Propofol 2 mg/kg is superior to propofol 1 mg/kg for tracheal intubation in children during sevoflurane induction.

BACKGROUND: Propofol has been used to facilitate tracheal intubation within a short time of sevoflurane induction without a muscle relaxant in children. We compared as the primary outcome the incidence of excellent intubating conditions after 8% sevoflurane and propofol 1 or 2 mg/kg. METHODS: One hundred and four patients (2-7 years) were randomly assigned to receive propofol 1 mg/kg in group SP1 (n=53) or propofol 2 mg/kg in group SP2 (n=51) after inhalation induction using sevoflurane 8% in oxygen. Forty-five seconds after propofol and controlled ventilation, intubating conditions were assessed using a four-point scoring system based on ease of laryngoscopy, vocal cords position, coughing, jaw relaxation and limb movement. Heart rate and systolic blood pressure were measured as baseline, after sevoflurane induction, propofol, intubation and at 2 and 5 min following intubation. RESULTS: Three patients in group SP1 were excluded from analysis. Time from sevoflurane induction to intubation (248.9±71.3 s in group SP1 vs. 230.9±61.3 s in group SP2) and endtidal sevoflurane before intubation (5.6±1.6% in group SP1 vs. 5.2±1.5% in group SP2) did not differ between the two groups. The incidence of excellent intubating conditions was significantly higher in group SP2 compared with group SP1 [47/51 (92%) vs. 28/50 (56%)]. The incidence of acceptable intubating conditions was significantly higher in group SP2 compared with group SP1 [48/51 (94%) vs. 35/50 (70%)]. No hemodynamic difference was noted at any time point between the two groups. CONCLUSION: Propofol 2 mg/kg during 8% sevoflurane induction resulted in a higher proportion of excellent intubating conditions compared with propofol 1 mg/kg.

Tracheal intubation following training with the GlideScope compared to direct laryngoscopy.

SUMMARY: Tracheal intubation using direct laryngoscopy has a high failure rate when performed by untrained medical personnel. This study compares tracheal intubation following direct laryngoscopy by inexperienced medical students when initially trained by using either the GlideScope, a video assisted laryngoscope, or a rigid (Macintosh) laryngoscope. Forty-two medical students with no previous experience in tracheal intubation were randomly divided into two equal groups to receive training with the GlideScope or with direct laryngoscopy. Subsequently, each medical student performed three consecutive intubations on patients with normal airways that were observed by a anaesthetist who was blinded to the training method. The rates of successful intubation were significantly higher in the Glidescope group after the first (48%), second (62%), and third (81%) intubations compared with the Macintosh group (14%, 14% and 33%; p = 0.043, 0.004 and 0.004, respectively). The mean (SD) times for the first, second, and third successful tracheal intubations were significantly shorter in the Glidescope group (59.3 (4.4) s, 56.6 (7.1) s and 50.1 (4.0) s) than the Macintosh group (70.7 (7.5) s, 73.7 (7.3) s and 67.6 (2.0) s; p = 0.006, 0.003 and 0.0001, respectively). Training with a video-assisted device such as the GlideScope improves the success rate and time for tracheal intubation in patients with normal airways when this is performed by inexperienced individuals following a short training programme.

Addition of ketamine to propofol for initiation of procedural anesthesia in children reduces propofol consumption and preserves hemodynamic stability.

