Felix Y. Lui

Blunt cerebrovascular injuries: does treatment always matter?

BACKGROUND Blunt cerebrovascular injuries (BCVI) have become an increasingly recognized entity. Stroke as a result of these injuries can have devastating consequences. Optimal screening criteria, diagnostic imaging, and therapy for BCVIs have not been elucidated. Our institution began to apply liberal screening criteria using a whole-body scanning protocol with multidetector computed tomographic (WB-MDCT) scans to diagnose these injuries. The purpose of this study is to describe a single institutions large experience in patients with BCVI in an effort to provide insight into the diagnosis and management of these injuries. METHODS All patients with a BCVI admitted to the R Adams Cowley Shock Trauma Center during a 30-month period were included in this study. Choice of diagnostic evaluation and treatment regimens were at the discretion of the treating attending physician. Review of medical records and all relevant radiographic studies were retrospectively performed for the purposes of this study. RESULTS During the study period, there were 12,667 patients admitted to the R Adams Cowley Shock Trauma Center. There were 147 patients identified with 200 carotid or vertebral artery injuries. The incidence of BVCI was 1.2%. Mortality was 13%. Anatomic injury risk factors for BCVI (major facial fractures, skull base fractures, cervical spine fractures or spinal cord injury, or traumatic brain injury) were found in only 78%. Major thoracic injury was found in 63% of patients with carotid artery injuries and cervical spine fractures or spinal cord injury was found in 74% of patients with vertebral artery injuries. The initial screening test employed was a WB-MDCT in 96% of patients of which 84% detected a BCVI. Treatments included endovascular therapy (22%), antiplatelet medications (36%), anticoagulation (10%), and combination therapy with antiplatelet agents and anticoagulation (18%). Thirty percent received no therapy, primarily due to contraindications from concomitant injuries. There were 18 (12%) patients who had a stroke. Of these patients, 8 (44%) had evidence of infarction at admission, 6 were diagnosed within 72 hours, and 4 were diagnosed after 1 week. Stroke-related mortality was 50%, whereas clinical follow-up after hospital discharge demonstrated only one patient with disability as a result of infarction. Of 10 patients who did not have stroke at admission, 3 were fully treated, 5 had specific contraindications to therapy, and 2 had no or false-negative imaging before infarction. Stroke rates for untreated patients were 25.8% and patients treated with any therapy had a stroke rate of 3.9% (p = 0.0003). Radiographic follow-up >1 month after injury demonstrated improvement in over 50% of patients. CONCLUSIONS BCVIs are not infrequent after blunt trauma. These injuries occur even in the absence of classically described risk factors. Liberal screening with WB-MDCT incorporates detection of these injuries into the initial diagnostic evaluation. Stroke occurs in a substantial number of patients and carries a very high mortality. However, nearly one third of patients with BCVI are not candidates for therapy. Treatment does reduce the risk of infarction in patients with BCVI, but strokes, when they occur, are not preventable.

The status of massive transfusion protocols in United States trauma centers: massive transfusion or massive confusion?

BACKGROUND: Massive transfusion protocol (MTP) utilization and makeup is unknown.

Contrast-induced nephropathy in elderly trauma patients.

BACKGROUND Computed tomography (CT) is the gold standard for the identification of occult injuries, but the intravenous (IV) contrast used in CT scans is potentially nephrotoxic. Because elderly patients have decreased renal function secondary to aging and chronic disease, we sought to determine the rate of acute kidney injury (AKI) in elderly trauma patients exposed to IV contrast. METHODS Medical records of patients older than 55 years evaluated at a level-one trauma center between January 2003 and July 2008 were reviewed. Contrast was nonionic, isosmolar, and administered in standard volumes. Groups were based on administration of contrast. AKI was defined as a 25% relative or 0.5 mg/dL absolute increase in serum creatinine within 72 hours of presentation [corrected]. RESULTS During the study period 1,371 patients older than 55 years were evaluated, and 1,152 met the inclusion criteria. CT was performed on 1,071 patients (96%); 71% of this group received IV contrast. There was no significant difference between the contrast and noncontrast groups in terms of baseline characteristics. Criteria for AKI were satisfied in 2.1% of all patients, including 1.9% the contrast group versus 2.4% in the noncontrast group. AKI diagnosed within 72 hours of patient presentation was an independent risk factor for in-hospital mortality and prolonged length of stay. CONCLUSIONS IV contrast media in elderly trauma patients is not associated with an increased risk of AKI. Development of AKI within 72 hours of admission is associated with mortality and increased length of stay.

