the recovery of the orbicularis oculi began earlier than the recovery of the adductor pollicis (26 +/- 9 min vs 34 +/- 9 min, P < 0.001). The delays of recovery at each site were strongly correlated (r = 0.87; P < 0.001) but the time lag between the responses varied greatly: 1 to 21 min, mean: 8 +/- 5 min, coefficient of variation: 56.6%. CONCLUSION: The orbicularis oculi should not be monitored alone for assessment of recovery from profound neuromuscular blockade by atracurium, as it predicts poorly the time of the recovery of the adductor pollicis.     

Neuromuscular effects of rocuronium during sevoflurane, isoflurane, and intravenous anesthesia

The potency and time course of action of rocuronium were studied in patients anesthetized with 66% nitrous oxide in oxygen and 1.5 minimum alveolar anesthetic concentration of sevoflurane or isoflurane, or a propofol infusion. Potency was estimated by using the single-bolus technique. Neuromuscular block was measured by stimulation of the ulnar nerve and by recording the force of contraction of the adductor pollicis muscle. The mean (95% confidence limits) of the 50% and 95% effective doses were estimated tobe 142 (129-157) and 265 (233-301) microg/ kg, 165 (146-187) and 324 (265-396) microg/kg, and 183 (163-207) and 398 (316-502) microg/kg during sevoflurane, isoflurane, and propofol anesthesia, respectively (P < 0.05 for sevoflurane versus propofol). The mean +/- SD times to onset of maximal block after rocuronium 0.6 mg/kg were 0.96 +/- 0.16, 0.90 +/- 0.16, and 1.02 +/- 0.15 min during sevoflurane, isoflurane, and propofol anesthesia, respectively. The respective times to recovery of the first response in the train-of-four (TOF) stimulation (T1) to 25% and 90% were 45 +/- 13.1 and 83 +/- 29.3 min, 35 +/- 6.1 and 56 +/- 15.9 min, and 35 +/- 9.2 and 55 +/- 19.4 min. The times to recovery of the TOF ratio to 0.8 were 103 +/- 30.7, 69 +/- 20.4, and 62 +/- 21.1 min, and the 25%-75% recovery indices were 26 +/- 11.7, 12 +/- 5.0, and 14 +/- 6.9 min, respectively. There were no differences among groups in the times for onset of action or to recovery of T1 to 25%. However, the times for recovery of T1 to 90%, TOF ratio to 0.8, and recovery index in the sevoflurane group were all significantly longer compared with the other two groups (P < 0.05, < 0.01, and < 0.01, respectively). We conclude that the effects of rocuronium, especially duration of action, are significantly enhanced during sevoflurane compared with isoflurane and propofol anesthesia. IMPLICATIONS: In routine clinical use, the effects of rocuronium are enhanced by sevoflurane, in comparison with isoflurane and propofol anesthesia, and the recovery is slower. Particular attention should be paid to monitoring of neuromuscular block during sevoflurane anesthesia.     

Neuromuscular blockade with vecuronium and its reversal with edrophonium during total intravenous anesthesia, neuroleptanalgesia and sevoflurane anesthesia

The neuromuscular blocking effect of vecuronium and its reversibility ith edrophonium were studied under total intravenous anesthesia (TIVA) and compared with those under NLA or sevoflurane anesthesia (SA) in 30 surgical patients. The degree of neuromuscular blockade was evaluated by acceleration of thumb adduction in response to supramaximal stimulation of the ulnar nerve using Accelograph (Biometer). TIVA was induced with droperidol 0.25 mg.kg-1, fentanyl 2-4 micrograms.kg-1 and ketamine 2 mg.kg-1, and maintained with continuous infusion of ketamine 2 mg.kg-1.h-1 with 30-35% O2 in air. NLA was induced with droperidol 0.25 mg.kg-1 and fentanyl 5-10 micrograms.kg-1 and maintained with 66% nitrous oxide in oxygen. SA was induced with thiamylal 5 mg.kg-1 i.v. and maintained with 66% nitrous oxide in oxygen supplemented with sevoflurane (1 MAC). A single bolus intravenous injection of vecuronium 0.1 mg.kg-1 was used for paralysis and reversed with edrophonium 0.75 mg.kg-1 followed by atropine 0.015 mg.kg-1 when the TOF ratio returned to 25%. The times required from administration of vecuronium to completion of maximal block with TIVA, NLA and SA were 196.5 +/- 52.2 sec, 182.5 +/- 47.6 sec and 166.0 +/- 69.0 sec, respectively. There was no significant difference among them. The times from completion of maximal block to 25% recovery of the twitch height in TIVA and NLA were 39.5 +/- 11.0 min and 37.4 +/- 5.8 min without significant difference. Those values, however, were significantly shorter than 64.5 +/- 35.2 min of SA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intubation conditions: importance of the rate of repetition of the train-of-four

