Reference range for tissue oxygen saturation in pregnancy using near-infrared spectroscopy.

OBJECTIVE: To estimate the reference range of tissue oxygen saturation (StO2) values in pregnancy. Near-infrared spectroscopy-derived StO2 is a noninvasive continuous measure used to predict hypoperfusion. Normal StO2 values have not been established in pregnant women. STUDY DESIGN: We enrolled 154 healthy pregnant women from an obstetric and gynecology resident clinic. Three sequential measurements were taken after securing the StO2 probe to the thenar eminence of one hand. One-way ANOVA was used to test for differences between trimesters and non-parametric methods to establish a reference range with 95% CI on the limits. RESULTS: The reference interval for the entire cohort of pregnant women is 73% (95% CI 72-75) to 92% (95% CI 89-93), similar to the normal range in the general population. We found no statistically significant difference in StO2 measurements between trimesters. Due to inadequate sample sizes we could not estimate a valid reference range for each trimester. CONCLUSION: We estimated a reference range for StO2 values in normal pregnant women. This information may contribute to the study of StO2 monitoring to predict impending shock in the obstetric patient.

Tissue oxygen saturation for the risk stratification of septic patients.

PURPOSE: Peripheral tissue oxygen saturation (Sto2) has shown promise as an early indicator of tissue hypoperfusion and as a risk stratification tool in various forms of shock. The purpose of this study was to determine if Sto2 would predict admission to an intensive (ICU) or progressive care unit in patients with early signs of sepsis. METHODS: In this prospective observational study, a rapid response team measured Sto2 levels in patients screening positive for sepsis. Using a logistic regression model, the value of Sto2 as a predictor for ICU admission within 72 hours of the initial assessment was determined. RESULTS: The 31 (47%) of 66 patients who required ICU admission within 72 hours of evaluation had a significantly lower Sto2 value (median, 78% vs 81%; P = .05). All patients with Sto2 less than 70% required ICU admission. A 1-point increase in Sto2 was associated with a 7% decrease in the odds of requiring ICU admission, and the area under the curve for Sto2 was 0.64 (0.51-0.77, P = .01). CONCLUSIONS: Low Sto2 levels in patients screening positive for sepsis are associated with an increased risk of ICU admission, but their reliability as a predictor is rather low. An Sto2 below 70% might be an interesting cutoff value for further study.

It takes an intensivist.

BACKGROUND: Our institution initiated the implementation of the Surviving Sepsis Campaign guidelines in 2006. We hypothesize that the addition of a surgical intensivist improved results more than the implementation of the guidelines alone. METHODS: We collected data on 273 patients who were admitted to the surgical intensive care unit for sepsis. The groups were divided into pre-bundle, n = 19; bundle, n = 186; and bundle-plus, n = 68, to denote the method by which the patients were treated for sepsis. RESULTS: There was no difference in age or sex between groups. There was a statistically significant decrease in length of stay (LOS) between the 3 groups, and in mortality between the bundle and bundle-plus treatment groups (P < .01). In addition, there was an average cost savings between each group. CONCLUSIONS: Implementation of evidence-based guidelines decreased LOS and decreased cost in our surgical intensive care unit. By adding the expertise of a surgical intensivist, we reduced LOS, cost, and relative risk of death even further than using the guidelines alone.

Outcomes and complications of open abdomen technique for managing non-trauma patients.