Screening for blunt cardiac injury: an Eastern Association for the Surgery of Trauma practice management guideline.

BACKGROUND Diagnosing blunt cardiac injury (BCI) can be difficult. Many patients with mechanism for BCI are admitted to the critical care setting based on associated injuries; however, debate surrounds those patients who are hemodynamically stable and do not otherwise require a higher level of care. To allow safe discharge home or admission to a nonmonitored setting, BCI should be definitively ruled out in those at risk. METHODS This Eastern Association for the Surgery of Trauma (EAST) practice management guideline (PMG) updates the original from 1998. English-language citations were queried for BCI from March 1997 through December 2011, using the PubMed Entrez interface. Of 599 articles identified, prospective or retrospective studies examining BCI were selected. Each article was reviewed by two members of the EAST BCI PMG workgroup. Data were collated, and a consensus was obtained for the recommendations. RESULTS We identified 35 institutional studies evaluating the diagnosis of adult patients with suspected BCI. This PMG has 10 total recommendations, including two Level 2 updates, two upgrades from Level 3 to Level 2, and three new recommendations. CONCLUSION Electrocardiogram (ECG) alone is not sufficient to rule out BCI. Based on four studies showing that the addition of troponin I to ECG improved the negative predictive value to 100%, we recommend obtaining an admission ECG and troponin I from all patients in whom BCI is suspected. BCI can be ruled out only if both ECG result and troponin I level are normal, a significant change from the previous guideline. Patients with new ECG changes and/or elevated troponin I should be admitted for monitoring. Echocardiogram is not beneficial as a screening tool for BCI and should be reserved for patients with hypotension and/or arrhythmias. The presence of a sternal fracture alone does not predict BCI. Cardiac computed tomography or magnetic resonance imaging can be used to differentiate acute myocardial infarction from BCI in trauma patients.

Pulseless electrical activity, focused abdominal sonography for trauma, and cardiac contractile activity as predictors of survival after trauma.

BACKGROUND Pulseless electrical activity (PEA) secondary to both blunt and penetrating trauma is associated with minimal survival. The pericardial view of the focused abdominal sonography for trauma (p-FAST) can differentiate between patients with and without organized cardiac activity and may assist in the decision to terminate ongoing resuscitation. METHODS A retrospective review was performed for all patients presenting to a level I trauma center from January 2006 through January/2009 who had PEA on arrival or developed PEA in the emergency department. Additional data abstracted included outcome, the p-FAST findings, and mechanism of injury. Recorded FAST examinations were reviewed by a blinded ultrasound trained physician. RESULTS During the study period 25 patients presented with PEA and three developed PEA during initial resuscitation. Contractile cardiac activity was present in nine patients with PEA on presentation and immediately after deterioration to PEA in the three patients developing PEA. Four patients had a penetrating mechanism and 24 were blunt. Two pericardial effusions were present on examination, both after blunt trauma. Three patients survived beyond the emergency department (89% early mortality). The survivors had presented in PEA with organized cardiac contractile activity on ultrasound and had tension pneumothorax, tension hemothorax, and hypovolemia treated. Two patients died in the operating room of uncontrolled hemorrhage and one patient died 6 days after admission because of closed head injury. CONCLUSIONS The presence of PEA at any time during initial resuscitation is a grave prognostic indicator. p-FAST is a useful test to identify contractile cardiac activity. p-FAST may identify those patients with potential for survival.

Compared to conventional ventilation, airway pressure release ventilation may increase ventilator days in trauma patients.

