The effects of endotracheal intubation with and without laryngoscopy on hemodynamic responses and intraocular pressure

It is a well-known entity that intubation with laryngoscope causes hemodynamic responses and increases intraocular pressure. We aimed to compare laryngoscopic intubation with newer perilaryngeal airway devices ILMA and PLA in terms of hemodynamic responses and intraocular pressure. After the approval of ethics committee, the patients under 60 years in, ASA I-II risk group and without any ophtalmic illnesses are involved in the study. Sixty patients were randomly divided into PLA, ILMA and endotracheal intubation with laryngoscop groups. After injection of 1.5-2.5 mg/kg propofol ve 0.6 mg/kg rocuronium intravenously and after achieving sufficient muscle relaxation, 2-4 mg/kg/h propofol infusion was continued to keep the bispectral index within 40 and 60, till 10 minutes after intubation. Lidocaine 0.5mg/kg i.v. was administered to prevent injection pain. Bispectral index remained within the range of 40 to 60 % during the induction period. In PLA group, appropriate endotracheal tubes with sterile lubricant were inserted through the airway device after placing the PLA. The same procedure was performed for ILMA group as well. The patients in intubation group were intubated orally with laryngoscope after application of sterile lubricants to the tracheal tubes. Anesthesia was continued with the infusion of 0.05-0.25 .g/kg/h remifentanil and inhalation of 4-7 % desflurane. Anesthesia was maintained to keep BIS between 40-60 %. Length, weight, body-mass index, thyromental distance, mouth openning, mallampati classes, heart rate, sistolic, diastolic and mean arterial pressures, SpO2, ETCO2, IOP and BIS were recorded. Before and after the induction, the placement of airway devices, the intubation, remove the airway devices and extubation. The parameters were compared among the three groups and within the groups according to the time. There were no statistically significant differences among the groups in terms of demographic properties, anesthesia and operation times, thyromental distance, mouth openning, mallampati score and BIS values. PLA was found to be superior when compared to ILMA, in terms of ease and time of placement. Heart rate was mostly affected in intubation group with laryngoscopy and the least response was in the PLA group. Arterial pressures were comparable for the three groups but pressures were significantly high after intubation in endotracheal intubation group in comparison within the groups. There were no significant difference among and within the groups in terms of SpO2 and ETCO2. IOP was higher in intubation group but there were also significant increase in all groups after intubation. In appropriate cases PLA and ILMA are reasonable alternatives to laryngoscopic intubation as they provide easier placement, minimal hemodynamic response and less IOP changes.