Kenji Inaba

The University of Arizona, Tucson, Arizona, United States

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Publications (300)588.85 Total impact

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    ABSTRACT: Tension pneumothorax can rapidly progress to cardiac arrest and death if not promptly recognized and appropriately treated. We sought to evaluate the effectiveness of traditional didactic slide-based lectures (SBLs) as compared with fresh tissue cadaver-based training (CBT) for placement of needle thoracostomy (NT).
    The Journal of Trauma and Acute Care Surgery 09/2014; 77(3 Suppl 2):S109-S113. · 2.35 Impact Factor
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    ABSTRACT: A missed cervical spine (CS) injury can have devastating consequences. When CS injuries cannot be ruled out clinically using the National Emergency X-Radiography Utilization Study low-risk criteria because of either a neurologic deficit or pain, the optimal imaging modality for CS clearance remains controversial.
    JAMA surgery. 07/2014;
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    ABSTRACT: The harmful effects of smoking have been well-documented in the medical literature for decades. To further the support of smoking cessation, we investigate the effect of smoking on a less studied population, the trauma patient.
    07/2014; 20(4):248-52.
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    ABSTRACT: Needle thoracostomy (NT) is a commonly taught intervention for tension pneumothorax (tPTX) but has a high failure rate. We hypothesize that standard 5-mm laparoscopic trocars may be a safe and more effective alternative.
    The Journal of Trauma and Acute Care Surgery 07/2014; 77(1):170-175. · 2.35 Impact Factor
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    ABSTRACT: BACKGROUND: Failure to achieve primary fascial closure (PFC) after damage control laparotomy is costly and carries great morbidity. We hypothesized that time from the initial laparotomy to the first take-back operation would be predictive of successful PFC. METHODS: Trauma patients managed with open abdominal techniques after damage control laparotomy were prospectively followed at 14 Level 1 trauma centers during a 2-year period. Time to the first take-back was evaluated as a predictor of PFC using hierarchical multivariate logistic regression analysis. RESULTS: A total of 499 patients underwent damage control laparotomy and were included in this analysis. PFC was achieved in 327 (65.5%) patients. Median time to the first take-back operation was 36 hours (interquartile range 24-48). After we adjusted for patient demographics, resuscitation volumes, and operative characteristics, increasing time to the first take-back was associated with a decreased likelihood of PFC. Specifically, each hour delay in return to the operating room (24 hours after initial laparotomy) was associated with a 1.1% decrease in the odds of PFC (odds ratio 0.989; 95% confidence interval 0.978-0.999; P = .045). In addition, there was a trend towards increased intra-abdominal complications in patients returning after 48 hours (odds ratio 1.80; 95% confidence interval 1.00-3.25; P = .05). CONCLUSION: Data from this prospective, multicenter study demonstrate that delays in returning to the operating room after damage control laparotomy are associated with reductions in PFC. These findings suggest that emphasis should be placed on returning to the operating room within 24 hours after the initial laparotomy if possible (and no later than 48 hours).
    Surgery 06/2014; · 3.37 Impact Factor
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    ABSTRACT: Forty percent of in-hospital deaths among injured patients involve massive truncal haemorrhage. These deaths may be prevented with rapid haemorrhage control and improved resuscitation techniques. The Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) Trial was designed to determine if there is a difference in mortality between subjects who received different ratios of FDA approved blood products. This report describes the design and implementation of PROPPR.
