Comparative Analysis of Peak Air Pressure and Oxygen Flow between Conventional and Modified Endotracheal Tube for Retromolar Intubation (PUNTUBE)- An In Vitro Study.

Abstract

In conventional practice for retromolar intubation, endotracheal tube (ET) is bent. This leads to compression of the inner diameter of the tube which in turn reduces airflow. Furthermore, conventionally ETs are stabilised in position using inflated tracheal cuff. Elastic sticky tapes around the exit pose hindrance for surgical procedures on the face. Surgical manipulation and maxillomandibular fixation may lead to compression, damage or accidental extubation of ET. We have developed a modified ET dedicated to retromolar intubation with innovative means for tube stabilisation to solve these problems. To study the efficacy of the tube, a comparative in vitro study was done on mannequins. Null hypothesis of no change in air pressure and oxygen concentration in bent conventional ET versus modified ET was formulated. Comparison was done on the basis of the peak air pressure (PEP) and oxygen concentration, which was checked using air-gas monitor. The mean PEP was found to be 24.29 psi with standard deviation (SD) of 9.54 in sequentially bent conventional tube. This was found to be only 10.35 psi with SD of 3.22 in modified ET. Oxygen delivery was found to be 3.96 L/min in bent conventional tube, which was 5.22 L/min in modified tube. Both the findings were statistically significant. Modified retromolar tube (PUNTUBE) has been found to be efficient in maintaining low PEP while delivering more oxygen as compared to bent conventional tube. Novel mode of tube stabilisation in the form of PUNSTAB is an easy and effective way of tube stabilisation.