Lenin Babu Elakkumanan

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.

An indigenous method to prevent intraoperative kinking of gas sampling line

1. Bist SS, Varshney S, Kumar R, Saxena RK. Neglected bronchial foreign body in an adult. JK Sci 2006;8:222-4. 2. Lerra S, Raj R, Aggarwal S, Saini VK, Nagarkar NM. A long standing foreign body in bronchus in an adult. A diagnostic dilemma. JK Sci 2011;13:27-8. 3. Singhal P, Sonkhya N, Srivastava SP. Migrating foreign body in the bronchus. Int J Pediatr Otorhinolaryngol 2003;67:1123-6. 4. Sayuti R, Fadzil A, Ahmad R. Impacted foreign body in secondary bronchus: Chest percussions during therapeutic bronchoscopy. Int J Pediatr Otorhinolaryngol Extra 2009;4:75-6. 5. Cotton EK, Abrams G, Vanhoutte J, Burrington J. Removal of aspirated foreign bodies by inhalation and postural drainage. A survey of 24 cases. Clin Pediatr (Phila) 1973;12:270-6.

Diagnostic accuracy of bedside tests for predicting difficult intubation in Indian population: An observational study.

Background: Unanticipated difficult intubation can be challenging to anesthesiologists, and various bedside tests have been tried to predict difficult intubation. Aims: The aim of this study was to determine the incidence of difficult intubation in the Indian population and also to determine the diagnostic accuracy of bedside tests in predicting difficult intubation. Settings and Design: In this study, 200 patients belonging to age group 18–60 years of American Society of Anesthesiologists I and II, scheduled for surgery under general anesthesia requiring endotracheal intubation were enrolled. Patients with upper airway pathology, neck mass, and cervical spine injury were excluded from the study. Materials and Methods: An attending anesthesiologist conducted preoperative assessment and recorded parameters such as body mass index, modified Mallampati grading, inter-incisor distance, neck circumference, and thyromental distance (NC/TMD). After standard anesthetic induction, laryngoscopy was performed, and intubation difficulty assessed using intubation difficulty scale on the basis of seven variables. Statistical Analysis: The Chi-square test or student t-test was performed when appropriate. The binary multivariate logistic regression (forward-Wald) model was used to determine the independent risk factors. Results: Among the 200 patients, 26 patients had difficult intubation with an incidence of 13%. Among different variables, the Mallampati score and NC/TMD were independently associated with difficult intubation. Receiver operating characteristic curve showed a cut-off point of 3 or 4 for Mallampati score and 5.62 for NC/TMD to predict difficult intubation. Conclusion: The diagnostic accuracy of NC/TM ratio and Mallampatti score were better compared to other bedside tests to predict difficult intubation in Indian population.

ECG artefacts mimicking atrial flutter in posterior fossa surgery

ECG artefacts are defined as abnormalities in the monitored ECG, which result from measurement of cardiac potentials on the body surface and are not related to the electrical activity of the heart. In the operation theatre, the use of various types of electrical equipment may interfere with ECG interpretation. We describe our experience with artefacts resembling atrial fibrillation when a nerve integrity monitoring device was used on a patient undergoing posterior fossa surgery for epidermoid tumour. These artefacts resemble serious arrhythmias and may result in unwanted interventions. To enable better identification of such artefacts, a 12-lead ECG should be considered as it will display rhythm in all the leads; while artefacts will present in only a few leads, true arrhythmia will be present in all the 12 leads. Our case report aims to increase awareness regarding ECG artefacts and to explain how to distinguish them from actual arrhythmias.

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.

Comparing slow and rapid bolus of ephedrine in pregnant patients undergoing planned cesarean section under spinal anesthesia

Background and Aims: While ephedrine was the preferred drug for treating spinal-induced hypotension in pregnancy, its use has declined because of resultant fetal acidosis. The objective of this randomized control trial was to compare the effects of a slow and rapid bolus of ephedrine on fetal acidosis, maternal blood pressure, and heart rate (HR) during cesarean section performed under spinal anesthesia. Material and Methods: Eighty full-term parturients scheduled for cesarean section under spinal anesthesia were randomly allocated into two groups. While both groups received 6 mg of ephedrine to treat hypotension, Group R (n = 40) received it as a rapid intravenous bolus and Group S (n = 40) received it slowly over 20 s with an infusion pump. The maternal vital parameters were recorded until delivery of the baby using a video camera. Umbilical cord blood was obtained using the three clamp method. Hemodynamic parameters, fetal acidosis, total number of ephedrine bolus used, peak HR after the ephedrine bolus, and occurrence of postoperative nausea and vomiting (PONV) were compared between the groups. Results: Mean increase in HR and blood pressure were significantly higher in Group R than the Group S after the first ephedrine bolus. Umbilical artery pH was significantly lower in Group R than in Group S (7.2 [6.8-7.3] vs. 7.3 [7.3-7.4], P < 0.01). A total number of ephedrine boluses were comparable in the two groups. 35% of the patients had PONV in Group R, whereas none had it in Group S (P < 0.01). Conclusion: Slow bolus of ephedrine is better than rapid bolus to treat spinal-induced hypotension during cesarean section in view of less fetal acidosis.