BACKGROUND: Damage control surgery and the open abdomen technique have been widely used in trauma. These techniques are now being utilized more often in non-trauma patients but the outcomes are not clear. We hypothesized that the use of the open abdomen technique in non-trauma patients 1) is more often due to peritonitis, 2) has a lower incidence of definitive fascial closure during the index hospitalization, and 3) has a higher fistula rate. METHODS: Retrospective case series of patients treated with the open abdomen technique over a 5-year period at a level-I trauma center. Data was collected from the trauma registry, operating room (OR) case log, and by chart review. The main outcome measures were number of operations, definitive fascial closure, fistula rate, complications, and length of stay. RESULTS: One hundred and three patients were managed with an open abdomen over the 5-year period and we categorized them into three groups: elective (n = 31), urgent (n = 35), and trauma (n = 37). The majority of the patients were male (69%). Trauma patients were younger (39 vs 53 years; P < 0.05). The most common indications for the open abdomen technique were intraabdominal hypertension in the elective group (n = 18), severe intraabdominal infection in the urgent group (n = 19), and damage control surgery in the trauma group (n = 28). The number of abdominal operations was similar (3.1-3.7) in the three groups, as was the duration of intensive care unit (ICU) stay (average: 25-31 days). The definitive fascial closure rates during initial hospitalization were as follows: 63% in the elective group, 60% in the urgent group, and 54% in the trauma group. Intestinal fistula formation occurred in 16%, 17%, and 11%, respectively, in the three groups, with overall mortality rates of 35%, 31%, and 11%. CONCLUSION: Intra-abdominal infection was a common reason for use of the open abdomen technique in non-trauma patients. However, the definitive fascial closure and fistula rates were similar in the three groups. Despite differences in indications, damage control surgery and the open abdomen technique have been successfully transitioned to elective and urgent non-trauma patients.

The dangling diaphragm sign: sensitivity and comparison with existing CT signs of blunt traumatic diaphragmatic rupture.

The objectives of our study were to describe a new CT sign of diaphragmatic injury, the "dangling diaphragm" sign, and assess its comparative utility relative to other signs in the diagnosis of diaphragmatic injury resulting from blunt trauma. CT scans of 16 blunt trauma patients (12 men and four women, mean age 36.6 years old) with surgically proven diaphragmatic injury and 32 blunt trauma patients (24 men and eight women; mean age 37.4 years old) without evidence of diaphragmatic injury at surgery were blindly reviewed by three board certified radiologists specializing in body imaging. Studies were evaluated for the presence of established signs of diaphragmatic injury, as well as the dangling diaphragm sign, in which the free edge of the torn hemidiaphragm curls inward from its normal course parallel to the body wall. The sensitivity and specificity of each sign were determined, as were the correlation between the signs and the interobserver agreement in evaluation of these findings. The radiologists' overall impression as to whether rupture was present was also recorded. In select cases, coronal and/or sagittal reformatted images were available, and they were reviewed following evaluation of the original axial images. Any change in interpretation due to these images was noted. The sensitivity of the radiologists' overall impression for detection of diaphragmatic injury was 77%, with 98% specificity. Individual signs of diaphragmatic injury had sensitivities ranging from 44% to 69%, with specificities of 98% to 100%. The dangling diaphragm sign had a sensitivity of 54% and a specificity of 98%, similar to the other signs. Multiple signs were present in most cases of diaphragmatic injury, and coronal and sagittal reformatted images had little impact. Diaphragmatic injury remains a challenging radiographic diagnosis. The dangling diaphragm is a conspicuous sign of diaphragmatic injury, and awareness of it may increase detection of diaphragmatic injury on CT studies.

An evaluation of multidetector computed tomography in detecting pancreatic injury: results of a multicenter AAST study.

BACKGROUND: Efforts to determine the suitability of low-grade pancreatic injuries for nonoperative management have been hindered by the inaccuracy of older computed tomography (CT) technology for detecting pancreatic injury (PI). This retrospective, multicenter American Association for the Surgery of Trauma-sponsored trial examined the sensitivity of newer 16- and 64-multidetector CT (MDCT) for detecting PI, and sensitivity/specificity for the identification of pancreatic ductal injury (PDI). METHODS: Patients who received a preoperative 16- or 64-MDCT followed by laparotomy with a documented PI were enrolled. Preoperative MDCT scans were classified as indicating the presence (+) or absence (-) of PI and PDI. Operative notes were reviewed and all patients were confirmed as PI (+), and then classified as PDI (+) or (-). As all patients had PI, an analysis of PI specificity was not possible. PI patients formed the pool for further PDI analysis. As sensitivity and specificity data were available for PDI, multivariate logistic regression was performed for PDI patients using the presence or absence of agreement between CT and operative note findings as an independent variable. Covariates were age, gender, Injury Severity Score, mechanism of injury, presence of oral contrast, presence of other abdominal injuries, performance of the scan as part of a dedicated pancreas protocol, and image thickness < or =3 mm or > or =5 mm. RESULTS: Twenty centers enrolled 206 PI patients, including 71 PDI (+) patients. Intravenous contrast was used in 203 studies; 69 studies used presence of oral contrast. Eight-nine percent were blunt mechanisms, and 96% were able to have their duct status operatively classified as PDI (+) or (-). The sensitivity of 16-MDCT for all PI was 60.1%, whereas 64-MDCT was 47.2%. For PDI, the sensitivities of 16- and 64-MDCT were 54.0% and 52.4%, respectively, with specificities of 94.8% for 16-MDCT scanners and 90.3% for 64-MDCT scanners. Logistic regression showed that no covariates were associated with an increased likelihood of detecting PDI for either 16- or 64-MDCT scanners. The area under the curve was 0.66 for the 16-MDCT PDI analysis and 0.77 for the 64-MDCT PDI analysis. CONCLUSION: Sixteen and 64-MDCT have low sensitivity for detecting PI and PDI, while exhibiting a high specificity for PDI. Their use as decision-making tools for the nonoperative management of PI are, therefore, limited.

