A brief episode of hypotension increases mortality in critically ill trauma patients

Development of a two-hit lethal liver injury model in swine

PURPOSE

Noncompressible truncal hemorrhage remains a leading cause of preventable death in the prehospital setting. Standardized and reproducible large animal models are essential to test new therapeutic strategies. However, existing injury models vary significantly in consistency and clinical accuracy. This study aims to develop a lethal porcine model to test hemostatic agents targeting noncompressible abdominal hemorrhages.

METHODS

We developed a two-hit injury model in Yorkshire swine, consisting of a grade IV liver injury combined with hemodilution. The hemodilution was induced by controlled exsanguination of 30% of the total blood volume and a 3:1 resuscitation with crystalloids. Subsequently, a grade IV liver injury was performed by sharp transection of both median lobes of the liver, resulting in major bleeding and severe hypotension. The abdominal incision was closed within 60 s from the injury. The endpoints included mortality, survival time, serum lab values, and blood loss within the abdomen.

RESULTS

This model was lethal in all animals (5/5), with a mean survival time of 24.4 ± 3.8 min. The standardized liver resection was uniform at 14.4 ± 2.1% of the total liver weight. Following the injury, the MAP dropped by 27 ± 8mmHg within the first 10 min. The use of a mixed injury model (i.e., open injury, closed hemorrhage) was instrumental in creating a standardized injury while allowing for a clinically significant hemorrhage.

CONCLUSION

This novel highly lethal, consistent, and clinically relevant translational model can be used to test and develop life-saving interventions for massive noncompressible abdominal hemorrhage.

Impact of resuscitation adjuncts on postintubation hypotension in patients with isolated traumatic brain injury

INTRODUCTION

Postintubation hypotension (PIH) is a risk factor of endotracheal intubation (ETI) after injury. For those with traumatic brain injury (TBI), one episode of hypotension can potentiate that injury. This study aimed to identify the resuscitation adjuncts that may decrease the incidence of PIH in this patient population.

METHODS

This is a 4-year (2019-2022) prospective observational study at a level I trauma center. Adult (18 years or older) patients with isolated TBI requiring ETI in the trauma bay were included. Blood pressures were measured 15 minutes preintubation and postintubation. Primary outcome was PIH, defined as a decrease in systolic blood pressure of ≥20% from baseline or to ≤80 mm Hg, or any decrease in mean arterial pressure to ≤60 mm Hg. Multivariable logistic regression was performed to identify the associations of preintubation vasopressor, hypertonic saline (HTS), packed red blood cell, and crystalloids on PIH incidence.

RESULTS

Of the 490 enrolled patients, 16% had mild (head AIS, ≤2), 35% had moderate (head AIS, 3-4), and 49% had severe TBI (head AIS, ≥5). The mean ± SD age was 42 ± 22 years, and 71% were male. The median ISS, head AIS, and Glasgow Coma Scale were 26 (19-38), 4 (3-5), and 6 (3-11), respectively. The mean ± SD systolic blood pressure 15 minutes preintubation and postintubation were 118 ± 46 and 106 ± 45, respectively. Before intubation, 31% received HTS; 10%, vasopressors; 20%, crystalloids; and 14%, at least 1 U of packed red blood cell (median, 2 [1-2] U). Overall, 304 patients (62%) developed PIH. On multivariable regression analysis, preintubation use of vasopressors and HTS was associated with significantly decreased odds of PIH independent of TBI severity, 0.310 (0.102-0.944, p = 0.039) and 0.393 (0.219-0.70, p = 0.002), respectively.

CONCLUSION

Nearly two thirds of isolated TBI patients developed PIH. Preintubation vasopressors and HTS are associated with a decreased incidence of PIH. Such adjuncts should be considered prior to ETI in patients with suspected TBI.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Critical hypertension in trauma patients following prehospital emergency anaesthesia: a multi-centre retrospective observational study

BACKGROUND

Critical hypertension in major trauma patients is associated with increased mortality. Prehospital emergency anaesthesia (PHEA) is performed for 10% of the most seriously injured patients. Optimising oxygenation, ventilation, and cerebral perfusion, whilst avoiding extreme haemodynamic fluctuations are the cornerstones of reducing secondary brain injury. The aim of this study was to report the differential determinants of post-PHEA critical hypertension in a large regional dataset of trauma patients across three Helicopter Emergency Medical Service (HEMS) organisations.

METHODS

A multi-centre retrospective observational study of consecutive adult trauma patients undergoing PHEA across three HEMS in the United Kingdom; 2015-2022. Critical hypertension was defined as a new systolic blood pressure (SBP) > 180mmHg within 10 min of induction of anaesthesia, or > 10% increase if the baseline SBP was > 180mmHg prior to induction. Purposeful logistical regression was used to explore variables associated with post-PHEA critical hypertension in a multivariable model. Data are reported as number (percentage), and odds ratio (OR) with 95% confidence interval (95%CI).

RESULTS

30,744 patients were attended by HEMS during the study period; 2161 received PHEA and 1355 patients were included in the final analysis. 161 (11.9%) patients had one or more new episode(s) of critical hypertension ≤ 10 min post-PHEA. Increasing age (compared with 16-34 years): 35-54 years (OR 1.76, 95%CI 1.03-3.06); 55-74 years (OR 2.00, 95%CI 1.19-3.44); ≥75 years (OR 2.38, 95%CI 1.31-4.35), pre-PHEA Glasgow Coma Scale (GCS) motor score four (OR 2.17, 95%CI 1.19-4.01) and five (OR 2.82, 95%CI 1.60-7.09), patients with a pre-PHEA SBP > 140mmHg (OR 6.72, 95%CI 4.38-10.54), and more than one intubation attempt (OR 1.75, 95%CI 1.01-2.96) were associated with post-PHEA critical hypertension.

CONCLUSION

Delivery of PHEA to seriously injured trauma patients risks haemodynamic fluctuation. In adult trauma patients undergoing PHEA, 11.9% of patients experienced post-PHEA critical hypertension. Increasing age, pre-PHEA GCS motor score four and five, patients with a pre-PHEA SBP > 140mmHg, and more than intubation attempt were independently associated with post-PHEA critical hypertension.

Comparison of mortality in emergency department patients with immediate versus delayed hypotension

BACKGROUND

Hypotension in the emergency department (ED) is known to be associated with increased mortality, however, the relationship between timing of hypotension and mortality has not been investigated. The objective of the study was to compare the mortality rate of patients presenting with hypotension with those who develop hypotension while in the ED.

METHODS

This was a retrospective cohort study in a large academic medical center collected from January 2018-December 2021. Patients were included if they were ≥ 18 years old and had at least one recorded systolic blood pressure (SBP) ≤ 90 in the ED. Patients were separated into medical and trauma presentations by chief compliant. The primary outcome was in-hospital mortality, which included any deaths between ED arrival and hospital discharge. Further analysis examined the association of time to the first hypotensive SBP measurement with mortality.

RESULTS

There were 212,085 adult patients who presented to the ED during the study period, with 4053 (1.9%) patients having at least one hypotensive blood pressure measurement. The mortality rate was 0.8% for all patients and 10.0% for patients with hypotension. There were 676 unique chief complaints, of which 86 (12.7%) were determined to be trauma related. This grouping resulted in 176,947(83.4%) patients classified as medical and 35,138(16.6%) patients as trauma. For patients presenting with medical complaints, there was not a significant difference in mortality for patients who were hypotensive on arrival and those who developed hypotension during their ED stay (RR 1.19 [95% CI:0.97-1.39]). Similarly, there was no difference for patients with trauma (RR 0.6 [95% CI: 0.31-1.24]). However, for all patients, there was a significant trend toward decreased mortality for every hour after arrival until the development of hypotension, and increased mortality with increasing number of hypotensive measurements recorded.

CONCLUSION

This study demonstrated hypotension in the ED was associated with a very significantly increased risk of in-hospital mortality. However, there was no significant increase in mortality between those patients with hypotension on arrival those who develop hypotension while in the ED. These finding underscore the importance of careful hemodynamic monitoring for patients in the ED throughout their stay.

