Pratik Doshi

Effect of Hemoglobin Transfusion Threshold on Cerebral Hemodynamics and Oxygenation

Cerebral dysfunction caused by traumatic brain injury may adversely affect cerebral hemodynamics and oxygenation leading to worse outcomes if oxygen capacity is decreased due to anemia. In a randomized clinical trial of 200 patients comparing transfusion thresholds <7 g/dl versus 10 g/dl, where transfusion of leukoreduced packed red blood cells was used to maintain the assigned hemoglobin threshold, no long-term neurological difference was detected. The current study examines secondary outcome measures of intracranial pressure (ICP), cerebral perfusion pressure (CPP), and brain tissue oxygenation (PbtO2) in patients enrolled in this randomized clinical trial. We observed a lower hazard for death (hazard ratio [HR]=0.12, 95% confidence interval [CI]=0.02-0.99) during the first 3 days post-injury, and a higher hazard for death after three days (HR=2.55, 95% CI=1.00-6.53) in the 10 g/dl threshold group as compared to the 7 g/dL threshold group. No significant differences were observed for ICP and CPP but MAP was slightly lower in the 7 g/dL group, although the decreased MAP did not result in increased hypotension. Overall brain tissue hypoxia events were not significantly different in the two transfusion threshold groups. When the PbtO2 catheter was placed in normal brain, however, tissue hypoxia occurred in 25% of patients in the 7 g/dL threshold group, compared to 10.2% of patients in the 10 g/dL threshold group (p=0.04). Although we observed a few differences in hemodynamic outcomes between the transfusion threshold groups, none were of major clinical significance and did not affect long-term neurological outcome and mortality.

The incidence of ARDS and associated mortality in severe TBI using the Berlin definition.

BACKGROUND The incidence of adult respiratory distress syndrome (ARDS) in severe traumatic brain injury (TBI) is poorly reported. Recently, a new definition for ARDS was proposed, the Berlin definition. The percentage of patients represented by TBI in the Berlin criteria study is limited. This study describes the incidence and associated mortality of ARDS in TBI patients. METHODS The study was an analysis of the safety of erythropoietin administration and transfusion threshold on the incidence of ARDS in severe TBI patients. Three reviewers independently assessed all patients enrolled in the study for acute lung injury/ARDS using the Berlin and the American-European Consensus Conference (AECC) definitions. A Cox proportional hazards model was used to assess the relationship between ARDS and mortality and 6-month Glasgow Outcome Scale (GOS) score. RESULTS Two hundred patients were enrolled in the study. Of the patients, 21% (41 of 200) and 26% (52 of 200) developed ARDS using the AECC and Berlin definitions, respectively, with a median time of 3 days (interquartile range, 3) after injury. ARDS by either definition was associated with increased mortality (p = 0.04) but not with differences in functional outcome as measured by the GOS score at 6 months. Adjusted analysis using the Berlin criteria showed an increased mortality associated with ADS (p = 0.01). CONCLUSION Severe TBI is associated with an incidence of ARDS ranging from 20% to 25%. The incidence is comparable between the Berlin and AECC definitions. ARDS is associated with increased mortality in severe TBI patients, but further studies are needed to validate these findings. LEVEL OF EVIDENCE Epidemiologic study, level II.

Using voluntary reports from physicians to learn from diagnostic errors in emergency medicine

