A comparative study on the perfomance between I-gel® and Classic laryngeal mask airway in anaesthetized spontaneously breathing patients

The classic Laryngeal Mask Airway (c-LMA) is a first generation supraglottic airway device with an inflatable cuff forming a low pressure seal around the laryngeal inlet and permitting ventilation. I-gel is a supraglottic airway device made of thermoplastic elastomer which is soft gel-like and transparent. Unlike the classic LMA(c-LMA), I-gel does not have an inflatable cuff. In view of this, the present study was undertaken to compare the performance of the two supraglottic airway devices in spontaneously breathing adult patients posted for elective surgeries under general anesthesia.To compare the ease of insertion, number of insertion attempts, time for insertion, airway leak pressure, hemodynamic changes as well as perioperative complications such as cough sore throat between patients using the two devices.Sixty patients admitted in SRM medical college and research center scheduled for various elective surgical procedures under general anesthesia belonging to ASA class I and II were included in the study. They were randomly divided into two groups of 30 each using a random number generator. In group I, I-gel supraglottic airway device was used and in Group 2 classic laryngeal mask airway was used. Data was collected using a questionair containing socio-demographic details, details regarding performance of the device as well as hemodynamic changes and perioperative complications.The insertion was easy in 25 patients (83.3%) in group I, while in group II 15 patients (50%) had easy insertion. P=0.0 1781. The mean time of insertion for I-gel was (20. 17± 3 .91 seconds) which was significantly shorter compared to c-LMA (26.80 ±7.24 seconds) (P<0.001).There was no statistically significant difference between the devices with respect to number of attempts of insertion. Even though the airway leak pressure is not statically significant, the mean oropharyngeal leak pressure for I-gel was 20.40±5.68 (mm Hg), which was higher than c-LMA 18.73±5.06 (mm Hg), which is well within the normal limits to prevent aspiration. There were no statistically significant differences in hemodynamic changes. No Blood staining was seen after removal of device in I-gel group where it was observed in 2 (7%) patients in c- LMA group. Post removal cough was more in c -LMA (13 .3%) than l-gel (P= 0.04 SS*). Pharyngo-Laryngeal morbidity was more with classic LMA. Sore throat was more with the classic LMA (13 .3%) when compared to I-gel group (3%).We conclude that I-gel is a better airway when compared to c-LMA with respect to ease of insertion, shorter duration for insertion, adequate oropharyngeal seal with lesser pharyngo-laryngeal morbidity and less incidence of airway trauma.

EFFECTS OF SEVOFLURANE, PROPOFOL, AND COMBINATION OF SEVOFLURANE AND PROPOFOL FOR CLASSIC LARYNGEAL MASK AIRWAY INSERTION IN ADULTS- A CLINICAL COMPARATIVE STUDY

Background and Aims:Although LMA insertion is less invasive than endotracheal intubation,it also requires adequate mouth opening and blunting of minimal airway reflexes. Propofol is considered an appropriate IV agent for LMA insertion owing to its prompt induction and suppression of airway reflexes but induction doses required are often associated with hypotension,pain and apnea.Sevoflurane on the other hand,has minimal respiratory irritability,better hemodynamic stability and less apnea, but is associated with delayed jaw relaxation. Our hypothesis is that the combination of sevoflurane and propofol may be of better outcome whereby the insertion conditions of the LMA may be optimized adequately,at the same time the potential side-effects of individual drugs are effectively curtailed. Methods: 90 patients aged 20-60yrs of ASA I and II, 30 in each group were induced with Propofol (2mg/kg) in Group P, 8% Sevoflurane in N O: O (67%:33%) TVB technique in Group S and Group SP with additional propofol (1mg/kg) in 2 2 Group SP after loss of eyelash reflex. Induction characteristics, hemodynamic parameters and complications were observed. Results: 87% of the patients of Group SP had successful LMA insertion at first attempt, compared to 53% and 40% in Group P and Group S respectively, which was statistically significant. Less apnea was seen in Group SP(20%) as compared to Group P(60%),which was statistically significant. Conclusion: Our study showed that the combination group stood out to be the best with highest successful LMA insertion at first attempt and less incidence of apnea.

Hyomental distance measured by ultrasound for size selection of laryngeal mask airway in female patients: a randomized controlled study

BackgroundOptimal size selection of classic laryngeal mask airway (LMA) remains a major challenge for anaesthesiologists. Because the body weight, current method to select LMA size, might not inconsistent with dimension of hypopharynx where LMA is positioned. Hyomental distance by ultrasound as an common parameter in upper airway may be considered a predictor of LMA size choice, that we conducted a randomized, controlled study to compare the efficacy of size selection between commonly recommended weight-based method and hyomental distance-based method.MethodsSeventy female patients undergoing breast cancer surgery were enrolled in our study and randomly assigned into either the hyomental distance group or weight group. The primary outcome was the correct rate of selection LMA without need for size adjustment or use of other devices. Secondary outcomes included injury rate, oropharyngeal leak pressure (OLP), and insertion attempts.ResultsTwo participants were excluded from weight group due to tracheal intubation. The correct rate of LMA size-selected were significant difference of 77.14% and 51.51% in hyomental distance group and weight group, respectively(P=0.027). Five (14.29%) and 7 (21.21%) patients were injured in hyomental-distance group and weight group, respectively. Values of OLP in two groups were 22 (19-24) cmH2O and 22 (19.5-24) cmH2O, respectively. The insertion attempts were the same in both groups and no statistical differences were observed regarding these three outcomes. ConclusionThe hyomental distance-based method possessed a higher success rate for LMA-classic size selection than did the weight-based method, with the same excellent OLP value, low possibility of injury, and a low number of insertion attempts as weight-based method. Trial registrationOur study was registered with the Chinese Clinical Trial Registry (ChiCTR1900021123), registered 29 January 2019.

Randomized comparative study between classic laryngeal mask airway and I gel Airway in obese patients having BMI 35-40 during elective non-abdominal surgery

The authors have removed this preprint from Research Square.