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Dive into the research topics where Tobias Haltmeier is active.

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Featured researches published by Tobias Haltmeier.


Journal of Trauma-injury Infection and Critical Care | 2015

Tourniquet use for civilian extremity trauma.

Kenji Inaba; Stefano Siboni; Shelby Resnick; Jay Zhu; Wong; Tobias Haltmeier; Elizabeth Benjamin; Demetrios Demetriades

BACKGROUND Unlike in the military setting, where the use of tourniquets has been well established, in the civilian sector their use has been far less uniform. The purpose of this study was to examine the outcomes associated with the use of tourniquets for civilian extremity trauma. STUDY DESIGN Adult (≥18 years) patients admitted to our institution with an extremity injury requiring tourniquet application from January 2007 to June 2014 were retrospectively reviewed. The primary outcome analyzed was limb loss. Secondary outcomes included death, hospital length of stay, and complications. RESULTS There were 87 patients who met inclusion criteria. Average age was 35.3 years, 90.8% were male, and 66.7% had penetrating injuries, with a median Injury Severity Score (ISS) of 6. Tourniquets were placed in the prehospital setting in 50.6%, in the emergency department in 39.1%, and in the operating room in 10.3% of patients. The windlass type Combat Application Tourniquet was the most commonly used type (67.8%), followed by a pneumatic system (24.1%) and self-made tourniquet (8.0%). The median duration of use was 75 minutes (interquartile range, 91) with no differences between groups (p = 0.547). Overall, 80.5% had a vascular injury (70.1% arterial), and a total of 99 limb operations were performed, including 15 amputations. Fourteen amputations (93.3%) occurred at the scene or were directly attributed to the extent of tissue damage with a median Mangled Extremity Severity Score (MESS) of 7 (interquartile range, 2). In the remaining patient, the tourniquet was lifesaving but likely contributed to limb loss. Seven patients sustained 13 other complications; however, none was directly attributed to tourniquet use. CONCLUSION Tourniquet use in the civilian sector is associated with a low rate of complications. With the low complication rate and high potential for benefit, aggressive use of this potentially lifesaving intervention is justified. LEVEL OF EVIDENCE Epidemiologic/prognostic study, level III.


Journal of Trauma-injury Infection and Critical Care | 2016

Emergent non-image-guided resuscitative endovascular balloon occlusion of the aorta (REBOA) catheter placement: A cadaver-based study.

Megan Linnebur; Kenji Inaba; Tobias Haltmeier; Todd E. Rasmussen; Jennifer Smith; Ranan Mendelsberg; Daniel Grabo; Demetrios Demetriades

BACKGROUND Emergent resuscitative endovascular balloon occlusion of the aorta (REBOA) insertion for critically injured patients in hemorrhagic shock is performed blindly with fluoroscopic imaging confirmation. The aim of this study was to determine a reliable method for initial REBOA catheter insertion with balloon deployment between the left subclavian artery takeoff and the celiac trunk (CT). METHODS Human cadaver study. External surface (sternal notch, mid-sternum, xiphoid) and intravascular (left subclavian artery [LSA], and CT) landmarks were measured from standardized left and right common femoral artery puncture sites. The landing zone (LZ, distance between LSA and CT) and margins of safety (distance from distal balloon edge to LSA and proximal balloon edge to CT) were calculated using intravascular landmarks. The probability of balloon deployment in the LZ using external landmarks was compared in univariate analysis using the Fisher exact test. RESULTS Ten cadavers were analyzed (seven males; mean body mass index, 19.4 kg/m2). Mean (SD) intravascular distances from femoral puncture sites to the LSA and CT were 54.8 (1.9) cm and 32.9 (1.9) cm. The mean (SD) LZ was 21.8 (3.8) cm. Mean (SD) surface distances from femoral puncture sites to the xiphoid, mid-sternum, and sternal notch were 31.8 (3.9) cm, 41.8 (3.3) cm, and 51.8 (3.2) cm. Inserting the catheter to a distance approximated by surface distance from the femoral puncture site to mid-sternum resulted in a 100% likelihood balloon deployment in the LZ for both sides. This was superior to the xiphoid and sternal notch (left site, p = 0.005; right site, p = 0.036; mean of both sites, p = 0.083). Using the mid-sternum landmark, the mean (SD) margins of safety to the LSA and CT were 10.7 (4.3) cm and 3.1 (3.4) cm. CONCLUSION When using the use of the mid-sternum landmark for REBOA balloon placement, the likelihood of balloon deployment in the LZ was 100% with an acceptable margin of safety.


Journal of Trauma-injury Infection and Critical Care | 2015

Early versus delayed same-admission laparoscopic cholecystectomy for acute cholecystitis in elderly patients with comorbidities.