    Injury 06/2014; · 1.93 Impact Factor
  • The American surgeon 06/2014; 80(6):165-167. · 0.92 Impact Factor
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    ABSTRACT: Introduction: Lyophilization may facilitate production of a safe, portable, easily storable, and transportable source of platelets for bleeding patients. The objective of this study was to examine the impact of lyophilized human and porcine platelets in a swine liver injury model of nonsurgical hemorrhage. Methods: Anesthetized pigs (40 kg) had a controlled 35% total blood volume bleed from the right jugular vein followed by cooling to 35°C and resuscitation with Ringer's lactate to achieve a 3:1 blood withdrawal resuscitation. Through a midline laparotomy, the liver was injured with two standardized 5 × 5-cm grids with lacerations 1 cm apart and 0.5 cm deep. After 2 min of uncontrolled hemorrhage, the animals were treated with placebo (n = 5), lyophilized human (n = 5, HP), or swine platelets (n = 5, SP). At 15 min, shed blood was calculated. The animals then underwent abdominal closure. At 48 h, the animals were killed for histopathologic evaluation of the lung, kidney, and heart. Results: Intraoperative blood loss at 15 min was significantly higher in the HP arm (SP: 4.9 ± 2.9 mL/kg, HP: 12.3 ± 4.7 mL/kg, and control: 6.1 ± 2.5 mL/kg; P = 0.013). Mortality at 48 h was 20% in all three arms, due to uncontrolled intra-abdominal bleeding. At the time the animals were killed, SP animals had a significantly higher hematocrit (SP: 22.0% ± 3.0%, HP: 15.1% ± 4.9%, and control: 13.9% ± 0.6%; P = 0.026). No significant difference was found in platelet count (SP: 319.3 ± 62.1 × 10/µL, HP:361.5 ± 133.6 × 10/µL, and control: 242.7 ± 42.5 × 10/µL; P = 0.259). Histopathology of kidneys, lungs, and heart demonstrated no evidence of thromboembolic complications. Conclusion: In this swine model of liver injury, human lyophilized platelets increased intraoperative blood loss. With the use of species-specific lyophilized platelets, however, this effect was abolished, with a decrease in blood loss at 48 h after injury.
    Shock (Augusta, Ga.) 05/2014; 41(5):429-434. · 2.87 Impact Factor
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    ABSTRACT: Venovenous extracorporeal life support (VV ECLS) has been reported in adult trauma patients with severe respiratory failure; however, ECLS is not available in many trauma centers, few trauma surgeons have experience initiating ECLS and managing ECLS patients, and there is currently little evidence supporting its use in severely injured patients. This study seeks to determine if VV ECLS improves survival in such patients. Data from two American College of Surgeons-verified Level 1 trauma centers, which maintain detailed records of patients with acute hypoxemic respiratory failure (AHRF), were evaluated retrospectively. The study population included trauma patients between 16 years and 55 years of age treated for AHRF between January 2001 and December 2009. These patients were divided into two cohorts as follows: patients who received VV ECLS after an incomplete or no response to other rescue therapies (ECLS) versus patients who were managed with mechanical ventilation (CONV). The primary outcome was survival to discharge, and secondary outcomes were intensive care unit and hospital length of stay (LOS), total ventilator days, and rate of complications requiring intervention. Twenty-six ECLS patients and 76 CONV patients were compared. Adjusted survival was greater in the ECLS group (adjusted odds ratio, 0.193; 95% confidence interval, 0.042-0.884; p = 0.034). Ventilator days, intensive care unit LOS, and hospital LOS did not differ between the groups. ECLS patients received more blood transfusions and had more bleeding complications, while the CONV patients had more pulmonary complications. A cohort of 17 ECLS and 17 CONV patients matched for age and lung injury severity also demonstrated a significantly greater survival in the ECLS group (adjusted odds ratio, 0.038; 95% confidence interval, 0.004-0.407; p = 0.007). VV ECLS is independently associated with survival in adult trauma patients with AHRF. ECLS should be considered in trauma patients with AHRF when conventional therapies prove ineffective; if ECLS is not readily available, transfer to an ECLS center should be pursued. Therapeutic study, level III.
    The journal of trauma and acute care surgery. 05/2014; 76(5):1275-81.
