Comparison of ProSeal LMA with Supreme LMA in paediatric patients.

BACKGROUND AND OBJECTIVE: Supreme laryngeal mask airway (S-LMA) has been improved in recent years, but comparative studies with a sizeable number of paediatric patients are limited in number. In this study, oropharyngeal leak pressures (OLPs) were compared between S-LMA and ProSeal laryngeal mask airway (P-LMA) in paediatric patients. METHODS: After obtaining approval from the ethics committee and written informed consent from the relatives of the patients, 60 patients, from 9 months to 5 years of age and 10-20 kg in weight, who were recommended for elective surgery were included in this prospective and randomised study. The patients were assigned to the S-LMA and P-LMA groups. OLP, insertion times, success rates, ease of airway device placement, fibre optical assessment, success rates and insertion times of an orogastric tube (OGT) were compared. RESULTS: P-LMA was placed successfully in all the patients. One patient was intubated in the S-LMA group. The outcomes of a total of 59 patients were analysed. The insertion times of the airway devices were shorter in the S-LMA group than in the P-LMA group (S-LMA; 12.2 ± 2.9, P-LMA; 15.4 ± 3.7 s) (P = 0.001). The first insertion attempts of airway device placement were similar. The OLPs were similar (P-LMA; 17.2 ± 2.3, S-LMA; 16.4 ± 1.7 cm H2 O). The fibre-optically determined anatomic position was better in the P-LMA group (P = 0.02). The insertion time of the OGT was shorter with S-LMA than with P-LMA (P = 0.01). CONCLUSION: Our findings suggest that S-LMA has OLPs similar to those of P-LMA in paediatric patients and that S-LMA provides successful positive pressure ventilation.

Tracheal intubation in morbidly obese patients: a comparison of the Intubating Laryngeal Mask Airway™ and Laryngeal Mask Airway CTrach™.

The aim of this study was to evaluate the efficacy of the Intubating Laryngeal Mask Airway™ (ILMA) and Laryngeal Mask Airway CTrach™ (LMA CTrach) in facilitating tracheal intubation in morbidly obese patients. Eighty patients (body mass index >40 kg x m(-2)) were randomly allocated to the ILMA or the LMA CTrach. The median (IQR [range]) total time taken for tracheal intubation was shorter with the ILMA than with the LMA CTrach (78 (63-105 [40-265]) s vs 128 (98-221 [60-423]) s, respectively; p<0.001). Significantly more manoeuvres were applied for the satisfactory ventilation and viewing of the glottis with the LMA CTrach (25% vs 55% with the ILMA; p=0.006). During the postoperative period, there was more sore throat with the LMA CTrach (p<0.02). We conclude that the ILMA results in shorter intubation times with fewer manoeuvres and sore throat compared with the LMA CTrach in the morbidly obese.

Ondansetron does not modify emergence agitation in children.

In this prospective, placebo-controlled study, we evaluated the effect of prophylactic ondansetron therapy on emergence agitation of children who underwent minor surgery below the umbilicus. Seventy children aged one to six years and American Society of Anesthesiologists physical status I were studied. Children were premedicated with midazolam rectally and were randomly assigned to receive either ondansetron (Group O) or placebo (Group P) in combination with caudal anaesthesia. Children in Group O received intravenous ondansetron (0.1 mg/kg for children weighing < 40 kg, 4 mg for children weighing > 40 kg) and Group P (n = 35) received normal saline 2 ml following anaesthesia induction with sevoflurane. Airway management was provided with LMA-Proseal without muscle relaxation and anaesthesia maintenance was provided with a 60:40 N2O:O2 mixture and sevoflurane. Emergence agitation was evaluated with a ten point scale and pain level was assessed every 10 minutes for the first 30 minutes after admission to the recovery room. There were no significant differences between the placebo and ondansetron groups with respect to demographic, anaesthetic and surgical details. Incidences of emergence agitation in ondansetron and placebo groups were similar (32.4% and 30.3% at 10 minutes respectively). Mean modified Children's Hospital of Eastern Ontario pain scale scores and mean ten-point scale scores and emergence agitation incidences decreased similarly after 10 minutes in both groups. Ready time for discharge was similar between the groups. Agitated patients had significantly increased ready time for discharge compared to non-agitated patients (P = 0.001). Prophylactic intravenous ondansetron administration does not reduce emergence agitation comparing to placebo after sevoflurane anaesthesia.