Advancement in the Cuffless and Noninvasive Measurement of Blood Pressure: A Review of the Literature and Open Challenges

Hypertension is a chronic condition that is one of the prominent reasons behind cardiovascular disease, brain stroke, and organ failure. Left unnoticed and untreated, the deterioration in a health condition could even result in mortality. If it can be detected early, with proper treatment, undesirable outcomes can be avoided. Until now, the gold standard is the invasive way of measuring blood pressure (BP) using a catheter. Additionally, the cuff-based and noninvasive methods are too cumbersome or inconvenient for frequent measurement of BP. With the advancement of sensor technology, signal processing techniques, and machine learning algorithms, researchers are trying to find the perfect relationships between biomedical signals and changes in BP. This paper is a literature review of the studies conducted on the cuffless noninvasive measurement of BP using biomedical signals. Relevant articles were selected using specific criteria, then traditional techniques for BP measurement were discussed along with a motivation for cuffless measurement use of biomedical signals and machine learning algorithms. The review focused on the progression of different noninvasive cuffless techniques rather than comparing performance among different studies. The literature survey concluded that the use of deep learning proved to be the most accurate among all the cuffless measurement techniques. On the other side, this accuracy has several disadvantages, such as lack of interpretability, computationally extensive, standard validation protocol, and lack of collaboration with health professionals. Additionally, the continuing work by researchers is progressing with a potential solution for these challenges. Finally, future research directions have been provided to encounter the challenges.

Hypotension Prediction Score for Endotracheal Intubation in Critically Ill Patients: A Post Hoc Analysis of the HEMAIR Study

BACKGROUND

Hypotension with endotracheal intubation (ETI) is common and associated with adverse outcomes. We sought to evaluate whether a previously described hypotension prediction score (HYPS) for ETI is associated with worse patient outcomes and/or clinical conditions.

METHODS

This study is a post hoc analysis of a prospective observational multicenter study involving adult (age ≥18 years) intensive care unit (ICU) patients undergoing ETI in which the HYPS was derived and validated on the entire cohort and a stable subset (ie, patients in stable condition). We evaluated the association between increasing HYPSs in both subsets and several patient-centered outcomes and clinical conditions.

RESULTS

Complete data for HYPS calculations were available for 783 of 934 patients (84%). Logistic regression analysis showed increasing odds ratios (ORs) for the highest risk category for new-onset acute kidney injury (OR, 7.37; 95% CI, 2.58-21.08); new dialysis need (OR, 8.13; 95% CI, 1.74-37.91); ICU mortality (OR, 16.39; 95% CI, 5.99-44.87); and hospital mortality (OR, 18.65; 95% CI, 6.81-51.11). Although not increasing progressively, the OR for the highest risk group was significantly associated with new-onset hypovolemic shock (OR, 6.06; 95% CI, 1.47-25.00). With increasing HYPSs, median values (interquartile ranges) decreased progressively (lowest risk vs. highest risk) for ventilator-free days (23 [18-26] vs. 1 [0-21], P < .001) and ICU-free days (20 [11-24] vs. 0 [0-13], P < .001). Of the 729 patients in the stable subset, 598 (82%) had complete data for HYPS calculations. Logistic regression analysis showed significantly increasing ORs for the highest risk category for new-onset hypovolemic shock (OR, 7.41; 95% CI, 2.06-26.62); ICU mortality (OR, 5.08; 95% CI, 1.87-13.85); and hospital mortality (OR, 7.08; 95% CI, 2.63-19.07).

CONCLUSIONS

As the risk for peri-intubation hypotension increases, according to a validated hypotension prediction tool, so does the risk for adverse clinical events and certain clinical conditions.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov (NCT02508948).

Injuries associated with hypotension after trauma: Is it always haemorrhage?

Introduction

Restricted fluid replacement strategy is one part of damage control resuscitation for patients with trauma haemorrhage. However, not all patients presenting with physiological symptoms suggestive of haemorrhage are bleeding. This descriptive study aims to compare demographics and injuries in adult and older trauma patients presenting to the Emergency Department with hypotension versus normotension.

Methods

This was a retrospective, descriptive data analysis from a UK trauma registry. The records from one major trauma centre were analysed between 2014–2019, and every hypotensive (systolic blood pressure <90 mmHg) trauma patient investigated for injuries associated with hypotension. The hypotensive threshold for older patients was also adjusted to 110 mmHg for sub-cohort analysis.

Results

6245 trauma patients were included, of which 255 (4.1%) arrived hypotensive at the Emergency Department. Significant blood loss was identified in 32.2% of those cases. In 27.1%, multiple potential associations obscured the underlying mechanism for the hypotension but were more commonly associated with hypotension than with normotension. Over a third (37.5%) were ≥65 years old. Neurological injuries occurred more frequently in both older hypotensive groups than younger patients.

Conclusions

This study sought to compare injuries of adult and older trauma patients to aid trauma teams with decision making. In severely injured hypotensive patients, significant blood loss was the principal association with hypotension. However, several factors can mimic bleeding in the hypotensive trauma patient, which should be carefully considered. A prospective study is needed to clarify the characteristics and causes of bleeding mimics.

Talk and Die: A Descriptive Analysis of Penetrating Trauma Patients

INTRODUCTION

"Talk and die" traditionally described occult presentations of fatal intracranial injuries, but we broaden its definition to victims of penetrating trauma.

METHODS

We conducted a descriptive analysis of patients with penetrating torso trauma who presented with a Glasgow Coma Scale verbal score ≥3 and died within 48 h of arrival from 2008 to 2018.

RESULTS

Sixty patients were identified. Eighteen (30.0%) required resuscitative thoracotomy with 7 (11.7%) dying in the trauma bay. Fifty-three (86.9%) patients went to the operating room, and 35 (66.0%) required multicavitary exploration. The most common injuries were hollow viscous (58.5%), intra-abdominal vascular (49.0%), liver (28.3%), pulmonary (26.4%), intrathoracic vascular (18.9%), and cardiac (15.75) injuries. Twenty-three (43.4%) patients survived their initial operation, but died in the first 48 h postoperatively.

CONCLUSIONS

Patients who "talk and die" most frequently have intra-abdominal vascular injures and require multicavitary exploration.

Cuffless Blood Pressure Measurement

Cuffless blood pressure (BP) measurement has become a popular field due to clinical need and technological opportunity. However, no method has been broadly accepted hitherto. The objective of this review is to accelerate progress in the development and application of cuffless BP measurement methods. We begin by describing the principles of conventional BP measurement, outstanding hypertension/hypotension problems that could be addressed with cuffless methods, and recent technological advances, including smartphone proliferation and wearable sensing, that are driving the field. We then present all major cuffless methods under investigation, including their current evidence. Our presentation includes calibrated methods (i.e., pulse transit time, pulse wave analysis, and facial video processing) and uncalibrated methods (i.e., cuffless oscillometry, ultrasound, and volume control). The calibrated methods can offer convenience advantages, whereas the uncalibrated methods do not require periodic cuff device usage or demographic inputs. We conclude by summarizing the field and highlighting potentially useful future research directions. Expected final online publication date for the Annual Review of Biomedical Engineering, Volume 24 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Monitoring, management, and outcome of hypotension in Intensive Care Unit patients, an international survey of the European Society of Intensive Care Medicine

INTRODUCTION

Hypotension in the ICU is common, yet management is challenging and variable. Insight in management by ICU physicians and nurses may improve patient care and guide future hypotension treatment trials and guidelines.

METHODS

We conducted an international survey among ICU personnel to provide insight in monitoring, management, and perceived consequences of hypotension.

RESULTS

Out of 1464 respondents, 1197 (81.7%) were included (928 physicians (77.5%) and 269 nurses (22.5%)). The majority indicated that hypotension is underdiagnosed (55.4%) and largely preventable (58.8%). Nurses are primarily in charge of monitoring changes in blood pressure, physicians are in charge of hypotension treatment. Balanced crystalloids, dobutamine, norepinephrine, and Trendelenburg position were the most frequently reported fluid, inotrope, vasopressor, and positional maneuver used to treat hypotension. Reported complications believed to be related to hypotension were AKI and myocardial injury. Most ICUs do not have a specific hypotension treatment guideline or protocol (70.6%), but the majority would like to have one in the future (58.1%).

CONCLUSIONS

Both physicians and nurses report that hypotension in ICU patients is underdiagnosed, preventable, and believe that hypotension influences morbidity. Hypotension management is generally not protocolized, but the majority of respondents would like to have a specific hypotension management protocol.

