Steven N. Parks

Admission base deficit predicts transfusion requirements and risk of complications

BACKGROUND Trauma center resource management could be facilitated by a readily available indicator of resource consumption. This marker should identify patients more likely to require transfusion and intensive care services and to develop complications. Base deficit (BD) has been shown to be a valuable indicator of shock, abdominal injury, fluid requirements, efficacy of resuscitation, and to be predictive of mortality after trauma. This study was performed to determine whether BD could be used to identify which patients were likely to require blood transfusion in the first 24 hours of hospitalization, and to develop shock-related complications and increased intensive care unit (ICU) and hospital stays. METHODS A retrospective review of 2,954 patients admitted to the Valley Medical Center Level I trauma service from July 1990 through August 1995 was done using the trauma registry and blood bank data bases. Medical record review was done to supplement missing data. RESULTS Transfusion requirements increased as the BD category became more severe (p < 0.001). Transfusions were required within 24 hours of admission in 72% of patients with a BD < or = -6 versus 18% of patients with a BD > -6 (p < 0.001, chi 2). Both ICU and hospital length of stay increased with worsening BD (p < 0.015 and p < 0.05, respectively). The frequency of adult respiratory distress syndrome (ARDS) (p < 0.01), renal failure (p = 0.015), coagulopathy (p < 0.001), and multiorgan system failure (MOF) (p = 0.002) all increased with increasingly severe BD. Discriminate analysis using Injury Severity Score (ISS) and BD category demonstrated predictive accuracy of 81%, 77%, and 77% for coagulopathy, ARDS, and MOF, respectively. Mortality also increased with worsening BD. When stratified by BD category, there was no difference between observed and predicted survival. CONCLUSIONS Admission BD identifies patients likely to require early transfusion and increased ICU and hospital stays, and be at increased risk for shock-related complications. Patients with BD < or = -6 should undergo type and cross-match rather than type and screen. The use of ISS and BD category probability curves may identify candidates for early invasive monitoring.

Base deficit is superior to pH in evaluating clearance of acidosis after traumatic shock.

OBJECTIVE This study was done to evaluate the differences in base deficit (BD) clearance, pH normalization, and the occurrence of complications between survivors and nonsurvivors after trauma. DESIGN Concurrent data entry with retrospective review. METHODS Trauma patients meeting registry criteria from July 1990 through August 1995 with arterial blood gases performed within 1 hour of admission and admission BD < or = -6 were included. Data was grouped by BD category (moderate, -6 to -9; severe, < or = -10). Group means +/- SEM were compared with a two-tailed t test. MEASUREMENTS AND MAIN RESULTS Six hundred seventy-four patients met entry criteria. Survivors in both the moderate and severe BD groups had improved their BD within 4 hours and normalized their BD by 16 hours. Nonsurvivors did not improve their BD category until 8 hours (for the severe group) and 16 hours (for the moderate group) and did not normalize BD before 24 hours. The BD differences between survivors and nonsurvivors were significant at each time interval, whereas pH differences were significant at 2 hours in the moderate group and at 2, 16, and 24 hours in the severe group. Patients who failed to improve their BD > -6 had an increased frequency of adult respiratory distress syndrome, multiple organ failure, and mortality. CONCLUSION Base deficit reveals differences in metabolic acidosis between survivors and nonsurvivors not shown by pH determinations and is clearly a better marker of acidosis clearance after shock.

Clearing the cervical spine in obtunded patients: the use of dynamic fluoroscopy.

OBJECTIVE Obtunded patients (Glasgow Coma Scale score of < 13) with normal cervical roentgenograms remain in collars until they can be clinically evaluated. Cervical collars provide incomplete immobilization and have complications. Our hypothesis was that cervical spines could be evaluated in obtunded patients with normal cervical roentgenograms using dynamic fluoroscopy. DESIGN This study was a prospective clinical evaluation. METHODS Obtunded trauma patients with normal cervical roentgenograms underwent fluoroscopic examination of the cervical spine through a full range of motion. RESULTS Fluoroscopic evaluations were done in 116 patients. There were 113 true negative examinations. Two patients had facet fractures not diagnosed on cervical roentgenograms, and no instability on fluoroscopy. One patient had a positive exam, with 2 mm of subluxation. There were no neurologic complications. Decubiti were present in 44% and were more frequent when the collar was on > 5 days (p = 0.029). CONCLUSIONS Dynamic fluoroscopy can safely and effectively clear the cervical spine in obtunded patients. Earlier removal of the collar decreases decubiti.