BACKGROUND: There is no ideal anesthesia protocol to perform short invasive procedures in pediatric oncology. The combination of propofol and ketamine may offer advantages over propofol alone. METHODS: In a prospective, randomized, double-blind study, we analyzed 63 consecutive procedures performed in 47 oncology children. All patients received 1 mug/kg fentanyl, followed by propofol 1 mg/kg in group P (n=33) or propofol 0.5 mg/kg and ketamine 0.5 mg/kg in group PK (n=30) for the initiation of anesthesia. The need for supplementation with propofol and/or fentanyl to maintain an adequate level of anesthesia was recorded. The hemodynamic and respiratory profile, recovery time and the occurrence of side effects were compared. RESULTS: Significantly more children required propofol (100% vs. 83.3%) and fentanyl (75.5% vs. 43.3%) rescue doses, and developed hypotension (63.6% vs. 23.4%) and bradycardia (48.5 vs. 23.4%) in group P compared with group PK, with a comparable incidence of respiratory adverse events and recovery times. However, 40% of children in group PK were agitated following recovery compared with 6% in group P. CONCLUSIONS: The combination of propofol and ketamine for invasive procedures in pediatric oncology resulted in reduced propofol and fentanyl consumption and preserved hemodynamic stability, but more children in the combination group recovered with agitation.

Medico-legal aspects in anesthesia: how to lead a happy life.

This article discusses medico-legal aspects in anesthesia. It underlines the standards of care by which anesthesiologists should abide by, as well as define malpractice, its causes, and ways to avoid it. The role of the expert witness is explained and the ethical guidelines to follow are outlined.

Treatment of postherpetic neuralgia: an update.

Postherpetic neuralgia (PHN) is a chronic pain syndrome that is often refractory to treatment and can last for years, causing physical and social disability, psychological distress, and increased use of the healthcare system. In this paper we provide an update on recent developments in the treatment of PHN. We emphasise the results of recent studies that provide an evidence-based approach for treating PHN that was not available until very recently. In randomised, controlled clinical trials, the topical lidocaine patch, gabapentin, and controlled release oxycodone have been shown to provide superior pain relief in patients with PHN when compared with placebo. It has also recently been demonstrated that the tricyclic antidepressant nortriptyline provides equivalent analgesic benefit when compared with amitriptyline, but is better tolerated. Based on these results, nortriptyline can now be considered the preferred antidepressant for the treatment of PHN, although desipramine may be used if the patient experiences unacceptable sedation from nortriptyline. The topical lidocaine patch, gabapentin and controlled release oxycodone all appear to be as effective as tricyclic antidepressants in the treatment of patients with PHN, and the results of these recent studies suggest that each of these treatments should be considered early in the course of treatment. Additional controlled trials are needed to compare the efficacy and tolerability of these 4 treatments- tricyclic antidepressants, gabapentin, the topical lidocaine patch and controlled release opioid analgesics--used singly and in various combinations in the treatment of patients with PHN.

Effects of eicosapentaenoic and gamma-linolenic acids (dietary lipids) on pulmonary surfactant composition and function during porcine endotoxemia.

STUDY OBJECTIVES: To investigate whether a diet enriched with fish and borage oils, with their high polyunsaturated fatty acid (PUFA) content, alters surfactant composition and function during endotoxemia. DESIGN: Prospective, randomized, blinded, controlled animal study. SETTING: Research laboratory at a medical center. PARTICIPANTS: Thirty-six 15- to 25-kg, disease-free, castrated male pigs. DIETS AND MEASUREMENTS: Three groups of pigs (n = 12 per group) were fed for 8 days diets containing either omega-6 fatty acids (FAs) (corn oil; diet A), or omega-3 FAs (fish oil; diet B), or a combination of omega-6 and omega-3 FAs (borage and fish oils; diet C). Eight of 12 pigs in each group received a 0.1-mg/kg bolus of Escherichia coli endotoxin followed by a continuous infusion (0. 075 mg/kg/h). One lung was subsequently isolated ex vivo, and pressure-volume curves were measured. The contralateral lung was lavaged, and surfactant was analyzed for total and individual phospholipids and FA composition. Minimum and maximum surface tension was measured by bubble surfactometry. RESULTS: Pigs fed either diet B or C had increased oleic acid (C(18:1) omega-9), eicosapentaenoic acid (EPA; C(20:5) omega-3), docosahexaenoic acid (C(22:6) omega-3), and total omega-3 and monounsaturated FAs in their surfactant PUFA pools. The relative percentage of linoleic acid (C(18:2) omega-6) and total omega-6 FAs were significantly lower from pigs fed diets B and C compared with diet A. Palmitic acid (C(16:0)) concentrations, the primary FA in surfactant, had a tendency to be lower in pigs fed diets B and C. There were no demonstrable effects on surfactant function or pulmonary compliance. CONCLUSIONS: Diets containing EPA or EPA and gamma-linolenic acid altered the PUFA composition of pulmonary surfactant, but without demonstrable effects on surfactant function during porcine endotoxemia.

