Comparing the efficacy of modified thenar eminence technique with conventional thenar eminence technique of mask ventilation during induction of general anaesthesia - A randomised crossover study.

Background and Aims: Mask ventilation is one of the important skills required for successful airway management. Following the induction of general anaesthesia, there could be airway obstruction due to fall back of the tongue or soft palate. This obstruction could be overcome by manoeuvring the mandible or inserting airways. The primary objective of the study was to compare the efficacy of modified thenar eminence technique of mask ventilation in improving expired tidal volume (VTE) over conventional thenar eminence technique and the secondary objective was to compare peak airway pressure (PMAX) and ease of mask ventilation between the two techniques. Methods: Seventy-six patients were randomised into group M and group C. In group M, the modified thenar eminence technique was performed for five consecutive breaths followed by conventional technique, and vice versa was followed in group C. In each breath, VTE, PMAX and end-tidal carbon dioxide were noted. Participants reported the ease of ventilation score using the Likert scale for each technique. Results: VTE was significantly more in modified thenar eminence technique than conventional technique [mean ± standard deviation, 370 ± 55 ml versus 313 ± 50 ml, P = 0.01]. Ease of ventilation score [median 1.70 (interquartile range (1-2)) versus 2.3 (2-3), P = 0.01] showed that modified technique was easier compared to conventional technique. Conclusion: Modified thenar eminence technique of mask ventilation is superior to the conventional technique in terms of VTE and ease of ventilation in the unanticipated difficult airway.

Assessment of effectiveness of cricoid pressure in preventing gastric insufflation during bag and mask ventilation: A randomized controlled trial.

BACKGROUND: Rapid sequence induction and intubation (RSII) with application of "Cricoid pressure" and avoidance of "facemask ventilation" (FMV) is believed to minimize the risk of pulmonary aspiration of gastric contents during general anesthesia. However, some patients may be at risk of developing hypoxemia and may benefit from FMV during RSII. The purpose of this study was to assess the effectiveness of "cricoid pressure" in preventing gastric insufflation during FMV using gastric ultrasonography. MATERIALS AND METHODS: Eighty-four adult patients were randomized to receive cricoid pressure (CP) or no cricoid pressure (NCP), during FMV after induction of general anesthesia. Gastric antral cross-sectional area (CSA) was measured with ultrasonography before and after FMV in supine and right lateral decubitus positions (LDP). Appearance of "comet tail" artifacts created by acoustic shadows of gas in the gastric antrum was noted. RESULTS: The incidence of insufflation indicated by "comet tail" artifacts during FMV was lower in group CP (17 vs 71%; P < 0.001). The lowest P aw at which gastric insufflation occurred was higher in group CP (20 vs 14 cmH2O). The change in mean gastric antral CSA was significantly lower in group CP than in group NCP in supine (0.02 vs 0.36 cm2, P = 0.012) and right LDP (0.03 vs 0.67 cm2, P < 0.001). CONCLUSION: Cricoid pressure is effective in preventing gastric insufflation during FMV at P aw less than 20 cmH2O. Observation of comet tail artifacts in gastric antrum along with measurement of change in antral CSA on ultrasound examination is a feasible and reliable method to detect gastric insufflation.

Comparison of dexmedetomidine with fentanyl for maintenance of intraoperative hemodynamics in hypertensive patients undergoing major surgery: A randomized controlled trial.

BACKGROUND: The objective of this study was to study and compare the effects of intravenous dexmedetomidine and fentanyl on intraoperative hemodynamics, opioid consumption, and recovery characteristics in hypertensive patients. METHODS: Fifty-seven hypertensive patients undergoing major surgery were randomized into two groups, Group D (dexmedetomidine, n = 29) and Group F (fentanyl, n = 28). The patients received 1 µg/kg of either dexmedetomidine or fentanyl, followed by 0.5 µg/kg/h infusion of the same drug, followed by a standard induction protocol. Heart rate (HR), mean arterial pressures (MAPs), end-tidal isoflurane concentration, and use of additional fentanyl and vasopressors were recorded throughout. RESULTS: Both dexmedetomidine and fentanyl caused significant fall in HR and MAP after induction and dexmedetomidine significantly reduced the induction dose of thiopentone (P = 0.026). After laryngoscopy and intubation, patients in Group D experienced a fall in HR and a small rise in MAP (P = 0.094) while those in Group F showed significant rise in HR (P = 0.01) and MAP (P = 0.004). The requirement of isoflurane and fentanyl boluses was significantly less in Group D. The duration of postoperative analgesia was longer in Group D (P = 0.015) with significantly lower postoperative nausea and vomiting (PONV) (P < 0.001). CONCLUSION: Infusion of dexmedetomidine in hypertensive patients controlled the sympathetic stress response better than fentanyl and provided stable intraoperative hemodynamics. It reduced the dose of thiopentone, requirement of isoflurane and fentanyl boluses. The postoperative analgesia was prolonged, and incidence of PONV was less in patients who received dexmedetomidine.