OBJECTIVES: To assess that neuromuscular relaxation onset of the adductor pollicis (AP) is related to neuromuscular stimulation rate. To assess that train-of-four (TOF) at 0.05 Hz is a more accurate indicator of optimal tracheal intubation time and conditions, than TOF at 0.08 Hz. STUDY DESIGN: Prospective, comparative, randomized double-blind study. PATIENTS: Forty adults, physical class ASA 1 or 2, undergoing general anaesthesia with tracheal intubation were allocated to two groups (n = 20) according to the sequence of stimulation of the AP: either TOF at 0.05 Hz (test group) or TOF at 0.08 Hz (control group). METHODS: Induction of anaesthesia was achieved with thiopentone, fentanyl and vecuronium (0.1 mg.kg-1). Neuromuscular monitoring was obtained with force displacement transducers attached to each AP. Tracheal intubation was performed once AP muscular response obtained with TOF at 0.05 Hz for test group and TOF at 0.08 Hz for control group was abolished. Results are expressed as mean +/- SEM. Fisher exact test was used for intubation conditions comparison. Curarization time between groups was compared with unpaired Student's t test (P < 0.05 accepted). RESULTS: TOF with 0.05 Hz stimulation significantly increased curarization time: 217 +/- 7 versus 162 +/- 6 s (P < 0.001). Intubation conditions were excellent in 95% and good in 5% of patients in the study group, compared to 15 and 40% in the control group, respectively (P < 0.01) in 45% of the control group patients coughing at intubation occurred. CONCLUSION: Low stimulation rate (TOF at 0.05 Hz) of AP is a reliable technique to determine the appropriate intubation time for patients paralyzed with vecuronium.     

Comparison of remifentanil in combination with isoflurane or propofol for short-stay surgical procedures

There are few data in the literature that describe the use of remifentanil when administered as a component of an inhalation or total i.v. anaesthetic (TIVA) technique. We studied 251 male and female patients, aged 18-75 years, ASA I-II, undergoing inguinal hernia repair, arthroscopic knee surgery or varicose vein surgery of at least 30 min duration without premedication. Patients were randomized to receive a remifentanil loading dose of 1.0 microgram kg-1 followed by a continuous infusion of 0.5 microgram kg-1 min-1 in combination with isoflurane (end-tidal concentration 0.6%), (Group I, n = 115) or propofol (initial infusion rate 9 mg kg-1 h-1 reduced to 6 mg kg-1 h-1 after 10 min), (Group P, n = 118). The remifentanil infusion rate was reduced by 50%, 5 min after tracheal intubation. Intraoperative stresses were treated with a remifentanil bolus (1 microgram kg-1) followed by an increase in the remifentanil infusion rate. At the insertion of the last suture, the remifentanil infusion and concomitant anaesthetic were switched off simultaneously. Times to spontaneous respiration, adequate respiration and tracheal extubation were significantly shorter in group I compared with group P (6.4 min vs 7.6 min, P < 0.01; 7.6 min vs 9.3, P < 0.003; 7.8 min vs 9.5 min, P < 0.015). Overall mean systolic blood pressures during surgery were greater in group P compared with group I (P < 0.05) but the absolute differences were clinically insignificant (4-5 mm Hg).     

