Elevated arterial base deficit in trauma patients: a marker of impaired oxygen utilization

Combination of Lactate and Base Deficit Levels at Admission to Predict Mortality in Blunt Trauma Patients

INTRODUCTION

Elevated lactate levels are associated with increased mortality in both trauma and non-trauma patients. The relation between base deficit (BD) and mortality is less clear. Traumatologists debate the utility of elevated lactate (EL) versus BD in predicting mortality. We hypothesized that EL (2mmol/L to 5mmol/L) and BD (≤-2mmol/L) in combination could predict mortality in blunt trauma patients.  Methods: This is a retrospective analysis of the trauma registry from 2012 to 2021 at a level 1 trauma center. Blunt trauma patients with admission lactate and BD values were included in the analysis. Exclusion criteria were age <18, penetrating trauma, unknown mortality, and unknown lactate or BD. Logistics regression of the total 5153 charts showed 93% of the patients presented with lactate levels <5mmol/L, therefore patients with lactate >5mmol/L were excluded as outliers. The primary outcome was mortality.

RESULTS

A total of 4794 patients (151 non-survivors) were included in the analysis. Non-survivors had higher rates of EL + BD (35.8% vs. 14.4%, p <0.001). When comparing survivors and non-survivors, EL + BD (OR 5.69), age >65 (5.17), injury severity score (ISS) >25 (8.87), Glasgow coma scale <8 (8.51), systolic blood pressure (SBP) <90 (4.2), and ICU admission (2.61) were significant predictors of mortality. Other than GCS <8 and ISS >25, EL + BD had the highest odds of predicting mortality.

CONCLUSION

Elevated lactate + BD on admission in combination represents a 5.6-fold increase in mortality in blunt trauma patients and can be used to predict a patient's outcome on admission. This combination variable provides an additional early data point to identify patients at elevated risk of mortality at the moment of admission.

Hemorrhagic Shock: Blood Marker Sequencing and Pulmonary Gas Exchange

BACKGROUND

The early identification of internal hemorrhage in critically ill patients may be difficult. Besides circulatory parameters, hemoglobin and lactate concentration, metabolic acidosis and hyperglycemia serve as laboratory markers for bleeding. In this experiment, we examined pulmonary gas exchange in a porcine model of hemorrhagic shock. Moreover, we sought to investigate if a chronological order of appearance regarding hemoglobin, lactatemia, standard base excess/deficit (SBED) and hyperglycemia exists in early severe hemorrhage.

METHODS

In this prospective, laboratory study, twelve anesthetized pigs were randomly allocated to exsanguination or a control group. Animals in the exsanguination group (n = 6) endured a 65% blood loss over 20 min. No intravenous fluids were administered. Measurements were taken before, immediately after, and at 60 min after the completed exsanguination. Measurements included pulmonary and systemic hemodynamic variables, hemoglobin concentration, lactate, base excess (SBED), glucose concentration, arterial blood gases, and a multiple inert gas assessment of pulmonary function.

RESULTS

At baseline, variables were comparable. Immediately after exsanguination, lactate and blood glucose were increased (p = 0.001). The arterial partial pressure of oxygen was increased at 60 min after exsanguination (p = 0.04) owing to a decrease in intrapulmonary right-to-left shunt and less ventilation-perfusion inequality. SBED was different to the control only at 60 min post bleeding (p < 0.001). Hemoglobin concentration did not change at any time (p = 0.97 and p = 0.14).

CONCLUSIONS

In experimental shock, markers of blood loss became positive in chronological order: lactate and blood glucose concentrations were raised immediately after blood loss, while changes in SBED lagged behind and became significant one hour later. Pulmonary gas exchange is improved in shock.

Effects of extremity trauma on physiological responses to hemorrhage in conscious rats