Pattern Recognition in Vital Signs Using Spectrograms

Spectrograms visualize the frequency components of a given signal which may be an audio signal or even a time-series signal. Audio signals have higher sampling rate and high variability of frequency with time. Spectrograms can capture such variations well. But, vital signs which are time-series signals have less sampling frequency and low-frequency variability due to which, spectrograms fail to express variations and patterns. In this paper, we propose a novel solution to introduce frequency variability using frequency modulation on vital signs. Then we apply spectrograms on frequency modulated signals to capture the patterns. The proposed approach has been evaluated on 4 different medical datasets across both prediction and classification tasks. Significant results are found showing the efficacy of the approach for vital sign signals. The results from the proposed approach are promising with an accuracy of 91.55% and 91.67% in prediction and classification tasks respectively.

Definition and incidence of hypotension in intensive care unit patients, an international survey of the European Society of Intensive Care Medicine

INTRODUCTION

Although hypotension in ICU patients is associated with adverse outcome, currently used definitions are unknown and no universally accepted definition exists.

METHODS

We conducted an international, peer-reviewed survey among ICU physicians and nurses to provide insight in currently used definitions, estimations of incidence, and duration of hypotension.

RESULTS

Out of 1394 respondents (1055 physicians (76%) and 339 nurses (24%)), 1207 (82%) completed the questionnaire. In all patient categories, hypotension definitions were predominantly based on an absolute MAP of 65 mmHg, except for the neuro(trauma) category (75 mmHg, p < 0.001), without differences between answers from physicians and nurses. Hypotension incidence was estimated at 55%, and time per day spent in hypotension at 15%, both with nurses reporting higher percentages than physicians (estimated mean difference 5%, p = 0.01; and 4%, p < 0.001).

CONCLUSIONS

An absolute MAP threshold of 65 mmHg is most frequently used to define hypotension in ICU patients. In neuro(trauma) patients a higher threshold was reported. The majority of ICU patients are estimated to endure hypotension during their ICU admission for a considerable amount of time, with nurses reporting a higher estimated incidence and time spent in hypotension than physicians.

Using the National Trauma Data Bank (NTDB) and machine learning to predict trauma patient mortality at admission

A 400-estimator gradient boosting classifier was trained to predict survival probabilities of trauma patients. The National Trauma Data Bank (NTDB) provided 799233 complete patient records (778303 survivors and 20930 deaths) each containing 32 features, a number further reduced to only 8 features via the permutation importance method. Importantly, the 8 features can all be readily determined at admission: systolic blood pressure, heart rate, respiratory rate, temperature, oxygen saturation, gender, age and Glasgow coma score. Since death was rare, a rebalanced training set was used to train the model. The model is able to predict a survival probability for any trauma patient and accurately distinguish between a deceased and survived patient in 92.4% of all cases. Partial dependence curves (Psurvival vs. feature value) obtained from the trained model revealed the global importance of Glasgow coma score, age, and systolic blood pressure while pulse rate, respiratory rate, temperature, oxygen saturation, and gender had more subtle single variable influences. Shapley values, which measure the relative contribution of each of the 8 features to individual patient risk, were computed for several patients and were able to quantify patient-specific warning signs. Using the NTDB to sample across numerous patient traumas and hospital protocols, the trained model and Shapley values rapidly provides quantitative insight into which combination of variables in an 8-dimensional space contributed most to each trauma patient's predicted global risk of death upon emergency room admission.

No Difference in Mortality Between Level I and II Trauma Centers for Combined Burn and Trauma

BACKGROUND

Trauma patients with burn injuries have higher morbidity and mortality rates compared with patients who solely experience burn or trauma injuries. There is a paucity of data regarding burn-trauma (BT) patient outcomes at level I (LI) trauma centers compared with level II (LII) centers. We hypothesized that BT patients at LI trauma centers have lower mortality rates than those at LII trauma centers.

METHODS

The Trauma Quality Improvement Program (2010-2016) was queried for patients aged ≥18 y who had BT injuries. Patients treated at an LI were compared with those at an LII center with a primary outcome of in-hospital mortality. Secondary outcomes included hospital length of stay (LOS) and intensive care unit (ICU) LOS. A multivariable logistic regression analysis was used to identify factors associated with all-cause mortality.

RESULTS

From 1971 BT patients, 1540 (78%) were treated at an LI trauma center, and 431 (22%) at an LII center. Compared with LII centers, LI BT patients had a longer median LOS (10 versus 7 d; P < 0.001) and ICU LOS (5 versus 4 d; P < 0.001). Both LI and LII centers had similar mortality rates (8.5% versus 7.0%; P = 0.300). On multivariable analysis, receiving care at an LI trauma center was not associated with decreased mortality (odds ratio 0.79, 95% confidence interval 0.42-1.48; P = 0.456).

CONCLUSIONS

We report that LI trauma center BT patients had an increased hospital and ICU LOS compared with those at LII centers. However, there was no significant difference in mortality between patients cared for at LI and LII trauma centers in risk-adjusted models.

Usefulness of focused cardiac ultrasonography for predicting fluid responsiveness in conscious, spontaneously breathing dogs

OBJECTIVE

To evaluate the diagnostic usefulness of focused cardiac ultrasonography and selected echocardiographic variables for predicting fluid responsiveness in conscious, spontaneously breathing dogs with various clinical conditions.

ANIMALS

26 dogs (15 males and 11 females) with a median age of 84 months (range, 12 to 360 months) and median body weight of 8 kg (range, 2 to 35 kg) referred for various clinical conditions.

PROCEDURES

Left ventricular end-diastolic internal diameter normalized to body weight (LVIDDn), left ventricular volume score (LVVS), left ventricular end-diastolic volume index (EDVI), aortic velocity time integral (VTI_Ao), and aortic peak flow velocity (Vmax_Ao) were echocardiographically measured before and after IV administration of a bolus of lactated Ringer solution (4 mL/kg) over a 1-minute period. Dogs were classified on the basis of the observed change in aortic stroke volume following fluid administration as responders (≥ 15%) or nonresponders (< 15%) to fluid administration. Receiver operating characteristic curves were generated for the ability of LVVS, LVIDDn, EDVI, VTI_Ao, and Vmax_Ao to predict responder status.

RESULTS

13 dogs were classified as responders and 13 as nonresponders. Areas under the receiver operating characteristic curves (95% confidence intervals) for predicting fluid responsiveness were as follows: VTI_Ao, 0.91 (0.74 to 0.99); LVIDDn, 0.85 (0.66 to 0.96); EDVI, 0.85 (0.65 to 0.96); LVVS, 0.85 (0.65 to 0.96); and Vmax_Ao, 0.75 (0.54 to 0.90).

CONCLUSIONS AND CLINICAL RELEVANCE

The evaluated echocardiographic variables were useful for noninvasive prediction of fluid responsiveness in conscious dogs and could be valuable for informing clinical decisions regarding fluid therapy.

Shock Index as a Predictor of Post-Intubation Hypotension and Cardiac Arrest; A Review of the Current Evidence

Endotracheal intubation is a lifesaving procedure that is performed in various settings within the hospital or even in the pre-hospital field. However, it can result in serious hemodynamic complications, such as post-intubation hypotension (PIH) and cardiac arrest. The most promising predictor of such complications is the shock index (SI), which holds great prognostic value for multiple disorders. On the other hand, most of the studies that have assessed the predictability of the pre-intubation SI have been small and were limited to a particular setting of a single center; thus, the results were not generalizable, and the predictive value vary according to the setting. This review comprehensively assessed the utility of the pre-intubation SI for predicting PIH and post-intubation cardiac arrest by classifying and comparing evidence compiled from various settings, such as pre-hospital settings, emergency departments (EDs), intensive care units (ICUs), and operating rooms (ORs). The vast majority of these studies, conducted in ED and ICU settings, which revealed a significant correlation between an elevated SI and PIH or post-intubation cardiac arrest. The reliability and simplicity of obtaining a pre-intubation SI value are important considerations that encourage the extension of its use to all in-hospital intubations. Further studies are required to assess the predictive value of the SI in the pre-hospital setting.