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    ABSTRACT: Background: The use of low molecular weight heparin (LMWH) for chemoprophylaxis of Venous Thromboembolic (VTE) in trauma patients is supported by level-1 evidence. Because Enoxaparin was the agent used in majority of studies establishing the efficacy of LMWH in VTE, it remains unclear if Dalteparin provides equivalent effect. Objective: To compare Dalteparin to Enoxaparin and investigate their equivalence as VTE prophylaxis in trauma. Patients/Setting: Trauma patients receiving VTE chemoprophylaxis in the Surgical Intensive Care Unit of a level-1 trauma center from 2009 (Enoxaparin) to 2010 (Dalteparin) were included. Measurements: The primary outcome was the incidence of clinically significant VTE. Secondary outcomes including heparin induced thrombocytopenia (HIT), major bleeding and drug acquisition cost savings. Equivalence margins were set between -5% and 5%. Main Results: 610 patient records (277 Enoxaparin, 333 Dalteparin) were reviewed. The two study groups did not differ significantly: blunt trauma: 67% vs. 62%, p=0.27; mean ISS: 17±10 vs. 16±10, p=0.34; APACHE II: 17±9 vs. 17±10, p=0.76; time to first dose LMWH: 69±98 vs. 65±67hrs, p=0.57). The rates of DVT (3.2% vs. 3.3%, p=1.00), PE (1.8% vs. 1.2%, p=0.74) and overall VTE (5.1% vs. 4.5%, p=0.85) did not differ. The absolute difference in incidence of overall VTE was 0.5% (95% confidence interval: -2.9%, 4.0%, p=0.85). The 95% CI was within the predefined equivalence margins. There were no significant differences in the frequency of HIT or major bleeding. The total year-on-year cost savings, achieved with 277 patients during the switch to Dalteparin was estimated to be $107,778. Conclusions: Dalteparin is equivalent to Enoxaparin in terms of venous thromboembolism in trauma patients and can be safely used in this population with no increase in complications and significant cost savings.
    European Journal of Trauma and Emergency Surgery 04/2014; 40(2):183-189. · 0.26 Impact Factor
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    ABSTRACT: Because of the automated nature of knowledge, experts tend to omit information when describing a task. A potential solution is cognitive task analysis (CTA). The authors investigated the percentage of knowledge experts omitted when teaching a cricothyrotomy to determine the percentage of additional knowledge gained during a CTA interview. Three experts were videotaped teaching a cricothyrotomy in 2010 at the University of Southern California. After transcription, they participated in CTA interviews for the same procedure. Three additional surgeons were recruited to perform a CTA for the procedure, and a "gold standard" task list was created. Transcriptions from the teaching sessions were compared with the task list to identify omitted steps (both "what" and "how" to do). Transcripts from the CTA interviews were compared against the task list to determine the percentage of knowledge articulated by each expert during the initial "free recall" (unprompted) phase of the CTA interview versus the amount of knowledge gained by using CTA elicitation techniques (prompted). Experts omitted an average of 71% (10/14) of clinical knowledge steps, 51% (14/27) of action steps, and 73% (3.6/5) of decision steps. For action steps, experts described "how to do it" only 13% (3.6/27) of the time. The average number of steps that were described increased from 44% (20/46) when unprompted to 66% (31/46) when prompted. This study supports previous research that experts unintentionally omit knowledge when describing a procedure. CTA is a useful method to extract automated knowledge and augment expert knowledge recall during teaching.
    Academic medicine: journal of the Association of American Medical Colleges 03/2014; · 2.34 Impact Factor
  • The journal of trauma and acute care surgery. 03/2014; 76(3):888-93.
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    ABSTRACT: The epidemic increase in the incidence of diabetes mellitus (DM) worldwide represents a potential source of surgical morbidity. The impact of DM on the need for surgical management and its effect on surgical outcomes for colonic diverticulitis have not been well defined. We investigated all DM versus non-DM patients admitted with a diagnosis of acute diverticulitis between January 1, 2003, and December 31, 2011, to a large urban safety net hospital. An administrative database search for patients with diverticulitis was divided into two groups: those with and without DM. They were retrospectively analyzed for severity of diverticulitis (Hinchey and Ambrosetti scores), mortality, length of hospital stay, need for operation, postoperative complications, and readmission rates. There were 1,019 admissions with acute diverticulitis, 164 (16.1%) of which had DM. DM versus non-DM patients presented with a higher Hinchey score of 3 or 4 (12.2% vs. 9.2%, p < 0.001), a more severe computed tomographic Ambrosetti score (43.9% vs. 31.7%, p < 0.001), older age, and significantly more comorbid conditions. There was no significant difference in the failure of nonoperative management (2.2% DM vs. 2.5% non-DM, p = 1.000), readmission, or death rates. Operated DM patients had a higher incidence of in-hospital infectious complications (28.7% vs. 8.2%, p < 0.001) and a higher incidence of acute renal failure (5.5% vs. 0.7%, p < 0.001). Although diabetic patients with colonic diverticulitis present at a more advanced level (as measured by Hinchey and Ambrosetti scores), the nonoperative success rate is similar to non-DM patients. Surgical management in DM patients is associated with a higher incidence of infectious complications and acute kidney injury. However, DM did not appear to increase operative mortality in surgically managed patients. These data suggest that greater attention should be placed on steps to reduce the negative impact of DM on both immune response and renal function in patients requiring surgery of colonic diverticulitis. Epidemiologic study, level III.