Although physiological responses to hemorrhage are well-studied, hemorrhage is often accompanied by trauma, and it remains unclear how injury affects these responses. This study examined effects of extremity trauma on cardiorespiratory responses and survival to moderate (37%; H-37) or severe (50%; H-50) hemorrhage in rats. Transmitter and carotid catheter implantation and extremity trauma (fibular fracture and muscle injury) were conducted 2 wk, 24 h, and 90 min, respectively, before conscious hemorrhage. Mean arterial pressure (MAP) and heart rate (HR; via telemetry), and respiration rate (RR), minute volume (MV), and tidal volume (TV; via plethysmography) were measured throughout the 25 min hemorrhage and remainder of the 4 h observation period. There were four groups: 1) H-37, no trauma (NT; n = 17); 2) H-37, extremity trauma (T, n = 18); 3) H-50, NT (n = 20); and 4) H-50, T (n = 20). For H-37, during and after hemorrhage, T increased HR (P ≤ 0.031) and MV (P ≤ 0.048) compared with NT rats. During H-50, T increased HR (0.041) and MV (P = 0.043). After hemorrhage, T increased MV (P = 0.008) but decreased HR (P = 0.007) and MAP (P = 0.039). All cardiorespiratory differences between T and NT groups were intermittent. Importantly, both survival time (159.8 ± 78.2 min vs. 211.9 ± 60.3 min; P = 0.022; mean ± SD) and percent survival (45% vs. 80%; P = 0.048) were less in T versus NT rats after H-50. Trauma interacts with physiological systems in a complex manner and no single cardiorespiratory measure was sufficiently altered to indicate that it alone could account for increased mortality after H-50.NEW & NOTEWORTHY In both civilian and military settings, severe hemorrhage rarely occurs in the absence of tissue trauma, yet many animal models for the study of hemorrhage do not include significant tissue trauma. This study using conscious unrestrained rats clearly demonstrates that extremity trauma worsens the probability of survival after a severe hemorrhage. Although no single cardiorespiratory factor accounted for the increased mortality, multiple modest time-related cardiorespiratory responses to the trauma were observed suggesting that their combined dysfunction may have contributed to the reduced survival.

Management of Hemorrhagic Shock: Physiology Approach, Timing and Strategies

Hemorrhagic shock (HS) management is based on a timely, rapid, definitive source control of bleeding/s and on blood loss replacement. Stopping the hemorrhage from progressing from any named and visible vessel is the main stem fundamental praxis of efficacy and effectiveness and an essential, obligatory, life-saving step. Blood loss replacement serves the purpose of preventing ischemia/reperfusion toxemia and optimizing tissue oxygenation and microcirculation dynamics. The "physiological classification of HS" dictates the timely management and suits the 'titrated hypotensive resuscitation' tactics and the 'damage control surgery' strategy. In any hypotensive but not yet critical shock, the body's response to a fluid load test determines the cut-off point between compensation and progression between the time for adopting conservative treatment and preparing for surgery or rushing to the theater for rapid bleeding source control. Up to 20% of the total blood volume is given to refill the unstressed venous return volume. In any critical level of shock where, ab initio, the patient manifests signs indicating critical physiology and impending cardiac arrest or cardiovascular accident, the balance between the life-saving reflexes stretched to the maximum and the insufficient distal perfusion (blood, oxygen, and substrates) remains in a liable and delicate equilibrium, susceptible to any minimal change or interfering variable. In a cardiac arrest by exsanguination, the core of the physiological issue remains the rapid restoration of a sufficient venous return, allowing the heart to pump it back into systemic circulation either by open massage via sternotomy or anterolateral thoracotomy or spontaneously after aorta clamping in the chest or in the abdomen at the epigastrium under extracorporeal resuscitation and induced hypothermia. This is the only way to prevent ischemic damage to the brain and the heart. This is accomplishable rapidly and efficiently only by a direct approach, which is a crush laparotomy if the bleeding is coming from an abdominal +/- lower limb site or rapid sternotomy/anterolateral thoracotomy if the bleeding is coming from a chest +/- upper limbs site. Without first stopping the bleeding and refilling the heart, any further exercise is doomed to failure. Direct source control via laparotomy/thoracotomy, with the concomitant or soon following venous refilling, are the two essential, initial life-saving steps.

Base Deficit ≥ 6 within 24 h of Injury is a risk factor for fracture nonunion in the polytraumatized patient

BACKGROUND

Polytrauma patients are at risk for fracture nonunion, but the reasons are poorly understood. Increased base deficit (BD) is associated with hypovolemic shock. Although shock delays bone healing in animal models, there have been no clinical studies evaluating the impact of BD on nonunion risk.

MATERIALS AND METHODS

Patients age ≥ 16 with injury severity score > 16 that presented to an academic Level One trauma center with an operative femur or tibia fracture were reviewed. Clinical notes and radiographs were assessed to determine fracture healing status. Patient demographics, injury characteristics, BD, and number of packed red blood cell transfusions were recorded. Bivariate and multivariate analyses of multiple risk factors associated with nonunion were conducted to investigate the association of BD with nonunion.

RESULTS

The union group was comprised of 243 fractures; there were 36 fractures in the nonunion group. The following predictors were associated with nonunion: smoking (p = 0.009), alcohol use (p < 0.001), open fracture (p < 0.001), and treatment for deep infection at fracture site (p = 0.016). Additionally, worst BD over 24 h ≥ 6 (p = 0.031) was significant for nonunion development. A multivariate logistic regression analysis revealed worst BD ≥6 over 24 h remained significantly associated with the development of nonunion (odds ratio 3.02, p = 0.011) when adjusting for other risk factors.