Newer design, newer problems: Unusual complication with Limb-O anaesthesia circuit

Several types of breathing circuits are available in anaesthesia practice.[1] Complications have been reported with almost all the breathing circuits.[2,3] Pre-use check of anaesthesia machine and circuits is recommended to avoid these complications.[4] Latest addition to the armamentarium of breathing circuit is Limb-O circuit [Figure 1]. This circuit is a ‘“double lumen’” single-tube breathing circuit. A flexible septum which runs along the entire length of breathing circuit divides the tube into two compartments. The manufacturers claim that this circuit has light weight, lower compliance and is thermally efficient. Here, we would like to report an unusual complication associated with this type of circuit.

Evaluation of simple pre-determined length insertion technique (SPLIT) with conventional method for oral fibreoptic intubation: A randomised cross-over study

Background and Aims: The difficulty during flexible fiber-optic bronchoscopy (FOB) guided tracheal intubation could be because of inability in visualising glottis, advancing and railroading of endotracheal tube. Several methods are available for visualising glottis, but none is ideal. Hence, this randomised controlled study was designed to evaluate the simple pre-determined length insertion technique (SPLIT) during oral FOB. Methods: Fifty-eight patients were randomised into Group C and Group P. General anaesthesia was maintained with sevoflurane and oxygen in spontaneous respiration. In Group C, conventional flexible fiberoptic laryngoscopy was done followed by SPLIT and vice versa in Group P. The time to visualise the glottis (T1), from glottic visualisation to pass beyond glottis (T2) and from incisors to pass beyond the glottis (T3) were noted from the recorded video. The time interval was analysed using Wilcoxon matched pairs test and Mann–Whitney U-test. Results: The T1was significantly less in SPLIT as compared to conventional technique (13 [10, 20.25] vs. 33 [22, 48] s). The T3was significantly less in SPLIT (24.5 [19.75, 30] vs. 44 [34, 61.25] s). The T1by SPLIT was comparable between residents and consultants (P = 0.09), whereas it was significantly more among residents than the conventional technique. The SPLIT was preferred by 91.3% anaesthesiologists. Conclusion: The SPLIT significantly lessened the time to visualise the glottis than conventional technique for FOB. The SPLIT was the preferred technique. Hence, we suggest using the SPLIT to secure the airway at the earliest and also as an alternative to conventional technique.

A modified insertion technique of ambu AuraGain™ laryngeal airway, a third-generation supraglottic airway to reduce the oral mucosal injury

Sir, Ambu AuraGainTM[1] is a new single-use supraglottic airway (SGA) device available in adult size 3, 4, and 5. It is an anatomically curved SGA with integrated gastric access and can be used as a conduit for direct endotracheal intubation assisted by a flexible scope.[1] The standard recommended insertion technique is as that of intubating laryngeal mask airway (LMA),[2] i.e., keeping the handle (Shaft) approximately parallel to the patient’s chest and then pushing the device along the hard palate after opening the mouth [Figure 1a]. With the previous experience of other faculty and residents with this device in our institute, we noticed that a higher tangential force is required for the placement due to bulky and acute angle of the device. Due to difficulty in insertion, few cases also resulted in oral mucosal injury in the form of bleeding and ulceration with inadequate sealing and higher airway pressure.

Comparison of different regimens of intravenous dexmedetomidine on duration of subarachnoid block

Background and Aims: Many studies have studied the effect of intravenous dexmedetomidine on the prolongation of the duration of the subarachnoid block (SAB). These studies had administered dexmedetomidine using different regimens. This study was designed to find out the suitable regimen with maximum advantages and minimum disadvantages. Material and Methods: Ninety-three ASA 1 and 2 patients scheduled to undergo surgeries under SAB were randomly allocated into three groups namely B, M, and BM. After SAB, Group B received 0.5 μg/kg of dexmedetomidine bolus over 15 min, Group M received 0.5 μg/kg/h of dexmedetomidine infusion until the end of surgery, Group BM received both bolus and infusion. Results: The time to achieve T10 sensory level (SL) was significantly faster in the Groups B and BM than in the Group M. Maximum block height achieved was T4 and was same in all the groups. The Time to achieve maximum SL and Bromage 3 was comparable in all groups. The two-segment regression time and time to reach Bromage 0 was significantly higher in Groups M and BM than Group B. The time for a first request of analgesia was similar in Groups M and BM. The maximum sedation attained in all groups was Ramsay Sedation Score of 3. Side effects such as bradycardia, hypotension, and desaturation were comparable between the groups. Conclusion: We conclude that the continuous infusion of dexmedetomidine results in more advantages than just a bolus dose. Therefore, we suggest using only the maintenance dose of intravenous dexmedetomidine after subarachnoid blockade for prolonging the duration and achieving sedation.