Comparison of the effect of LMA and ETT on ventilation and intragastric pressure in pediatric laparoscopic procedures.

BACKGROUND: The aim of our study was to compare classic laryngeal mask airway (LMA-C) with the endotracheal tube (ETT) in pediatric laparoscopic surgery to evaluate the intragastric pressures (IGP) using intragastric pressure monitoring. We also sought to investigate the related influence on respiratory parameters. METHODS: The Ethics Committee of the Health Institution approved the study protocol. A total of 40 patients, ASA I-II, three and a half months to 12 years old were included in this randomized study. Two study groups were formed: the ETT group and the LMA-C group. A nasogastric tube was inserted following induction to evacuate any intragastric gas and fluid before application of either LMA-C or ETT. The change in IGP was measured with a transducer, which was attached to the nasogastric tube. IGP, peak airway pressures (PAP), SPO2 and ETCO2 were recorded. Repeated ANOVA measures were used to evaluate the change in IGP, PAP, SPO2 and ETCO2 times in both groups. RESULTS: The change in IGP was not significant among the groups except at 15 and 30 minutes (P<0.05). The changes in PAP, SPO2, and ETCO2 levels were not significant. CONCLUSION: The perioperative intragastric pressure evaluation failed to show any significant change in intragastric pressures and ventilation parameters due to the application of LMA-C in this study. We advocate LMA-C application as a feasible anesthetic device in pediatric laparoscopic surgery.

Is nerve stimulation needed during an ultrasound-guided lateral sagittal infraclavicular block?

BACKGROUND: The objective of the study was to evaluate the influence of ultrasound (US) guidance alone vs. neurostimulation (NS) and US (NSUS) guidance techniques on block performance time and block success rate for the lateral sagittal infraclavicular block (LSIB). METHODS: In a randomized and prospective manner, 110 adult patients scheduled for distal upper limb surgery were allocated to the US or the NSUS groups. In the US group, a local anesthetic (LA) was administered only with US guidance to produce a 'U'-shaped distribution around the axillary artery. In the NSUS group, LA was administered under US guidance only after electrolocation of one of the median, ulnar or radial nerve-type responses. A total of 30 ml of LA (10 ml of levobupivacaine 5 mg/ml and 20 ml of lidocaine 20 mg/ml) was administered in both groups. Sensory block was tested at 10 min intervals for 30 min. Successful block was defined as analgesia or anesthesia of all five nerves distal to the elbow. RESULTS: Block success rate was 94.5% in both groups. Block performance time was significantly shorter in the US than the NSUS group (157 +/- 50 vs. 230 +/- 104 s) (P=0.000). Block onset time was similar in both groups (12.5 +/- 4.8 in the US vs. 12.8 +/- 5.4 min in the NSUS groups). There were two arterial punctures in the NSUS group. CONCLUSIONS: During LSIB performance US guidance alone produces block success rate identical to both US and NS guidance yet with a shorter block performance time.

Tracheal intubation in patients with rigid collar immobilisation of the cervical spine: a comparison of Airtraq and LMA CTrach devices.

The aim of this study was to evaluate the effectiveness of the Airtraq and CTrach in lean patients with simulated cervical spine injury after application of a rigid cervical collar. Eighty-six consenting adult patients of ASA physical status 1 or 2, who required elective tracheal intubation were included in this study in a randomised manner. Anaesthesia was induced using 1 microg kg(-1) fentanyl, 3 mg kg(-1) propofol and 0.6 mg kg(-1) rocuronium, following which a rigid cervical collar was applied. Comparison was then made between tracheal intubation techniques using either the AirTraq or CTrach device. The mean (SD) time to see the glottis was shorter with the Airtraq than the CTrach (11.9 (6.8) vs 37.6 (16.7)s, respectively; p < 0.001). The mean (SD) time taken for tracheal intubation was also shorter with the Airtraq than the CTrach (25.6 (13.5) and 66.3 (29.3)s, respectively; p < 0.001). There was less mucosal damage in the Airtraq group (p = 0.008). Our findings demonstrate that use of the Airtraq device shortened the tracheal intubation time and reduced the mucosal damage when compared with the CTrach in patients who require cervical spine immobilisation.