CONCLUSIONS

A BD ≥ 6 within 24 h of admission was associated with a significantly increased risk of developing lower extremity fracture nonunion in polytrauma patients, even after adjusting for multiple other risk factors. Acute post-traumatic acidosis may have effects on long-term fracture healing.

Diagnostic value of intravenous oxygen saturation compared with arterial and venous base excess to predict hemorrhagic shock in multiple trauma patients

Introduction:

In this study, with the help of peripheral vein sampling, Spvo2, and peripheral artery and vein sampling, we examined base excess (BE) in trauma patients and determined its diagnostic value for hemorrhagic shock.

Methods:

In this cross-sectional study, from 64 patients with abdominal, pelvic and chest Blunt trauma who have a score of 2 or higher trauma during treatment, blood samples were taken from peripheral vein to measure oxygen saturation and peripheral vein and artery for BE measurements and were compared in order to assess their diagnostic value in predicting the occurrence of hemorrhagic shock.

Results:

Out of 60 examined patients, 43 (71.67%) patients were diagnosed with hemorrhagic shock. The correlation for the percentage of oxygen saturation of the peripheral blood and the rate of arterial and venous BE for these r^2patients were 17.0 and 09.0, respectively, with a P value greater than 0.005. In the case of the percentage of oxygen saturation of the peripheral blood, the sensitivity and specificity were 93.03 and 11.76%, respectively. The positive and negative likelihood ratios were 1.05 and 0.59, respectively. The positive and negative predictive values were 72.73 and 40%, respectively.

Conclusion:

In general, the results of this study showed that arterial and venous excess base levels had a proper correlation, specificity and sensitivity for diagnosing and predicting hemorrhagic shock, while the percentage of oxygen saturation of peripheral blood and BE arterial and venous levels had not proper correlation to detect and predict hemorrhagic shock.

Utility of venous blood gases for the assessment of traumatic shock: a prospective observational study

BACKGROUND

ABG samples are often obtained in trauma patients to assess shock severity. Venous blood gas (VBG) sampling, which is less invasive, has been widely used to assess other forms of shock. The study aim was to determine the agreement between VBG and ABG measurements in trauma.

METHODS

Patients were enrolled at an Australian trauma centre between October 2016 and October 2018. Bland-Altman limits of agreement (LOA) between paired blood gas samples taken <30 min apart were used to quantify the extent of agreement. The impact of using only VBG measurements was considered using an a priori plan. Cases where venous sampling failed to detect 'concerning levels' were flagged using evidence-based cut-offs: pH ≤7.2, base deficit (BD) ≤-6, bicarbonate <21 and lactate ≥4. Case summaries of these patients were assessed by independent trauma clinicians as to whether an ABG would change expected management.

RESULTS

During the study period 176 major trauma patients had valid paired blood gas samples available for analysis. The median time difference between paired measurements was 11 min (IQR 6-17). There was a predominance of men (81.8%) and blunt trauma (92.0%). Median Injury Severity Score was 13 (range 1-75) and inpatient mortality was 6.3%. Mean difference (ABG-VBG) and LOA between paired arterial and venous measurements were 0.036 (LOA -0.048 to 0.120) for pH, -1.27 mmol/L (LOA -4.35 to 1.81) for BD, -0.64 mmol/L (LOA -1.86 to 0.57) for lactate and -1.97 mmol/L (LOA -5.49 to 1.55) for bicarbonate. Independent assessment of the VBG 'false negative' cases (n=20) suggested an ABG would change circulatory management in two cases.

CONCLUSIONS

In trauma patients VBG and ABG parameters displayed suboptimal agreement. However, in cases flagged as VBG 'false negative' independent review indicated that the availability of an ABG was unlikely to change management.

Combined effects of dexmedetomidine and vatinoxan infusions on minimum alveolar concentration and cardiopulmonary function in sevoflurane-anesthetized dogs

OBJECTIVE

To evaluate the effects of combined infusions of vatinoxan and dexmedetomidine on inhalant anesthetic requirement and cardiopulmonary function in dogs.

STUDY DESIGN

Prospective experimental study.

METHODS

A total of six Beagle dogs were anesthetized to determine sevoflurane minimum alveolar concentration (MAC) prior to and after an intravenous (IV) dose (loading, then continuous infusion) of dexmedetomidine (4.5 μg kg^-1 hour^-1) and after two IV doses of vatinoxan in sequence (90 and 180 μg kg^-1 hour^-1). Blood was collected for plasma dexmedetomidine and vatinoxan concentrations. During a separate anesthesia, cardiac output (CO) was measured under equivalent MAC conditions of sevoflurane and dexmedetomidine, and then with each added dose of vatinoxan. For each treatment, cardiovascular variables were measured with spontaneous and controlled ventilation. Repeated measures analyses were performed for each response variable; for all analyses, p < 0.05 was considered significant.