Effect of epidural analgesia on postoperative ileus after ileal pouch-anal anastomosis.

Epidural analgesia has been reported to enhance gastrointestinal motility and shorten postoperative ileus. Postoperative ileus can be influenced by many factors, including the operative procedure. Our aim was to evaluate the effect of supplemental epidural anesthesia and postoperative analgesia on ileus after ileal pouch-anal anastomosis (IPAA). This was a retrospective review of 50 consecutive nonrandomized patients undergoing IPAA over a 10 year period by a single surgeon. 27 patients received general anesthesia and parenteral analgesia. 23 patients received supplemental epidural anesthesia and analgesia. The two groups were comparable with respect to age, sex, diagnosis, and American Society of Anaesthesiology status. Operative time, blood loss, and transfusion requirements were also similar, but massive (>1,000 mL) blood loss was more frequent in the general group (37% vs 13%, P < .05). Twelve (44%) patients in the general group and seven (30%) in the epidural group had complications (NS). Mean duration of nasogastric suction, tube reinsertion, and interval to taking liquid and regular diets was similar in the two groups. Mean pain scores for the first 24 hours were significantly lower in the epidural group (1.9 +/- 1.0 vs 2.5 +/- 0.6, P < 0.05). Supplemental epidural anesthesia and analgesia does not shorten clinical postoperative ileus after a complex colorectal procedure (IPAA).

New technique for superior hypogastric plexus block.

BACKGROUND AND OBJECTIVES: : The classical technique for blocking the superior hypogastric plexus (SHP) described by Plancarte sometimes renders the desired needle placement difficult. This article describes an alternative approach for blocking the SHP. METHODS: Three patients with pelvic pain from endometriosis underwent an anterior approach to block the SHP with fluoroscopic guidance. The ages of the patients ranged from 21 to 34 years, pain duration ranged from 2 to 4 years, and pain score on a visual analog scale of 0-10 ranged from 7 to 8. RESULTS: All patients had significant pain relief immediately after the block. The pain scores postblock ranged from 0 to 4/10. The duration of pain relief varied from 1 to 14 days. The contrast material localized at the L5 vertebral body in the posteroanterior and lateral views. CONCLUSION: We present a new approach to block the SHP with fluoroscopic guidance in patients with chronic benign pelvic pain.

Immediate post-operative vocal changes in patients using laryngeal mask airway versus endotracheal tube.

