Eight physiological variables--tidal volume, breathing rate, end-tidal carbon dioxide fraction, oxygen fraction in the anesthetic circuit, oxygen saturation by pulse oximetry, systolic and diastolic blood pressure, and heart rate--recorded on-line by a commercially available automated system were compared with the same variables recorded on handwritten anesthesia records. We quantified the differences between the automated and handwritten records generated from the same 30 patients (2,412 minutes of general anesthesia for elective eye surgical procedures). Considering the design of the study, we claim that the differences between both records were caused by the incompleteness or inaccuracy of the handwritten records, except in two instances. The amounts of missing or erroneous data for these eight physiological variables were expressed as fraction ("error fractions") of the time being recorded, designated EFm and EFe, respectively. For the first five variables the EFm on the handwritten records ranged between 0.23 and 0.31, and the EFe ranged between 0.01 and 0.06. For the last three variables the EFm range was 0.08 to 0.13, and the EFe range was 0.05 to 0.11. Most of these missing or erroneous data occurred during the period of induction (first 15 minutes) and at the end of the case (last 10 minutes). The EFm and EFe during induction had increased to 0.62 and 0.26, respectively, and to 0.76 and 0.06, respectively, at the end of the case. Erroneous data were observed on the automated records for the tidal volume during induction (EFe = 0.0044) and for the oxygen fraction during maintenance (EFe = 0.0024). The effect of averaging by the recordkeeper is discussed. The results of this study indicate the clinical relevance of automated record keeping.

We determined the dose-response relationship, the onset time, the duration, and the recovery time of a rocuronium neuromuscular block under four anesthesia techniques. Patients were equally randomized to four different groups (n = 20) receiving 0.5%-1% halothane, 1.5%-2% enflurane, 1.2%-1.8% isoflurane end-tidal concentration in 34%/66% O2/N2O, or 6.0 mg.kg-1 x h-1 propofol without N2O for anesthesia and alfentanil for analgesia. Strength of thumb adduction in response to single and train-of-four stimulation of the ulnar nerve was quantitated. Rocuronium 0.15, 0.2, 0.25, and 0.3 mg/kg were given intravenously. When maximal depression of twitch tension occurred, supplemental doses up to a total of 0.5 mg/kg were given. If required, additional doses of 0.15 mg/kg were given at 25% recovery of control twitch tension. Standard hemodynamics, end-tidal CO2, and anesthetic gas concentrations were monitored continuously. The mean ED50 (SD) was 0.133 (+/- 0.009) mg/kg for the halothane group, 0.118 (+/- 0.012) mg/kg for the enflurane group, 0.069 (+/- 0.026) mg/kg for the isoflurane group, and 0.167 (+/- 0.007) mg/kg for the total intravenous anesthesia (TIVA) group, respectively. There was a statistically significant difference between the halothane and TIVA, and between the enflurane and TIVA groups (P < 0.05). Rocuronium has a short onset time and an intermediate duration of action. The neuromuscular blocking potency and pharmacodynamic profile are moderately influenced by volatile anesthetics.

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