RESULTS

Dexmedetomidine reduced sevoflurane MAC by 67% (0.64 ± 0.1%), mean ± standard deviation in dogs. The addition of vatinoxan attenuated this to 57% (0.81 ± 0.1%) and 43% (1.1 ± 0.1%) with low and high doses, respectively, and caused a reduction in plasma dexmedetomidine concentrations. Heart rate and CO decreased while systemic vascular resistance increased with dexmedetomidine regardless of ventilation mode. The co-administration of vatinoxan dose-dependently modified these effects such that cardiovascular variables approached baseline.

CONCLUSIONS AND CLINICAL RELEVANCE

IV infusions of 90 and 180 μg kg^-1 hour^-1 of vatinoxan combined with 4.5 μg kg^-1 hour^-1 dexmedetomidine provide a meaningful reduction in sevoflurane requirement in dogs. Although sevoflurane MAC-sparing properties of dexmedetomidine in dogs are attenuated by vatinoxan, the cardiovascular function is improved. Doses of vatinoxan >180 μg kg^-1 hour^-1 might improve cardiovascular function further in combination with this dose of dexmedetomidine, but beneficial effects on anesthesia plane and recovery quality may be lost.

Admission base deficit is superior to lactate in identifying shock and resuscitative needs in trauma patients

BACKGROUND

Base Deficit (BD) and lactate have been used as indicators of shock and resuscitation. This study was done to evaluate the utility of BD and lactate in identifying shock and resuscitative needs in trauma patients.

METHODS

A prospective observational study was performed from 3/2014-12/2018. Data included demographics, admission systolic BP, ISS, BD, lactate, blood transfusion, and outcomes. BD and lactate were modeled continuously and categorically and compared.

RESULTS

2271 patients were included. BD and lactate were moderately correlated (r² = 0.63 p < 0.001). On univariate regression, BD and lactate were associated with transfusion requirement and mortality (p < 0.001), but on multivariate regression, only BD was associated with transfusion requirement and mortality (OR = 1.2, p < 0.001; OR = 1.1, p < 0.001, respectively). BD discriminated better than lactate for hypotension, higher ISS, increased transfusion requirements and mortality.

CONCLUSIONS

Admission BD and lactate levels are correlated following injury, but BD is superior to lactate in identifying shock, resuscitative needs and mortality in severely injured trauma patients.

Literature review and methodological considerations for understanding circulating risk biomarkers following trauma exposure

Exposure to traumatic events is common. While many individuals recover following trauma exposure, a substantial subset develop adverse posttraumatic neuropsychiatric sequelae (APNS) such as posttraumatic stress, major depression, and regional or widespread chronic musculoskeletal pain. APNS cause substantial burden to the individual and to society, causing functional impairment and physical disability, risk for suicide, lost workdays, and increased health care costs. Contemporary treatment is limited by an inability to identify individuals at high risk of APNS in the immediate aftermath of trauma, and an inability to identify optimal treatments for individual patients. Our purpose is to provide a comprehensive review describing candidate blood-based biomarkers that may help to identify those at high risk of APNS and/or guide individual intervention decision-making. Such blood-based biomarkers include circulating biological factors such as hormones, proteins, immune molecules, neuropeptides, neurotransmitters, mRNA, and noncoding RNA expression signatures, while we do not review genetic and epigenetic biomarkers due to other recent reviews of this topic. The current state of the literature on circulating risk biomarkers of APNS is summarized, and key considerations and challenges for their discovery and translation are discussed. We also describe the AURORA study, a specific example of current scientific efforts to identify such circulating risk biomarkers and the largest study to date focused on identifying risk and prognostic factors in the aftermath of trauma exposure.

Point-of-care blood analysis of hypotensive patients in the emergency department

OBJECTIVE

The aim of this study is to compare a point-of-care (POC) analysis, Enterprise POC (epoc), using the capillary blood obtained from skin puncture with conventional laboratory tests using arterial and venous blood in hypotensive patients.

METHODS

This study was conducted at the emergency department of a tertiary care hospital between June and November 2018. 231 hypotensive patients were enrolled. Three types of blood samples (capillary blood from skin puncture and arterial and venous blood from blood vessel puncture) were collected and analyzed. We compared a total of 13 parameters (pH, pCO2, pO2, HCO3-, Ca2+, lactate, Na+, K+, Cl-, glucose, Hb, Hct, and creatinine) between the POC analysis and reference analyzers by performing the equivalence test and Bland-Altman plot analysis.

RESULTS

In hypotensive patients, with the exception of two parameters (pCO2, pO2), the pH, HCO3-, Ca2+, lactate, Na+, K+, Cl-, glucose, Hb, Hct, and creatinine parameters measured by the POC analysis were equivalent to or correlated with the reference values. In the patients with cardiac arrest group, nine parameters (pH, HCO3-, Ca2+, Na+, K+, glucose, Hb, Hct, and creatinine) analyzed by the epoc system were equivalent to the reference values.