Diltiazem-lidocaine combination for the attenuation of cardiovascular responses to tracheal intubation in hypertensive patients

PURPOSE: Hypertensive patients are prone to haemodynamic changes after laryngoscopy and tracheal intubation. This study was undertaken to compare the efficacy of a combination of diltiazem and lidocaine with that of each drug alone for suppressing the cardiovascular responses to tracheal intubation. METHODS: Sixty hypertensive patients (ASA II), defined as systolic blood pressure > 160 mmHg and/or diastolic blood pressure > 95 mmHg (World Health Organization), undergoing elective surgery received, in a randomized, double-blind manner, 0.3 mg.kg-1 diltiazem, 1.5 mg.kg-1 lidocaine, or 0.3 mg.kg-1 diltiazem plus 1.5 mg.kg-1 lidocaine i.v. (n = 20 of each) before the initiation of laryngoscopy. Anaesthesia was induced with 5 mg.kg-1 thiopentone i.v., and tracheal intubation was facilitated with 2 mg.kg-1 succinylcholine i.v. after precurarization with 0.02 mg.kg-1 vecuronium i.v. Changes in heart rate (HR), mean arterial pressure (MAP) and rate-pressure product (RPP) were measured before and at immediate, 1, 2, 3, 5 and 10 min after tracheal intubation. RESULTS: The inhibitory effects of diltiazem-lidocaine combination on cardiovascular responses to tracheal intubation was greater than those of diltiazem or lidocaine as a sole medicine (RPP; 10,602 +/- 1448 (combination) vs 11,787 +/- 1345 (diltiazem), 15,428 +/- 1756 (lidocaine), mean +/- SD, P < 0.05). CONCLUSION: Prophylactic therapy with diltiazem-lidocaine combination is more effective than diltiazem or lidocaine alone for attenuating the cardiovascular changes associated with tracheal intubation in hypertensive patients.     

Acute cytotoxicity testing with cultured human lung and dermal cells

STUDY OBJECTIVE: To determine if 450 micrograms/kg (1.5 times the ED95) of rocuronium would result in a comparable onset with a shorter duration of action when compared with 600 micrograms/kg (2 times the ED95). DESIGN: Randomized, single-blind study. SETTING: Teaching hospital. PATIENTS: 85 ASA physical status I and II children ages 2 through 12, undergoing elective surgery with an inhalation induction using halothane. INTERVENTIONS: Group 1 received 600 micrograms/kg rocuronium, and Group 2 received 450 micrograms/kg rocuronium. MEASUREMENTS AND MAIN RESULTS: The two groups were compared using a Student's t-test, with p < 0.05 significant. The time of onset, or time to 95% suppression of neuromuscular twitch with standard errors, was 140 +/- 13 seconds (range 46 to 365 sec) in Group 1 and 148 +/- 13 seconds (range 82 to 345 sec) in Group 2 (NS = not significant). The times to 25% return of twitch from baseline (T25) in Groups 1 and 2 were 28 +/- 1.5 minutes (range 14 to 45 min) and 26 +/- 1.6 minutes (range 10 to 55 min), respectively (NS). The differences between these two doses in onset of, and recovery from, block were not found to be statistically significant. The results, however, excluded 5% of the higher dose group and 31% of the lower dose group who did not achieve 95% suppression of twitch. Time to maximal suppression of neuromuscular blockade, however, was not statistically significant for the 85 patients with a time of 270 +/- 28 seconds (range 91 to 605 sec) with a mean maximal suppression of 98.7% in Group 1 and 313 +/- 25 seconds (range 91 to 899 sec) with a mean maximal suppression of 93.1% in Group 2. CONCLUSION: The two doses of rocuronium did not differ statistically in onset or duration. Rocuronium at 600 micrograms/kg offers more reliability than 450 micrograms/kg in achieving adequate muscle relaxation, and the lower dose may result in a significantly large number of patients who may have inadequate intubating conditions.     

The effects of age on onset and recovery from atracurium, rocuronium and vecuronium blockade

