No abstract

In anesthesia and critical care, invasive arterial blood pressure monitoring is the gold standard against which other methods of monitoring are compared. In this assessment of the Philips MP90 monitor, the objective was to determine whether or not oscillometric measurements were within the accuracy standards set by the Association for the Advancement of Medical Instrumentation (AAMI) and the British Hypertension Society (BHS). Three hundred and one invasive and noninvasive paired measurements were obtained from eleven adult patients on the neurosurgical service at Stanford University Medical Center. Bland-Altman plots were created to assess agreement between the two measurement systems. Paired correlation analysis, bias and precision calculations were performed. Oscillometric blood pressure measurements correlated with arterial measurements yielding Pearson r values of 0.68, 0.67 and 0.62 for systolic, diastolic and mean pressures, respectively (P < 0.01.) Mean differences with 95% confidence intervals were -3.8 mmHg +/- 13.6, -2.4 mmHg +/- 10.0, and 4.0 mmHg +/- 13.1 for systolic, diastolic and mean pressures, respectively. The mean difference for these measurements was

hour after induction of anesthesia, both RE and SE increased with respective peak values of 96 and 81. We increased the propofol and remifentanil target concentrations to values that caused hypotension, and treated him with ephedrine boluses, but this treatment failed to alter the RE and SE. The train-offour response elicited four twitches, indicating inadequate neuromuscular blockade. We treated the patient with 4 mg of cisatracurium, causing both RE and SE to abruptly decrease to 20 and 18 respectively, and BSR increased to 33 (Fig. 1).EMG artifact increased the RE and SE values, while depressing the BSR. This differs from prior reports suggesting that only RE is sensitive to EMG interference (1,2).