Comparison between the streamlined liner of pharyngeal airway TM [slipa] and the laryngeal mask airway unique TM for spontaneous ventilation anaesthesia

ABSTRACT

The newly developed disposable streamlined of pharyngeal airway [SLIPATM] has recently been introduced into clinical practice. It has no inflatable cuff, because the shape of the SLIPATM closely resembles anatomy of the pharynx. The current study compared the SLIPATM and the LMA Unique TM with respect to insertion success rate, ease of insertion and insertion time, maximum air way sealing pressure, respiratory variables during spontaneous ventilation, haemodynamic response to the insertion of study devices, and postoperative adverse events related to these devices in 80 adult patients [ASA I-II] undergoing routine general surgery, orthopedic, urologic and gynecologic of short, moderate duration under general anaesthesia and through spontaneous ventilation. There was significant rise in MAP from the baseline value [73.8 +/- 12.0 mmHg] at all five minutes interval following insertion of the SLIPA with maximum rise [87.1 +/- 14.9 mmHg] seen at two minutes. There was significant rise in mean arterial blood pressure [MAP] from the baseline value [74.1 +/- 10.3 mmHg] at one and two minutes following insertion of the LMA Unique with maximum rise [81.1 +/- 11.2 mmHg] seen at one minute. MAP was significantly higher with SLIPA than with LMA Unique at two, three, four, and five minutes. There was no significant difference between the two groups with respect to oxygen saturation, inspired and expired tidal volume [TV ins, TV exp], and end-tidal carbon dioxide concentration throughout the surgical procedure. There was no statistical significant difference between the study groups with respect to the rate of successful insertion [96% and 98% in the SLIPATM and LMA Unique TM groups, respectively], and its scale. In the SLIPATM group, insertion was rated straight forward in 87%, slightly difficult in 10%, obviously difficult in 0%, and failure in 2% of patients. In the LMATM Unique group, insertion was rated straightforward in 89%, slightly difficult in 8%, obviously difficult in 2%, and failure in 0% of patients. Regarding to insertion time and peak airway sealing pressure there was no significant difference between the two SGA. With respect to adverse events related to the study air way devices, no regurgitation of gastric contents was observed in any patients, there was a significantly higher incidence of blood on the device with the SLIPA [11/40 versus 4/40 with LMA unique]. Also complaints of sore throat were noticed at significantly higher rate in the LMATM unique group than in SLIPATM group [19%, 3% respectively], 30 minutes after arrival in the post-anesthetic care unit. No cases of sore throat reported at the 24[th] hour postoperatively in both groups. Both the SLIPA and the LMA unique appear to be effective in establishing a clinically patent airway in patients who are spontaneously breathing under general anesthesia during operations of short or intermediate duration. They have similar insertion and functional characteristics. The SLIPA has significant haemodynamic effects on the study patients with frequent blood traces on the device in comparison with the LMA Unique. Fewer patients in the SLIPA group complained of a sore throat suggesting that the SLIPA might increase patients comfort after minor surgery