Elderly patients may show an age-related decline in physiologic functions, which may be responsible for the prolonged duration of some neuromuscular blocking agents. Previous studies have yielded conflicting results as to the effects of these drugs in the elderly. METHODS: After obtaining informed consent and approval of the Ethics Committee, we compared onset and recovery times of single IV doses of atracurium, rocuronium, and vecuronium given to 108 patients divided into three groups according to age (18-50, 51-64, > or = 65 years). Following oxazepam premedication and fentanyl and thiopentone induction, patients were randomly allocated to receive atracurium, rocuronium or vecuronium (0.5, 0.6, or 0.1 mg/kg, respectively) in < or = 0.8 vol.% enflurane (end-tidal)-nitrous oxide anaesthesia. Muscular relaxation was assessed by electromyographic (EMG) recording of the adductor pollicis muscle after supramaximal single-twitch stimulation of the ulnar nerve every 10 s. Onset time and recovery to 25%, 75% and 90% of twitch control values (DUR25, 75, 90) were recorded. Creatinine clearance predicted from serum creatinine (Ccr) was correlated with recovery from neuromuscular block. RESULTS: Onset time was not different among groups or relaxants. The results showed a prolonged duration of action for atracurium (DUR75, DUR90), rocuronium (DUR25, DUR75), and vecuronium (DUR25) in the elderly. A number of patients did not reach DUR75 or DUR90. There was a significant relationship between age and failure to return to control values during recovery from neuromuscular block, especially after atracurium and rocuronium. Ccr showed a negative correlation with age for all relaxants, but a negative significant correlation between Ccr and recovery was found only for rocuronium. CONCLUSIONS: This study suggests that onset time for atracurium, rocuronium and vecuronium is not age-dependent. Recovery was prolonged in the elderly for all three relaxants. This effect appears to be secondary to changes in body composition and function accompanying the aging process. Neither atracurium nor vecuronium depends significantly on the kidney for elimination, but the negative correlation between Ccr and rocuronium suggests an appreciable role for the kidney in the elimination of this relaxant. The long recovery times observed in this study could also be related to enflurane anaesthesia. We suggest that failure of EMG responses to return to baseline values during recovery from neuromuscular block may be related to age, especially for atracurium and rocuronium.     

Negative pressure ventilation vs. spontaneous assisted ventilation during rigid bronchoscopy. A controlled randomised trial

BACKGROUND: Ventilation during interventional rigid bronchoscopy (IRB) under general anaesthesia (jet ventilation, positive pressure ventilation and spontaneous assisted ventilation) may offer some difficulties. This study compares the effectiveness during IRB of intermittent negative pressure ventilation (INPV) and spontaneous assisted ventilation (SAV). METHODS: Thirty-eight patients submitted to IRB were randomised into two groups: SAV or INPV. All patients received a total intravenous anaesthesia; INPV patients were paralysed. Pre- and intra-operative arterial blood gases and O2 flow through a rigid bronchoscope were assessed. The endoscopist applying a subjective score evaluated the operating conditions. RESULTS: Patients of the INPV group, as compared to the SAV group, required a lower dosage of fentanyl (2.6 +/- 1.8 micrograms.kg-1.h-1 vs. 6.6 +/- 4.8 micrograms.kg-1.h-1), a lower O2 supply (3.3 +/- 2.8 l/min vs. 11.6 +/- 3.4 l/min), a shorter recovery time (5.4 +/- 2.9 min vs. 9.8 +/- 7.1 min) and no manually assisted ventilation (0 +/- 0 vs. 1 +/- 1.1 n degree/procedure). Intraoperative PaCO2 was higher in the SAV (8.1 +/- 1.3 kPa) than in the INPV group (5.0 +/- 1.6 kPa) and intraoperative pH differed in the two groups (7.26 +/- 0.05, SAV vs. 7.47 +/- 0.08, INPV). Operating conditions, as assessed by a subjective score, were considered better with INPV than with SAV (4.9 vs. 4.3). CONCLUSIONS: As compared to SAV, INPV in paralysed patients during IRB reduces administration of opioids, shortens recovery time, prevents respiratory acidosis, excludes the need for manually assisted ventilation, reduces O2 need and affords optimal surgical conditions. INPV appears a safe, non-invasive and effective ventilatory management during IRB.     