CONCLUSION

Most parameters, except pO2, measured by the epoc system using the capillary blood in hypotensive patients were equivalent to or correlated with those measured by the reference analyzers.

Predicting mortality in patients with disseminated intravascular coagulation after cardiopulmonary bypass surgery by utilizing two scoring systems

: We evaluated clinical and laboratory biomarkers of disseminated intravascular coagulation (DIC) following cardiac surgery in the cardiothoracic surgical ICU (CTICU) to predict mortality. We retrospectively analyzed CTICU patients with suspected DIC identified from the hospital laboratory database, and calculated International Society on Thrombosis and Haemostasis (ISTH) and the Japanese Association for Acute Medicine (JAAM) DIC scores to predict DIC-related mortality. The predictive accuracy of the JAAM and ISTH DIC scoring system were then assessed by logistic regression analysis and receiver operative characteristics analysis, and compared to other potential predictors of mortality (e.g., Acute Physiology and Chronic Health Evaluation II, systemic inflammatory response syndrome criteria, laboratory variables). Our study showed a 30-day mortality rate of 71% in CTICU patients with DIC. The JAAM DIC score offered the best predictive accuracy [area under the curve (AUC): 0.723, 95% % confidence interval (CI): 0.638-0.947, P = 0.021], when compared with ISTH DIC score (AUC: 0.707, 95% CI: 0.491-0.923, P = 0.066) and Acute Physiology and Chronic Health Evaluation II (AUC: 0.687, 95% CI: 0.483-0.891, P = 0.110). A JAAM DIC score at least 6 was reported in 89% of the nonsurvivors and 46% of survivors (P = 0.010), and predicted mortality [odds ratio: 9.33 (1.50-58.20)] with a 73% sensitivity and a 78% specificity. Our results also show a strong relationship between acid-base derangement and mortality. This initial evaluation of DIC-related mortality in the CTICU found the standardized JAAM DIC scoring system in combination with acid-base laboratory values were most useful to predict mortality in postcardiac surgery patients with DIC. Additional prospective studies are needed to further validate our findings.

Prognostic Value of Arterial Blood Gas Indices Regarding the Severity of Traumatic Injury and Fractures of the Femur and Pelvis

Objective:

To evaluate the prognostic value of arterial blood gas (ABG) indices, especially base excess (BE), regarding the severity of traumatic injury.

Methods:

A total number of 96 trauma patients with fractures of femur and pelvis were included in this study. Demographic characteristics and clinical information of samples were recorded. The results of ABG test and hemoglobin (Hb) were evaluated at two time intervals (on admission and 6 hours later). The outcome of the patients was evaluated at the end of the study (dead or alive). The ABG indices included O2 saturation (O2Sat), PH, PO2, PCO2, bicarbonate (HCO3) and base excess (BE). The mean of the hemodynamic and ABG indices were compared between those who were discharged and mortality cases. The confounders were compensated using a multivariate logistic regression model.

Results:

Overall 94 trauma patients with long and pelvic fractures were included. There were 69 (73.4%) men and 25 (26.6%) women among the patients with mean age of 37.43 ± 20.07 years. The mortality rate was 10 (10.6%). The most common mechanism of injury was motorcycle accident in 41 (43.6%) and car collision in 43 (45.7%) patients. We found that mortality was significantly associated with amount of FFP transfusion (p=0.005), but was not associated with amount of transfused packed cells (p=0.113). We also found that mortality was associated with lower BP after 6 hours of admission (p=0.001), higher HR on admission (p=0.036), lower HR after 6 hours (p=0.017), lower O2Sat on admission (p<0.001), higher PCO2 after 6 hours and lower BE on admission (p=0.025).    

Conclusion:

The ABG indices including O2Sat, BE and PCO2 are considered prognostic determinants of outcome in trauma patients with long and pelvic fractures. These findings can be considered as fundamental studies to achieve new diagnostic methods.  

Base deficit is superior to lactate in trauma

BACKGROUND

Base Deficit (BD) and lactate have been used as indicators of shock and resuscitation. This study was done to determine the association of BD and lactate and to determine if one is superior.

METHODS

A retrospective review from 3/2014-12/2016 was performed. Data included demographics, systolic BP, ISS, BD, lactate, blood transfusion, and outcomes. BD and lactate were modeled continuously and categorically and compared.

RESULTS

1191 patients were included. BD and lactate correlated strongly (r = -0.76 p < 0.001). Higher lactate and more negative BD were associated with transfusion and mortality. On multivariate regression, only BD was associated with transfusion (OR = 0.8, p < 0.001). As a categorical variable, worsening BD was associated with decreased BP, higher ISS, increased transfusions and worse outcomes.