The comparison of stroke volume variation with central venous pressure in predicting fluid responsiveness in septic patients with acute circulatory failure.

PURPOSE: The present study was designed to investigate the efficacy of stroke volume variation (SVV) in predicting fluid responsiveness and compare it to traditional measures of volume status assessment like central venous pressure (CVP). METHODS: Forty-five mechanically ventilated patients in sepsis with acute circulatory failure. Patients were not included when they had atrial fibrillation, other severe arrhythmias, permanent pacemaker, or needed mechanical cardiac support. Furthermore, excluded were patients with hypoxemia and a CVP >12. Patients received volume expansion in the form of 500 ml of 6% hydroxyethyl starch. RESULTS: The volume expansion-induced increase in  cardiac index (CI) was >15% in 29 patients (labeled responders) and <15% in 16 patients (labeled nonresponders). Before volume expansion, SVV was higher in responders than in nonresponders. Receiver operating characteristic curves analysis showed that SVV was a more accurate indicator of fluid responsiveness than CVP. Before volume expansion, an SVV value of 13% allowed discrimination between responders and nonresponders with a sensitivity of 78% and a specificity of 89%. Volume expansion-induced changes in CI weakly and positively correlated with SVV before volume expansion. Volume expansion decreased SVV from 18.86 ± 4.35 to 7.57 ± 1.80 and volume expansion-induced changes in SVV moderately correlated with volume expansion-induced changes in CI. CONCLUSIONS: When predicting fluid responsiveness in mechanically ventilated patients in septic shock, SVV is more effective than CVP. Nevertheless, the overall correlation of baseline SVV with increases in CI remains poor. Trends in SVV, as reflected by decreases with volume replacement, seem to correlate much better with increases in CI.

Propofol-ketamine and propofol-fentanyl combinations for nonanesthetist-administered sedation.

OBJECTIVES: There is a need to compare propofol requirement between propofol-ketamine (PK) and propofol-fentanyl (PF) given as nonanesthetist-administered propofol sedation during pediatric esophagogastroduodenoscopy (EGD). METHODS: The study was a parallel-group, randomized, double-blind comparison of the need for additional doses of propofol in the first minute after sedation induction between PK and PF, administered by rotating trainees in pediatrics for sedation during pediatric EGD. A total of 95 children with American Society of Anesthesiologists class I to III between 3 and 12 years undergoing EGD were included and randomized to either of the groups. After midazolam premedication, children received either 0.5 mg/kg ketamine (PK) or 1 µg/kg of fentanyl (PF) followed by a mandatory 1 mg/kg of propofol. Additional doses of propofol of 0.5 mg/kg each were given to achieve sedation induction (modified Ramsay scale level 6), and further doses were administered during the procedure as required. A total of 92 children (PK, n = 47; PF, n = 45) were analyzed. P < 0.05 was considered significant. RESULTS: There was no difference in the propofol dose required for successful scope introduction and also in the need for additional propofol doses and the total additional propofol doses required in the first minute after sedation induction. Propofol injection pain was higher in the PF group (odds ratio 1.78). The adverse events and recovery time were similar. There was no escalation of care, airway intubations, death, or disability. CONCLUSIONS: Nonanesthetist-administered propofol sedation is feasible in teaching hospitals. Propofol requirement is similar in both PK and PF combination regimens, but the lower frequency of propofol injection pain may favor the use of PK.

Comparison of i-gel supraglottic airway and LMA-ProSeal™ in pediatric patients under controlled ventilation.

BACKGROUND: i-gel™ and the ProSeal™ laryngeal mask airway (PLMA) are two supraglottic airway devices with gastric channel used for airway maintenance in anesthesia. This study was designed to evaluate the efficacy of i-gel compared with PLMA for airway maintenance in pediatric patients under general anesthesia with controlled ventilation. MATERIALS AND METHODS: A total of 60 American Society of Anesthesiologists physical status 1 and 2 patients were included in the study and randomized to either i-gel or PLMA group. After induction of anesthesia using a standardized protocol for all the patients, one of supraglottic airway devices was inserted. Insertion parameters, ease of gastric tube insertion and fiber-optic scoring of the glottis were noted. Airway parameters such as end-tidal carbon dioxide (EtCO2), peak airway pressures and leak airway pressures were noted. Patients were observed for any complications in the first 12 h of the post-operative period. RESULTS: Both groups were comparable in terms of ease of insertion, number of attempts and other insertion parameters. Ease of gastric tube insertion, EtCO2, airway pressures (peak and leak airway pressure) and fiber-optic view of the glottis were comparable in both groups. There were no clinically significant complications in the first 12 h of the post-operative period. CONCLUSION: i-gel is as effective as PLMA in pediatric patients under controlled ventilation.