Tobias Haltmeier; Elizabeth Benjamin; Kenji Inaba; Lydia Lam; Demetrios Demetriades

BACKGROUND The optimal timing of same-admission laparoscopic cholecystectomy (LC) for acute cholecystitis (AC) in elderly patients, especially those with significant comorbidities, is not clear. METHODS This is a National Surgical Quality Improvement Program study, which included patients older than 65 years undergoing LC for AC. Patients with choledocholithiasis were excluded. Patients were divided into two subgroups as follows: no significant comorbidities (American Society of Anesthesiologists [ASA] score ⩽ 2) and significant comorbidities (ASA score > 2). Patients undergoing LC within 24 hours of admission (early LC) were compared with patients undergoing LC later than 24 hours after admission (delayed LC), using univariable and multivariable regression analyses. RESULTS A total of 4,011 patients were included in the study. Early LC was performed in 38.0% and delayed LC in 62.0% of the patients. Regression analysis identified early LC as an independent predictor for shorter anesthesia time and postoperative length of stay, overall and in the subgroup with an ASA score greater than 2. CONCLUSION Early, within 24 hours of admission, LC for AC in patients older than 65 years with significant comorbidities is associated with shorter postoperative stay and no increase in postoperative complications or conversion to open cholecystectomy. LEVEL OF EVIDENCE Therapeutic study, level IV.


Journal of Trauma-injury Infection and Critical Care | 2016

The prognostic value of neutrophil to lymphocyte ratio on mortality in critically Ill trauma patients.

Evren Dilektasli; Kenji Inaba; Tobias Haltmeier; Wong; Damon Clark; Elizabeth Benjamin; Lydia Lam; Demetrios Demetriades

BACKGROUND Recent studies suggest that the neutrophil-lymphocyte ratio (NLR) as a marker of inflammation is associated with mortality in surgical patients. The aim of this study was to determine the prognostic impact of NLR in critically ill trauma patients. METHODS This is a retrospective cohort study involving all trauma patients 16 years or older admitted to the surgical intensive care unit of a Level 1 trauma center (January 2013 to January 2014). The predictive capacity of NLR on mortality was assessed using a receiver operating characteristic curve analysis. To identify the effect of the NLR on survival, a separate log-rank test was used. Multivariable Cox proportional hazard modeling was used to identify independent predictors of mortality. RESULTS During the study period, 1,356 patients met inclusion criteria. Of these, 74% were male, 86% sustained blunt trauma, and the median age was 49 years (interquartile range [IQR], 35). The median Glasgow Coma Scale (GCS) score and Injury Severity Score (ISS) were 15 (IQR, 3) and 13 (IQR, 14), respectively. With the use of the receiver operating characteristic curve analyses at intensive care unit Days 2 and 5, optimal NLR cutoff values of 8.19 and 7.92 were calculated by maximizing the Youden index. Kaplan-Meier curves revealed an NLR greater than or equal to these cutoff values as a marker for increased in-hospital mortality (p < 0.001, log-rank test). The Cox regression model demonstrated that an NLR greater than 8.19 and 7.92 are independently associated with in-hospital mortality at Days 2 and 5, respectively (hazard ratio, 1.602 [p = 0.019] and 3.758 [p < 0.001]). CONCLUSION NLR is associated with mortality in critically ill trauma patients. Prospective validation of its role as a predictive marker for outcomes is warranted. LEVEL OF EVIDENCE Prognostic study, level III.


Injury-international Journal of The Care of The Injured | 2016

The utility of chest X-ray as a screening tool for blunt thoracic aortic injury☆

Adam Gutierrez; Kenji Inaba; Stefano Siboni; Zachary Effron; Tobias Haltmeier; Paul Jaffray; Sravanthi Reddy; Alexander Lofthus; Elizabeth Benjamin; Joseph DuBose; Demetrios Demetriades