Single vs. double stimulation during a lateral sagittal infraclavicular block.

BACKGROUND: The objective of this study was to evaluate the influence of single vs. dual control during an ultrasound-guided lateral sagittal infraclavicular block on the efficacy of sensory block and the time of block onset. METHODS: In a prospective manner, 60 adult patients scheduled for distal upper limb surgery were randomly allocated to single (Group S) or double stimulation (Group D) groups. A local anesthetic (LA) mixture of 20 ml of levobupivacaine 5 mg/ml and 20 ml of lidocaine 20 mg/ml with 5 microg/ml epinephrine (total 40 ml) was administered in both groups. In the Group S following a median, an ulnar or a radial nerve response, the entire LA was administered at a single site. In Group D 10 ml of LA was administered following the electrolocation of the musculocutaneous nerve and 30 ml LA was injected following median, ulnar or radial nerves. A successful block was defined as analgesia or anesthesia of all five nerves distal to the elbow. Sensory and motor blocks were tested at 5-min intervals for 30 min. RESULTS: The block was successful in 27 patients in Group S and 28 patients in Group D. The time from starting the block until satisfactory anesthesia was significantly shorter in Group D than in Group S (19.3 vs. 23.2 min) (P<0.05). Total sensory scores were significantly higher in the double stimulation group at 20 and 30 min after the block performance (P<0.05). CONCLUSIONS: Although the block performance time was longer in the double stimulation group, block onset time and extent of anesthesia were more favorable in the double stimulation group.

A new supraglottic airway device: LMA-supreme, comparison with LMA-Proseal.

BACKGROUND AND OBJECTIVE: The LMA-Supreme() (S-LMA()) is a new supraglottic airway device that presents combined features of flexibility, curved structure and single use and a different cuff structure. The purpose of this study was to compare the oropharyngeal leak pressures (OLP) of LMA-Proseal() (P-LMA()) and S-LMA(). METHODS: Sixty adult patients were prospectively and randomly allocated to undergo insertion of P-LMA() (n=30) or S-LMA() (n=30). The cuffs were inflated until the intracuff pressure (ICP) reached 60 cm H(2)O. Orogastric leak pressures, insertion times, first attempt success rates, fiberoptical assessment of position, cuff pressures, orogastric tube (OGT) placement and OGT insertion times were compared. Unblinded observers collected intraoperative data and blinded observers collected post-operative data. RESULTS: The first insertion attempts and time taken to provide an effective airway were similar between the groups. Two patients (P-LMA(), n=1; S-LMA(), n=1) were intubated due to excessive oropharyngeal leak and in one patient (P-LMA(), n=1) due to failed OGT placement. OLPs were similar (P-LMA(); 26.9+/-6.6 S-LMA(); 26.1+/-5.2). ICP increased significantly in the P-LMA() at the 30 and 60 min during anesthesia (P-LMA(); 80.1+/-12.8, 92.9+/-14.4, S-LMA(); 68.3+/-10.9, 73.7+/-15.6). OGT placement was successful in all patients in the S-LMA(), but failed in five patients in the P-LMA() (P=0.02). Fiberoptically determined anatomic position was better with the P-LMA() (P=0.03). CONCLUSION: Our findings suggest that S-LMA() had leak pressures similar to the P-LMA(), and this new airway device proved to be successful during both spontaneous and positive pressure ventilation.

Comparison of nerve stimulation vs. ultrasound-guided lateral sagittal infraclavicular block.

BACKGROUND: A nerve stimulation-guided lateral sagittal infraclavicular block (LSIB) has been proven to be an effective block. The purpose of this study was to evaluate whether the use of ultrasound (US) guidance would further improve the block quality of LSIB. METHODS: In a prospective manner, 80 adult patients scheduled for hand, wrist and forearm surgery were randomly allocated to US or nerve stimulation (NS) groups. A needle was inserted into a sagittal plane, 20 degrees dorsally, until muscle twitches were observed in synchrony with the stimulation. In the US group, the block was performed using the same puncture site but under ultrasonic guidance. The final position of the needle was verified with the use of a nerve stimulator. A local anesthetic mixture of 20 ml of levobupivacaine, 5 mg/ml and 20 ml of lidocaine and 20 mg/ml with 5 microg/ml epinephrine (total 40 ml) was administered in both groups. RESULTS: The block was successful in 37 patients in the NS group and 38 patients in the US group. Block efficacy was better in the US group than the group NS in radial nerve distribution at 20 min (P<0.05). In the US group, there was a slight tendency toward better block density in other nerve areas also but these differences were not significant. Vascular puncture was noted in three patients in the NS group and none in the US group. CONCLUSIONS: The block success rate was high and comparable in both groups. There was a trend toward improved block quality in the US group, although not significant.