CONCLUSIONS

BD and lactate are strongly related. BD was superior to lactate in assessing the need for transfusion. The BD categories discriminate high risk trauma patients better than lactate.

Early pH Change Predicts Intensive Care Unit Mortality

Aim of the Study:

Metabolic acidosis is associated with increased mortality in critically ill patients. We hypothesized that early correction of acidosis of presumed metabolic origin results in improved outcomes.

Patients and Methods:

We conducted a prospective, observational study from February 2015 to June 2016 in a 12 bed mixed intensive care unit (ICU) of a 1000 bed tertiary care hospital in the north of India. ICU patients aged above 18 years with an admission pH ≥7.0 to <7.35 of presumed metabolic origin were included. Arterial blood gas parameters including pH, PaO₂, PaCO₂, HCO₃⁻, Na⁺, K⁺, Cl⁻, anion gap (AG), base excess, and lactate at 0, 6, and 24 h along with other standard laboratory investigations were recorded. The primary outcome was to assess the impact of early pH changes on mortality at day 28 of ICU.

Results:

A total of 104 patients with 60.6% males and 91.3% medical patients were included in the study. Sepsis of lung origin (60.6%) was the predominant etiology. By day 28, 68 (65.4%) patients had died. Median age was 49.5 years, weight 61.7 kg, Sequential Organ Failure Assessment, and Acute Physiologic and Chronic Health Evaluation II scores were 16 and 12, respectively. Nonsurvivors had a higher vasopressor index (P < 0.01), lactate and central venous oxygen saturation (P < 0.05), and lower pH (P < 0.05). A pH correction/change of ≥1.16% during the first 24 h had the best receiver operating characteristic for predicting survival at day 28, with area under the curve (95% confidence interval, 0.72 [0.62–0.82], P < 0.05) compared to HCO₃^-, BE, lactate, and AG.

Conclusions:

Metabolic acidosis is associated with higher mortality in ICU. The rate of change in pH may better predict ICU mortality than other metabolic indices.

Correlation of arterial blood gas markers and lactate levels with outcomes in pediatric traumatic brain injury

Background:

Various physical markers have been used to predict outcome of traumatic brain injury in children. However, the utility of metabolic alterations for prognostication has been poorly described. Thus, we aim to correlate arterial blood gas markers and lactate levels with outcomes in children with moderate to severe traumatic brain injury.

Methods:

This is a retrospective cohort study that included all patients <16 years old who presented to the Emergency Department with moderate to severe traumatic brain injury (Glasgow Coma Scale ⩽13). Serial arterial blood gas results and lactate levels in the first five days of admission to a pediatric intensive care unit (PICU) were reviewed. Primary outcome was in-hospital mortality. Secondary outcomes were 28-day ventilator-free and PICU-free days. A stepwise logistic regression analysis in conjunction with receiver operating characteristic analysis were used to identify variables that were associated with in-hospital mortality. Secondary outcomes were analyzed using multiple linear regression.

Results:

Among the 43 patients analyzed, more than half of the patients (60%) had severe traumatic brain injury (Glasgow Coma Scale 8). Twenty-seven of the 43 (65%) patients underwent neurosurgical intervention and overall mortality was 9/43 (20.9%). The worst base excess and lactate levels of Day 2 of PICU stay were found to be most predictive for mortality with maximal area-under-curve (95% confidence interval) of 0.967 (0.906, 1.000). Worst lactate level on day 2 of PICU stay was also found to be associated with ventilator-free days and PICU-free days.

Conclusion:

In children with moderate to severe traumatic brain injury, base excess and lactate on Day 2 of PICU stay were predictors of mortality, duration of mechanical ventilation and length of PICU stay.

Comparison of compensatory reserve and arterial lactate as markers of shock and resuscitation

BACKGROUND

During traumatic hemorrhage, the ability to identify shock and intervene before decompensation is paramount to survival. Lactate is extremely sensitive to shock, and its clearance has been demonstrated a useful gauge of shock and resuscitation status. Though lactate can be measured in the field, logistical constraints render it impractical in certain environments. The compensatory reserve represents a new clinical measurement reflecting the remaining capacity to compensate for hypoperfusion. We hypothesized the compensatory reserve index (CRI) would be an effective surrogate marker of shock and resuscitation compared to lactate.

METHODS

The CRI device was placed on consecutive patients meeting trauma center activation criteria and remained on the patient until discharge, admission, or transport to operating suite. All subjects had a lactate level measured as part of their routine admission metabolic analysis. Time-corresponding CRI and lactate values were matched in regards to initial and subsequent lactate levels. Mean time from lactate sample collection to data availability in the electronic medical record was calculated. Predictive capacity of CRI and lactate in predicting hemorrhage was determined by receiver-operator characteristic curve analysis. Correlation analysis was performed to determine if any association existed between changing CRI and lactate values.

