[Comparison of different tests to determine difficult intubation in pediatric patients]. / Comparação de diferentes testes para determinar intubação difícil em pacientes pediátricos.

BACKGROUND: The difficulties with airway management is the main reason for pediatric anesthesia-related morbidity and mortality. OBJECTIVE: To assess the value of modified Mallampati test, Upper-Lip-Bite test, thyromental distance and the ratio of height to thyromental distance to predict difficult intubation in pediatric patients. DESIGN: Prospective analysis. MEASUREMENTS AND RESULTS: Data were collected from 5 to 11 years old 250 pediatric patients requiring tracheal intubation. The Cormack and Lehane classification was used to evaluate difficult laryngoscopy. Sensitivity, specificity, positive predictive value and AUC values for each test were measured. RESULTS: The sensitivity and specificity of modified Mallampati test were 76.92% and 95.54%, while those for ULBT were 69.23% and 97.32%. The optimal cutoff point for the ratio of height to thyromental distance and thyromental distance for predicting difficult laryngoscopy was 23.5 (sensitivity, 57.69%; specificity, 86.61%) and 5.5cm (sensitivity, 61.54%; specificity, 99.11%). The modified Mallampati was the most sensitive of the tests. The ratio of height to thyromental distance was the least sensitive test. CONCLUSION: These results suggested that the modified Mallampati and Upper-Lip-Bite tests may be useful in pediatric patients for predicting difficult intubation.

Lateral Trendelenburg with the injected side down after the block improves the efficacy of the axillary approach to brachial plexus block.

PURPOSE: We hypothesized that, after axillary block, positioning the patient in a lateral position with the injected side down and simultaneously in a 20° Trendelenburg position will increase the success rate and quality of the block. METHODS: Fifty patients with chronic renal failure (ASA 2-3) scheduled for arteriovenous fistula surgery were included in this study. In all patients, 30-40 ml of 0.25 % levobupivacaine were injected into the axillary sheath. The block was performed as three injections (multiple injection technique) with the arm in 90° abduction and 90° flexion in the supine position. Patients were randomly allocated to two groups. Group I (n = 25) patients were kept in the supine position after the block. Group II (n = 25) patients were positioned laterally after the block with the injected arm down and in a 20° Trendelenburg position. Sensory and motor block were evaluated at 2, 4, 6, 8, 10, 15, 20, and 25 min after the administration of the block. Thus, the patients in group II were evaluated in a lateral position during the first 30 min. Throughout the surgery and the recovery period, sensory and motor block were evaluated at 30-min intervals. RESULTS: There were no significant intergroup differences in the effects on radial, ulnar, median, and musculoskeletal nerve blockade. Thirty minutes after the injection, the patients in group II had higher levels of sensory axillary nerve blockade. Subscapular and thoracodorsal nerve motor block were not detected in group I, while 84 % of the patients in group II experienced blockade of both of these nerves (p < 0.01). CONCLUSION: We conclude that, for patients undergoing an axillary block, positioning the patient laterally with the injected side down and in a 20° Trendelenburg position increases the success rate and quality of the block.

Using temporomandibular joint mobility to predict difficult tracheal intubation.

The aim of this prospective study was to determine the reliability of temporomandibular joint (TMJ) mobility measurements for predicting difficult intubation. To evaluate the accuracy in predicting difficult intubation by TMJ mobility measurement, 762 patients requiring general anesthesia with tracheal intubation for elective surgery were enrolled in this prospective, observational, single-blind study. Maximum mouth opening, right-left jaw excursion, and degrees of protraction were determined with a digital inclinometer. Incisor gap was measured using a vernier caliper during full mouth opening. After induction of anesthesia using a standard protocol, the patient's grade of laryngeal view by Cormack-Lehane classification was documented by an anesthesiologist. We found that the degrees of protraction and incisor gap in the easy intubation group were significantly higher than those in the difficult intubation group. The incisor gap was found to be more sensitive (88.37%) and more specific (95.71%) than protraction degrees (58.14% and 59.76%, respectively). The results revealed that measurements of the incisor gap and degrees of protraction may be useful routine screening tests for preoperative prediction of difficult intubation.

Effects of bupivacaine versus levobupivacaine on pulmonary function in patients with chronic obstructive pulmonary disease undergoing urologic surgery: a randomized, double-blind, controlled trial.

BACKGROUND: There are limited data to determine the impact of subarachnoid blockade with local anesthetics on perioperative pulmonary function. The effects of local anesthetics used in spinal anesthesia are very important in terms of respiratory function in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVE: The aim of this study was to evaluate the effects of bupivacaine versus levobupivacaine on pulmonary function in patients with COPD undergoing urologic surgery. METHODS: Patients were randomized into 2 groups: group B (n = 25) received 3 mL of hyperbaric 0.5% bupivacaine; group L (n = 25) received 3 mL of isobaric 0.5% levobupivacaine. Both agents were administered intrathecally. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow rate (PEFR), vital capacity (VC), and FEV1/FVC ratio were measured using spirometry 10 and 30 minutes after spinal anesthesia and 30 minutes after completion of the operation. An arterial blood gas test was performed before and after spinal anesthesia. RESULTS: Fifty male patients aged 40 to 80 years completed the study. There were no differences in the results of preoperative and postoperative FVC, FEV1, PEFR, VC, FEV1/FVC ratio, and arterial blood gas between the bupivacaine (n = 25) and levobupivacaine (n = 25) groups. However, patients who took bupivacaine showed a significant decrease in intraoperative PEFR at 30 minutes compared with baseline, a result not seen in patients who took levobupivacaine (P = 0.036 and P = 0.282, respectively). CONCLUSIONS: In 50 patients with moderate COPD undergoing urologic surgery, hyperbaric bupivacaine caused a decrease in intraoperative PEFR compared with baseline because of higher level block; however, the effects of hyperbaric bupivacaine and isobaric levobupivacaine on pulmonary function in these patients showed equally effective potencies for spinal anesthesia.