Objectives Diagnostic errors are common in the emergency department (ED), but few studies have comprehensively evaluated their types and origins. We analysed incidents reported by ED physicians to determine disease conditions, contributory factors and patient harm associated with ED-related diagnostic errors. Methods Between 1 March 2009 and 31 December 2013, ED physicians reported 509 incidents using a department-specific voluntary incident-reporting system that we implemented at two large academic hospital-affiliated EDs. For this study, we analysed 209 incidents related to diagnosis. A quality assurance team led by an ED physician champion reviewed each incident and interviewed physicians when necessary to confirm the presence/absence of diagnostic error and to determine the contributory factors. We generated descriptive statistics quantifying disease conditions involved, contributory factors and patient harm from errors. Results Among the 209 incidents, we identified 214 diagnostic errors associated with 65 unique diseases/conditions, including sepsis (9.6%), acute coronary syndrome (9.1%), fractures (8.6%) and vascular injuries (8.6%). Contributory factors included cognitive (n=317), system related (n=192) and non-remedial (n=106). Cognitive factors included faulty information verification (41.3%) and faulty information processing (30.6%) whereas system factors included high workload (34.4%) and inefficient ED processes (40.1%). Non-remediable factors included atypical presentation (31.3%) and the patients’ inability to provide a history (31.3%). Most errors (75%) involved multiple factors. Major harm was associated with 34/209 (16.3%) of reported incidents. Conclusions Most diagnostic errors in ED appeared to relate to common disease conditions. While sustaining diagnostic error reporting programmes might be challenging, our analysis reveals the potential value of such systems in identifying targets for improving patient safety in the ED.

Association of transfusion red blood cell storage age and blood oxygenation, long-term neurologic outcome, and mortality in traumatic brain injury.

BACKGROUND The effect of red blood cell (RBC) storage on oxygenation in critically ill patients is still unknown. The objective of this study was to determine the association of RBC storage with oxygenation, long-term neurologic recovery, and death after traumatic brain injury. METHODS We used data from a 2 × 2 factorial randomized controlled trial of administration of erythropoietin or placebo and of assignment to transfusion threshold of less than 7g/dL or less than 10 g/dL in neurosurgical intensive care units in two US Level 1 trauma centers. Patients had severe traumatic brain injury with closed head injury, were unable to follow commands, and were enrolled within 6 hours of injury. Blood oxygenation 1 hour after the transfusion as measured by jugular venous oxygen saturation (n = 59) was the primary outcome. Secondary outcomes were brain tissue oxygenation (n = 77), 6-month Glasgow Outcome Scale (GOS) score (n = 122) collected using a structured interview and dichotomized into favorable (good recovery or moderate disability) or unfavorable outcome (severe disability, vegetative state, or dead), and mortality (n = 125). RBC age was defined as the maximum age of RBCs over all units in one transfusion per patient. For long-term outcomes, RBC age was defined as the mean age over all units given. RESULTS We failed to detect an association of RBC age with jugular venous oxygen saturation (linear regression &bgr; = 1.59; 95% confidence interval [CI], −2.99 to 6.18; p = 0.49), brain tissue oxygenation (linear regression &bgr; = 0.20; 95% CI, −0.23 to 0.63; p = 0.36), GOS score (odds ratio, 1.37; 95% CI, 0.53–3.57; p = 0.52), and mortality (hazard ratio, 1.35; 95% CI, 0.61–2.98; p = 0.46). CONCLUSION Limitations of this study include the fact that the RBC ages were not randomized, although this was a prospective study. We conclude that older blood does not seem to have adverse effects in severe traumatic brain injury. LEVEL OF EVIDENCE Prognostic study, level III.

Voluntary Medical Incident Reporting Tool to Improve Physician Reporting of Medical Errors in an Emergency Department

Introduction Medical errors are frequently under-reported, yet their appropriate analysis, coupled with remediation, is essential for continuous quality improvement. The emergency department (ED) is recognized as a complex and chaotic environment prone to errors. In this paper, we describe the design and implementation of a web-based ED-specific incident reporting system using an iterative process. Methods A web-based, password-protected tool was developed by members of a quality assurance committee for ED providers to report incidents that they believe could impact patient safety. Results The utilization of this system in one residency program with two academic sites resulted in an increase from 81 reported incidents in 2009, the first year of use, to 561 reported incidents in 2012. This is an increase in rate of reported events from 0.07% of all ED visits to 0.44% of all ED visits. In 2012, faculty reported 60% of all incidents, while residents and midlevel providers reported 24% and 16% respectively. The most commonly reported incidents were delays in care and management concerns. Conclusion Error reporting frequency can be dramatically improved by using a web-based, user-friendly, voluntary, and non-punitive reporting system.

