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J A Pino

Publications and source records attributed to J A Pino.

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In vitro assessment of a flow-through fluorometric blood gas monitor.

The Gas-STAT blood gas monitor uses fluorometric techniques to continuously monitor blood gas tensions and acid-base status in the extracorporeal perfusion circuit during cardiac surgery. We evaluated the in vitro performance of this instrument by using a tonometry loop to simulate the clinical environment and to provide controlled gas tensions and pH in the circulating fluid. In this article we report the in vitro study in which 35 Gas-STAT blood gas sensors were used to assess the precision, stability, response time, and specificity of the instrument and to confirm the sterile integrity of its flow-through cells. The blood gas monitor exhibited precision values for pH, carbon dioxide tension (PCO2), and oxygen tension (PO2) of 0.1%, 1.3%, and 1.0%, respectively; stabilities were 0.002 units/h for pH, 0.5 mm Hg/h for PCO2, and 1.4 mm Hg/h for PO2; time constants (tau, a response to within 1/e of a new gas tension, approximately 63%) were 81 seconds for PCO2 and 72 seconds for PO2. No significant interference was detected in in vitro tests of 30 drugs and metabolites typically encountered during cardiac surgery. Bacterial challenge of the flow-through cell membranes showed that they provide an effective barrier isolating the sensors from contaminants in the fluid path. Our quality control consisted of measurement of a midrange gas standard as an unknown immediately following sensor calibration; this simple program is proposed as a complement to the manufacturer's operating procedures.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Gas Analysis

Clinical assessment of a flow-through fluorometric blood gas monitor.

We performed an observational study to evaluate a flow-through fluorometric instrument (Gas-STAT) that continuously measures the carbon dioxide tension (PCO2), oxygen tension (PO2), and pH of blood in the cardiopulmonary bypass circuit. Setup and calibration of the instrument typically required 20 minutes. During bypass, 129 blood samples were drawn from 16 patients for comparison with conventional measurements obtained with a blood gas machine. Data for each variable, within each sensor, were analyzed by linear regression. The ranges of the standard errors of the estimate were 0.7 to 4.2 mm Hg for PCO2, 18.3 to 78.7 mm Hg for the high PO2 range, 1.4 to 7.1 mm Hg for the low PO2 range, and 0.008 to 0.049 for pH. The regression lines differed from the identity line (P less than 0.05) in at least one variable in most patients, and large deviations from the line of identity in both slope and intercept were common. Among 58 sensors evaluated, failures occurred in 5 (2.9%) of the 174 optodes, and minor leakage occurred in 2 (3.4%) of the flow-through cells. We conclude that although this flow-through fluorometric instrument is an adequate monitor of trends in blood gases during cardiopulmonary bypass, it is not accurate enough to supplant conventional laboratory measurements.

Blood Gas Analysis

Hyperthyroidism.

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Low risk of contrast media-induced acute renal failure in nonazotemic type 2 diabetes mellitus.

The risk of developing contrast media-induced acute renal failure was studied in 49 randomly selected nonazotemic type 2 adult diabetic patients subjected to IVU. There were 19 men and 30 women in the group whose mean age was 62 +/- 10 years (range, 38 to 82 years). In preparation for IVU, patients were neither dehydrated nor given a laxative. The IVU was performed in the morning, using sodium diatrizoate and meglumine diatrizoate. Serum creatinine levels were measured pre-IVU and on days 1, 3, and 6 after the IVU. A total of three patients (6%) had an elevation of serum creatinine greater than 25% above the baseline by post-IVU day 3. One patient developed oliguria (less than 400 ml/24 hr) that lasted 2 days. Creatinine clearances of the three patients showing contrast media toxicity were 74, 60, and 105 ml/min pre-IVU. In each of the three patients, a return to pre-IVU serum creatinine concentration was noted within 2 weeks. It is concluded that the risk of acute renal failure post-IVU is small in hydrated nonazotemic type 2 diabetic patients.

Acute Kidney Injury