BACKGROUND Airway pressure release ventilation (APRV) is used both as a rescue therapy for patients with acute lung injury and as a primary mode of ventilation. Unlike assist-control volume (ACV) ventilation that uses spontaneous breathing trials, APRV weaning consists of gradual decreases in supporting pressure. We hypothesized that the APRV weaning process increases total ventilator days compared with those of spontaneous breathing trials–based weaning. METHODS A retrospective review of a Level I trauma center’s database identified trauma admissions from January 1, 2007, to December 31, 2010, which required mechanical ventilation for more than 24 hours and survived. Demographics, injuries, in-hospital complications, ventilation mode(s), and total ventilator days were abstracted. RESULTS A total of 362 patients fulfilled study entry criteria; 53 patients with more than one ventilator mode change were excluded. Seventy-five patients were successfully liberated from mechanical ventilation on APRV and 234 on ACV. The APRV and ACV groups, respectively, were similar in age (46.1 vs. 44.6 years) and sex (72% vs. 73% male) but differed in Injury Severity Score (20.8 vs. 17.5; p = 0.03). Patients on APRV had higher rates of abdominal compartment syndrome (6.7% vs. 0.8%, p = 0.003) and were more likely to have a higher chest Abbreviated Injury Scale (AIS) score ≥3 (57.3% vs. 30.8%, p < 0.001). Ventilator days were significantly greater in the APRV group (19.6 vs. 10.7 days, p < 0.001). Multiple regression was performed to adjust for the clinical differences between the two groups, identifying APRV as an independent predictor for increased number of ventilator days (B = 6.2 ± 1.5, p < 0.001) in addition to male sex, abdomen AIS score of 3 or higher, spine AIS score of 3 or higher, acute renal failure, and sepsis. CONCLUSION APRV is frequently used for patients who are more severely injured or who develop in-hospital complications such as pneumonia. However, after controlling for potential confounding factors in a multiple regression model, the APRV mode itself seems to increase ventilator days. LEVEL OF EVIDENCE Therapeutic study, level IV.

A physicochemical approach to acid-base balance in critically ill trauma patients minimizes errors and reduces inappropriate plasma volume expansion

BACKGROUND This study assesses if a physicochemical (PC) approach to acid-base balance improves the accuracy of acid-base diagnosis, and reduces inappropriate fluid loading. METHODS Hundred consecutive patients with trauma admitted to a surgical intensive care unit at a level I trauma center were prospectively analyzed. Demographics, acid-base data and diagnoses, and interventions were collected. Patients were cared for by one physician using a PC approach, or four using conventional (CONV) acid-base balance techniques. The diagnoses and interventions made by CONV physicians were reviewed by the PC physician for accuracy and appropriateness using PC techniques. Data are mean +/- SD or percents; p values reflect PC evaluation of CONV analysis. RESULTS There were 50 PC patients and 50 CONV. There were no differences in age (p = 0.13), injury severity score (p = 0.21), number of operations (p = 0.87), transfusions (p = 0.87), or survival (p = 0.15). CONV missed 12 diagnoses of metabolic acidosis (p = 0.03), 10 of hyperchloremic metabolic acidosis (p = 0.003), 11 metabolic alkalosis (p = 0.02), and 19 tertiary disorders (p < 0.001). CONV missed 38 diagnoses of increased unmeasured ions (p < 0.001). PC normalized their acid-base balance sooner than CONV (3.3 days +/- 3.4 days vs. 8.3 days +/- 7.4 days, p < 0.01). CONCLUSIONS A PC approach improves acid-base diagnosis accuracy. CONV often miss acidosis (particularly those because of hyperchloremia), alkalosis, and tertiary disorders. Inappropriate volume loading follows in the wake of misinterpretation of increased base deficit using CONV and is avoided using PC. PC-directed therapy normalizes acid-base balance more rapidly than CONV.

The Use of Magnetic Resonance Imaging in the Diagnosis of Suspected Appendicitis in Pregnancy : Shortened Length of Stay Without Increase in Hospital Charges

IMPORTANCE Making an accurate diagnosis of appendicitis in pregnancy is critical for maternal and fetal outcomes. OBJECTIVE To determine whether magnetic resonance (MR) imaging in pregnant patients with suspected appendicitis improves outcomes, minimizes length of stay (LOS), and lowers hospital charges. DESIGN, SETTING, AND PARTICIPANTS Retrospective review at a university tertiary referral center of all pregnant patients seen with abdominal pain and suspected appendicitis who were followed up through delivery during an 11-year period. MAIN OUTCOMES AND MEASURES Time to operation, LOS, complications, nontherapeutic exploration, fetal outcomes, and hospital charges. RESULTS Seventy-nine patients were included in this study, 34 of whom had pathology-confirmed appendicitis. Thirty-one patients underwent MR imaging. A trend toward fewer operations (odds ratio [OR], 0.45; 95% CI, 0.18-1.16; P = .07) was observed in the MR imaging group. Seven nontherapeutic explorations were performed in the non-MR imaging group and 1 nontherapeutic exploration in the MR imaging group (OR, 0.44; 95% CI, 0.08-2.32; P = .13). Patients in the MR imaging group were more frequently discharged from the emergency department (OR, 0.35; 95% CI, 0.13-0.94; P = .04) and had shorter LOS (33.7 vs 64.8 hours, P < .001). Gestational age, time to operation, and the presence of perforated appendicitis were similar between groups. No patient discharged without operation returned with appendicitis in either group. On multivariable analysis, the receipt of MR imaging (P < .001) and the absence of operative intervention (P = .001) were associated with shorter LOS. The mean hospital charges were similar in those with vs without appendicitis. One fetal loss occurred in the non-MR imaging group. CONCLUSIONS AND RELEVANCE Magnetic resonance imaging in pregnant patients with suspected appendicitis does not affect clinical outcomes or hospital charges. It allows safe discharge from the emergency department and improves resource use.

