Blood pressure variability as an indicator of sepsis severity in adult emergency department patients.

STUDY OBJECTIVE: Quantify the correlation between blood pressure variability (BPV) and markers of illness severity: serum lactate (LAC) or Sequential Organ Failure Assessment (SOFA) scores. METHODS: We performed a secondary analysis of data from a prospective, observational study evaluating fluid resuscitation on adult, septic, ED patients. Vital signs and fluid infusion volumes were recorded every 15min during the 3h following ED arrival. BPV was assessed via average real variability (ARV): the average of the absolute differences between consecutive BP measurements. ARV was calculated for the time periods before and after 3 fluid infusion milestones: 10-, 20-, and 30-mL/kg total body weight (TBW). Spearman's rho correlation coefficient analysis was utilized. A p-value<0.05 was considered statistically significant. RESULTS: Forty patients were included. Mean fluid infusion was 33.7mL/kg TBW (SD 22.1). All patients received fluid infusion≥10mL/kg TBW, 25 patients received fluid infusion>20mL/kg TBW, and 16 patients received fluid infusion>30mL/kg TBW. Mean initial LAC was 4.0mmol/L (SD 3.2). Mean repeat LAC was 3.1mmol/L (SD 3.2), obtained an average of 6.6h (SD 5.3) later. Mean SOFA score was 7.0 (SD 4.4). BPV correlated with both follow-up LAC (r=0.564; p=0.023) and SOFA score (r=0.544; p=0.024) among the cohort that received a fluid infusion>20-mL/kg TBW. CONCLUSION: With the finding of a positive correlation between BPV and markers of illness severity (LAC and SOFA scores), this pilot study introduces BPV analysis as a real-time, non-invasive tool for continuous sepsis monitoring in the ED.

The Clinical Significance of Patient Specimen Transport Modality: Pneumatic Tube System Impact on Blood Gas Analytes.

INTRODUCTION: A pneumatic tube system (PTS) is a cost-effective, rapid transport modality that utilizes induced pressure changes. We evaluated the clinical importance of 2 transport modalities, human courier and PTS, for blood gas specimens. METHODS: Following open heart surgery, 35 simultaneous pairs of arterial and venous blood gas specimens were analyzed from 20 subjects. Of each pair, one specimen was transported to the blood gas laboratory via a human courier and the other via a SwissLog PTS. Transport modalities were compared using the Bland-Altman limits of agreement method. RESULTS: Compared with the walked specimen, the bias for PaO2 was -8.0 mm Hg (95% CI, -40.0 to 24.5 mm Hg); PaCO2 , -0.94 mm Hg (95% CI, -3.76 to 1.86 mm Hg); PvO2 , -0.60 mm Hg (95% CI, -6.90 to 5.70 mm Hg); PvCO2 , -0.58 mm Hg (95% CI, -3.12 to 1.92 mm Hg) for the PTS specimen. CONCLUSION: The difference in the PO2 and PCO2 of paired (walked vs tubed) arterial and venous blood gas specimens demonstrated a slight bias. PaO2 values demonstrated the greatest bias, however not clinically important. Thus, PTS transport does not impact clinical interpretations of blood gas values.

Overestimation of mortality risk and preoperative anxiety in patients undergoing elective general surgery procedures: a propensity matched analysis.

BACKGROUND: Deficiencies in risk communication have been identified in perioperative medicine. Objective measurement of risk overestimation by general surgery patients has not been performed. In addition, it is unknown if surgical risk overestimation is associated with the development of preoperative anxiety. The main objective of the current investigation was to examine the association between overestimation of surgical mortality risk and the development of preoperative anxiety. METHODS: Patients estimation of surgical morality risk was compared to the actual mortality risk obtained by the American College of Surgeons national database. Preoperative anxiety was evaluated using a validated instrument. Propensity matched analysis was performed to examine an independent association between mortality risk overestimation and preoperative anxiety. RESULTS: 138 patients completed the study. 40 out of 138 (29%) patients overestimated their surgical mortality risk by at least 5%. 31 out of 138 (22%) patients estimated their surgical mortality risk by at least 10%. Patients who overestimated mortality risk (≥5%) were more likely to have postponed the surgery voluntarily, 9 out of 40 (23%) compared to patients who did not overestimate risk, 1 out of 98 (1%), P < 0.001. After propensity matching to control for covariate imbalances, overestimation of mortality risk was associated with the development of preoperative anxiety, OR (95%CI) of 9.5 (2.7-32.9). CONCLUSIONS: Overestimation of perioperative mortality risk is common in patients undergoing general surgery and it is associated with preoperative anxiety and voluntarily delays of surgical treatment. Improved communication strategies are needed to minimize misleading risk perception in surgical patients.