Outcomes of Patients Requiring Blood Pressure Control Before Thrombolysis with tPA for Acute Ischemic Stroke

Introduction The purpose of this study was to assess safety and efficacy of thrombolysis in the setting of aggressive blood pressure (BP) control as it compares to standard BP control or no BP control prior to thrombolysis. Methods We performed a retrospective review of patients treated with tissue plasminogen activator (tPA) for acute ischemic stroke (AIS) between 2004–2011. We compared the outcomes of patients treated with tPA for AIS who required aggressive BP control prior to thrombolysis to those requiring standard or no BP control prior to thrombolysis. The primary outcome of interest was safety, defined by all grades of hemorrhagic transformation and neurologic deterioration. The secondary outcome was efficacy, determined by functional status at discharge, and in-hospital deaths. Results Of 427 patients included in the analysis, 89 received aggressive BP control prior to thrombolysis, 65 received standard BP control, and 273 required no BP control prior to thrombolysis. Patients requiring BP control had more severe strokes, with median arrival National Institutes of Health Stroke Scale of 10 (IQR [6–17]) in patients not requiring BP control versus 11 (IQR [5–16]) and 13 (IQR [7–20]) in patients requiring standard and aggressive BP lowering therapies, respectively (p=0.048). In a multiple logistic regression model adjusting for baseline differences, there were no statistically significant differences in adverse events between the three groups (P>0.10). Conclusion We observed no association between BP control and adverse outcomes in ischemic stroke patients undergoing thrombolysis. However, additional study is necessary to confirm or refute the safety of aggressive BP control prior to thrombolysis.

High-Velocity Nasal Insufflation in the Treatment of Respiratory Failure: A Randomized Clinical Trial

Study objective: We compare high‐velocity nasal insufflation, a form of high‐flow nasal cannula, with noninvasive positive‐pressure ventilation in the treatment of undifferentiated respiratory failure with respect to therapy failure, as indicated by requirement for endotracheal intubation or cross over to the alternative therapy. Methods: This was a multicenter, randomized trial of adults presenting to the emergency department (ED) with respiratory failure requiring noninvasive positive‐pressure ventilation. Patients were randomly assigned to high‐velocity nasal insufflation (initial flow 35 L/min; temperature 35°C (95°F) to 37°C (98.6°F); FiO2 1.0) or noninvasive positive‐pressure ventilation using an oronasal mask (inspiratory positive airway pressure 10 cm H2O; expiratory positive airway pressure 5 cm H2O). The primary outcome was therapy failure at 72 hours after enrollment. A subjective outcome of crossover was allowed as a risk mitigation to support deferment of informed consent. Noninferiority margins were set at 15 and 20 percentage points, respectively. Results: A total of 204 patients were enrolled and included in the analysis, randomized to high‐velocity nasal insufflation (104) and noninvasive positive‐pressure ventilation (100). The intubation rate (high‐velocity nasal insufflation=7%; noninvasive positive‐pressure ventilation=13%; risk difference=–6%; 95% confidence interval –14% to 2%) and any failure of the assigned arm (high‐velocity nasal insufflation=26%; noninvasive positive‐pressure ventilation=17%; risk difference 9%; confidence interval –2% to 20%) at 72 hours met noninferiority. The effect on PCO2 over time was similar in the entire study population and in patients with baseline hypercapnia. Vital signs and blood gas analyses improved similarly over time. The primary limitation was the technical inability to blind the clinical team. Conclusion: High‐velocity nasal insufflation is noninferior to noninvasive positive‐pressure ventilation for the treatment of undifferentiated respiratory failure in adult patients presenting to the ED.