Analgesia following appendicectomy--the value of peritoneal bupivacaine

PURPOSE: Peritoneal inflammation is an important feature in many patients presenting with appendicitis. The contribution of peritoneal nerve fibres to pain experienced after appendicectomy has received little attention. METHOD: In this prospective double blind randomized study a consecutive series of 60 patients undergoing appendicectomy for suspected appendicitis were enrolled. A dose of 1.5 mg.kg-1 bupivacaine 0.5% was used. Group one patients received the entire dose of bupivacaine subcutaneously. Group two patients received half the dose subcutaneously (s.c.) and half the dose to the peritoneum. Pain scores were assessed pre-operatively and at 30 min, 12 and 24 hr post-operatively using a visual analogue scale. Time to first analgesia and total analgesia requirements in the first 24 hr were recorded. RESULTS: The patients receiving the s.c. combined with peritoneal bupivacaine had a lower pain score 30 min post-operatively (32 +/- 2 vs 54 +/- 4; P < 0.0001), a longer time to first analgesia (248 +/- 20 vs 164 +/- 17 min; P = 0.002) as well as lower opioid (68 +/- 5 vs 100 +/- 7 mg; P = 0.0002) and non steroidal analgesic requirements (65 +/- 6 vs 96 +/- 6 mg; P = 0.007) in the first 24 hr post-operatively. CONCLUSION: A combination of s.c. and peritoneal infiltration with bupivacaine is superior to skin infiltration alone in the relief of pain post appendicectomy.     

A case report of complete inversion of the bladder in an old woman

BACKGROUND: The inhaled anaesthetic desflurane is characterized by a rapid wash-in and wash-out and may be useful for short paediatric ENT procedures. Therefore, this study was designed to compare the effects of desflurane or isoflurane on intubating conditions and recovery characteristics in paediatric ENT patients. METHODS: In this prospective, randomised investigation, we studied 44 children scheduled for ENT surgery, aged 4-12 yr and classified ASA I-II. After thiopentone induction (5-8 mg/kg) the lungs were ventilated by face mask and the vaporizer was dialed to 1 MAC (age-adapted) of desflurane of isoflurane. A reduced dose of vecuronium (0.05 mg/kg) was administered, and intubating conditions were rated 3 min later. Following tracheal intubation, 50% nitrous oxide were added, and the concentration of desflurane or isoflurane was adjusted according to clinical needs. At the end of surgery all anaesthetics were discontinued simultaneously and recovery times were recorded. RESULTS: Intubating conditions were rated significantly better for desflurane (excellent or good 20 of 22) than for isoflurane (12 of 22). Recovery times were significantly shorter for desflurane than for isoflurane (mean +/- SE): spontaneous ventilation 4.0 +/- 0.5 min vs. 6.0 +/- 0.7 min, extubation 8.4 +/- 0.7 vs. 11.4 +/- 1.1 min and arrival at PACU 11.5 +/- 0.8 vs. 16.6 +/- 1.5 min. No airway complications (coughing, laryngospasm, or desaturation < 97%) were noted for either anaesthetic. CONCLUSIONS: Following an intravenous induction improved intubating conditions, shorter recovery times and the lack of airway complications make desflurane a suitable alternative to isoflurane for paediatric ENT anaesthesia.     

Drug retention, efflux, and resistance in tumor cells

This prospective, randomized trial of paediatric surgical outpatients, premedicated with oral midazolam, was designed to determine if an intravenous thiopentone induction of anaesthesia prolongs postoperative recovery compared to an inhalation induction with halothane. One hundred children, one to ten years of age, undergoing ENT surgical procedures of 30-60 min duration received midazolam 0.5 mg.kg-1 with atropine 0.03 mg.kg-1 and were randomized to either halothane (Group 1, n = 50) or a thiopentone induction (Group 2, n = 50) technique, followed by a standardized anaesthetic-protocol. Time to extubation was significantly greater in the thiopentone group (8.8 +/- 4 min vs 7.1 +/- 3 min, P < 0.05). Patients receiving thiopentone were also more sedated than the halothane group on arrival in the PARR (3.9 +/- 1.5, 3.3 +/- 1.7, respectively P < 0.05), but the differences disappeared after 30 min. Children premedicated with oral midazolam who receive an intravenous thiopentone induction have a slightly prolonged emergence from anesthesia compared to children induced with halothane.     