Hemodynamic Effects of Propofol for Induction of Rapid Sequence Intubation in Traumatically Injured Patients

Present guidelines for emergency intubation in traumatically injured patients recommend rapid sequence intubation (RSI) as the preferred method of airway management but specific pharmacologic agents for RSI remain controversial. To evaluate hemodynamic differences between propofol and other induction agents when used for RSI in trauma patients. Single-center, retrospective review of trauma patients intubated in the emergency department. Patients were divided in two groups based on induction agent, propofol or nonpropofol. The primary outcome was incidence of hypotension within 30 minutes of intubation. Secondary outcomes included hospital length of stay and inhospital mortality. The study protocol was approved by the Institutional Review Board. Of the 744 patients identified, 83 were analyzed, 43 in the propofol group and 40 in the nonpropofol group. Groups were similar at baseline in terms of pre-RSI hemodynamics, injury mechanism, initial Glasgow Coma Score, and Injury Severity Score. On univariate analysis, although not statistically significant, postintubation hypotension was more common in patients who received propofol compared with those who did not, 39.5 per cent versus 22.5 per cent (P = 0.9). When adjusted for age, Injury Severity Score, and pre-RSI hemodynamics, the risk of hypotension among propofol-treated patients was significantly higher (OR = 3.64; 95% Confidence interval 1.16–13.24). There were no significant differences between groups in hospital length of stay or mortality. Propofol increases the odds of postintubation hypotension in traumatically injured patients. Considerable caution should be used when contemplating the use of propofol the for induction of injured patients requiring RSI because other agents possess more favorable hemodynamic profiles.

Inpatient Trauma Mortality after Implementation of the Affordable Care Act in Illinois

Introduction

Illinois hospitals have experienced a marked decrease in the number of uninsured patients after implementation of the Affordable Care Act (ACA). However, the full impact of health insurance expansion on trauma mortality is still unknown. The objective of this study was to determine the impact of ACA insurance expansion on trauma patients hospitalized in Illinois.

Methods

We performed a retrospective cohort study of 87,001 trauma inpatients from third quarter 2010 through second quarter 2015, which spans the implementation of the ACA in Illinois. We examined the effects of insurance expansion on trauma mortality using multivariable Poisson regression.

Results

There was no significant difference in mortality comparing the post-ACA period to the pre-ACA period incident rate ratio (IRR)=1.05 (95% confidence interval [CI] [0.93–1.17]). However, mortality was significantly higher among the uninsured in the post-ACA period when compared with the pre-ACA uninsured population IRR=1.46 (95% CI [1.14–1.88]).

Conclusion

While the ACA has reduced the number of uninsured trauma patients in Illinois, we found no significant decrease in inpatient trauma mortality. However, the group that remains uninsured after ACA implementation appears to be particularly vulnerable. This group should be studied in order to reduce disparate outcomes after trauma.

Predictors of Mortality in Blunt Multi-Trauma Patients: A Retrospective Review

Purpose

The purpose of this study was to identify risk factors predicting mortality in multiple blunt trauma patients so as to prompt appropriate management during trauma resuscitation.

Method

To assess risk factors potentially related to mortality in multiple blunt trauma patients, we reviewed the medical records of 1419 multiple blunt trauma patients who were admitted to the emergency department. The patients were divided into two groups; the survival group (n=1308) and the death group (n=111). Initial data collected on arrival in the emergency department were analyzed.

Results

In the study, 67.4% (n=956) of 1419 patients were male, 32.6% (n=463) were female. The average age was 21.19±0.50 years (range 1-92). After controlling for the factors significantly related to outcome (all p<0.05), death due to multiple blunt trauma was more likely in patients who were of older age, who had major chest injury, who had intra-abdominal solid organ injury and who had low Glasgow Coma Scale (GCS) score and low Revised Trauma Score (RTS).

Conclusion

We conclude that older age, major chest injury, intra-abdominal solid organ injury, low GCS and low RTS were identified as possible risk factors for mortality in multiple blunt trauma patients.

Presenting hypertension, burn injury, and mortality in combat casualties

INTRODUCTION

The effect of presenting hypertension is poorly studied in combat casualties. We hypothesized that elevated mean arterial pressure (MAP) on presentation to combat hospitals would be associated with poor outcomes.

METHODS

Data was obtained from the Department of Defense Trauma Registry and the Armed Forces Medical Examiner System. Variables analyzed included presenting vital signs to Role II-III military theater hospital, demographic variables, injury severity score (ISS), location and mechanism of injury, presence of traumatic brain injury (TBI), acute kidney injury (AKI), and mortality. Patients were stratified by decile of MAP and logistic regression analysis was employed to adjust for confounders.

RESULTS

A total of 4072 subjects injured from February 2002 to February 2011 were identified. Compared to patients in the middle deciles of presenting MAP, patients in the highest and lowest MAP deciles were the only groups that demonstrated a higher mortality on univariate analysis (OR 2.06, 95% CI 1.16-2.31 and OR 2.86, 95% CI 1.76-4.67, respectively), and this relationship persisted after adjustment for ISS, HR, temperature, presence of burn injury, TBI, and AKI. Burn injury was associated with mortality in the full multivariate analysis. However, further analysis limited to patients without burn injury did not demonstrate an association between high MAP and mortality (OR 0.84, 95% CI 0.36-1.99; p=0.70). Conversely, when limited to patients with burn injury, high MAP was associated with mortality (OR 3.78, 95% CI 1.74-8.20; p=0.001).

CONCLUSION

The relationship between mortality and presenting MAP appears to be U-shaped, demonstrating increased mortality in the lowest and highest deciles. However, mortality in the highest MAP decile appears to be limited to casualties with associated burn injury, even after adjustment for TBI, AKI, and ISS, which takes into account the severity of the burn injury. Physicians should recognize that burn patients presenting with an elevated MAP are at an increased risk for poor outcomes.

LEVEL OF EVIDENCE

III.

A novel model of highly lethal uncontrolled torso hemorrhage in swine

INTRODUCTION

A reproducible, lethal noncompressible torso hemorrhage model is important to civilian and military trauma research. Current large animal models balancing clinical applicability with standardization and internal validity. As such, large animal models of trauma vary widely in the surgical literature, limiting comparisons. Our aim was to create and validate a porcine model of uncontrolled hemorrhage that maximizes reproducibility and standardization.

METHODS

Seven Yorkshire-cross swine were anesthetized, instrumented, and splenectomized. A simple liver tourniquet was applied before injury to prevent unregulated hemorrhage while creating a traumatic amputation of 30% of the liver. Release of the tourniquet and rapid abdominal closure following injury provided a standardized reference point for the onset and duration of uncontrolled hemorrhage. At the moment of death, the liver tourniquet was quickly reapplied to provide accurate quantification of intra-abdominal blood loss. Weight and volume of the resected and residual liver segments were measured. Hemodynamic parameters were recorded continuously throughout each experiment.

RESULTS

This liver injury was rapidly and universally lethal (11.2 ± 4.9 min). The volume of hemorrhage (35.8% ± 6% of total blood volume) and severity of uncontrolled hemorrhage (100% of animals deteriorated to a sustained mean arterial pressure <35 mmHg for 5 min) were consistent across all animals. Use of the tourniquet effectively halted preprocedure and postprocedure blood loss allowing for accurate quantification of amount of hemorrhage over a defined period. In addition, the tourniquet facilitated the creation of a consistent liver resection weight (0.0043 ± 0.0003 liver resection weight: body weight) and as a percentage of total liver resection weight (27% ± 2.2%).

CONCLUSIONS

This novel tourniquet-assisted noncompressible torso hemorrhage model creates a standardized, reproducible, highly lethal, and clinically applicable injury in swine. Use of the tourniquet allowed for consistent liver injury and precise control over hemorrhage. Recorded blood loss was similar across all animals. Improving reproducibility and standardization has the potential to offer improvements in large animal translational models of hemorrhage.

LEVEL OF EVIDENCE

Level I.

Impact of pelvic fractures on the early clinical outcomes of severely injured trauma patients

BACKGROUND

Pelvic fractures contribute to morbidity and mortality following injury. We sought to study the impact of pelvic fractures on the clinical course and outcomes of trauma patients with a pelvic fracture in comparison to patients with similar injury severity without pelvic fracture to identify potential parameters to track patients' clinical course post-injury.

METHODS

A cohort of 206 consecutive blunt trauma survivors, studied over a 5-year period in a level I trauma center of which 75 patients (36.4%) had a pelvic fracture, was included in the study. To perform a retrospective cohort study with matched controls, 60 patients of the pelvic fracture group [(PF), 41 males and 19 females; age: 40 ± 17; injury severity score (ISS): 26.6 ± 9.3] were compared to 60 patients without pelvic fracture (non-PF) trauma as controls (41 males and 19 females; age: 40 ± 13; ISS: 26.9 ± 7.7), both with matching age (±5 years), sex, and ISS (±5 points).

