Comparison Of Stress Response Performing Endotracheal Intubation By Direct Laryngoscopy, Fibreoptic Intubation And Intubation By The Glidescope Laryngoscope

Stress response is regulated by two primary neuroendocrine systems—the hypothalamuspituitary- adrenocortical (HPA) and sympathetic adrenomedullary (SAM) systems. Salivary alphaamylase (AA) levels can be used as an index of the SAM activity, and serum cortisol as an index of HPA activity. The aim of the study was to compare patient stress response to different intubation techniques. Sixty adult patients, ASA I-III, scheduled for elective abdominal surgery were included in this study, with median age of 54±18 years. Patients were prospectively randomly divided into three groups-intubation with a GlideScope (GS), Macintosh laringoscope (ML) and PENTAX fibreoptic bronchoscope (FB). After preoxygenation for 3 min anaesthesia was induced with fentanyl 2 mkg/kg, mivacuronium 0.2 mg/kg and propofol 2 mg/kg, injected intravenously over 20 seconds. Intubation was started 2 min after mivacuronium injection. Anaesthesia was maintained with sevoflurane 1-2 vol% and fentanyl 1 mkg/kg as needed. Intubation time (IT) was measured, blood and saliva samples were collected before and shortly after intubation. Haemodynamic response was recorded. Intubation time was statistically significantly longer in the FB group (120±65 s) versus the ML group (29±5 s) and GS group (26±9 s), P < 0.05. In the three patients groups the initial AA level was similar (54±20 KU/ml, P > 0.05). In GS patients the alpha amylase level after intubation significantly decreased (42±15 KU/ml, P < 0.05), but in ML and FB patients—significantly increased (68±24 KU/ml and 73±32 KU/ml, respectively, P < 0.05). After intubation, blood cortisol did not differ between the ML (377±181 U/ml) and GS (484±61 U/ml) patient groups, but was significantly higher (P < 0.05) in the FB group (530±79 U/ml). Both heart rate and blood pressure increased during intubation, the difference between groups was not significant. All intubations were successful, but in the FB patient group IT was significantly longer than in the ML and GS patient group. IT in the GS and FB patient groups did not statistically significantly differ. In our opinion, shorter and more confident intubations with a GlideScope produce less nociceptive stimulus and less stress to the patient. Intubations using GlideScope videolaryngoscope causes lesser stress response in comparison to intubation with a Macintosh laryngoscope or fibreoptic bronchoscope.