Clinical performance of an in-line, ex vivo point-of-care monitor: a multicenter study.

BACKGROUND: The management of critically ill infants and neonates includes frequent determination of arterial blood gas, electrolyte, and hematocrit values. An objective of attached point-of-care patient monitoring is to provide clinically relevant data without the adverse consequences associated with serial phlebotomy. METHODS: We prospectively determined the mean difference (and SD of the difference) from laboratory methods of an in-line, ex vivo monitor, the VIA LVM Blood Gas and Chemistry Monitoring System (VIA LVM Monitor; Metracor Technologies, Inc.), in 100 critically ill neonates and infants at seven children's hospitals. In doing so, we examined monitor stability with continuous use. In vivo patient test results from laboratory benchtop analyzers were compared with those from the VIA LVM Monitor on paired samples. In a separate in vitro comparison, benchtop analyzer and monitor test results were compared on whole-blood split samples. RESULTS: A total of 1414 concurrent, paired-sample measurements were obtained. The mean differences (SD of differences) from laboratory methods and r values for the combined data for the VIA LVM Monitor from the seven sites were 0.001 (0.026) and 0.97 for pH, 0.7 (3.6) mmHg and 0.94 for PCO(2), 4.2 (9.6) mmHg and 0.98 for PO(2), 0.0 (2.9) mmol/L and 0.87 for sodium, 0.1 (0.2) mmol/L and 0.96 for potassium, and 0.3% (2.9%) and 0.90 for hematocrit. Performance results were similar among the study sites with increasing time of monitor use and between in vivo paired-sample and in vitro split-sample test results. CONCLUSION: The VIA LVM Monitor can be used to assess critically ill neonates and infants.

Coronary dilators and cardioplegia.

The distribution in the myocardium of cardioplegic solution is demonstrated in dog hearts with the aid of indocyanine green. When papaverine or nitroglycerin are added to the solution, a much improved diffusion is observed. Papaverine appears to be a better coronary dilator. We deduce from this observation that myocardial protection during ischemic arrest for open-heart surgery is enhanced considerably when coronary dilation is assured.

Pharmacodynamics of fentanyl citrate in patients undergoing aortocoronary bypass.

The pharmacodynamics of fentanyl citrate were studied in two groups of patients. One group underwent surgery with cardiopulmonary bypass (CPB) and the other group had surgery without CPB; the latter group represented the controls. Apneic periods were considerably longer (2.70 +/- 0.90 hr) for the CPB patients than for the control patients (1.75 +/- 0.75 hr). The total plasma fentanyl concentration at which apnea ceased was not statistically different between the two groups. Minor differences were attributed to the massive dilution of plasma proteins after the adding of priming fluid to the heart-lung machine. This prolongation of apnea is of considerable clinical importance because it means that CPB patients must remain mechanically ventilated for longer periods.