RESULTS

Statistically significant differences were observed in Intensive Care Unit (ICU) length of stay (LOS), total LOS, and Marshall MOD score between PF and non-PF groups, respectively. Acid-base markers such as pH, lactate, LDH, and base deficit were all significantly altered in PF compared to non-PF cohort upon admission. Moreover, our analysis showed significant differences in inflammatory biomarkers (Prolactin, CRP, and IL-6), and clinical parameters (CPK, Hgb, Platelets count, and WBC) over the 7-day clinical course in patients with PF when compared to non-PF cohort.

CONCLUSION

In this matched cohort, patients with pelvic fractures exhibited biochemical and physiological alterations upon admission. Furthermore, our results suggest that pelvic fracture affects the clinical outcomes in severely injured patients, independently of injury severity, mechanism of injury, age or gender.

The Incidence of hypotension with continuous infusion atracurium compared to cisatracurium in the Intensive Care Unit

Background:

A drug shortage of cisatracurium led to use of atracurium as an alternative neuromuscular blocker (NMB). Cisatracurium may be preferred due to less histamine release and potentially less hypotension. The study purpose is to compare the incidence of hypotension with continuous infusion atracurium to continuous infusion cisatracurium in ICU patients.

Materials and Methods:

This retrospective cohort analysis reviewed 119 ICU patients who received either continuous infusion atracurium (56) or cisatracurium (63). The primary outcome was the incidence of hypotension (mean arterial pressure <60mmHg). Secondary outcomes included: incidence of blood pressure decrease of >20% from baseline, time to first hypotensive episode, treatment for hypotension during NMB use, hospital mortality, ICU and hospital length of stay (LOS), duration of mechanical ventilation (MV), and NMB duration.

Results:

Hypotension occurred in 64.3% of atracurium patients and 58.7% of cisatracurium patients (P = 0.58), with 60.7% experiencing >20% drop in blood pressure in atracurium group and 54.0% in cisatracurium (P = 0.58). Median time to first hypotensive episode was 9.4[Interquartile range 1.17-19.7] hours atracurium and 4.4[1.5-13.9] hours cisatracurium (P = 0.36). There were no differences between atracurium and cisatracurium groups respectively for median ICU LOS (10.5 days and 12.4 days, P = 0.34), hospital LOS (14.0 days and 17.7 days, P = 0.37), MV duration (9.3 days and 10.5 days, P = 0.43), infusion duration (34.5 hours and 25 hours P = 0.27), or hospital mortality (62.5% and 53.9%, P = 0.336). Hypotension treatment was similar between groups.

Conclusions:

The incidence of hypotension was similar between atracurium and cisatracurium. Critical drug shortages may provide an opportunity to study alternative drug therapy.

Physiological changes associated with routine nursing procedures in critically ill are common: an observational pilot study

BACKGROUND

Nursing procedures that are routinely performed in the intensive care unit (ICU) are assumed to have minimal side effects. However, these procedures may sometimes cause physiological changes that negatively affect the patient. We hypothesized that physiological changes associated with routine nursing procedures in the ICU are common.

METHODS

A clinical observational study of 16 critically ill patients in a nine-bed mixed university hospital ICU. All nursing procedures were observed, and physiological data were collected and subsequently analyzed. Minor physiological changes were defined as minimal changes in respiratory or circulatory variables, and major physiological changes were marked as hyper/hypotension, bradycardia/tachycardia, bradypnea/tachypnea, ventilatory distress, and peripheral blood oxygen desaturation.

RESULTS

In the 16 patients, 668 procedures generated 158 major and 692 minor physiological changes during 187 observational hours. The most common procedure was patient position change, which also generated the majority of the physiological changes. The most common major physiological changes were blood oxygen desaturation, ventilatory distress, and hypotension, and the most common minor changes were arterial pressure alteration, coughing, and increase in respiratory rate.

CONCLUSION

In this pilot study, we examined physiological changes in connection with all regular routine nursing procedures in the ICU. We found that physiological changes were common and sometimes severe.

The Diagnosis and Hemodynamic Monitoring of Circulatory Shock: Current and Future Trends

Circulatory shock is a complex clinical syndrome encompassing a group of conditions that can arise from different etiologies and presented by several different hemodynamic patterns. If not corrected, cell dysfunction, irreversible multiple organ insufficiency, and death may occur. The four basic types of shock, hypovolemic, cardiogenic, obstructive and distributive, have features similar to that of hemodynamic shock. It is therefore essential, when monitoring hemodynamic shock, to making accurate clinical assessments which will guide and dictate appropriate management therapy. The European Society of Intensive Care has recently made recommendations for monitoring hemodynamic shock. The present paper discusses the issues raised in the new statements, including individualization of blood pressure targets, prediction of fluid responsiveness, and the use of echocardiography as the first means during the initial evaluation of circulatory shock. Also, the place of more invasive hemodynamic monitoring techniques and future trends in hemodynamic and metabolic monitoring in circulatory shock, will be debated.

Liver trauma

Management of blunt or penetrating injury to the liver remains a significant challenge to trauma surgeons. Liver injury remains common in both blunt and penetrating trauma of the abdomen. Unstable patients require immediate laparotomy. Selective patients can be managed without surgery and with careful monitoring. There has been a recent resurgence in the role of temporary packing in the management of liver trauma. Other commonly used techniques are resectional debribement and suture ligation of bleeding vessels. Complications include haemorrhage, bile leak and sepsis. Mortality is mainly due to damage to major hepatic blood vessels or other associated non-hepatic injuries. With improved understanding of the major causes of death from hepatic injury, improved resuscitation and intensive care, mortality has fallen below 10%.

The organizational structure of an intensive care unit influences treatment of hypotension among critically ill patients: A retrospective cohort study

PURPOSE

Prior studies report that weekend admission to an intensive care unit is associated with increased mortality, potentially attributed to the organizational structure of the unit. This study aims to determine whether treatment of hypotension, a risk factor for mortality, differs according to level of staffing.

METHODS

Using the Multiparameter Intelligent Monitoring in Intensive Care database, we conducted a retrospective study of patients admitted to an intensive care unit at Beth Israel Deaconess Medical Center who experienced one or more episodes of hypotension. Episodes were categorized according to the staffing level, defined as high during weekday daytime (7 am-7 pm) and low during weekends or nighttime (7 pm-7 am).

RESULTS

Patients with a hypotensive event on a weekend were less likely to be treated compared with those that occurred during the weekday daytime (P = .02). No association between weekday daytime vs weekday nighttime staffing levels and treatment of hypotension was found (risk ratio, 1.02; 95% confidence interval, 0.98-1.07).

CONCLUSION

Patients with a hypotensive event on a weekend were less likely to be treated than patients with an event during high-staffing periods. No association between weekday nighttime staffing and hypotension treatment was observed. We conclude that treatment of a hypotensive episode relies on more than solely staffing levels.

Resveratrol decreases nitric oxide production by hepatocytes during inflammation

INTRODUCTION

The production of excessive amounts of nitric oxide (NO) through inducible nitric oxide synthase (iNOS) contributes to organ injury, inflammation, and mortality after shock. Resveratrol (RSV) is a natural polyphenol that decreases shock-induced hepatic injury and inflammation. We hypothesized that RSV would mediate these effects by decreasing hepatocyte iNOS production.

METHODS

Rat hepatocytes were isolated, cultured with varying concentrations of RSV, and then stimulated to induce iNOS with interleukin-1 and interferon. Induction of iNOS protein was measured by Western blot, iNOS mRNA by polymerase chain reaction, and NO production was measured by culture supernatant nitrite. Activation of intracellular signaling pathways involving Akt, c-Jun N-terminal kinase (JNK), and nuclear factor κB (NF-κB) were measured by Western blot using isoform-specific antibodies.

RESULTS

RSV decreased the expression of iNOS mRNA, protein, and supernatant nitrite in a dose-dependent manner. Our previous work demonstrated that Akt and JNK both inhibit hepatic iNOS production, whereas NF-κB increases iNOS expression. Analysis of signaling pathways in this study demonstrated that RSV increased JNK phosphorylation but decreased Akt phosphorylation and increased NF-κB activation.

CONCLUSION

RSV decreases cytokine-induced hepatocyte iNOS expression, possibly through up-regulation of the JNK signaling pathway. RSV merits further investigation to determine its mechanism as a compound that can decrease inflammation after shock.