Lateral sagittal infraclavicular block: clinical experience in 380 patients.

BACKGROUND: The purpose of this study was to evaluate the clinical utility and block success rate of 'lateral sagittal infraclavicular block (LSIB)' in a large-scale clinical study. METHODS: Adult patients scheduled for hand, wrist and forearm surgery between March 2005 and June 2007 were prospectively included into the study. Using a nerve stimulator LSIB was performed. In the LSIB technique the puncture site is immediately adjacent to the most medial point of the coracoid process and the anterior surface of the clavicula. The needle is inserted caudally in a sagittal plane, 20 degrees dorsally (downwards), until muscle twitches are observed in synchrony with the stimulation. A Local anesthetic mixture of either 20 ml bupivacaine 5 mg/ml or 20 ml of levobupivacaine 5 mg/ml and 20 ml of lidocaine 20 mg/ml with 5 microg/ml epinephrine (total volume 40 ml) was administered following electrolocation of the median, radial or ulnar nerve. RESULTS: Three-hundred and eighty patients were included into the study. Block was successful in 341 (89.7%) patients without any need for local anesthetic supplementation. We had complete failure in 17 (4.5%) patients and these patients received general anesthesia. Twenty-two (5.8%) patients needed either infiltration of local anesthetic at the site of skin incision or supplementation of the block at the axilla. No other complications other than vascular punctures - 25 patients (6.6%) - were observed. CONCLUSIONS: LSIB provided a clinically acceptable success rate and our results are in agreement with other studies assessing this approach.

Prediction of difficult tracheal intubation in Turkish patients: a multi-center methodological study.

BACKGROUND AND OBJECTIVE: Preoperative evaluation is important in the detection of patients at risk for difficult airway management. It is still unclear whether true prediction is possible and which variables should be chosen for evaluation. The aim of this prospective, multi-centre study was to investigate the incidence of difficult intubation, the sensitivity and positive predictive values of clinical screening tests and whether combining two or more of these tests will improve the prediction of difficult intubation in Turkish patients. METHODS: Seven study sites from six regions in Turkey participated in this study. One thousand six hundred and seventy-four ASA physical status I-III patients, scheduled to undergo elective surgery under general anaesthesia, were included. RESULTS: The incidence of difficult intubation was 4.8% and increased with age (P < 0.05). The incidence of difficult intubation was significantly higher in patients who had a Mallampati III or IV score, a decreased average thyromental and sternomental distance, decreased mouth opening, or decreased protrusion of the mandible (P < 0.05). Mouth opening and Mallampati III-IV were found to be the most sensitive criteria when used alone (43% and 35%, respectively). Combination of tests did not improve these results. CONCLUSIONS: There is still no individual test or a combination of tests that predict difficult intubations accurately. Tests with higher specificity despite low positive predictive value are needed.

Comparison of laryngeal tube with laryngeal mask airway in anaesthetized and paralysed patients.

BACKGROUND AND OBJECTIVE: The laryngeal mask has become a widely accepted alternative to endotracheal intubation and mask ventilation. The laryngeal tube is a relatively new supraglottic airway device for airway management. We compared the new version of the laryngeal tube with the laryngeal mask. METHODS: In a randomized design, either a laryngeal tube (n = 66) or a laryngeal mask (n = 66) were inserted. Ease of insertion, oxygenation and ventilation, spirometry data and postoperative airway morbidity were determined. RESULTS: After successful insertion, it was possible to maintain oxygenation and ventilation in all the patients. Insertion success rates after the first, second and third attempts were 84.8% (n = 56), 12.1% (n = 8) and 3% (n = 2) for the laryngeal tube compared with 56.1% (n = 37), 25.8% (n = 17) and 18.2% (n = 12) for the laryngeal mask (P = 0.001). There was no significant difference in peak airway pressure, and dynamic compliance between the groups (P > 0.05). Blood on the cuff after removal of the device was noted in one patient with the laryngeal tube and in 10 patients with the laryngeal mask. Six patients in the laryngeal mask group complained of hoarseness (P = 0.012). CONCLUSION: With respect to clinical function, the new version of the laryngeal tube and the laryngeal mask are similar and either device can be used to establish a safe and effective airway in paralysed patients.

