Reevaluation of the utilization of arterial blood gas analysis in the Intensive Care Unit: effects on patient safety and patient outcome.

PURPOSE: Arterial blood gas (ABG) analysis is a useful tool to evaluate hypercapnia in the context of conditions and diseases affecting the lungs. Oftentimes, indications for ABG analysis are broad and nonspecific and lead to frequent testing without test results influencing patient management. MATERIALS AND METHODS: Electronic charts of 300 intensive care unit (ICU) patients at a single institution were reviewed retrospectively. Reassessment of indications for ABGs led to a decrease of the number of ABGs in the ICU between March and November 2012. Data relating to ventilator days, length of stay, number of reintubations, mortality, complications after arterial puncture, demographics, and medications in 159 ICU patients between December 2011 and February 2012 (group 1) were compared with 141 ICU patients between December 2012 and February 2013 (group 2). Subgroup analysis in ventilated patients was performed. RESULTS: A decrease of number of ABGs per patient (6.12 ± 5.9, group 1 vs 2.03 ± 1.66, group 2 in ventilated patients; P = .007) was found along with a decrease in the number of ventilator days per patient (P = .004) and a shorter length of stay for ventilated patients in group 2 compared with group 1 (P = .04). CONCLUSION: A significant decrease of ABGs obtained in the ICU does not negatively impact patient outcome and safety. A decrease in the number of ABGs per patient allows cost-efficient patient care with a lower risk for complications.

Effects of early inhaled epoprostenol therapy on pulmonary artery pressure and blood loss during LVAD placement.

OBJECTIVE: Several strategies have been used to reduce the incidence of right ventricular failure after left ventricular assist device (LVAD) placement, including pulmonary vasodilation. The inhaled prostacyclin, epoprostenol, selectively dilates the pulmonary vasculature of ventilated areas of the lung, but also has been shown to inhibit platelet aggregation.(1) The authors evaluated the impact of early initiation of epoprostenol administration during LVAD placement on pulmonary artery pressures, use of vasoactive drugs, and blood loss. DESIGN: Retrospective data review. SETTING: Single center, university hospital. PARTICIPANTS: A total of 37 consecutive patients undergoing LVAD (HeartMate II) placement were included. INTERVENTIONS: In the first group of 23 patients (group 1), inhaled epoprostenol was not initiated until weaning from cardiopulmonary bypass (CPB). In a subsequent group of 14 patients (group 2), inhaled epoprostenol was started shortly after induction of anesthesia and continued throughout and post-CPB. MEASUREMENTS: Mean and systolic pulmonary artery pressures (mPAP, sPAP), vasoactive drugs, as well as hemodynamic parameters, blood loss, and use of blood products were recorded at the following time points: Baseline (BL), pre-CPB, post-CPB, and during postoperative days (POD) 0, 1, and 2. Data are presented as mean±SD or median [25%, 75%]. RESULTS: Groups did not differ in demographic characteristics and comorbidities. BL sPAP (41±13 v 46±15 mmHg; p = 0.051) and mPAP (32±8 v 34±8 mmHg; p = 0.483) values were not different between the groups. Systolic and mPAP in group 1 were significantly lower in the postoperative period compared with BL (sPAP on POD 0: 34±6 mmHg; p<0.001; mPAP on POD 0, 1, and 2: 24±4 mmHg, 25±4 mmHg, 27±6 mmHg; p<0.001-0.003)). In contrast, in group 2, sPAP as well as mPAP were significantly lower during weaning from CPB (sPAP: 37±8; p = 0.002; mPAP: 28±5 mmHg; p = 0.016) as well as in the postoperative period (sPAP on POD 0, 1 and 2: 34±7, 35±7, and 37±10 mmHg; p<0.001-0.004; mPAP on POD 0, 1, and 2: 24±4 mmHg, 25±5 mmHg, 27±6 mmHg; p<0.001-0.006). Blood loss on postoperative day 0 was significantly lower in group 1 (1646 mL [1137, 2300] v 2915 mL [2335, 6155]; p = 0.006). Epoprostenol was a significant predictor of blood loss in the regression model (p<0.001) but did not predict a change in sPAP. CONCLUSIONS: Inhaled prostacyclin reduces sPAP and mPAP in the postoperative period after LVAD placement regardless of the timing of initiation. Early initiation seems to reduce sPAP as well as mPAP more effectively during the weaning process from CPB. However, early initiation is associated with an increased blood loss in the immediate postoperative period. The concept of preventively "bathing" the lung in prostacyclin should be evaluated critically in a prospective fashion to adequately examine this question.

Volatile anesthetics-induced neuroinflammatory and anti-inflammatory responses.

Volatile anesthetics have been the major anesthetics used clinically for more than 150 years. They provide all components of general anesthesia and are easy to be applied and monitored with modern equipment and technology. In addition to having anesthetic property, volatile anesthetics have multiple other effects. Many studies have clearly shown that volatile anesthetics can reduce systemic and local inflammatory responses induced by various stimuli in humans and animals. On the other hand, recent animal studies have shown that volatile anesthetics may induce mild neuroinflammation. These dual effects on inflammation may have significant biological implications and are briefly reviewed here.

The ability of anesthesia providers to visually estimate systolic pressure variability using the "eyeball" technique.

BACKGROUND: Systemic arterial respiratory variation has been shown to be a reliable predictor of changes in cardiac output after fluid administration. Arterial respiratory variation is often estimated from visual examination of the arterial waveform tracing. Our goal in this study was to assess the ability of anesthesia providers to visually estimate systolic pressure variation (SPV) as a percentage of systolic blood pressure (SPV). METHODS: Fifty anesthesia providers were recruited and asked to visually examine 10 recorded arterial waveform tracings (played in real time), to estimate SPV, and to state whether or not a fluid bolus was indicated. After completion of the examination, the participants were shown the original tracings, the true value for SPV, and their estimate. The percentage of incorrect physician decisions to administer or not administer additional fluid was analyzed using a binomial proportion confidence interval. Clinical utility was also assessed using clinical significance analysis. Limits of agreement were analyzed using the nonparametric approach recommended by Bland and Altman. RESULTS: The mean bias was +1.2%. The nonparametric limits of agreement were -5.1 and 7.5%, and contained 82% of values. Actual physician decisions were incorrect 4.4% of the time (95% confidence interval [CI] 2.8% to 6.6%). On the basis of the clinical significance analysis, only 1% of treatments based on the visual estimation would have been incorrect. CONCLUSION: Visual estimates of respiratory variation are within clinically reasonable limits 82% of the time and lead to erroneous management decisions in 4.4% of measurements.