Elevated serum creatine phosphokinase is associated with mortality and inotropic requirement in critically injured adults

BACKGROUND

Hemeproteins such as free myoglobin can undergo autoxidation and catalyse lipid peroxidation, increasing oxidative stress. Creatine phosphokinase (CPK) elevation is a marker for free myoglobin after myocyte damage. Since oxidative injury is a key mechanism of injury-related organ dysfunction, we hypothesised that serum CPK levels correlate with mortality and need for inotropic medication and duration of inotropic support, i.e. shock, among critically injured patients.

METHODS

We conducted a retrospective review of 17,847 patients admitted to a single Trauma Intensive Care Unit over 9 years. 2583 patients with serum CPK levels were included in the analysis. Patient data were collected continuously into an electronic ICU repository. Univariate analysis was accomplished using Spearman correlation and the Mann–Whitney U test. Propensity score adjustment models accounting for potential confounders were used to assess the independent effect of CPK level on mortality, need for inotropic support, and duration of inotropic support.

RESULTS

Median CPK was significantly higher in patients who died (916 [IQR 332, 2472] vs. 711 [253, 1971], p = 0.004) and in those who required inotropic medications (950 [353, 2525] vs. 469 [188, 1220], p < 0.001). After adjusting for propensity score and potential confounders the odds of mortality increased by 1.10 (95% CI 1.02–1.19, p = 0.020) and the odds of inotropic medication use increased by 1.30 (95% CI 1.22–1.38, p < 0.001) per natural log unit increase in CPK. There was a significant association between CPK level and duration of inotropic support (Spearman's rho .237, p < 0.001) that remained significant in a propensity score-adjusted model.

CONCLUSION

In critically injured patients, elevated serum CPK level is independently associated with mortality, need for inotropic medication, and duration of inotropic support. This study is the first to evaluate the relationship of CPK level and mortality in addition to surrogate measures of shock in a population of critically injured patients. If these associations are verified prospectively, there may be a role for treatment with hemeprotein reductants, such as paracetamol, to mitigate the effects of shock and end-organ dysfunction.

A multicenter study of the point prevalence of drug-induced hypotension in the ICU

OBJECTIVE

To determine the point prevalence of drug-induced hypotension episodes in critically ill patients, to assess the episodes resulting from error, and to describe how episodes are treated.

DESIGN

Multicenter observational, 24-hour snapshot study.

SETTING

Forty-seven ICUs in 27 institutions located in the United States, Canada, and Singapore.

PATIENTS

A total of 688 ICU patients were evaluated.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were included in the study if they had an episode of hypotension in the 24 hours prior to the clinical pharmacists' evaluation. The definition for a hypotensive episode is either a systolic blood pressure less than 90 mm Hg or a decrease in systolic blood pressure of 30 mm Hg over a 2-hour period. Each episode of unintentional hypotension was assessed for suspected drug-related causes. When a drug-related cause was suspected, an objective assessment tool, the modified Kramer, was used to determine causality. A score of at least "possible" was considered drug induced, referred to as a "drug-related hazardous condition." A drug-related hazardous condition is the temporal gap (intermediate stage) between the identification of an adverse drug reaction and the subsequent onset of drug-induced injury, known as an "adverse drug event." Drug-induced episodes were evaluated for medication errors and treatment. One hundred fifty-eight patients experienced 204 hypotensive episodes that were considered unintentional and drug related. Common drugs implicated included propofol, fentanyl, metoprolol, lorazepam, hydralazine, and furosemide. A total of 54 episodes (26.5%) resulted from medication errors. Common error types were improper dose/quantity (46%) and prescribing (25%). A total of 56.9% episodes were treated.

CONCLUSIONS

Many hypotensive episodes in the ICU are drug related and require treatment. A substantial portion of these episodes result from errors and are therefore preventable. This presents opportunities to improve prescribing including optimizing drug dosing to avoid possible patient harm from drug-induced hypotension.

Central role for MCP-1/CCL2 in injury-induced inflammation revealed by in vitro, in silico, and clinical studies

The translation of in vitro findings to clinical outcomes is often elusive. Trauma/hemorrhagic shock (T/HS) results in hepatic hypoxia that drives inflammation. We hypothesize that in silico methods would help bridge in vitro hepatocyte data and clinical T/HS, in which the liver is a primary site of inflammation. Primary mouse hepatocytes were cultured under hypoxia (1% O2) or normoxia (21% O2) for 1-72 h, and both the cell supernatants and protein lysates were assayed for 18 inflammatory mediators by Luminex™ technology. Statistical analysis and data-driven modeling were employed to characterize the main components of the cellular response. Statistical analyses, hierarchical and k-means clustering, Principal Component Analysis, and Dynamic Network Analysis suggested MCP-1/CCL2 and IL-1α as central coordinators of hepatocyte-mediated inflammation in C57BL/6 mouse hepatocytes. Hepatocytes from MCP-1-null mice had altered dynamic inflammatory networks. Circulating MCP-1 levels segregated human T/HS survivors from non-survivors. Furthermore, T/HS survivors with elevated early levels of plasma MCP-1 post-injury had longer total lengths of stay, longer intensive care unit lengths of stay, and prolonged requirement for mechanical ventilation vs. those with low plasma MCP-1. This study identifies MCP-1 as a main driver of the response of hepatocytes in vitro and as a biomarker for clinical outcomes in T/HS, and suggests an experimental and computational framework for discovery of novel clinical biomarkers in inflammatory diseases.

Does vasopressor therapy have an indication in hemorrhagic shock?

This review aimed to answer whether the vasopressors are useful at the early phase of hemorrhagic shock. Data were taken from published experimental studies and clinical trials. Published case reports were discarded. A search of electronic database PubMed was conducted using keywords of hemorrhagic shock, vasopressors, vasoconstrictors, norepinephrine, epinephrine, vasopressin. The redundant papers were not included. We identified 15 experimental studies that compared hemorrhagic shock resuscitated with or without vasopressors, three retrospective clinical studies, and one controlled trial. The experimental and clinical studies are discussed in the clinical context, and their strengths as well as limitations are highlighted. There is a strong rationale for a vasopressor support in severe hemorrhagic shock. However, this should be tempered by the risk of excessive vasoconstriction during such hypovolemic state. The experimental models must be analyzed within their own limits and cannot be directly translated into clinical practice. In addition, because of many biases, the results of clinical trials are debatable. Therefore, based on current information, further clinical trials comparing early vasopressor support plus fluid resuscitation versus fluid resuscitation alone are warranted.

The value of the difference between ED and prehospital vital signs in predicting outcome in trauma

INTRODUCTION

Traditional vital signs are seen as an important part of trauma assessment, despite their poor predictive value in this regard.

OBJECTIVE

This study evaluated whether the difference between systolic blood pressure (SBP), heart rate (HR), respiratory rate (RR) and shock index (SI) taken in the emergency department (ED) and prehospital can predict 48 h mortality postadmission following trauma.

METHODS

Retrospective cohort was obtained from the Trauma Audit and Research Network. Subjects were excluded if head or spinal injuries, prehospital intubation or CPR were present. Main outcome was 48 h mortality. The difference (delta, Δ) between ED and prehospital values were used as study variables (ie, ΔSI=SI-ED minus SI-prehospital). Accuracy was assessed using area under receiver operator characteristic curve (AUROC). AUROC coordinates were used to identify 95% specificity cut points and described further using sensitivity and likelihood ratios (LRs).

RESULTS

Significant AUROC statistics were revealed for ΔSBP (0.57) and ΔRR (0.56) for the full sample, ΔSBP (0.62) and ΔSI (0.65) for moderate, and ΔRR (0.6) for severe injury. Best LRs were 3.4 and 2.4 for ΔRR and ΔSI, respectively, but sensitivities were low (<=26%). Cut point values for ΔSBP, ΔRR and ΔSI were 37 mm Hg, 8 breaths/min and 0.2, respectively.

DISCUSSION

ΔSBP and ΔRR performed best overall, but ΔSI performed best in the moderate injury group, suggesting earlier identification with ΔSI. Use of Δ values result in good rule-in of 48 h mortality and may supplement trauma treatment decisions.

A dynamic view of trauma/hemorrhage-induced inflammation in mice: principal drivers and networks

BACKGROUND

Complex biological processes such as acute inflammation induced by trauma/hemorrhagic shock/ (T/HS) are dynamic and multi-dimensional. We utilized multiplexing cytokine analysis coupled with data-driven modeling to gain a systems perspective into T/HS.