Effect of magnesium sulfate infusion on sevoflurane consumption, hemodynamics, and perioperative opioid consumption in lumbar disc surgery.

BACKGROUND: Magnesium sulphate administration was initially reported to reduce postoperative analgesic requirements. Subsequent reports, though, were inconsistent. Specifically, we tested the hypotheses that intraoperative magnesium sulfate administration reduces postoperative requirement for opioids, secondary outcomes were intraoperative muscle relaxant, sevoflurane consumptions and postoperative pain. METHODS: Fifty American society of anesthesiology status (ASA) I-II patients who gave a written informed consent were scheduled for elective lumbar disc surgery. The Institutional Review Board approved the study. Patients were randomly assigned to the placebo group (n = 25) or magnesium group (n = 25). Patients assigned to the magnesium group were given an initial infusion of 30 mg/kg (over 10 minutes) starting immediately after anesthesia and completed before intubation. The infusion was then continued at 10 mg/kg/hr throughout surgery. General anesthesia was induced with propofol, 2.5 mg/kg, and maintained with sevoflurane 2 percent in a 50 percent O2/50 percent N2O mixture. The sevoflurane concentration was adjusted to keep bispectral index (BIS) values between 45 and 60. Both groups were given atracurium, 0.6 mg/kg, and a remifentanil infusion at an initial dose of 0.1 mg/kg/h. The remifentanil infusion was adjusted to maintain heart rate and mean arterial pressure (MAP) within 20 percent of baseline values. Atracurium administration was repeated when the train of four (TOF) ratio exceeded 0.30. Intubation conditions were scored. At the end of surgery, the authors assessed recovery using early recovery criteria and Aldrete recovery scores. Postoperative analgesia was maintained with morphine via patient-controlled analgesia. RESULTS: Heart rate, MAP and pulse oximetry (SPO2) values were similar in the groups at all times. Intubating conditions were similar except that the increase in MAP was greater in the placebo group. Neither BIS values nor sevoflurane consumption differed between the groups; however, significantly less atracurium [95% CI = 4.1 (2.8, 5.5)] and remifentanil [95% CI = 0.14 (0.07, 0.20)] was used in the magnesium group. Side effects, Aldrete scores, and early recovery parameters were all similar in the groups. In the first 24 hours, visual analogue scale (VAS) values for pain were greater in the placebo than in the magnesium group. The magnesium group consumed significantly less morphine [95% CI = 11 (6, 16)]. CONCLUSION: Intraoperative magnesium administration significantly reduced muscle relaxant and opioid requirements; more importantly, it also reduced postoperative pain and opioid use.

A comparison of oral midazolam, oral tramadol, and intranasal sufentanil premedication in pediatric patients.

BACKGROUND: This study was designed to evaluate the efficacy and safety of oral midazolam, tramadol drops, and intranasal sufentanil for premedication of pediatric patients. METHODS: Sixty children, three to 10 years of age, who were designated as American Society of Anesthesiologists physical status 1 and who were undergoing adenotonsillectomy as inpatients were randomized to receive a dosage of 0.5 mg/kg (total of 4 ml) midazolam in cherry juice (n=20, Group M), 3 mg/kg tramadol drops (n=20, Group T), or 2 microg/kg intranasal sufentanil (n=20, Group S). Clinical responses (sedation, anxiolysis, cooperation) and adverse effects (respiratory, hemodynamic, etc.) were recorded. Safety was assessed by continuous oxygen saturation monitoring and observation. Vital signs (blood pressure, pulse, oxygen saturation, respiratory rate) were recorded before drug administration (baseline) and then every 10 minutes until the induction of anesthesia. RESULTS: Mean blood pressure decreased significantly after five minutes of intranasal sufentanil administration relative to Groups M (p < 0.01) and T (p < 0.05), whereas heart rate remained unchanged. Oxygen saturation and respiratory rate decreased significantly after 20 and 30 minutes of intranasal sufentanil administration relative to Groups M and T (p < 0.05). Anxiety scores showed rates of 45 percent in Group M, 5 percent in Group T, and 40 percent in Group S. Anxiety scores in Groups M and S were better than those of Group T (p < 0.01). Cooperation scores for face-mask acceptance showed rates of 85 percent in Group M, 45 percent in Group T, and 85 percent in Group S (p < 0.01). CONCLUSION: Intranasal sufentanil and oral midazolam are more appropriate premedication options than tramadol drops in children.