Weihan Chu

All Publications

• Validation of Test Performance and Clinical Time Zero for an Electronic Health Record Embedded Severe Sepsis Alert. Applied clinical informatics Rolnick, J., Downing, N. L., Shepard, J., Chu, W., Tam, J., Wessels, A., Li, R., Dietrich, B., Rudy, M., Castaneda, L., Shieh, L. 2016; 7 (2): 560-572

  Abstract

  Increasing use of EHRs has generated interest in the potential of computerized clinical decision support to improve treatment of sepsis. Electronic sepsis alerts have had mixed results due to poor test characteristics, the inability to detect sepsis in a timely fashion and the use of outside software limiting widespread adoption. We describe the development, evaluation and validation of an accurate and timely severe sepsis alert with the potential to impact sepsis management.To develop, evaluate, and validate an accurate and timely severe sepsis alert embedded in a commercial EHR.The sepsis alert was developed by identifying the most common severe sepsis criteria among a cohort of patients with ICD 9 codes indicating a diagnosis of sepsis. This alert requires criteria in three categories: indicators of a systemic inflammatory response, evidence of suspected infection from physician orders, and markers of organ dysfunction. Chart review was used to evaluate test performance and the ability to detect clinical time zero, the point in time when a patient develops severe sepsis.Two physicians reviewed 100 positive cases and 75 negative cases. Based on this review, sensitivity was 74.5%, specificity was 86.0%, the positive predictive value was 50.3%, and the negative predictive value was 94.7%. The most common source of end-organ dysfunction was MAP less than 70 mm/Hg (59%). The alert was triggered at clinical time zero in 41% of cases and within three hours in 53.6% of cases. 96% of alerts triggered before a manual nurse screen.We are the first to report the time between a sepsis alert and physician chart-review clinical time zero. Incorporating physician orders in the alert criteria improves specificity while maintaining sensitivity, which is important to reduce alert fatigue. By leveraging standard EHR functionality, this alert could be implemented by other healthcare systems.

  View details for DOI 10.4338/ACI-2015-11-RA-0159

  View details for PubMedID 27437061

  View details for PubMedCentralID PMC4941860

• Preoperative Angiotensin-converting Enzyme Inhibitor Use is Not Associated With Increased Postoperative Pain and Opioid Use CLINICAL JOURNAL OF PAIN Turan, A., Atim, A., Dalton, J. E., Keeyapaj, W., Chu, W., Bernstein, E., Fu, A., Ho, L. J., Saager, L., Sessler, D. I. 2013; 29 (12): 1050-1056

  Abstract

  Angiotensin-converting enzyme inhibitors (ACEIs) increase potent proinflammatory and pain mediators in local tissues. Consistent with these observations, animal and human studies demonstrate that ACEIs have hyperalgesic and proinflammatory properties. However, there is no information in literature whether or not the use of ACEIs is associated with increased postoperative pain. Specifically, we tested the primary hypothesis that use of ACEIs is independently associated with increased opioid requirements and pain scores during the initial 72 hours after surgery.Data from 9993 patients undergoing colorectal resection, hysterectomy, nephrectomy, or open prostatectomy were obtained from the Cleveland Clinic Perioperative Health Documentation System. A propensity-matching procedure was used to pair ACEI users to similar nonusers. Corresponding estimates and Bonferroni-adjusted 95% confidence intervals for the effect of ACEIs on each outcome were also estimated. The exact matching procedure, based on type of surgery and propensity score, identified 1038 matched pairs. The final analyzed subsample size was 212.The adjusted difference in mean 72-hour postoperative using a time-weighted average pain score was estimated at +0.17 [-0.40, +0.74] units on the verbal response scale. This was not statistically significant (P=0.50). Opioid use was estimated by the percent difference in mean 72-hour total postoperative intravenous morphine equivalent dose at -8.1% [-46%, +56%], which was not statistically significant (P=0.72). In conclusion, after controlling for all available factors, we found no significant difference that postoperative pain-as defined by either pain scores or opioid requirements-differed between patients taking ACEIs and patients not taking ACEIs.

  View details for DOI 10.1097/AJP.0b013e318287a258

  View details for Web of Science ID 000329937400011

  View details for PubMedID 24189772

• Consequences of Succinylcholine Administration to Patients Using Statins ANESTHESIOLOGY Turan, A., Mendoza, M. L., Gupta, S., You, J., Gottlieb, A., Chu, W., Saager, L., Sessler, D. I. 2011; 115 (1): 28-35

  Abstract

  Statins cause structural changes in myocytes and provoke myotoxicity, myopathy, and myalgias. Thus, patients taking statins may be especially susceptible to succinylcholine-induced muscle injury. The authors tested the hypothesis that succinylcholine increases plasma concentrations of myoglobin, potassium, and creatine kinase more in patients who take statins than in those who do not and that succinylcholine-induced postoperative muscle pain is aggravated in statin users.Patients who took statins for at least 3 months and those who had never used statins were enrolled. General anesthesia was induced and included 1.5 mg/kg succinylcholine for intubation. The incidence and degree of fasciculation after succinylcholine administration were recorded. Blood samples were obtained before induction and 5 and 20 min and 24 h after succinylcholine administration. Patients were interviewed 2 and 24 h after surgery to determine the degree of myalgia.The authors enrolled 38 patients who used statins and 32 who did not. At 20 min, myoglobin was higher in statin users versus nonusers (ratio of medians 1.34 [95% CI: 1.1, 1.7], P = 0.018). Fasciculations in statin users were more intense than in nonusers (P = 0.047). However, plasma potassium and creatine kinase concentrations were similar in statin users and nonusers, as was muscle pain.The plasma myoglobin concentration at 20 min was significantly greater in statin users than nonusers, although the difference seems unlikely to be clinically important. The study results suggest that the effect of succinylcholine given to patients taking statins is likely to be small and probably of limited clinical consequence.

  View details for DOI 10.1097/ALN.0b013e31822079fa

  View details for Web of Science ID 000291925400008

  View details for PubMedID 21606827