Routine evaluation of the cervical spine in head-injured Patients with dynamic fluoroscopy : A reappraisal

BACKGROUND The mechanism for clearing the cervical spine in patients with altered mental status remains controversial. Recommendations have ranged from removal of the cervical collar after 24 hours in patients with normal radiographs, to indefinite immobilization in a cervical collar, and recently cervical flexion-extension examinations using dynamic fluoroscopy. The purpose of this study was to evaluate the efficacy and safety of dynamic fluoroscopy flexion-extension examinations in identifying ligamentous cervical spine injury and clearing the cervical spine in patients with altered mental status after trauma. METHODS Patients with a Glasgow Coma Scale score < 13 for greater than 48 hours after admission and normal cervical spine radiographs were candidates for fluoroscopic evaluation. The protocol required visualization of the entire cervical spine, through T1, through full extension and flexion under the direct supervision of a radiologist. Oblique fluoroscopic views were obtained, as necessary, to visualize the cervicothoracic junction. Demographic data, fluoroscopy time, total time per study, true and false positives and negatives, and complications were recorded. RESULTS From July 1992 through December 1999, fluoroscopic examinations were performed on 301 patients. There were 297 true-negative examinations, 2 true-positive examinations (stable injuries), 1 false-negative examination, and 1 false-positive examination. The incidence of ligamentous injury identified by fluoroscopy in this study was 2 of 301 (0.7%). Unstable cervical spine ligamentous injuries were identified in only 0.02% of all trauma patients. One patient developed quadriplegia when fluoroscopic evaluation was performed after two protocol violations. CONCLUSION Unstable cervical spine ligamentous injury without fracture is a rare occurrence. The cervical spine may be cleared after a normal cervical spine series (plain radiograph and computed tomographic scan) as recommended in the 1998 Eastern Association for the Surgery of Trauma guidelines. If dynamic fluoroscopy is to be used, adherence to the protocol, including review of the cervical spine radiographs before fluoroscopy and visualization of the entire cervical spine, C1-T1, is mandatory to ensure patient safety.

Routinely Repeated Computed Tomography after Blunt Head Trauma: Does it Benefit Patients?

BACKGROUND Computed tomography of the head (HCT) is an integral part of the diagnosis and management of the patient with head injury, but the utility of repeated HCT performed solely for routine follow-up in the patient with blunt head trauma has not been defined. In the absence of clinical indications, routinely repeated HCT, even in patients with significant brain injury, does not contribute to patient care. METHODS Trauma registry records at a Level I trauma center from July 1, 1997, to June 30, 2002, were reviewed. Patients with severe blunt head injury (Abbreviated Injury Scale score > or = 3) admitted to the intensive care unit and who had a repeat HCT scan obtained for scheduled follow-up were included. Those patients with initial craniotomy, repeat HCT more than 72 hours after the initial HCT, or repeat HCT ordered for clinical indications were excluded. Data included were age, mechanism of injury, time to initial (HCT1) and repeat HCT (HCT2), indications for HCT2, and HCT findings. Additional data included Glasgow Coma Scale (GCS) score (admission and at HCT2); Injury Severity Score; occurrence of hypotension, coagulopathy, or elevated intracranial pressure (ICP); interventions made; and patient outcome. RESULTS Entry criteria were met in 462 patients. Most were injured in motor vehicle crashes; the average age was 36 years and the mean initial GCS score was 9. The mean time to HCT1 was 1.3 hours and the mean time to HCT2 was 22.6 hours. HCT2 showed worsening in 85 patients (18.4%), and 16 patients had interventions in response to HCT2 (repeat HCT in 8, ICP monitoring or drainage in 6, and craniotomy in 2). No patient undergoing routine repeat HCT without other clinical findings required intervention. All patients with worsening HCT findings requiring intervention had coagulopathy, hypotension, ICP elevation, or marked decrease in GCS score. CONCLUSION In the absence of clinical indicators or risk factors, repeat HCT after blunt head injury does not alter patient management and is unnecessary.

Predicting Performance on the American Board of Surgery Qualifying and Certifying Examinations: A Multi-institutional Study

BACKGROUND We sought to determine whether US Medical Licensing Examination (USMLE) Step 1 score, American Board of Surgery (ABS) In-Training Examination (ABSITE) score, and other variables are associated with failing the ABS qualifying and certifying examinations. Identifying such factors may assist in the early implementation of an academic intervention for at-risk residents. DESIGN Retrospective review. SETTING Seventeen general surgery training programs in the western United States. PARTICIPANTS Six hundred seven residents who graduated in 2000-2007. MAIN OUTCOME MEASURES First-time pass rates on the qualifying and certifying examinations, US vs non-US medical school graduation, USMLE Steps 1 and 2 scores, ABSITE scores, operative case volume, fellowship training, residency program type, and mandatory research. RESULTS The first-time qualifying and certifying examination pass rates for the 607 graduating residents were 78% and 74%, respectively. On multivariable analysis, scoring below the 35th percentile on the ABSITE at any time during residency was associated with an increased risk of failing both examinations (odds ratio, 0.23 [95% confidence interval, 0.08-0.68] for the qualifying examination and 0.35 [0.20-0.61] for the certifying examination), as was scoring less than 200 on the USMLE Step 1 (0.36 [0.21-0.62] for the qualifying examination and 0.62 [0.42-0.93] for the certifying examination). A mandatory research year was associated with an increased likelihood of passing the certifying examination (odds ratio, 3.3 [95% confidence interval, 1.6-6.8]). CONCLUSIONS Residents who are more likely to fail the ABS qualifying and certifying examinations can be identified by a low USMLE Step 1 score and by poor performance on the ABSITE at any time during residency. These findings support the use of the USMLE Step 1 score in the surgical residency selection process and a formal academic intervention for residents who perform poorly on the ABSITE.

