BACKGROUND:The benefits of physician-staffed emergency medical services (EMS) for trauma patients remain unclear because of the conflicting results on survival. Some studies suggested potential delays in definitive hemostasis due to prolonged prehospital stay when physicians are dispatched to the scene. We examined hypotensive trauma patients who were transported by ambulance, with the hypothesis that physician-staffed ambulances would be associated with increased in-hospital mortality, compared with EMS personnel-staffed ambulances. METHODS:A retrospective cohort study that included hypotensive trauma patients (systolic blood pressure ≤ 90 mm Hg at the scene) transported by ambulance was conducted using the Japan Trauma Data Bank (2004Bank ( -2019. Physician-staffed ambulances are capable of resuscitative procedures, such as thoracotomy and surgical airway management, while EMS personnel-staffed ambulances could only provide advanced life support. In-hospital mortality and prehospital time until the hospital arrival were compared between patients who were classified based on the type of ambulance. Inverse probability weighting was conducted to adjust baseline characteristics including age, sex, comorbidities, mechanism of injury, vital signs at the scene, injury severity, and ambulance dispatch time. RESULTS:Among 14,652 patients eligible for the study, 738 were transported by a physician-staffed ambulance. In-hospital mortality was higher in the physician-staffed ambulance than in the EMS personnel-staffed ambulance (201/699 [28.8%] vs. 2287/13,090 [17.5%]; odds ratio, 1.90 [1.61-2.26]; adjusted odds ratio, 1.22 [1.14-1.30]; p < 0.01), and the physician-staffed ambulance showed longer prehospital time (50 [36-66] vs. 37 [29-48] min, difference = 12 [11-12] min, p < 0.01). Such potential harm of the physician-staffed ambulance was only observed among patients who arrived at the hospital with persistent hypotension (systolic blood pressure < 90 mm Hg on hospital arrival) in subgroup analyses. CONCLUSION:Physician-staffed ambulances were associated with prolonged prehospital stay and increased in-hospital mortality among hypotensive trauma patients compared with EMS personnel-staffed ambulance.

Background The beneficial effect of epinephrine during resuscitation from out-of-hospital cardiac arrest (OHCA) has been inconclusive, and potential harm has been suggested, particularly in trauma victims. Although no significant improvement in neurological outcomes has been found among resuscitated patients using epinephrine, including trauma patients, the use of epinephrine is recommended in the Advanced Trauma Life Support protocol. Given that the use of vasopressors was reported to be associated with increased mortality in patients with massive bleeding, the undesirable effects of epinephrine during the resuscitation of traumatic OHCA should be elucidated. We hypothesised that resuscitation with epinephrine would increase mortality in patients with OHCA following trauma. Methods This study is a post-hoc analysis of a prospective, multicentre, observational study on patients with OHCA between January 2012 and March 2013. We included adult patients with traumatic OHCA who were aged ≥15 years and excluded those with missing survival data. Patient data were divided into epinephrine or no-epinephrine groups based on the use of epinephrine during resuscitation at the hospital. Propensity scores were developed to estimate the probability of being assigned to the epinephrine group using multivariate logistic regression analyses adjusted for known survival predictors. The primary outcome was survival 7 days after injury, which was compared among the two groups after propensity score matching. Results Of the 1125 adults with traumatic OHCA during the study period, 1030 patients were included in this study. Among them, 822 (79.8%) were resuscitated using epinephrine, and 1.1% (9/822) in the epinephrine group and 5.3% (11/208) in the no-epinephrine group survived 7 days after injury. The use of epinephrine was significantly associated with decreased 7-day survival (odds ratio = 0.20; 95% CI = 0.08–0.48; P < 0.01), and this result was confirmed by propensity score-matching analysis, in which 178 matched pairs were examined (adjusted odds ratio = 0.11; 95% CI = 0.01–0.85; P = 0.02). Conclusions The relationship between the use of epinephrine during resuscitation and decreased 7-day survival was found in patients with OHCA following trauma, and the propensity score-matched analyses validated the results. Resuscitation without epinephrine in traumatic OHCA should be further studied in a randomised controlled trial.

High oxygen tension in blood and/or tissue affects clinical outcomes in several diseases. Thus, the optimal target PaO 2 for patients recovering from cardiac arrest (CA) has been extensively examined. Many patients develop hypoxic brain injury after the return of spontaneous circulation (ROSC); this supports the need for oxygen administration in patients after CA. Insufficient oxygen delivery due to decreased blood flow to cerebral tissue during CA results in hypoxic brain injury. By contrast, hyperoxia may increase dissolved oxygen in the blood and, subsequently, generate reactive oxygen species that are harmful to neuronal cells. This secondary brain injury is particularly concerning. Although several clinical studies demonstrated that hyperoxia during post-CA care was associated with poor neurological outcomes, considerable debate is ongoing because of inconsistent results. Potential reasons for the conflicting results include differences in the definition of hyperoxia, the timing of exposure to hyperoxia, and PaO 2 values used in analyses. Despite the conflicts, exposure to PaO 2 > 300 mmHg through administration of unnecessary oxygen should be avoided because no obvious benefit has been demonstrated. The feasibility of titrating oxygen administration by targeting SpO 2 at approximately 94% in patients recovering from CA has been demonstrated in pilot randomized controlled trials (RCTs). Such protocols should be further examined.

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Background Angiography has been conducted as a hemostatic procedure for trauma patients. While several complications, such as tissue necrosis after embolization, have been reported, little is known regarding subsequent acute kidney injury (AKI) due to contrast media. To elucidate whether emergency angiography would introduce kidney dysfunction in trauma victims, we compared the incidence of AKI between patients who underwent emergency angiography and those who did not. Methods A retrospective cohort study was conducted using a nationwide trauma database (2004–2019), and adult trauma patients were included. The indication of emergency angiography was determined by both trauma surgeons and radiologists, and AKI was diagnosed by treating physicians based on a rise in serum creatinine and/or fall in urine output according to any published standard criteria. Incidence of AKI was compared between patients who underwent emergency angiography and those who did not. Propensity score matching was conducted to adjust baseline characteristics including age, comorbidities, mechanism of injury, vital signs on admission, Injury Severity Scale (ISS), degree of traumatic kidney injury, surgical procedures, and surgery on the kidney, such as nephrectomy and nephrorrhaphy. Results Among 230,776 patients eligible for the study, 14,180 underwent emergency angiography. The abdomen/pelvis was major site for angiography (10,624 [83.5%]). Embolization was performed in 5,541 (43.5%). Propensity score matching selected 12,724 pairs of severely injured patients (median age, 59; median ISS, 25). While the incidence of AKI was rare, it was higher among patients who underwent emergency angiography than in those who did not (140 [1.1%] vs. 67 [0.5%]; odds ratio = 2.10 [1.57–2.82]; p < 0.01). The association between emergency angiography and subsequent AKI was observed regardless of vasopressor usage or injury severity in subgroup analyses. Conclusions Emergency angiography in trauma patients was probably associated with increased incidence of AKI. The results should be validated in future studies.