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D Porembka

Publications and source records attributed to D Porembka.

6 recordsLinked to original sources
PubMed1997

Avoidance of nitrous oxide and increased isoflurane during alfentanil based anesthesia decreases the incidence of postoperative nausea.

Postoperative nausea and vomiting have been associated with the use of nitrous oxide. Alfentanil, when combined with nitrous oxide, also results in a high incidence of postoperative nausea and vomiting. To further define this emesis-potentiating effect of N2O, 119 patients were chosen for study and divided into two groups: group A (n = 59) was administered a mixture of alfentanil, N2O, and O2 with 0.25% isoflurane, group B (n = 60) was administered a mixture of oxygen, room air, isofluorane, and alfentanil. The incidence of postoperative nausea and vomiting was ascertained by a blinded observer in the recovery room. All 119 patients were scheduled for extra-abdominal procedures (excluding thoracotomial, intracranial, ophthalmologic, and middle ear surgery). Patients with a previous history of nausea and vomiting, hiatal hernias, reflux esophagitis, or morbid obesity were excluded. The incidence of vomiting was 5% (3/60) in group B and 15% (8/59) in group A (P = 0.067). Forty-four percent (26/59) of the patients in group A and 20% (12/59) in group B were nauseated postoperatively (P = 0.005). Our data suggest that elimination of N2O from alfentanil-based anesthetics lessens the incidence of nausea.

Adolescent↗
PubMed1995

A model for technology assessment as applied to closed loop infusion systems. Technology Assessment Task Force of the Society of Critical Care Medicine.

OBJECTIVES: To test a model for the assessment of critical care technology on closed loop infusion control, a technology that is in its early stages of development and testing on human subjects. DATA SOURCES: A computer-assisted search of the English language literature and reviews of the gathered data by experts in the field of closed loop infusion control systems. STUDY SELECTION: Studies relating to closed loop infusion control that addressed one or more of the questions contained in our technology assessment template were analyzed. Study design was not a factor in article selection. However, the lack of well-designed clinical outcome studies was an important factor in determining our conclusions. DATA EXTRACTION: A focus person summarized the data from the selected studies that related to each of the assessment questions. The preliminary data summary developed by the focus person was further analyzed and refined by the task force. Experts in closed loop systems were then added to the group to review the summary provided by the task force. These experts' comments were considered by the task force and this final consensus report was developed. DATA SYNTHESIS: Closed loop system control is a technological concept that may be applicable to several aspects of critical care practice. This is a technology in the early stages of evolution and much more research and data are needed before its introduction into usual clinical practice. Furthermore, each specific application and each device for each application (e.g., nitroprusside infusion, ventilator adjustment), although based on the same technological concept, are sufficiently different in terms of hardware and computer algorithms to require independent validation studies. CONCLUSIONS: Closed loop infusion systems may have a role in critical care practice. However, for most applications, further development is required to move this technology from the innovation phase to the point where it can be evaluated so that its role in critical car practice can be defined. Each application of closed loop infusion systems must be independently validated by appropriately designed research studies. Users should be provided with the clinical parameters driving each closed loop system so that they can ensure that it agrees with their opinion of acceptable medical practice. Clinical researchers and leaders in industry should collaborate to perform the scientifically valid, outcome-based research that is necessary to evaluate the effect of this new technology. The original model we developed for technology assessment required the addition of several more questions to produce a complete analysis of an emerging technology. An emerging technology should be systematically assessed (using a model such as the model developed by the Society of Critical Care Medicine), before its introduction into clinical practice in order to provide a focus for human outcome validation trials and to minimize the possibility of widespread use of an unproven technology.

Algorithms↗
PubMed1993

Airway pressure release ventilation.

BACKGROUND: Elevated airway pressures during mechanical ventilation are associated with hemodynamic compromise and pulmonary barotrauma. We studied the cardiopulmonary effects of a pressure-limited mode of ventilation (airway pressure release ventilation) in patients with the adult respiratory distress syndrome. METHODS: Fifteen patients requiring intermittent mandatory ventilation (IMV) and positive end-expiratory pressure (PEEP) were studied. Following measurement of hemodynamic and ventilatory data, all patients were placed on airway pressure release ventilation (APRV). Cardiorespiratory measurements were repeated after a 2-hour stabilization period. RESULTS: During ventilatory support with APRV, peak inspiratory pressure (62 +/- 10 vs 30 +/- 4 cm H2O) and PEEP (11 +/- 4 vs 7 +/- 2 cm H2O) were reduced compared with IMV. Mean airway pressure was higher with APRV (18 +/- 5 vs 24 +/- 4 cm H2O). There were no statistically significant differences in gas exchange or hemodynamic variables. Both cardiac output (8.7 +/- 1.8 vs 8.4 +/- 2.0 L/min) and partial pressure of oxygen in arterial blood (79 +/- 9 vs 86 +/- 11 mm Hg) were essentially unchanged. CONCLUSIONS: Our results suggest that while airway pressure release ventilation can provide similar oxygenation and ventilation at lower peak and end-expiratory pressures, this offers no hemodynamic advantages.