Validation of a prehospital trauma triage tool: a 10-year perspective.

BACKGROUND: Triage of the trauma patient in the field is a complex and challenging issue, especially deciding when to use aeromedical transport. The American College of Surgeons Committee on Trauma recently defined an acceptable under-triage rate [seriously injured patient not taken to a trauma center (TC)] as 5%, whereas over-triage rates may be as high as 25% to 50%. Effective utilization of prehospital helicopter transport requires both accurate assessment of patients and effective communication. The rural county adjacent to our developed trauma system uses standardized triage criteria to identify patients for direct transport to our TCs. We hypothesized these criteria accurately identify major trauma victims (MTV) and further that communication could be simplified to expedite transport. METHODS: Prehospital personnel use a MAP (mechanism, anatomy, and physiology) scoring system to triage trauma patients. Patients with > or = 2 "hits" are defined as MTV. In 2004, the triage policy was changed so that MTV would be transported directly to a TC without base hospital consultation (previously required). The Emergency Medical Services (EMS) Medical Director reviewed cases transported to the TC to determine the appropriateness of triage decisions (over- and under-triage using the American College of Surgeons Committee on Trauma definitions). Data were compared before and after this policy change. RESULTS: For 2004 to 2006, we evaluated 676 air transports to TC and compared them to 468 in the prior 56 months. The overall transport rate increased slightly 7% to 10%. During the study period the over-triage rate was 31% compared with 21%, before the policy change. The MAP triage tool yielded a 93.8% sensitivity and a 99.5% specificity. Therefore, it determined the need for air-medical transport out of a rural environment into an established trauma system with > 90% accuracy. CONCLUSIONS: Prehospital personnel can accurately use a trauma triage tool to identify MTV. Eliminating base station contact, a potential for introducing communication error, did increase over-triage but still well within accepted limits. The system change also resulted in the transport of a greater proportion of minor trauma patients who later proved to have major injuries.

A county hospital surgical practice: a model for acute care surgery.

BACKGROUND: Trauma surgery has changed significantly over the past decade. Nonoperative evidence-based algorithms have become common and surgical trauma volume has become increasingly difficult to maintain. The acute care surgery (ACS) model, which integrates trauma, critical care, and emergency surgery, has been proposed as a future model of trauma practice. METHODS: Database information from an academic, county-based, trauma center was reviewed. A performance improvement surgical procedure database and level I trauma registry from 2005 were used to evaluate one center's ACS practice. RESULTS: There were 2,276 cases performed by 7 full-time and 5 part-time surgeons. Elective cases accounted for 64% (1,480) of caseload, emergency/urgent general surgery accounted for 32% (719) of cases, and emergency trauma surgeries accounted for 4% (96 procedures in 77 patients). In all, 23% were performed after hours. The ACS model supported controllable hours, adequate surgical volume, excellent patient care, and an appealing clinical practice. CONCLUSION: Surgical practice in a county-run trauma hospital can be similar to the ACS model, with positive results in terms of clinical volume and physician satisfaction. As clinical practices shift to the ACS model, there are lessons to be learned from currently existing, thriving, long-standing similar prototypes.