Intraoperative Evaluation of Effects of Different Gas Mixtures (Oxygen 100%, O2 50%:N2O 50%, Air on Cuff Pressure of PLMA (Proseal LMA)

Introduction:- we study the intra operative evaluation of different gas mixture(oxygen 100%, O2 50%:N2O 50%, AIR on cuff pressure of PLMA. Aims and Objectives:- To study intracuff pressure changes and the change in final volume of gas mixture during inflation and deflation during intraoperative period and postoperative complications. Material and Methods:- This double blind, prospective Study was conducted in Department of Anaesthesiology, Maharishi Markandeshwar Institute of Medical Sciences and Research, Mullana, Ambala following approval from institutional ethical committee and written informed patient consent. The sample size of 120 patient aged 18 to 60 years, belonging to ASA physical status 1 and 2 undergoing surgery in general anesthesia with PLMA as airway device divided into three group on the basis of PMLA cuff gas mixture:-Group O - oxygen 100%, Group ON - Nitrous 50%: Oxygen 50%, Group A – Air. Results and Conclusion:- Combination of N2O and O2 resulted in decreased intracuff pressure and air lead to a slight increase in intracuff pressure with O2 providing relatively stable cuff pressures. Keywords: PLMA,100% Oxygen, Air, Oxygen 50% N2O 50%, Air.

To Compare the Efficacy of Betamethasone Gel and Lignocaine Gel Applied over Endotracheal Tube to Reduce Post Operative Sore Throat and Cough

Background: Post-operative sore throat, cough and hoarseness of the voice are often common, uncomfortable sequelae after tracheal intubation with inflammation being the most common pathogenesis. Post operative sore throat and cough has a multifactorial aetiology that includes patient-related factors such as age, sex, and smoking, as well as intubation factors such as technique, duration, tube size, intracuff pressure, cuff design, trauma to the pharyngolaryngeal mucosa and various factors. Objectives: To compare the incidence of post operative sore throat, cough after endotracheal tube intubation when applying betamethasone gel and lignocaine jelly. Materials and Methods: At Saveetha Medical College and Hospital in Thandalam, Chennai, a prospective controlled double blinded study was done among patients who were scheduled for elective procedures under general anaesthesia with orotracheal intubation. The study comprised 60 patients who met the study's inclusion and exclusion criteria. The 60 patients were divided into two study groups each enrolled with 30 patients. Before the study could begin, approval from the institutional research board was required. Before the study began, an informed, written consent was obtained. The method used was Qualitative observational randomised double blind study by using a computer-generated random number table and the sealed envelope approach, patients were assigned to one of two equal groups. Following a pre-anaesthetic evaluation, 60 patients of either sex, aged 18 to 60 years, with an ASA physical status of I or II, who were undergoing elective surgery (likely to last up to 240 minutes) under general anaesthesia with orotracheal intubation and met the above inclusion criteria were included in the study. The differences between the study groups were analysed by chi square test and the “p” value used as a cut off for estimating statistical significance between groups is 0.05. Results: The incidence and severity of post operative sore throat and cough after endotracheal intubation during 6 and 24 hours was found to be statistically significantly in patients in whom betamethasone was used. The results are significant at p<0.05. At 6 hours the incidence of post operative sore throat for betamethasone and lignocaine was 12% and 30% respectively. At 24 hours the incidence of post operative sore throat for betamethasone and lignocaine was 9.36% and 25.2% respectively. At 6 hours the incidence of post operative cough for betamethasone and lignocaine was 8.4% and 24%.At 24 hours the incidence of post operative cough for betamethasone and lignocaine was 7.2% and 21.6% respectively. Conclusion: The use of 0.05 percent betamethasone gel to lubricate the endotracheal tube before intubation helps to reduce the time it takes for symptoms to resolve.

Effects of Head and Neck Position on Nasotracheal Tube Intracuff Pressure: A Prospective Observational Study

To prevent endotracheal tube-related barotrauma or leakage, the intracuff pressure should be adjusted to 20–30 cm H2O. However, changes in the nasotracheal tube intracuff pressure relative to neck posture are unclear. In this study, we investigated the effect of head and neck positioning on nasotracheal tube intracuff pressure. Fifty adult patients with nasotracheal tubes who were scheduled for surgery under general anesthesia were enrolled. Following intubation, intracuff pressure was measured by connecting the pilot balloon to a device that continuously monitors the intracuff pressure. Subsequently, the intracuff pressure was set to 24.48 cm H2O (=18 mmHg) for the neutral position. We recorded the intracuff pressures based on the patients’ position during head flexion, extension, and rotation. The initial intracuff pressure was 42.2 cm H2O [29.6–73.1] in the neutral position. After pressure adjustment in the neutral position, the intracuff pressure was significantly different from the neutral to flexed (p < 0.001), extended (p = 0.003), or rotated (p < 0.001) positions. Although the median change in intracuff pressure was <3 cm H2O when each patient’s position was changed, overinflation to >30 cm H2O occurred in 12% of patients. Therefore, it is necessary to adjust the intracuff pressure after tracheal intubation and each positional change.