RESULTS

Receiver-operator characteristic (ROC) curves were generated and area under the curve was 0.8052 and 0.8246 for CRI and lactate, respectively. There was no significant difference in each parameter's ability to predict hemorrhage (p = 0.8015). The mean duration from lactate sample collection to clinical availability was 44 minutes whereas CRI values were available immediately. Analysis of the concomitant change in serial CRI and lactate levels revealed a Spearman's correlation coefficient of -0.73 (p < 0.01).

CONCLUSION

CRI performed with equivalent predictive capacity to lactate with respect to identifying initial perfusion status associated with hemorrhage and subsequent resuscitation.

LEVEL OF EVIDENCE

Diagnostic, Level II.

Returning from the acidotic abyss: Mortality in trauma patients with a pH < 7.0

INTRODUCTION

We hypothesized that a pH of <7.0 on presentation would correlate with almost universal mortality in trauma patients.

METHODS

A retrospective cohort study was performed on a Level I trauma center registry from 2013 to 2014. Hospital mortality was the primary outcome, which was compared by pH cohort (<7.0 or ≥7.0) using standard univariate statistics and multivariate logistic regression.

RESULTS

There were 593 patients included in the analysis: 66 in <7.0, 527 in ≥7.0. Mortality was 3× higher in the <7.0 pH cohort (62.1 vs. 20.3%; p < 0.0001), however there was no threshold for a pH below which there was 100% mortality. After controlling for these confounding variables, initial pH was found to be an independent predictor of inpatient mortality: pH < 7.0 (OR 6.33, 3.29-12.19; p < 0.0001).

CONCLUSION

This data indicates that while patients with severe acidosis are at increased risk for mortality, a pH < 7.0 is still recoverable in select cases.

Can venous base excess replace arterial base excess as a marker of early shock and a predictor of survival in trauma?

INTRODUCTION

Arterial base excess is an established marker of shock and predictor of survival in trauma patients. However, venous blood is more quickly and easily obtained. This study aimed to determine if venous base excess could replace arterial base excess as a marker in trauma patients at presentation and if venous base excess is predictive of survival at 24 hours and one week.

METHODS

This was a prospective study of 394 trauma patients presenting to the emergency department of a tertiary hospital over a 17-month period. Data on base excess at presentation, vital signs, shock index (SI), injury severity score (ISS), and mortality at 24 hours and one week was collected and analysed.

RESULTS

Arterial and venous blood gas tests were performed on 260 and 134 patients, respectively. Patients were stratified into groups based on their SI and ISS for analysis. There was no statistical difference between mean venous blood gas and arterial blood gas levels at presentation when SI > 0.7, regardless of ISS (p > 0.05). The mortality rate was 4.57%. Both venous and arterial base excess was lower in nonsurvivors compared to survivors (p < 0.05). However, at 24 hours and one week, the difference in base excess values at presentation between survivors and nonsurvivors was greater when using venous base excess compared to arterial base excess (11.53 vs. 4.28 and 11.41 vs. 2.66, respectively).

CONCLUSION

In conclusion, venous base excess can replace arterial base excess in trauma patients as a means of identifying and prognosticating early shock.

Endpoints of Resuscitation for the Victim of Trauma

Useful resuscitation endpoints must serve both to diagnose the need for and to ensure the ongoing adequacy of resuscitation. To this end, traditional measures of organ perfusion are now widely appreciated to be grossly inadequate. Useful endpoints or milestones range from the global, to the regional, to the cellular specific. Understanding the basic principles of perfusion-related dysoxia in trauma and hemorrhage and its potential rapid transition to involve inflammatory and immune responses on cellular oxygen utilization will aid the clinician in choosing and appropriately interpreting endpoint monitoring data. There also appears to be an optimal window of opportunity for monitoring to help mitigate the development of more complicated inflammatory states. This article reviews the underlying need for endpoint selection (both global and regional, biochemical and functional) and monitoring during resuscitation of the polytrauma patient. At this juncture it appears that early use of a blend of global markers such as lactate and base deficit coupled with an available sensitive regional monitor such as gastric tonometry may offer the best combination of current technology to guard against early perfusion-related dysoxia. Future techniques involving optical spectroscopy offer the exciting potential to assess oxygenation at the cellular level. This may aid in ultra-early detection and resolution of perfusion-related dysoxia in addition to recognizing its transition to more complex inflammatory-mediated circulatory and metabolic failure.