BACKGROUND The early and accurate identification of patients with blunt thoracic aortic injury (BTAI) remains a challenge. Traditionally, a portable AP chest X-ray (CXR) is utilized as the initial screening modality for BTAI, however, there is controversy surrounding its sensitivity. The purpose of this study was to assess the sensitivity of CXR as a screening modality for BTAI. METHODS After IRB approval, all adult (≥18 yo) blunt trauma patients admitted to LAC+USC (01/2011-12/2013) who underwent CXR and chest CT were retrospectively reviewed. Final radiology attending CXR readings were reviewed for mediastinal abnormalities (widened mediastinum, mediastinal to chest width ratio greater than 0.25, irregular aortic arch, blurred aortic contour, opacification of the aortopulmonary window, and apical pleural haematoma) suggestive of aortic injury. Chest CT final attending radiologist readings were utilized as the gold standard for diagnosis of BTAI. The primary outcome analyzed was CXR sensitivity. RESULTS A total of 3728 patients were included in the study. The majority of patients were male (72.6%); mean age was 43 (SD 20). Median ISS was 9 (IQR 4-17) and median GCS was 15 (IQR 14-15). The most common mechanism of injury was MVC (48.0%), followed by fall (20.6%), and AVP (16.9%). The total number of CXRs demonstrating a mediastinal abnormality was 200 (5.4%). Widened mediastinum was present on 191 (5.1%) of CXRs, blurred aortic contour on 10 (0.3%), and irregular aortic arch on 4 (0.1%). An acute aortic injury confirmed by chest CT was present in 17 (0.5%) patients. Only 7 of these with CT-confirmed BTAI had a mediastinal abnormality identified on CXR, for a sensitivity of 41% (95% CI: 19-67%). CONCLUSION The results from this study suggest that CXR alone is not a reliable screening modality for BTAI. A combination of screening CXR and careful consideration of other factors, such as mechanism of injury, will be required to effectively discriminate between those who should and should not undergo chest CT.


Surgery | 2015

Serum transthyretin is a predictor of clinical outcomes in critically ill trauma patients

Vincent J. Cheng; Kenji Inaba; Tobias Haltmeier; Adam Gutierrez; Stefano Siboni; Elizabeth Benjamin; Lydia Lam; Demetrios Demetriades

BACKGROUND In surgery patients, low preoperative serum transthyretin (TTR) level is associated with greater rates of infection and mortality. However, the predictive value of TTR on surgical outcomes after major trauma has not yet been studied. METHODS Critically ill trauma patients who underwent surgery for trauma and had TTR preoperatively measured after admission to the surgical intensive care unit (ICU) at the LAC+USC Medical Center (01/2008-05/2014) were identified retrospectively. Univariable and multivariable regression analyses determined the significance of TTR on outcomes. RESULTS We identified 348 patients. Univariable analysis indicated that patients with lower TTR had more infections (P < .001), higher mortality (P = .007), longer hospital stay (P < .001), longer ICU stay (P < .001), and increased ventilator days (P < .001). Even after adjusting for differences in patient characteristics, lower TTR level was associated with greater infectious complication rates (P = .001), greater mortality (P = .005), longer hospital stay (P = .013), longer ICU stay (P = .030), and increased ventilator days (P = .044). CONCLUSION In critically ill trauma patients, low serum TTR level is associated with poorer clinical outcomes, and its prognostic utility warrants further study.


American Journal of Surgery | 2017

The effects of body mass index on complications and mortality after emergency abdominal operations: The obesity paradox

Elizabeth Benjamin; Evren Dilektasli; Tobias Haltmeier; Elizabeth Beale; Kenji Inaba; Demetrios Demetriades

BACKGROUND Recent literature suggests that obesity is protective in critically illness. This study addresses the effect of BMI on outcomes after emergency abdominal surgery (EAS). METHODS Retrospective, ACS-NSQIP analysis. All patients that underwent EAS were included. The study population was divided into five groups based on BMI; regression models were used to evaluate the role of obesity in morbidity and mortality. RESULTS 101,078 patients underwent EAS; morbidity and mortality were 19.5% and 4.5%, respectively. Adjusted mortality was higher in underweight patients (AOR 1.92), but significantly lower in all obesity groups (AORs 0.73, 0.66, 0.70, 0.70 respectively). Underweight and class III obesity was associated with increased complications (AOR 1.47 and 1.30), while mild obesity was protective (AOR 0.92). CONCLUSIONS Underweight patients undergoing EAS have increased morbidity and mortality. Although class III obesity is associated with increased morbidity, overweight and class I obesity were protective. All grades of obesity may be protective against mortality after EAS relative to normal weight patients.


JAMA Surgery | 2015

Negative Finding From Computed Tomography of the Abdomen After Blunt Trauma

Elizabeth Benjamin; Stefano Siboni; Tobias Haltmeier; Alexander Lofthus; Kenji Inaba; Demetrios Demetriades

(P < .001). The rate monotonically decreased with age, from 16.5% for men 20 to 39 years of age to 6.9% for men 50 to 59 years of age to 1.4% for men 70 years of age or older (P < .001). The factors associated with a higher likelihood of CPM included younger age (eg, 20-39 years vs ≥70 years, with an adjusted odds ratio of 15.3 [95% CI, 7.7-30.4]), white race (blacks vs whites, with an adjusted odds ratio of 0.6 [95% CI, 0.40.9]), and private insurance (Medicaid vs private insurance, with an adjusted odds ratio of 0.5 [95% CI, 0.2-1.0]) (Table 2).