Serotonin syndrome due to an overdose of moclobemide and clomipramine. A potentially life-threatening association

The speeds of onset of pancuronium, atracurium and vecuronium are increased by prior administration of magnesium sulphate. A prospective, randomized, double-blind, controlled, clinical study was performed to examine the effects of prior i.v. administration of magnesium sulphate 60 mg kg-1 on the neuromuscular blocking effects of rocuronium 0.6 mg kg-1 during isoflurane anaesthesia. Neuromuscular function was measured electromyographically (Relaxograph) in 30 patients who received either magnesium sulphate 60 mg kg-1 or normal saline, 1-min before rocuronium 0.6 mg kg-1. Mean onset times were similar in the two groups (magnesium sulphate 71 (SD 20) s; normal saline 75 (23) s), but times to initial, 10% and 25% recovery from neuromuscular block were significantly longer in the magnesium sulphate group (42.1 (16.3), 49.0 (12.4) and 56.5 (13.2) min, respectively) than in the saline group (25.1 (9.1), 33.0 (11.1) and 35.6 (13.2) min, respectively) (P < 0.05 in all three cases). Administration of magnesium sulphate was not associated with adverse haemodynamic effects. Prior administration of magnesium sulphate, under the study conditions described, prolonged rocuronium-induced neuromuscular block but did not increase speed of onset.     

Thiopental or etomidate for rapid sequence induction with rocuronium

We have assessed the effect of the choice of i.v. induction agent on intubation conditions, 60 s after administration of rocuronium 0.6 mg kg-1. We studied 60 adult patients, allocated randomly to one of two groups. Anaesthesia was induced with alfentanil 10 micrograms kg-1 followed by thiopental 5 mg kg-1 (AT-R group; n = 30) or etomidate 0.3 mg kg-1 (AE-R group; n = 30). Both groups received rocuronium 0.6 mg kg-1. Laryngoscopy was started 60 s later and intubation conditions were evaluated according to a standard score, which considered ease of laryngoscopy, condition of the vocal cords and reaction to intubation. In the AT-R group, overall intubation conditions were scored as excellent in 20 patients, good in nine and fair in the remaining patient. In the AE-R group, overall intubating conditions were excellent in 24 and good in six patients. The difference between the two groups was not significant. Of the three components of the intubation score assessed, response to intubation stimulus was significantly less pronounced in group AE-R compared with group AT-R (P < 0.05): group AE-R, no reaction in 24 patients, slight diaphragmatic movement in five and mild coughing in one patient; group AT-R, no reaction in 13, slight diaphragmatic movement in 14, mild coughing in two and severe coughing in one patient. We conclude that etomidate as part of an induction regimen containing alfentanil and rocuronium attenuated the reaction to intubation to a greater extent than thiopental.     

The haemodynamic effects of rocuronium and vecuronium are different under balanced anaesthesia

BACKGROUND: Rocuronium has been reported to have minimal haemodynamic effects. However, this conclusion has been drawn primarily from investigations conducted under narcotic-based anaesthesia. This study was designed to evaluate the cardiovascular effects of rocuronium under isoflurane/N2O/fentanyl anaesthesia and to compare rocuronium's haemodynamic effects to those of vecuronium and pancuronium. METHODS: Anaesthesia was induced with fentanyl 2 micrograms/kg, thiopentone 4 mg/kg, and suxamethonium 0.5 mg/kg in 75 ASA I or II patients. After tracheal intubation, anaesthesia was maintained with isoflurane 0.5% and N2O 50% in oxygen. Five min after intubation (baseline), patients randomly received either vecuronium 100 micrograms/kg, rocuronium 600 micrograms/kg, rocuronium 900 micrograms/kg, rocuronium 1200 micrograms/kg, or pancuronium 140 micrograms/kg. One min after administration of muscle relaxant, mean arterial pressure (MAP) and heart rate (HR) were recorded and were subsequently measured at 1-min intervals for the next 4 min. RESULTS: HR decreased significantly (P < 0.05) at all times compared to baseline in patients receiving vecuronium. HR significantly (P < 0.05) increased in those receiving rocuronium 1200 micrograms/kg or pancuronium. Patients who received vecuronium had a significant (P < 0.05) decrease in MAP at all times compared to baseline. Comparing results between groups, patients who received rocuronium or pancuronium had significantly (P < 0.05) higher MAP compared to those administered vecuronium. CONCLUSION: The haemodynamic effects of rocuronium and vecuronium are different under balanced anaesthesia. Rocuronium may attenuate the fall in MAP that often occurs under balanced anaesthesia without surgical stimulation.