Uncovering System Errors Using a Rapid Response Team: Cross-coverage Caught in the Crossfire

BACKGROUND Because of the 80-hour work week, extensive service cross-coverage creates great potential for patient care errors. These patient care emergencies are increasingly managed using a rapid response team (RRT) to reduce patient morbidity. We examine the proximate causes of a surgical RRT activation. We hypothesize that most RRTs would occur during cross-coverage hours and be preventable or potentially preventable. METHODS All surgical RRTs more than a 15-month period were captured using a nursing database and the note from the staffing intensivist/fellow. RRTs were reviewed for appropriateness (pre-existing criteria) and proximate cause. Proximate causes were further classified as patient disease, team error, nursing error, or system error as well as preventable, potentially preventable, or nonpreventable. RESULTS Of 98 RRT activations, complete data were available for 82 (84%); 100% met activation criteria; and 76 (93%) occurred between 2100 and 0600. Seventy-six patients were 48 hours to 72 hours postoperative; six had nonoperatively managed injuries. The most common reason for activation was impending respiratory failure and acute volume overload (n = 72; 88%). RRT therapies included diuretics (n = 72), antiarrhythmics (n = 48), oxygen (n = 82), and bronchodilators (n = 36); only 2 received blood component therapy. Seventy-eight patients (95%) were transferred to higher level of care (61, surgical intensive care unit; 17, SSDU). Only 46% of patients required intubation. Performance improvement review identified 90% of physician related RRTs as preventable/potentially preventable because of errors in judgment or omission. Four RRTs because of patient disease were unpreventable. Two potentially preventable errors were each ascribed to RN or system concerns. CONCLUSION RRT activations principally result from team-based errors of omission, more often occur between 2100 and 0600, and are more often preventable or potentially preventable. Careful attention to fluid balance and medications for comorbid diseases would reduce RRT needs.

Development of a computed tomography-based scoring system for necrotizing soft-tissue infections.

BACKGROUND Necrotizing soft-tissue infections (NSTIs) are associated with significant morbidity and mortality, but a definitive nonsurgical diagnostic test remains elusive. Despite the widespread use of computed tomography (CT) as a diagnostic adjunct, there is little data that definitively correlate CT findings with the presence of NSTI. Our goal was the development of a CT-based scoring system to discriminate non-NSTI from NSTI. METHODS Patients older than 17 years undergoing CT for evaluation of soft-tissue infection at a tertiary care medical center over a 10-year period (2000-2009) were included. Abstracted data included comorbidities and social history, physical examination, laboratory findings, and operative and pathologic findings. NSTI was defined as soft-tissue necrosis in the dictated operative note or the accompanying pathology report. CT scans were reviewed by a radiologist blinded to clinical and laboratory data. A scoring system was developed and the area under the receiver operating characteristic curve was calculated. RESULTS During the study period, 305 patients underwent CT scanning (57% men; mean age, 47.4 years). Forty-four patients (14.4%) evaluated had an NSTI. A scoring system was retrospectively developed (table). A score >6 points was 86.3% sensitive and 91.5% specific for the diagnosis of NSTI (positive predictive value, 63.3%; negative predictive value, 85.5%). The area under the receiver operating characteristic curve was 0.928 (95% confidence interval, 0.893-0.964). The mean score of the non-NSTI group was 2.74. CONCLUSIONS We have developed a CT scoring system that is both sensitive and specific for the diagnosis of NSTIs. This system may allow clinicians to more accurately diagnose NSTIs. Prospective validation of this scoring system is planned.