Role of capnography in safe sedation of vitrectomy patients

The aim of this study was to evaluate the efficiency of the capnography monitorization added to routine monitorization on oxygen desaturation, hypoxemia and other vital parameters. 100 adult patients had elective vitrectomy under sedation were included in this study. Patients were divided to "experiment" (capnography added to routine monitorization) and "control" (capnography not added to routine monitorization) groups. Each of the groups had 50 patients. Hypoxemia, desaturation, tachycardia, bradycardia, additional maneuvers for airway were compared between groups qualitatively and quantitatively. Increase and decrease in end-tidal carbondioxide (EtCO2) levels, hypoxemia, desaturation, Integrated Pulmonary Index (IPI) levels requiring attention (5-7) and intervention (1-4) were determined in experiment group, frequencies and possible relations between each of them and other paramaters were assessed. Desaturation rate and count in the experiment group were significantly lower than the control group (p<0,001). Bradycardia rate and count in the experiment group were significantly lower than the control group (p<0,01). No significant difference was seen between groups in terms of hypoxemia, tachycardia and additional maneuvers. 76% (38/50) of experiment group patients had decrease in EtCO2, 10% (5/50) increase in EtCO2, 38% (19/50) apnea, 52% (26/50) IPI levels requiring attention, 14% (7/50) IPI levels requiring intervention. There were significant relationships between IPI levels requiring attention and EtCO2 levels (p<0,05), bradypnea (p<0,001), verbal and tactil stimuli (VTS) (p<0,05). IPI levels requiring intervention were significantly related to hypoxemia (p<0,05), bradypnea (p<0,05), apnea (p<0,001), VTS (p<0,01), the duration of anesthesia and procedure (p<0,05) also. With addition of the capnography to routine monitorization of sedatized vitrectomy patients; oxygen desaturation and bradycardia can less likely to be occured and with instant follow-up of the EtCO2, apnea and IPI levels; respiratory depression can be recognized before oxygen desaturation develops.