Risk Factors for Acute Postoperative Sort Throat (POST) After Supraglottic Device Use

Background. To identify risk factors for acute postoperative sort throat (POST) after general anesthesia using a supraglottic airway device (SAD) in adults undergoing elective tympanoplasty.Methods. The medical records of 1424 adults who underwent elective tympanoplasty under general anesthesia using an SAD were reviewed retrospectively. Patients received one of four SADs at the discretion of the anesthesiologists: flexible reinforced LMA (FLMA), Ambu AuraFlex FLMA, or two local brand devices (Tuoren FLMA or Tuoren Esophageal Drainage LMA). POST upon discharge from the postanesthesia care unit (PACU) was measured using a visual analog sale (VAS) and categorized as no pain, mild pain, and moderate to severe pain. Data regarding potential risk factors for POST were collected from the medical records. Results. The mean patient age was 43.24 years; 622 patients were male and 802 were female. The overall incidence of POST during the PACU stay was 38.1%. Female sex, certain types of SAD, higher intracuff pressure, and longer duration of surgery were independent risk factors for POST on multivariate logistic regression analysis. Compared to FLMA, both the Tuoren FLMA and the Tuoren Esophageal Drainage LMA were risk factors for POST. The Tuoren Esophageal Drainage LMA was the strongest independent risk factor for moderate to severe POST.Conclusions. Use of local brand SADs contributed to the development of POST after elective tympanoplasty under general anesthesia. The Tuoren Esophageal Drainage LMA was the strongest predictor of moderate to severe POST.

Correlation and variation of cuff inflating volumes and pressures in different adult models of laryngeal mask: a prospective randomized trial

Background: Hyperinflation of laryngeal mask cuffs may carry the risk of airway complications. The manufacturer recommends inflating cuff until the intracuff pressure reaches 60 cmH2O, or inflate with the volume of air to not exceed the maximum recommended volume. We prospectively assessed the correlation of cuff inflating volumes and pressures, and the appropriated the cuff inflating volumes to generate an intracuff pressure of 60 cmH2O in the adult laryngeal masks from different manufacturers. Methods: Two groups of eighty patients requiring laryngeal mask size 3 and 4 during general anesthesia were randomized into 4 subgroups for each size of the laryngeal mask: Soft Seal® (Portex®), AuraOnceTM (Ambu®), LMA-ClassicTM (Teleflex®) and LMA-ProSealTM (Teleflex®). After insertion, the cuff was inflated with 5-ml increments of air up to the maximum recommended volume. After each 5-ml intracuff pressure was measured, the volume of air that generated the intracuff pressure of 60 cmH2O was recorded. Results: Mean(SD) volume of air required to achieve the intracuff pressure of 60 cmH2O in Soft Seal®, AuraOnceTM, LMA-ClassicTM, LMA-ProSealTM laryngeal mask size 3 were 11.80(1.88), 9.20(1.88), 8.95(1.50) and 13.50(2.48) ml, respectively, and these volumes in laryngeal mask size 4 were 14.45(4.12), 12.55(1.85), 11.30(1.95) and 18.20(3.47) ml, respectively. The maximum recommended volume resulted in high intracuff pressures (>60 cmH2O) in all laryngeal mask types and sizes studied. Conclusion: Pressure-volume curves of adult laryngeal masks are all in sigmoidal shape. Cuff designs and materials can effect pressure and volume correlation. Approximately half of the maximum recommended volume is required to achieve the intracuff pressure of 60 cmH2O except LMA-ProSealTM which required two-thirds of the maximum recommended volume. Trial registration: Thai Clinical Trials Registry, TCTR20150602001, May 28, 2015

Correlation and variation of cuff inflating volumes and pressures in different adult models of laryngeal mask airway: a prospective randomized trial

Background : Hyperinflation of laryngeal mask cuffs may carry the risk of airway complications. The manufacturer recommends inflating cuff until the intracuff pressure reaches 60 cmH 2 O, or inflate with the volume of air to not exceed the maximum recommended volume. We prospectively assessed the correlation of cuff inflating volumes and pressures, and the appropriated the cuff inflating volumes to generate an intracuff pressure of 60 cmH 2 O in the adult laryngeal masks from different manufacturers. Methods : Two groups of eighty patients requiring laryngeal mask size 3 and 4 during general anesthesia were randomized into 4 subgroups for each size of the laryngeal mask: Soft Seal ® (Portex ® ), AuraOnce TM (Ambu ® ), LMA-Classic TM (Teleflex ® ) and LMA-ProSeal TM (Teleflex ® ). After insertion, the cuff was inflated with 5-ml increments of air up to the maximum recommended volume. After each 5-ml intracuff pressure was measured, the volume of air that generated the intracuff pressure of 60 cmH 2 O was recorded . Results : Mean(SD) volume of air required to achieve the intracuff pressure of 60 cmH 2 O in Soft Seal ® , AuraOnce TM , LMA-Classic TM , LMA-ProSeal TM laryngeal mask size 3 were 11.80(1.88), 9.20(1.88), 8.95(1.50) and 13.50(2.48) ml, respectively, and these volumes in laryngeal mask size 4 were 14.45(4.12), 12.55(1.85), 11.30(1.95) and 18.20(3.47) ml, respectively. The maximum recommended volume resulted in high intracuff pressures (>60 cmH 2 O) in all laryngeal mask types and sizes studied. Conclusion : Pressure-volume curves of adult laryngeal masks are all in sigmoidal shape. Cuff designs and materials can effect pressure and volume correlation. Approximately half of the maximum recommended volume is required to achieve the intracuff pressure of 60 cmH 2 O except LMA-ProSeal TM which required two-thirds of the maximum recommended volume. Trial registration: Thai Clinical Trials Registry, TCTR20150602001, May 28, 2015