METHODOLOGY/PRINCIPAL FINDINGS

Mice were subjected to surgical cannulation trauma (ST) ± hemorrhagic shock (HS; 25 mmHg), and followed for 1, 2, 3, or 4 h in each case. Serum was assayed for 20 cytokines and NO(2) (-)/NO(3) (-). These data were analyzed using four data-driven methods (Hierarchical Clustering Analysis [HCA], multivariate analysis [MA], Principal Component Analysis [PCA], and Dynamic Network Analysis [DyNA]). Using HCA, animals subjected to ST vs. ST + HS could be partially segregated based on inflammatory mediator profiles, despite a large overlap. Based on MA, interleukin [IL]-12p40/p70 (IL-12.total), monokine induced by interferon-γ (CXCL-9) [MIG], and IP-10 were the best discriminators between ST and ST/HS. PCA suggested that the inflammatory mediators found in the three main principal components in animals subjected to ST were IL-6, IL-10, and IL-13, while the three principal components in ST + HS included a large number of cytokines including IL-6, IL-10, keratinocyte-derived cytokine (CXCL-1) [KC], and tumor necrosis factor-α [TNF-α]. DyNA suggested that the circulating mediators produced in response to ST were characterized by a high degree of interconnection/complexity at all time points; the response to ST + HS consisted of different central nodes, and exhibited zero network density over the first 2 h with lesser connectivity vs. ST at all time points. DyNA also helped link the conclusions from MA and PCA, in that central nodes consisting of IP-10 and IL-12 were seen in ST, while MIG and IL-6 were central nodes in ST + HS.

CONCLUSIONS/SIGNIFICANCE

These studies help elucidate the dynamics of T/HS-induced inflammation, complementing other forms of dynamic mechanistic modeling. These methods should be applicable to the analysis of other complex biological processes.

Surgical intensive care unit--the trauma surgery perspective

PURPOSE

This review addresses and summarizes the key issues and unique specific intensive care treatment of adult patients from the trauma surgery perspective.

MATERIALS AND METHODS

The cornerstones of successful surgical intensive care management are fluid resuscitation, transfusion protocol and extracorporeal organ replacement therapies. The injury-type specific complications and unique pathophysiologic regulatory mechanisms of the traumatized patients influencing the critical care treatment are discussed.

CONCLUSIONS

Furthermore, the fundamental knowledge of the injury severity, understanding of the trauma mechanism, surgical treatment strategies and specific techniques of surgical intensive care are pointed out as essentials for a successful intensive care therapy.

Just one drop: the significance of a single hypotensive blood pressure reading during trauma resuscitations

BACKGROUND

Single, isolated hypotensive blood pressure (BP) measurements frequently are ignored or considered "erroneous." Although their clinical significance remains unknown, we hypothesized that single, isolated hypotensive BP readings during trauma resuscitations signify the presence of severe injuries that often warrant immediate intervention.

METHODS

A prospective observational study was performed on all trauma patients admitted from June 2008 to January 2009. Patients with a single systolic blood pressure (SBP) reading <110 mm Hg during their trauma resuscitation were evaluated, and demographics, hemodynamics, resuscitation (fluids, blood products, and duration), injuries, and operative or endovascular management were analyzed. Single and multiple variable logistic regression analyses were performed. Cutpoint analysis of the entire range of lowest single SBP measurements determined which SBP value best predicted the need for immediate therapeutic intervention.

RESULTS

Patients (n = 145) were predominantly male (77.2%) but age (mean, 35.1 +/- 15.3 years) and injury mechanisms varied (penetrating, 46.2%; blunt, 53.8%). Cutpoint analysis determined that a single SBP reading <105 mm Hg best predicted the need for immediate therapeutic intervention. Although 38.1% patients with isolated SBP <105 mm Hg measurements underwent immediate therapeutic operative or endovascular procedures, only 10.4% (p < 0.001) with isolated SBP >or=105 mm Hg required these procedures. Patients were 12.4 times (confidence interval: 2.6-59.2; p = 0.002) more likely to undergo immediate therapeutic intervention than those with a single SBP >or=105 mm Hg.

CONCLUSIONS

Single, isolated hypotensive BP measurements during trauma resuscitations should not be ignored or dismissed. Instead, our results suggest that a single SBP reading <105 mm Hg is associated with severe injuries that often require immediate operative or endovascular treatment and surgical intensive care unit admission.

The mean prehospital machine; accurate prehospital non-invasive blood pressure measurement in the critically ill patient

OBJECTIVE

Non-invasive blood pressure recordings may be inaccurate in the critically ill patient and measurement difficulties are intensified in the prehospital setting. This may adversely impact upon outcomes for many critically ill patients, particularly those with traumatic brain injury and/or lengthy prehospital times. This study aimed to validate a non-invasive, oscillometric, ambulatory blood pressure measuring device, the Oscar 2, Model 222 (SunTech Medical, Morrisville, USA) during the ambulance transport of critically ill patients.

METHODS

We have previously shown that mean arterial blood pressures observed by Intensive Care Unit nurses from a patient monitor can be considered interchangeable with reference intra-arterial integrated mean pressures. In the current study, we compared non-invasive device mean pressures to intra-arterial pressures observed by retrieval nurses from the patient monitor, during the ambulance transportation of critically ill patients. Device performance was required to fulfil the Association for the Advancement of Medical Instrumentation (AAMI) protocol requirements. Additionally, linear mixed effects analyses and Bland-Altman comparisons were undertaken.

RESULTS

For 157 measurements recorded from 23 patients, when the Oscar 2 did not indicate a measurement was associated with a fault, the device fulfilled the AAMI protocol requirements, with a mean error of -1.1 mmHg (standard deviation 7.8 mmHg), 95% confidence intervals (linear mixed effects analysis) -2.9, 0.8; P = 0.26. Bland-Altman plots indicated uniform agreement across a wide range of blood pressures. Sixteen percent of recordings were associated with a patient, environment, or device generated fault.

CONCLUSIONS

When the Oscar 2 does not indicate a fault has occurred, clinicians may be confident the mean pressure, within acceptable limits, is accurate, even during ambulance motion, administration of high doses of vasopressors and mechanical ventilation. The Oscar 2 appears to be an accurate and rugged out-of-hospital device.

Translational systems approaches to the biology of inflammation and healing

Inflammation is a complex, non-linear process central to many of the diseases that affect both developed and emerging nations. A systems-based understanding of inflammation, coupled to translational applications, is therefore necessary for efficient development of drugs and devices, for streamlining analyses at the level of populations, and for the implementation of personalized medicine. We have carried out an iterative and ongoing program of literature analysis, generation of prospective data, data analysis, and computational modeling in various experimental and clinical inflammatory disease settings. These simulations have been used to gain basic insights into the inflammatory response under baseline, gene-knockout, and drug-treated experimental animals for in silico studies associated with the clinical settings of sepsis, trauma, acute liver failure, and wound healing to create patient-specific simulations in polytrauma, traumatic brain injury, and vocal fold inflammation; and to gain insight into host-pathogen interactions in malaria, necrotizing enterocolitis, and sepsis. These simulations have converged with other systems biology approaches (e.g., functional genomics) to aid in the design of new drugs or devices geared towards modulating inflammation. Since they include both circulating and tissue-level inflammatory mediators, these simulations transcend typical cytokine networks by associating inflammatory processes with tissue/organ impacts via tissue damage/dysfunction. This framework has now allowed us to suggest how to modulate acute inflammation in a rational, individually optimized fashion. This plethora of computational and intertwined experimental/engineering approaches is the cornerstone of Translational Systems Biology approaches for inflammatory diseases.

Transfusion management of trauma patients

The management of massively transfused trauma patients has improved with a better understanding of trauma-induced coagulopathy, the limitations of crystalloid infusion, and the implementation of massive transfusion protocols (MTPs), which encompass transfusion management and other patient care needs to mitigate the "lethal triad" of acidosis, hypothermia, and coagulopathy. MTPs are currently changing in the United States and worldwide because of recent data showing that earlier and more aggressive transfusion intervention and resuscitation with blood components that approximate whole blood significantly decrease mortality. In this context, MTPs are a key element of "damage control resuscitation," which is defined as the systematic approach to major trauma that addresses the lethal triad mentioned above. MTPs using adequate volumes of plasma, and thus coagulation factors, improve patient outcome. The ideal amounts of plasma, platelet, cryoprecipitate and other coagulation factors given in MTPs in relationship to the red blood cell transfusion volume are not known precisely, but until prospective, randomized, clinical trials are performed and more clinical data are obtained, current data support a target ratio of plasma:red blood cell:platelet transfusions of 1:1:1. Future prospective clinical trials will allow continued improvement in MTPs and thus in the overall management of patients with trauma.