Journal of Trauma-injury Infection and Critical Care | 2016

Isolated blunt severe traumatic brain injury in Bern, Switzerland, and the United States: A matched cohort study.

Tobias Haltmeier; Beat Schnüriger; Elizabeth Benjamin; Monika Brodmann Maeder; Michael Künzler; Stefano Siboni; Kenji Inaba; Demetrios Demetriades

BACKGROUND The ideal prehospital management of patients with severe traumatic brain injury (TBI) including the impact of endotracheal intubation (ETI) and physicians on scene is unclear. Prehospital management differs substantially in Switzerland and the United States: in Switzerland, there is usually a physician on scene who may provide ETI and other advanced life support procedures, whereas in the United States, prehospital management (including ETI) is performed by paramedics. METHODS This is a retrospective cohort-matched study of patients with isolated blunt severe TBI (head Abbreviated Injury Scale [AIS] score, 4–5) and no major extracranial injuries, using Bern University Hospital data from the Swiss PEBITA [Patient-relevant Endpoints after Brain Injury from Traumatic Accidents] (TBI-specific) database and the US National Trauma Data Bank from 2009 to 2010. A 1:4 cohort matching of Bern and US patients was performed. Matching criteria were sex, age (±10 years), exact field Glasgow Coma Scale (GCS) score, exact head AIS score, and injury type (subdural hematoma, epidural hematoma, intraparenchymal hemorrhage, intraventricular hemorrhage, brain edema/swelling, brain stem injury). The matched cohorts were compared with univariable analysis (Fisher’s exact test and Mann-Whitney U-test). RESULTS Matching of the Bern (n = 128) and US (n = 86,375) cohort resulted in 355 matched cases (71 Bern and 284 US patients). Bern patients had significantly longer scene times (median, 23.0 minutes vs. 9.0 minutes, p < 0.001) and more frequent prehospital ETI (31.0% vs. 18.7%, p = 0.034) and air transportation (39.4% vs. 19.4%, p < 0.001). No significant difference in procedures (craniotomy/craniectomy, intracranial pressure monitoring, tracheotomy), intensive care unit and total hospital lengths of stay, ventilator days, and in-hospital mortality (14.1% vs. 15.8%, p = 0.855) was found between the two cohorts. CONCLUSION When taking into account the limitation that patient- and injury-related factors, but not in-hospital treatment variables, were matched, the more frequent prehospital ETI and presence of a physician on scene in the Swiss cohort compared with the US cohort had no significant effect on outcomes, including intensive care unit and total hospital lengths of stay, ventilator days, and in-hospital mortality. LEVEL OF EVIDENCE Therapeutic study, level IV.


Journal of Trauma-injury Infection and Critical Care | 2015

Deep organ space infection after emergency bowel resection and anastomosis: The anatomic site does not matter.

Elizabeth Benjamin; Stefano Siboni; Tobias Haltmeier; Kenji Inaba; Lydia Lam; Demetrios Demetriades

BACKGROUND Deep organ space infection (DOSI) is a serious complication after emergency bowel resection and anastomosis. The aim of this study was to identify the incidence and risk factors for the development of DOSI. METHODS National Surgical Quality Improvement Program database study including patients who underwent large bowel or small bowel resection and primary anastomosis. The incidence, outcomes, and risk factors for DOSI were evaluated using univariate and multivariate analyses. RESULTS A total of 87,562 patients underwent small bowel, large bowel, or rectal resection and anastomosis. Of these, 14,942 (17.1%) underwent emergency operations and formed the study population. The overall mortality rate in emergency operations was 12.5%, and the rate of DOSI was 5.6%. A total of 18.0% required ventilatory support in more than 48 hours, and 16.0% required reoperation. Predictors of DOSI included age, steroid use, sepsis or septic shock on admission, severe wound contamination, and advanced American Society of Anesthesiologists classification. The anatomic location of resection and anastomosis was not significantly associated with DOSI. CONCLUSION Patients undergoing emergency bowel resection and anastomosis have a high mortality, risk of DOSI, and systemic complications. Independent predictors of DOSI include wound and American Society of Anesthesiologists classification, sepsis or septic shock on admission, and steroid use. The anatomic location of resection and anastomosis was not significantly associated with DOSI. LEVEL OF EVIDENCE Epidemiologic/prognostic study, level III.

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Kenji Inaba

University of Southern California

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Demetrios Demetriades

University of Southern California

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Elizabeth Benjamin

University of Southern California

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Stefano Siboni

University of Southern California

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Lydia Lam

University of Southern California

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Evren Dilektasli

University of Southern California

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Damon Clark

University of Southern California

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Elizabeth Beale

University of Southern California

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Vincent J. Cheng

University of Southern California

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