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Additional file 2.

Additional file 1.

To assess the impact of short time hypnosis for retro-bulbar anesthesia on ventilation in patients undergoing ophthalmic surgery of the anterior eye chamber. In all patients, a combined continuous transcutaneous carbon dioxide tension (PtcCO2) and partial oxygen saturation (SpO2) measurement was applied in addition to routine monitoring. To enable unconscious application of retro-bulbar anesthesia, intravenous thiopental was given in one to multiple bolus doses. Transient breathing support included chin lift, Esmarch maneuver and manual hand-bag ventilation via face mask. Main endpoints were apnea time, recovery time according to the Richmond Agitation Sedation Scale, as well as SpO2 and PtcCO2 readings at predefined time points. Fifty-two patients with a mean age of 68 ± 13 years were included. Average thiopental dose was 2.7 ± 0.6 mg/kg. In seven (13.5%) patients repeated doses of thiopental were necessary to a total of 3.3 ± 1.1 mg/kg. Except one patient, no severe, significant or clinical relevant hypercapnia or desaturation periods were observed, and the occurring elevation of PtcCO2 values did not correlate with the application of repeated doses of thiopental or the need for the Esmarch maneuver. Higher PtcCO2 values were associated with the presence of hypertension and smoking. Apnea (p

Objective: The aim of this study was to validate the V-Sign digital sensor (SenTec AG, Therweil, Switzerland) for combined noninvasive assessment of pulse oxymetric oxygen saturation (SpO2) and transcutaneous carbon dioxide tension (PtcCO2) in adults after cardiac surgery. Methods: In twenty one patients, aged 51-86years, simultaneous measurements of blood gases with the V-Sign Sensor and with two Nellcor Durasensors (model DS-100A), one at the opposite earlobe and one with a finger clip, were compared first during hyper-, normo- and hypocapnia and at different pulse rates using a pacemaker, and then at 2-h intervals up to 8h. Agreement was assessed by Bland-Altman analysis. Results: PtcCO2 data of three patients were excluded because of calibration failure of the device. Median (range) PtcCO2 for the remaining patients was 5.49 (3.3-7.6) kPa and arterial carbon dioxide tension (PaCO2) was 5.43 (3.61-7.41) kPa. Corresponding mean bias was +0.05kPa and limits of agreement (LOA) were −1.2/+1.3kPa. During normo- and hypoventilation, mean bias was good at +0.02 and +0.04kPa respectively, but limits of agreement were poor at −0.67/+0.69 and −0.81/+0.88kPa. In 10 patients, an initial overshoot of PtcCO2 was observed. Mean bias of SpO2 and pulse rate was close to zero (−1.5% and +0.001bpm respectively), but limits of agreement were unacceptably high (−21.4/+18.4% and −22.3/+22.3bpm). Conclusions: In the present state of development the SenTeC Digital monitor V-Sign device has serious limitations. Additional efforts are necessary to eliminate calibration failures and the initial overshoot of PtcCO2 as well as to improve detection of SpO2 and pulse rate