Severe Liver Trauma in the Face of Coagulopathy A Case for Temporary Packing and Early Reexploration

Most liver injuries lend themselves to satisfactory hemostasis and drainage, with or without resectional debridement. A small number of injuries will necessitate massive blood transfusion with clinically significant coagulopathy developing in about half of these patients despite prophylactic infusion of fresh frozen plasma and platelet concentrates. In our experience, after major, discrete arterial and venous vessels are individually ligated, the diffuse ooze from the raw surfaces can be effectively controlled by temporary packing of the liver. Packing provides time for coagulopathy and hypothermia to be corrected and for urgent diagnostic maneuvers to be completed safely. Packs should be removed early (within 24 to 48 hours postoperatively), and surgery performed as indicated by the injury. No intraabdominal abscesses have been encountered among our 12 patients who underwent temporary packing of their liver injuries.

Intracranial pressure monitor placement by midlevel practitioners.

BACKGROUND The timely treatment of patients with head injuries is affected by the availability and commitment of neurosurgeons. Use of midlevel practitioners (MLPs) may permit more efficient neurosurgical coverage. Intracranial pressure monitoring is among the most frequently used neurosurgical procedures. The purpose of this study was to examine the placement of intracranial pressure (ICP) monitors by MLPs. METHODS Medical records and trauma registry data for a Level I trauma center were reviewed from December 1993 to June 1997. Patients who had ICP monitors placed were included. Patient data recorded were age, mechanism of injury, injury type, ICP monitor placement and length of placement, complications related to the ICP monitor, and outcomes. RESULTS Two hundred ten patients had 215 monitors placed. ICP monitors were placed by neurosurgeons (105), MLPs (97), and general surgery residents (13), and remained in place a mean of 4 days. No major complications attributable to ICP monitor placement occurred; 19 minor complications (malfunction, dislodgment) were noted. Eleven monitors placed by neurosurgeons (10%), seven placed by MLPs (7%), and one placed by a resident (8%) had complications. CONCLUSION ICP monitor placement by MLPs is safe. Use of MLPs may aid neurosurgeons in providing prompt monitoring of patients with head injuries.

Are automated blood pressure measurements accurate in trauma patients

BACKGROUND Automated blood pressure (BP) determinations by oscillometry are reported to be as accurate as invasive monitoring for systolic pressures as low as 80 mm Hg. Automated BP devices are widely used by prehospital providers and in hospital operating rooms, emergency departments, and intensive care units, although the accuracy of automated BP has not been demonstrated in trauma patients. We hypothesized that automated BP is less accurate than manual BP in trauma patients. The purpose of this study was to determine the accuracy of automated BP versus manual BP in trauma patients. METHODS A retrospective review of patients who met trauma activation criteria admitted to a Level I trauma center over a 30-month period was conducted. Patients were included if both manual BP and automated BP were measured within 5 minutes of admission. Additional data collected included Injury Severity Score, base deficit, and emergency department resuscitation volume. Statistical analysis was performed using paired t test, chi2, and linear regression analysis. Significance was attributed to a value of p < 0.05. RESULTS From January 2000 through June 2002, 388 patients met inclusion criteria. Patients were grouped by manual BP levels: group 1, BP < or = 90 mm Hg (n = 92); group 2, BP 91-110 mm Hg (n = 119); and group 3, BP > or = 110 mm Hg (n = 177). The mean automated BP measurements were significantly higher than the manual measurements in groups 1 and 2 (26 and 16 mm Hg, respectively; p < 0.001). Of the 92 patients with manual BP < or = 90, 45 (49%) had automated BP > or = 100. The base deficit (-5, -3, and -2 for groups 1, 2, and 3, respectively; p < 0.01), Injury Severity Score (30, 25, and 18; p < 0.01), and volume of resuscitative fluid and blood (p < 0.001) all decreased with higher BP group. CONCLUSION Injury severity, degree of acidosis, and resuscitation volume were more accurately reflected by manual BP. Automated BP determinations were consistently higher than manual BP, particularly in hypotensive patients. Automated BP devices should not be used for field or hospital triage decisions. Manual BP determinations should be used until systolic blood pressure is consistently > or = 110 mm Hg.

Necrotizing amebic colitis: A frequently fatal complication

Acute necrotizing amebic colitis is an uncommon but life threatening development with a high mortality rate, even when properly diagnosed and treated. We report six cases of acute necrotizing amebic colitis, none of which were diagnosed preoperatively. At operation, five of the six patients had friable, necrotic, and gangrenous colon. A right hemicolectomy with ileostomy was performed in two patients and a subtotal colectomy with ileostomy was performed in four patients. Five of the six patients died within 4 weeks of operation. The sole survivor was the patient who had received metronidazole preoperatively. Only after histologic examination of the surgical specimen was the diagnosis made in all cases. If the diagnosis can be made preoperatively and antiamebic therapy instituted, surgical resection may decrease the high mortality rate of this disease.