Clonidine addition prolongs the duration of caudal analgesia.

BACKGROUND: In this study, using a dose-ranging design, we examined the effects of clonidine with 0.125% bupivacaine on the duration of post-operative analgesia in caudal anaesthesia in children. METHODS: We conducted a controlled, prospective study of clonidine in caudal anaesthesia in 60 children, aged 1-10 years, undergoing elective inguinal hernia repair. Induction and maintenance of anaesthesia were performed by inhalation of sevoflurane and nitrous oxide. The children were randomized in a double-blind fashion to four groups, and were given a caudal anaesthetic with either 0.125% plain isobaric bupivacaine (1 ml/kg) or bupivacaine plus 1, 1.5 or 2 microg/kg of clonidine. The blood pressure and heart rate were recorded peri-operatively. Analgesia was evaluated by the modified Children's Hospital of Eastern Ontario Pain Scale (mCHEOPS) or a visual analogue scale (VAS). Paracetamol was given when the mCHEOPS score was greater than five or when the VAS score was greater than 30 mm. The monitoring of scores for pain, haemodynamic changes and post-operative nausea and vomiting was performed by nurses blind to the study allocation. RESULTS: The duration of analgesia was found to be significantly longer in the group given bupivacaine plus 2 microg/kg of clonidine (median, 650 min; range, 300-900 min). Peri-operative hypotension and bradycardia, post-operative respiratory depression and motor block were not recorded in any patient. CONCLUSIONS: The addition of clonidine to 0.125% bupivacaine prolongs the duration of post-operative analgesia without any respiratory or haemodynamic side-effects.

Spinal anesthesia for arthroscopic knee surgery.

BACKGROUND AND OBJECTIVE: The purpose of the study was to compare the effects of adding 50 microg of morphine, 25 microg of fentanyl or saline to 6 mg of hyperbaric bupivacaine on postoperative analgesia and time to urination in patients undergoing arthroscopic knee surgery under spinal anesthesia. METHODS: The study was designed in a prospective, randomized, double-blinded and placebo-controlled manner. Sixty ASA I-II patients were randomized into the following three groups: Group BM: 6 mg of bupivacaine and 50 microg of morphine, Group BF: 6 mg of bupivacaine and 25 microg of fentanyl, and Group BS: 6 mg of bupivacaine and saline. Selective spinal anesthesia was performed in a lateral decubitus position, with the operative knee dependent for 10 min. RESULTS: In all groups satisfactory anesthesia was provided during the operation. There was a statistically significant difference between all the groups in times to voiding [Group BM 422 +/- 161 min; Group BF 244 +/- 163 min; Group BS 183 +/- 54 min (mean +/- SD)]. The incidence of pruritus was significantly greater in Group BM (80%) and BF (65%) in comparison with Group BS (no pruritus) (P < 0.05). The incidence of nausea was significantly increased in Group BM (35%) in comparison with Group BF (10%) and Group BS (P < 0.05). Analgesic consumption was significantly greater in Group BS in comparison with Groups BM and BF (P < 0.01). CONCLUSIONS: We conclude that during spinal anesthesia even mini-dose intrathecal morphine is not acceptable for outpatient surgery due to side-effects, especially severely prolonged time to urination.

Carbon monoxide poisoning - a cause of increased QT dispersion.

