Haemodynamic and Bispectral Index Response to Insertion of the Streamlined Liner of the Pharynx Airway (SLIPA™): Comparison with the Laryngeal Mask Airway

Abstract

The newly developed supralaryngeal airway Streamlined Liner of the Pharynx Airway (SLIPA™) has been compared successfully to the LMA™, but the haemodynamic response to its insertion has not been evaluated in a randomised study. We compared haemodynamic and Bispectral index(BIS) responses to insertion of the SLIPA™ with classic LMA™ after standardising the anaesthetic technique using BIS to monitor and control the anaesthetic depth. One hundred patients were randomised to receive either a classic LMA™ or SLIPA™ following induction with fentanyl and propofol titrated to a target BIS of 40 and compared heart rate, mean arterial pressure and BIS responses to insertion. There was a significant rise in mean arterial pressure from the pre-stimulus value (73.8 [10.6] mmHg, mean ± SD) at two and three minutes (P <0.05) following insertion of the LMA™ with maximum rise (80.8 [11.5] mmHg) seen at two minutes. There was a significant rise in mean arterial pressure from the pre-stimulus value (73.2 [12.6] mmHg) atone, two, three, four and five minutes (P <0.05) following insertion of the SLIPA™ with maximum rise (86.9 [15.1] mmHg) observed at three minutes. Mean arterial pressure was significantly higher (P <0.05) with SLIPA™ at two, three, four and five minutes. BIS increased significantly (P <0.05) at one, two, three, four and five minutes following insertion of both the devices, but there was no significant difference between the groups. There was a significantly higher (P=0.001) incidence of blood on the device with the SLIPA™ (20/50 vs. 6/50 with LMA™). Thus, insertion of SLIPA™ causes significantly higher blood-pressure response but similar BIS response compared to the LMA™.