OBJECTIVE AND HYPOTHESIS: (1) To examine the vocal symptoms and acoustic changes perceived in the short period immediately after laryngeal mask airway, and (2) to compare these findings in patients using laryngeal mask airway and endotracheal tube. MATERIALS AND METHODS: A total of 27 patients were enrolled. They were evaluated pre-operatively and then at 2 and 24 hours post-operatively. Patients were divided into two subgroups, laryngeal mask airway and endotracheal tube. Patients were asked about the presence or absence of the following: hoarseness, vocal fatigue, loss of voice, throat-clearing sensation, globus pharyngeus and throat pain. Patients then underwent acoustic analysis of their voice, measuring the average fundamental frequency, relative average perturbation, shimmer, noise to harmony ratio, voice turbulence index, habitual pitch and maximum phonation time. RESULTS: In the laryngeal mask airway group, there was an increase in the incidence of all vocal symptoms two hours post-operatively, except for globus pharyngeus. The increase was statistically significant for vocal fatigue, loss of voice and throat pain. All the symptoms had reverted back to a normal baseline level by 24 hours. There was a decrease in the maximum phonation time and habitual pitch, with an increase in all the perturbation parameters, two hours post-operatively. At 24 hours, an increase was still present for shimmer, noise to harmony ratio and voice turbulence index. The maximum phonation time and habitual pitch reverted back to normal values. In the endotracheal tube group, there was a significant increase two hours post-operatively in the incidence of hoarseness, loss of voice and throat pain. At 24 hours, all the symptoms reverted to baseline, except for vocal fatigue and throat pain. Two hours post-operatively, there was a significant decrease in maximum phonation time and an increase in all other parameters (however, the latter was significant only for relative average perturbation and noise to harmony ratio). At 24 hours, there was a significant increase in the maximum phonation time and a persistent (but statistically insignificant) increase in the average fundamental frequency, habitual pitch, noise to harmony ratio and voice turbulence index. At two hours, there was more loss of voice and vocal fatigue in the laryngeal mask airway group, compared with the endotracheal tube group. At 24 hours, these symptoms were comparable in both groups. Comparing changes in acoustic parameters to baseline values in both groups, there were no statistically significant changes. CONCLUSION: Shortly after reversal of anaesthesia, laryngeal symptoms following laryngeal mask airway are no less significant than those experienced following endotracheal tube anaesthesia. Both methods can be regarded as nontraumatic, in view of the lack of significant vocal symptoms and acoustic changes 24 hours after anaesthesia.

Supplementation of pre-oxygenation in morbidly obese patients using nasopharyngeal oxygen insufflation.

During apnoea following induction of anaesthesia, morbidly obese patients may suffer a rapid decrease in oxygen saturation. This study compares pre-oxygenation alone with pre-oxygenation followed by nasopharyngeal oxygen insufflation on the onset of desaturation occurring during the subsequent apnoea. A randomised controlled trial was performed in 34 morbidly obese patients undergoing gastric bypass or gastric band surgery. Seventeen patients received nasopharyngeal oxygen supplementation following pre-oxygenation (Study group, body mass index = 41.8 (6.9) kg.m(-2)), and the other 17 patients received pre-oxygenation alone (Control group, body mass index = 42.7 (5.4) kg.m(-2)). Time from the onset of apnoea until S(p)o(2) fell to 95% was compared between the two groups with a cut-off of 4 min. In the control group, the S(p)o(2) fell from 100% to 95% during the subsequent apnoea in 145 (27) s, with a significantly negative correlation (r(2) = 0.66, p < 0.05) between the time to desaturation to 95% and the body mass index. In the study group, the S(p)o(2) was maintained in 16 of 17 patients at 100% for 4 min when apnoea was terminated. In conclusion, nasopharyngeal oxygen insufflation following pre-oxygenation in morbidly obese patients delays the onset of oxyhaemoglobin desaturation during the subsequent apnoea.

Effect of low-dose dexmedetomidine or clonidine on the characteristics of bupivacaine spinal block.

BACKGROUND: The purpose of this study was to compare the onset and duration of sensory and motor block, as well as the hemodynamic changes and level of sedation, following intrathecal bupivacaine supplemented with either dexmedetomidine or clonidine. METHODS: In a prospective, double-blind study, 60 patients undergoing transurethral resection of prostate or bladder tumor under spinal anesthesia were randomly allocated to one of three groups. Group B received 12 mg of hyperbaric bupivacaine, group D received 12 mg of bupivacaine supplemented with 3 microg of dexmedetomidine and group C received 12 mg of bupivacaine supplemented with 30 microg of clonidine. The onset times to reach peak sensory and motor levels, and the sensory and motor regression times, were recorded. Hemodynamic changes and the level of sedation were also recorded. RESULTS: Patients in groups D and C had a significantly shorter onset time of motor block and significantly longer sensory and motor regression times than patients in group B. The mean time of sensory regression to the S1 segment was 303 +/- 75 min in group D, 272 +/- 38 min in group C and 190 +/- 48 min in group B (B vs. D and B vs. C, P < 0.001). The regression of motor block to Bromage 0 was 250 +/- 76 min in group D, 216 +/- 35 min in group C and 163 +/- 47 min in group B (B vs. D and B vs. C, P < 0.001). The onset and regression times were not significantly different between groups D and C. The mean arterial pressure, heart rate and level of sedation were similar in the three groups intra-operatively and post-operatively. CONCLUSIONS: Dexmedetomidine (3 microg) or clonidine (30 microg), when added to intrathecal bupivacaine, produces a similar prolongation in the duration of the motor and sensory block with preserved hemodynamic stability and lack of sedation.