BACKGROUND: Carbon monoxide (CO) poisoning is associated with direct cardiovascular toxicity. QT dispersion (QTd) of the ECG is an indirect measure of heterogeneity of ventricular repolarization, which may contribute to ventricular arrhythmias. Our aim was to study QTd in patients with acute CO poisoning. METHODS: CO intoxication was confirmed by arterial blood gas analysis. A control group consisted of age- and sex-matched individuals admitted to the hospital for unrelated clinical conditions. 12-lead ECG's were recorded on admission and repeated 1 week after discharge from the hospital. QT dispersion was defined as the difference between the greatest and the least QT intervals in any of the 12 leads. RESULTS: Seventeen intoxicated patients, aged 5-46 years, had mean carboxyhemoglobin levels of 22.5 +/- 11.1%. On admission, corrected QT intervals of the intoxicated patients were significantly increased compared to the control group (431 +/- 18 ms vs. 404 +/- 28 ms, P = 0.008), but not the QT interval (358 +/- 25 ms vs. 345 +/- 20 ms, P = 0.17). Mean QTd and cQTd values (46 +/- 15 ms and 62 +/- 13 ms) of the intoxicated patients were significantly increased compared to the control group (17 +/- 4 ms and 33 +/- 15 ms, P < 0.0001 for both). Both QTd and cQTd decreased significantly after discharge from the hospital (P = 0.0001). CONCLUSION: Although QT dispersion increased in patients with CO poisoning, none of ECG's showed ventricular arrhythmia. Increased QTd in the absence of QT interval prolongation may have a lowered arrhythmogenic potential of CO poisoning.

The effect of preemptive intravenous morphine on postoperative analgesia and surgical stress response.

BACKGROUND: Although initial studies of preemptive analgesia showed that preoperative blockade with local anaesthetics or preoperative administration of systemic opioids was more effective in reducing postoperative pain than control conditions involving no treatment, the result of subsequent investigations comparing the effects of preoperative treatment with the same treatment initiated after surgery have produced inconsistent RESULTS. The reasons for the lack of consistency are not clear. Studies about the relationship of preemptive analgesia and both analgesic consumption and surgical stress response are limited. The purpose of this study was to evaluate the effect of preemptive intravenous morphine on both postoperative analgesic consumption and surgical stress response. METHODS: Sixty patients, ASA I or II, aged 20-60, undergoing total abdominal hysterectomy plus bilateral salpingo-oopherectomy and double-blinded were randomly assigned to three groups of 20 patients. Group I (n=20) received 0.15 mg/kg of morphine following induction and placebo saline during peritoneal closure. Group II (n=20) received placebo saline following induction and 0.15 mg/kg of morphine during peritoneal closure. Group III (n=20) received placebo saline both during induction and peritoneal closure. Blood cortisol, glucose levels and leukocyte count were measured in the pre and postoperative period. RESULTS: Postoperative total morphine consumption was significantly lower in group I compared with group III (p<0.001). In all groups, plasma cortisol levels increased significantly within 4 hours of surgery as compared to pre-op values (p<0.001). Plasma glucose also increased to a significantly higher level in all groups in the postoperative 30 min and 8 hours than in the pre-op values (p<0.001). Postoperative leukocytosis was observed in all groups and the leukocyte count was significantly greater during postoperative 24 h than pre-op values (p<0.001). CONCLUSIONS: Preemptive morphine 0.15 mg/kg intravenous has decreased total morphine consumption but has failed to suppress the surgical stress response.

The effect of midazolam-thiopental coinduction on recovery in minor surgery.

PURPOSE: The effects of midazolam-thiopental coinduction on recovery were investigated and compared with thiopental induction. METHODS: Fifty patients, ASA 1 or 2, undergoing minor orthopedic surgery, were randomly divided into coinduction and thiopental groups. During preoxygenation, the patients received midazolam 0.1 mg.kg(-1) (coinduction group) or saline (thiopental group) 1 min before induction of anesthesia with thiopental. Isoflurane and nitrous oxide were used to maintain anesthesia. Isoflurane concentration was adjusted to keep blood pressure within +/-20% of the preoperative value. The time to awaken (open eyes, give name and birth-date) and the time to discharge readiness were recorded. Psychomotor tests, including simple light reaction time (SLRT), sedation analogue scale (SAS), and digit span test, were performed pre- and postoperatively. RESULTS: The induction dose of thiopental was significantly lower in the coinduction group. End-tidal isoflurane concentration during surgery was also lower in the coinduction group. There were no significant differences in awakening times and discharge readiness between the two groups. Although SAS values were lower in the coinduction group than in the thiopental group 8 and 24 h after anesthesia, other test results were similar in both groups. The frequency of nausea and vomiting in the recovery period was lower in the coinduction group. CONCLUSION: We conclude that midazolam-thiopental coinduction is a suitable technique when used in conjunction with isoflurane in day-case surgery.