    The journal of trauma and acute care surgery. 03/2014; 76(3):704-709.
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    ABSTRACT: Currently, there is no established system for assessing disease severity in emergency general surgery (EGS) patients. The purpose of this project was to develop a uniform grading system for measuring anatomic severity of disease in this patient population. The Committee on Patient Assessment and Outcomes of the American Association for the Surgery of Trauma developed a proposal by consensus of experts for grading severity of EGS diseases. It was then reviewed and approved by the Board of Managers of the American Association for the Surgery of Trauma. A uniform grading system for measuring anatomic severity of disease in EGS is described, with specific grades for eight commonly encountered gastrointestinal conditions. These grades range from Grade I through Grade V, reflecting an escalating clinical progression from mild disease limited within the organ itself to severe disease that is widespread. This article provides a unified grading system for measuring anatomic severity of disease that is essential to advance the science of EGS. Once validated, a description of disease grade should be included in the emerging EGS registries and in research studies involving EGS patients.
    The journal of trauma and acute care surgery. 03/2014; 76(3):884-7.
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    ABSTRACT: Penetrating thoracoabdominal trauma, with potential injury to two anatomic cavities, significantly challenges surgical management, yet this injury pattern has not been reviewed across a large patient series. The trauma registry of a major level 1 center was queried for all adult patients admitted with thoracoabdominal stab wounds between January 1996 and December 2011. The study identified 617 patients; 11% arrived hypotensive (systolic blood pressure < 90 mm Hg), 6.5% had Glasgow Coma Scale (GCS) score less than 8, and 3.6% were in cardiac arrest. Of those arriving alive, 350 (59%) of 595 underwent surgery (88% laparotomy, 3% thoracotomy, and 9% both procedures). Nontherapeutic laparotomy was performed on 12.3% of these patients. Cardiac injury occurred in 71% (29 of 41) of the patients arriving alive undergoing thoracotomy. Among this group, only 1 (2.4%) of 41 had a major thoracic vessel or aortic injury without cardiac trauma. Diaphragmatic injury (DI) occurred in 224 (38%) of 595, with 72 (32.1%) of these 224 demonstrating no computed tomographic evidence of DI. Either hollow viscus injury or DI occurred in 50%. Only 36.8% of liver, 58% of spleen, and 29.8% of kidney injuries required surgical repair. The need for dual-cavitary intervention was associated with a precipitous increase in patient mortality. Patients with thoracoabdominal stab wounds present considerable clinical challenges due to high surgical need, high occult DI incidence, persistently high rates of negative laparotomy, and significant mortality with dual-cavitary intervention. Many patients with solid-organ injuries do not require intervention. High incidence of hollow viscus injury and DI ultimately limits nonoperative management. Laparoscopy is necessary to exclude occult DI. In unstable patients, determination of which anatomic cavity to explore primarily requires exclusion of cardiac injury. In those with equivocal clinical or ultrasonographic evidence of cardiac trauma, laparotomy, with transdiaphragmatic pericardial window, if a causative abdominal injury is not immediately apparent, seems the most effective strategy. Epidemiologic study, level III.
    The journal of trauma and acute care surgery. 02/2014; 76(2):418-23.
  • The American surgeon 02/2014; 80(2):207-209. · 0.92 Impact Factor
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    ABSTRACT: Introduction Falls are a leading cause of unintentional injury among adults, especially those over 65 years of age. With increasing longevity and improving access to healthcare, falls are affecting a more mobile senior citizen population that does not fit the typical profile. We set out to evaluate the current nature of these falls in the elderly. Methods This is a two-year retrospective chart review of all falls in patients 65 years or older at an urban Level 1 trauma center. Demographics, location and height of fall, associated injuries and outcomes were obtained from chart review. Results There were 400 patients meeting inclusion criteria. The cohort had a mean age of 78.3 ± 8.8, 50% male, and 72.5% had at least one co-morbidity. Non-ground level falls (Non-GLFs) were recorded in 56 patients (14%). These patients suffered a significantly higher injury burden. Non-GLFs were associated with significantly higher ICU length of stay (2.6±5.6 vs. 4.6±6.7 days, p = 0.016) and a trend towards higher mortality than GLFs. Conclusions Falls remain a source of considerable healthcare expenditure, especially among the elderly. Non-GLF account for 14% of cases and are associated with a significantly higher burden of injury and morbidity. Fall prevention strategies should include these active older individuals at risk of high level falls.