Carbon dioxide rebreathing caused by deformed silicon leaflet in the expiratory unidirectional valve.

Rebreathing of carbon dioxide caused by incompetent 'cage and disc' unidirectional valves has been reported earlier. Some manufacturers have changed the design of unidirectional valves to 'flexible leaflets'. We report a series of cases where a deformed membrane leaflet in expiratory unidirectional valves led to rebreathing of carbon dioxide.

Comparison of analgesic efficacy of transversus abdominis plane block with direct infiltration of local anesthetic into surgical incision in lower abdominal gynecological surgeries.

BACKGROUND: Transversus abdominis plane block is a safe, simple and effective technique of providing analgesia for lower abdominal surgeries with easily identifiable landmarks. AIMS: To compare the analgesic efficacy of transversus abdominis plane block with that of direct infiltration of local anesthetic into surgical incision in lower abdominal procedures. SETTINGS AND DESIGN: Prospective randomized controlled trial in lower abdominal surgeries done under general anesthesia. MATERIALS AND METHODS: 52 ASA I-II patients undergoing lower abdominal gynecological procedures under general anesthesia were divided randomly into two groups each after written informed consent. A bilateral TAP block was performed on Group T with 0.25% bupivacaine 0.6 ml/kg with half the volume on either side intra-operatively after skin closure before extubation using a short bevelled needle, whereas Group I received local infiltration intra-operatively after skin closure with the same amount of drug. The time taken for the first rescue analgesic and visual analog score (VAS) was noted, following which, the patient was administered intravenous morphine 0.1 mg/kg and connected to an intravenous patient controlled analgesia system with morphine for 24 hrs from the time of block administration. 24 h morphine requirement was noted. VAS and sedation scores were noted at 2, 4, 6 and 24 h postoperatively. STATISTICAL ANALYSIS USED: The results were analyzed with SPSS 16. A P value < 0.05 was considered significant. Duration of analgesia and 24 h morphine requirement was analysed by Student's t-test. VAS scores, with paired comparisons at each time interval, were performed using the t-test or Mann-Whitney U-test, as appropriate. Categorical data were analyzed using Chi square or Fisher's exact test. RESULTS: In Group T, the time to rescue analgesic was significantly more and the VAS scores were lower (P = 0.001 and 0.003 respectively). The 24 hr morphine requirement and VAS at 2, 4, 6 and 24 h were less in the Group T (P = 0.001). Incidence of PONV was significant in Group I (P = 0.043), whereas Group T were less sedated at 2 and 4 h (P = 0.001 and 0.014). CONCLUSIONS: Transversus abdominis plane block proved to be an effective means of analgesia for lower abdominal surgeries with minimal side-effects.

Optimal external laryngeal manipulation versus McCoy blade in active position in patients with poor view of glottis on direct laryngoscopy.

Successful endotracheal intubation requires a clear view of glottis. Optimal external laryngeal manipulation may improve the view of glottis on direct laryngoscopy with Macintosh blade, but it requires another trained hand. Alternatively, McCoy laryngoscope with elevated tip may be useful. This study has been designed to compare the two techniques in patients with poor view of glottis. Two hundred patients with 'Grade 2 or more' view of glottis on direct laryngoscopy with Macintosh blade are included in the study. Optimal external laryngeal manipulation was applied, followed by laryngoscopy with McCoy blade in activated position; and the view was noted in both situations. The two interventions were compared using Chi-square test. The overall changes, in the views, were analyzed with Wilcoxon signed rank test. Both the techniques improved the view of glottis significantly (P<0.05). Optimal external laryngeal manipulation was significantly better than McCoy laryngoscope in active position, especially in patients with Grade 3 or 4 baseline view, poor oropharyngeal class, decreased head extension and decreased submandibular space (odds ratio = 2.36, 3.17, 3.22 and 26.48 respectively). To conclude, optimal external laryngeal manipulation is a better technique than McCoy laryngoscope in patients with poor view of glottis on direct laryngoscopy with Macintosh blade.