Adult↗
PubMed1992

Laboratory and clinical evaluation of the impact Uni-Vent 750 portable ventilator.

BACKGROUND: Transportation of critically ill, mechanically ventilated patients from intensive care units for diagnostic and therapeutic procedures has become common in the last decade. Maintenance of adequate oxygenation and ventilation during transport is essential. We evaluated the Impact Uni-Vent 750 portable ventilator in the laboratory and in the clinical arena to determine its usefulness during inhospital transport. MATERIALS & METHODS: In the laboratory, we determined the Uni-Vent 750's ability to assure tidal volume (VT) delivery in the face of decreasing compliance of a test lung and tested the alarm systems. Using a two-compartment lung model modified to simulate spontaneous breathing, we also evaluated the responsiveness of the demand valve. The clinical evaluation was accomplished by comparing arterial blood gas values and ventilator settings in the intensive care unit before transport to those during transport. RESULTS: As lung compliance was reduced from 0.1 to 0.02 mL/cm H2O [1.0 to 0.20 L/kPa], a slight, statistically insignificant decrease in delivered tidal volume was observed. All alarm systems operated according to manufacturer's specifications. The demand valve triggered appropriately with PEEP from 0 to 20 cm H2O [0 to 1.96 kPa]. Sensitivity settings less than -6 cm H2O [-0.59 kPa] sometimes resulted in inability to trigger the demand valve. During patient transport, arterial blood gas values and ventilator settings were comparable to those observed in the ICU. Because an FIO2 of 1.0 was used during transport, mean (SD) PaO2 was significantly greater 89 (26) vs 341 (78) [11.8 (3.5) vs 45.3 (10.4) kPa]. CONCLUSIONS: The Uni-Vent 750 is a reliable transport ventilator, capable of maintaining adequate oxygenation and ventilation in a majority of mechanically ventilated patients. The Uni-Vent 750's ability to (1) provide CMV, AMV, and SIMV; (2) provide low and high pressure alarms; and (3) provide PEEP compensation is unique among portable ventilators.

Adult↗
PubMedDate not supplied

Effects of body temperature on accuracy of continuous cardiac output measurements.

Intermittent measurement of cardiac output is routine in the critically ill surgical patient. A new catheter allows real-time continuous measurement of cardiac output. This study evaluated the impact of body temperature variation on the accuracy of these measurements compared to standard intermittent bolus thermodilution technique. This prospective study in a university hospital surgical intensive care unit included 20 consecutive trauma patients. Data were collected with pulmonary artery catheters, which allowed both continuous (COC) and bolus (COB) thermodilution measurements. The catheter was placed through either the subclavian or internal jugular vein. Measurements for COB were performed using a bolus (10 cm3) of ice-cold saline with a closed-injectate delivery system at end-expiration. Computer-generated curves were created on a bedside monitor, and the average of three measurements within 10% of one another was used as COB. COC was determined as the average of the displayed CO before and after thermodilution CO measurements. Body temperature was measured from the pulmonary artery catheter and was grouped as < or =36.5 degrees C, 36.6-38.4 degrees C, and > or =38.5 degrees C. COB and COC were compared for agreement by plotting the mean of the differences (COB - COC) between the methods. The differences were plotted against the average of each pair and analyzed with linear regression. One hundred seventy-eight paired measurements were made over a period of 1 to 3 days. CO ranged from 3.7 to 15.5 L/min. Eighty-one percent of measurements were at a temperature of 36.5-38.4 degrees C. Approximately 7% of measurements were at a temperature below 36.5 degrees C and 11.2% were in patients with a core temperature above 38.5 degrees C. Correlation between the two techniques was 0.96, 0.91, and 0.82 for temperatures of < or =36.5 degrees C, 36.6-38.4 degrees C, and > or = 38.5 degrees C, respectively. In conclusion, the COC measurements correlate well with COB in trauma patients with a core temperature < or =38.5 degrees C. The accuracy degraded at higher temperatures, which may be related to the smaller signal-to-noise ratio at elevated body temperatures.

Adult↗