[Vasopressin for therapy of persistent traumatic hemorrhagic shock: The VITRIS.at study]

While fluid management is established in controlled hemorrhagic shock, its use in uncontrolled hemorrhagic shock is being controversially discussed, because it may worsen bleeding. In the irreversible phase of hemorrhagic shock that was unresponsive to volume replacement, airway management and catecholamines, vasopressin was beneficial due to an increase in arterial blood pressure, shift of blood away from a subdiaphragmatic bleeding site towards the heart and brain and decrease of fluid resuscitation requirements. The purpose of this multicenter, randomized, controlled, international trial is to assess the effects of vasopressin (10 IU IV) vs. saline placebo IV (up to 3 injections at least 5 min apart) in patients with prehospital traumatic hemorrhagic shock that persists despite standard shock treatment. The study will be carried out by helicopter emergency medical service teams in Austria, Germany, Czech Republic, Portugal, the Netherlands and Switzerland. Inclusion criteria are adult trauma patients with presumed traumatic hemorrhagic shock (systolic arterial blood pressure <90 mmHg) that does not respond to the first 10 min of standard shock treatment (endotracheal intubation, fluid resuscitation and use of vasopressors) after arrival of the first emergency physician at the scene. The time window for randomization will close after 30 min of shock treatment. Exclusion criteria are terminal illness, no intravenous access, age <18 years, injury >60 min before randomization, cardiac arrest before randomization, presence of a do-not-resuscitate order, untreated tension pneumothorax, untreated cardiac tamponade, or known pregnancy. Primary study end-point is the hospital admission rate, secondary end-points are hemodynamic variables, fluid resuscitation requirements and hospital discharge rate.

Controversies in Fluid Resuscitation

The optimal degree of resuscitation in the initial control and resuscitative phase of trauma care remains unclear. Many attempts have been made with animal studies to determine the optimal degree and method of resuscitation. Human studies were first conducted in 1994 and the results were inconclusive and have not been replicated. The question of the volume, rate, and type of fluid to be infused for initial control and adequate resuscitation of the trauma patient remains to be answered.

Development of renal failure during the initial 24 h of intensive care unit stay correlates with hospital mortality in trauma patients

BACKGROUND

Although multiple organ failure is the leading late cause of death, there is controversy about the impact of acute organ dysfunction and failure on trauma survival.

METHODS

Consecutive adult trauma admissions between January 2000 and June 2003, excluding isolated head traumas and burns, were analysed for parameters of organ function during the first 24 h following intensive care unit (ICU) admission using the Sequential Organ Failure Assessment (SOFA) scoring system. A national prospectively collected ICU data registry was used for analysis, including data from 22 ICUs in university and central hospitals in Finland.

RESULTS

The study population consisted of 1044 eligible trauma admissions; 32% of the cases were treated at university hospital level, the rest being secondary referral central hospital admissions. The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 15 (SD8), ICU mortality was 5.6% and a further 1.6% of patients died during their post-ICU hospital stay. Forty-five per cent of the patients were categorized as having multiple traumas. In univariate analysis, APACHE II > or = 25 [odds ratio (OR), 35; 95% confidence interval (CI), 18-66] and renal failure (OR, 29.5; 95% CI, 14-63) produced the highest ORs for ICU mortality. In the APACHE II-, sex- and age-adjusted logistic regression model, renal failure was a significant risk factor for both ICU and hospital mortality (OR, 11.8; 95% CI, 3.9-35.4; OR, 8.2; 95% CI, 2.9-23.2, respectively).

CONCLUSION

The development of renal failure during the initial 24 h of ICU stay remained an independent risk factor for mortality in trauma patients requiring intensive care treatment even after adjusting for the APACHE II score, age and sex.

Validation of stroke work and ventricular arterial coupling as markers of cardiovascular performance during resuscitation

BACKGROUND

Resuscitation regimens based on stroke work index (SWI) and ventricular-arterial coupling (VAC) are controversial. The Signal Interpretation and Monitoring (SIMON) system continuously collects and stores physiologic intensive care unit (ICU) bedside data at 3- to 5-second intervals. The purpose of this study was to demonstrate the capabilities of a completely automated data management system by further evaluating SWI-based resuscitation.

METHODS

This study was a retrospective review of all severely injured patients requiring a pulmonary artery catheter (PAC) for acute postinjury resuscitation. Patients with a severe head injury were excluded. Hemodynamic (HD) data (21 million datapoints) were densely acquired and archived by SIMON. Mean values of HD variables were compared between survivors and nonsurvivors. Receiver operator characteristic (ROC) curves were constructed for HD variables. Threshold values which maximized sensitivity and specificity were determined.

RESULTS

Eighty-eight patients over a 19-month time period met criteria and were included in the analysis. SWI was significantly greater in survivors versus nonsurvivors (4421 +/- 1278 versus 3163 +/- 1066 mm Hg . mL/m, p = 0.0008). VAC was quantified by the ratio (RATIO) of afterload (Ea) to contractility (Ees). RATIO (Ea/Ees) in survivors was significantly better than in nonsurvivors (1.9 +/- 1.1 vs. 2.9 +/- 1.0, p = 0.002). ROC curves identified threshold values of 3250 mm Hg x mL/m for SWI and 2.1 for RATIO (AUC = 0.78 and 0.82, respectively).

CONCLUSION

Previous work demonstrating the use of SWI and VAC as resuscitation guidelines was supported through the use of a powerful ICU data management system (SIMON). The emergence of these "new vital signs" may change the way injured patients are evaluated and resuscitated in the ICU.

Is anything new in adult blunt splenic trauma?

Several decades ago, a shift occurred in the management of adult splenic injuries. Influenced by the experience in pediatric trauma patients, adult trauma surgeons began turning from mandatory operative treatment of all splenic injuries toward nonoperative management. Nonoperative treatment is now the most common method of management for patients with splenic injuries and is the most common method of splenic salvage. However, controversy exists about how to appropriately select patients for nonoperative treatment since bleeding from splenic injuries can incur significant morbidity and mortality. Recent refinements in the management of adult blunt splenic injuries will be reviewed.

Early embolization and vasopressor administration for management of life-threatening hemorrhage from pelvic fracture

BACKGROUND

In this retrospective study, we reviewed our protocol for management of hemodynamically unstable patients with pelvic injury.

METHODS

We managed the patients with the same predetermined plan including controlled hemodynamic resuscitation with early use of vasopressors and pelvic angiography as a first-line treatment.

RESULTS

Of 311 patients with pelvic fracture, 32 hemodynamically unstable patients (10.3%) underwent pelvic angiography, which was followed by embolization in 25 cases. Angiography was successful for 24 patients (96%) and extrapelvic bleeding was diagnosed in 5 patients (15%). Three of six laparotomies performed before angiography were nontherapeutic. One of seven laparotomies performed after angiography was negative.

CONCLUSION

A protocol for management of patients with pelvic injury and hemodynamic instability that is associated with controlled resuscitation including vasopressor and early pelvic angioembolization is effective for treating pelvic hemorrhage and diagnosing extrapelvic hemorrhage. Further studies are needed to confirm the respective place of angiographic and surgical control of bleeding.

Surgical Complications and Causes of Death in Trauma Patients that Require Temporary Abdominal Closure

Temporary abdominal closure (TAC) has increasingly been employed in the management of severely injured patients to avoid abdominal compartment syndrome (ACS) and as part of damage control surgery (DCS). Although the use of TAC has received great interest, few data exist describing the morbidity and mortality associated with its use in trauma victims. The main goal of this study is to describe the incidence of surgical complications following the use of TAC as well as to define the mortality associated with this procedure. A retrospective review of patients admitted to a state-designated level 1 trauma center from April 2000 to February 2003 was performed. Inclusion criteria were age >18 years, traumatic injury, and need for exploratory laparotomy and use of TAC. A total of 120 patients were included in the study. The overall mortality of trauma patients requiring TAC was 59.2 per cent. The most common causes of death were acute inflammatory process (50.7%), followed by hypovolemic shock (43.7%). The incidence of surgical complications was 26.6 per cent. Intra-abdominal abscesses were the most frequent surgical complication (10%). After multiple logistic regression analysis, increasing age and a numerically greater initial base deficit were found to be independent predictors of mortality in trauma patients that require TAC.