Prospective, Randomized Comparison of Proseal Laryngeal Mask Airway and Endotracheal Tube in Adults Selected for Elective Laparoscopic Abdominal Surgery

Both PLMA and SLIPA were easy to insert (100% success) and ventilate with maximum sealing pressure of 30cm H2o (P = 0.4) with no muscle relaxant. No significant difference (P = 0.265) in intubation time between PLMA and ETT were observed in the study. A significant SpO2 change (P = 0.804, 0.561, 0.657, 0.248, 0.561) measured Pre op, Pre intubation, lmt, 3 mt and 5mts after intubation and there were no significant EtCO2 changes (P =0.861, 0.251, 0.44) measured after intubation was observed. Blood staining in 1/25 cases with PLMA and 2/25 cases with ETT with a P value of 0.561was seen.


INTRODUCTION
Laryngeal mask airway (LMA) is a recommended and a better alternate to face mask. But from the day since it was development the LMA has challenged the assumption that tracheal intubation is the only approved method to maintain a clear

Original Research Article
airway and provide positive pressure ventilation [1,2]. To meet the complications of this Proseal laryngeal mask airway (PLMA) in 2000, with some alterations were designed to enable partition of gastro intestinal and respiratory tract, improve airway seal, enable positive pressure ventilation and diagnose mask displacement. A Drain tube (DT) is the other mask which help in diagnosis of mask misplacement, decreases risk of gastric insufflation, regurgitation, and aspiration of gastric contents. With this background this stud was conceptualized to compare Endotracheal tube and Proseal LMA for elective laparoscopic abdominal surgery.

Study Design
Prospective, Randomized, Comparative single blinded case control study. The study was carried out in Sree Balaji medical college, Chennai from November 2010 to may 2011. The study was conducted in 50 patients in the age group of 18 years and above belonging to ASA I and II Posted for elective laparoscopic abdominal surgery.
The patients who had come for laparoscopic surgery were screened for comorbid illness and difficult airway. Age, Height and Weight were assessed. the patients were randomized in to 2 groups using closed envelope technique as proseal LMA group and endotracheal tube group. Patient was premedicated with Inj. Glycopyrrolate 0.2 µg/kg body weight and Inj. Fentanyl 2 µg/Kg. Pre oxygenated with 100% oxygen at a flow rate of 8L/mt. by using tight fitting facemask for 5 mts. Patient was induced with Inj. Propofol 2 mg/Kg & paralysed with Inj.suxamethonium 2mg/kg. In the Proseal Laryngeal mask airway group, device was inserted and cuff was inflated with 20ml room air. With the PLMA, we filled the proximal 3 cm of the drain tube with the water soluble lubricant jelly. After completion of surgery and adequate neuromuscular recovery patient was reversed with Inj. Neostigmine 50 µg/kg and Inj. Glycopyrrolate 0.4 mg. All data were collected, tabulated and expressed as Mean +/ standard deviation. Appropriate statistical analysis was conducted. All quantitative data were compared using unpaired student's test. All qualitative data were compared using Chi square test. P values were calculated for all tests. A P values 0 to 0.01 was considered as 1% significant, 0.011 to 0.05 was considered as 5% significant, and >0.05 wasconsidered as not significant.

RESULTS
PLMA insertion was successfully in 21/25 cases in first attempt while 4 patients 4/25 required second attempt. With ETT all 25 patients were intubated in first attempt. The time taken for PLMA/ETT from introduction into oral cavity to the final confirmation of its proper positioning. Time taken for intubation with PLMA is 37.36 and with ETT is 32.4 ( Fig. 1).Gastric distension was assessed by surgeon who was operating. It was Assessed just after peritoneal deflation. Student's 't' test revealed P value of 0.161 which is not significant. This indicates that PLMA provides good airway seal and adequate pulmonary ventilation (Fig. 2). SPO2 was measured pre operatively, just before intubation, lmt, 3mt and 5mt after intubation. The actual values are documented in the tabular column (Table 1). there was no significant oxygenation difference between two techniques.
Blood staining m the a1rway noted after extubation which indicates airway trauma Heart rate, systolic blood pressure Diastolic blood pressure and mean arterial pressure were measured pre operatively, pre intubation , l mt, 3mt and 5mts after intubation.
The actual values are documented in the tabular column. No significant difference in heart rate between two techniques and Laryngospasm did not occur in both the groups were observed. Hence there was a significant haemodynamic response with ETT when compared to PLMA.

CONSENT AND ETHICAL APPROVAL
The study was carried out after obtaining Institutional Ethical committee clearance and patient's written informed consent.