Preoperative caudal block prevents emergence agitation in children following sevoflurane anesthesia.

BACKGROUND: The frequency of emergence agitation in children is increased following sevoflurane anesthesia. However, controversies still exist concerning the exact etiology of this postanesthetic problem. Although this phenomenon is present with adequate pain relief or even following pain-free procedures, pain is still regarded as a major contributing factor. METHODS: In a prospective, randomized, double-blind study, we enrolled 48 premedicated and calm 2-6-year-old children undergoing inguinal hernia repair. We assigned children to one of two groups: children assigned to the caudal group (n = 24) received a caudal block to supplement sevoflurane, while children assigned to the fentanyl group (n = 24) received a bolus injection of 1 microg kg(-1) intravenous fentanyl before skin incision to supplement sevoflurane. In the post anesthesia care unit, all children were received by their parent, and the incidence of emergence agitation and pain scores, as well as hemodynamic changes, were compared in both groups. RESULTS: Forty-four children completed the study. In the fentanyl group, 59% of the children were agitated following emergence from anesthesia as compared to 4.5% in the caudal group (P < 0.001). Also, pain scores, mean values of heart rate and blood pressure as well as morphine requirement were significantly higher in the post anesthesia care unit in the fentanyl group compared to the caudal group. CONCLUSION: Our results show that in children undergoing inguinal hernia repair, pain control with a preoperative caudal block as compared to intraoperative intravenous fentanyl significantly reduces the incidence of emergence agitation and pain scores following sevoflurane anesthesia.

An unusual case of hyperkalaemia-induced cardiac arrest in a paediatric patient during transfusion of a 'fresh' 6-day-old blood unit.

A well-recognized complication of the transfusion of red blood cells (RBCs) is hyperkalaemia. This occurs in paediatric or adult patients receiving massive transfusion and can lead to cardiac arrest. Hyperkalaemia may follow the transfusion of 'stored' RBCs and/or haemolysed units, and depends on the quantity and rate of transfusion. We report on an unusual case of hyperkalaemia-induced cardiac arrest during transfusion of a 'fresh' blood unit. A 62-day-old baby girl was scheduled for a construction of a Blalock-Taussig shunt, after the completion of anastomosis, and upon release of vascular control, there was bleeding at the anastomotic site that was controlled with a suture placement. To compensate for the blood loss, a stat order was given for a push of 120 mL of RBCs over 10 min through the inferior vena cava central line. The blood unit was 6 days old and had been gamma-irradiated 48 h earlier. Shortly after the transfusion, the patient's electrocardiogram showed changes typical of hyperkalaemia; she then went into cardiac asystole. The blood unit potassium concentration was 55.3 mmol L-1, which flushed the atrioventricular node during transfusion. This is the first report of a high potassium level found in a 'fresh', less than 7 days old, nonhaemolysed RBC blood unit. The high concentration of potassium in this unit seems to be due to accelerated alterations of the RBC sodium/potassium adenosine triphosphatase pump (Na+/K+ pump), resulting in the release of intracellular potassium. This early and severe alteration of the pump and the unusually high potassium level may be due to as yet unexplained causes, warranting awareness, future investigation and routine saline washing of 'fresh' RBCs for paediatric patients who are candidates for central line transfusion.