    American journal of surgery 01/2014; · 2.36 Impact Factor
  • The American surgeon 01/2014; 80(6). · 0.92 Impact Factor
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    ABSTRACT: Background The effect of diabetes and the role of laparoscopic surgery on outcomes following appendectomy for acute appendicitis is not known. Methods National Surgical Quality Improvement Program study, including patients with acute appendicitis and no significant comorbidities (American Society of Anesthesiologists grade I or II) who underwent appendectomy. Diabetic patients were matched (1:3) with non-diabetic patients. The primary outcomes were 30-day mortality, surgical site infections (SSI) and systemic infectious complications (SIC). Results SSI were encountered more frequently in the diabetic group as compared to the non-diabetic group (6.1 vs 4.3%, p=0.010). Also, the hospital length of stay was significantly longer in the diabetic group. In the diabetic group, laparoscopic appendectomy did not affect mortality, re-operation, SSI and SIC rates, in patients with or without peritonitis (p>0.05), but the hospital length of stay was significantly shorter when compared to the open procedure. Conclusion Patients with diabetes and no significant comorbidities, have a higher risk of developing SSIs and longer hospital stay than patients without diabetes. Laparoscopic appendectomy had no effect on SSIs in patients with diabetes.
    The American Journal of Surgery. 01/2014;
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    ABSTRACT: Background The role of angiointervention (ANGIO) in the management of high-grade liver injuries is not clear and there are concerns about increased complications. Methods NTDB study, isolated grade IV and V blunt liver injuries. Patients with major associated intra-abdominal or extra-abdominal injuries were excluded. Logistic regression analysis was performed to identify independent predictors of mortality and complications. Results 6,402 patients met the criteria for inclusion. Laparotomy was performed in 32% and non-operative management in 68%. Overall, 11% underwent ANGIO. Patients in the ANGIO group were significantly more likely to be older than 55 years than non-ANGIO patients and more likely to have ISS>25. After stepwise logistic regression, ANGIO was an independent predictor of survival (p<0.001). In the group of patients managed operatively, it was independently associated with a lower mortality (p<0.001). Similarly, in the non-operative group it was independently associated with a lower mortality (5.4% vs 9.5%,p=0.008). ANGIO was associated with increased systemic complications. Conclusion ANGIO in blunt, severe liver injuries is associated with reduced mortality and increased complications, in both operative and non-operative management.
    The American Journal of Surgery. 01/2014;

Publication Stats

2k Citations
588.85 Total Impact Points


  • 2008–2014
    • The University of Arizona
      • Department of Surgery
      Tucson, Arizona, United States
    • University of Texas Medical Branch at Galveston
      • Department of Surgery
      Galveston, TX, United States
  • 2007–2014
    • University of California, Los Angeles
      • • Department of Surgery
      • • Division of Pediatric Surgery
      Los Angeles, California, United States
    • University of Miami Miller School of Medicine
      • Department of Surgery
      Miami, FL, United States
  • 2006–2014
    • University of Southern California
      • Department of Surgery
      Los Angeles, California, United States
  • 2006–2013
    • Keck School of Medicine USC
      Los Angeles, California, United States
  • 2012
    • University of Maryland Medical Center
      Baltimore, Maryland, United States
    • University of Aberdeen
      Aberdeen, Scotland, United Kingdom
  • 2010–2012
    • University of Maryland, Baltimore
      Baltimore, Maryland, United States
    • Alpert Medical School - Brown University
      • Department of Surgery
      Providence, RI, United States
  • 2008–2012
    • Cedars-Sinai Medical Center
      • Cedars Sinai Medical Center
      Los Angeles, CA, United States
  • 2011
    • Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center
      Torrance, California, United States
    • Tripler Army Medical Center
      Honolulu, Hawaii, United States
    • Hospices Civils de Lyon
      Lyons, Rhône-Alpes, France
  • 2009
    • Los Angeles County Museum of Art
      Los Angeles, California, United States