Elevated Admission Base Deficit Is Associated with a Complex Dynamic Network of Systemic Inflammation Which Drives Clinical Trajectories in Blunt Trauma Patients

We hypothesized that elevated base deficit (BD) ≥ 4 mEq/L upon admission could be associated with an altered inflammatory response, which in turn may impact differential clinical trajectories. Using clinical and biobank data from 472 blunt trauma survivors, 154 patients were identified after excluding patients who received prehospital IV fluids or had alcohol intoxication. From this subcohort, 84 patients had a BD ≥ 4 mEq/L and 70 patients with BD < 4 mEq/L. Three samples within the first 24 h were obtained from all patients and then daily up to day 7 after injury. Twenty-two cytokines and chemokines were assayed using Luminex™ and were analyzed using two-way ANOVA and dynamic network analysis (DyNA). Multiple mediators of the innate and lymphoid immune responses in the BD ≥ 4 group were elevated differentially upon admission and up to 16 h after injury. DyNA revealed a higher, sustained degree of interconnectivity of the inflammatory response in the BD ≥ 4 patients during the initial 16 h after injury. These results suggest that elevated admission BD is associated with differential immune/inflammatory pathways, which subsequently could predispose patients to follow a complicated clinical course.

A comparison of initial lactate and initial base deficit as predictors of mortality after severe blunt trauma

BACKGROUND

After injury, base deficit (BD) and lactate are common measures of shock. Lactate directly measures anaerobic byproducts, whereas BD is calculated and multifactorial. Although recent studies suggest superiority for lactate in predicting mortality, most were small or analyzed populations with heterogeneous injury severity. Our objective was to compare initial BD with lactate as predictors of inhospital mortality in a large cohort of blunt trauma patients all presenting with hemorrhagic shock.

MATERIALS AND METHODS

The Glue Grant multicenter prospective cohort database was queried; demographic, injury, and physiologic parameters were compiled. Survivors, early deaths (≤24 h), and late deaths were compared. Profound shock (lactate ≥ 4 mmol/L) and severe traumatic brain injury subgroups were identified a priori. Chi-square, t-test, and analysis of variance were used as appropriate for analysis. Multivariable logistic regression and area under the receiver operating characteristic curve analysis assessed survival predictors. P < 0.05 was significant.

RESULTS

A total of 1829 patients met inclusion; 289 (15.8%) died. Both BD and lactate were higher for nonsurvivors (P < 0.00001). After multivariable regression, both lactate (odds ratio [OR] 1.17; 95% confidence interval [CI]: 1.12-1.23; P < 0.00001) and BD (OR 1.04; 95% CI: 1.01-1.07; P < 0.005) predicted overall mortality. However, when excluding early deaths (n = 77), only lactate (OR 1.12 95% CI: 1.06-1.19; P < 0.0001) remained predictive but not BD (OR 1.00 95% CI: 0.97-1.04; P = 0.89). For the shock subgroup, (n = 915), results were similar with lactate, but not BD, predicting both early and late deaths. Findings also appear independent of traumatic brain injury severity.

CONCLUSIONS

After severe blunt trauma, initial lactate better predicts inhospital mortality than initial BD. Initial BD does not predict mortality for patients who survive >24 h.

Rigid Intramedullary Nailing of Femoral Shaft Fractures for Patients Age 12 and Younger: Indications and Technique

Femoral shaft fractures are common injuries in the pediatric and adolescent age groups. Rigid intramedullary nailing is an excellent treatment option for older children and adolescents, particularly for length-unstable fractures and larger patients (>49 kg). Appropriate indications, contraindications, and preoperative assessment are described. The rigid nailing surgical technique is detailed including positioning, operative steps, pearls, and pitfalls. Complications and the reported outcomes of lateral trochanteric entry nailing are reviewed from the published series.

Hemodynamic Changes Following Routine Fluid Resuscitation in Patients With Blunt Trauma

Background

The management of trauma patients is often difficult. The American college of surgeons suggests using advanced trauma life support (ATLS) measures. ATLS is regarded as the gold standard for the resuscitation of cases with acute life threatening injuries.

Objectives

To assess the change in base excess (BE) values and central venous pressure (CVP) one and six hours after injection of 1000 cc normal saline in trauma patients admitted to the ICU.

Patients and Methods

According to the inclusion and exclusion criteria, patients were randomly selected to participate in the project. Inclusion criteria included trauma patients admitted to the ICU with a CVP line and who had indication for hydration. In trauma patients, at the zero time period, BP, PR, RR and CVP were measured, and a blood gas test was used to assess Hb, pH, BE, PO₂, HCO₃ and PCO₂. Then 1000 cc of normal saline was injected, and after one and six hours, the same values were re-evaluated.

Results

The mean age of the patients was 38.1 ± 3.9 (range 15 - 60). The mean duration of hospitalization was 7.4 ± 4.4 (range 1 - 21) days. The mean ISS for these patients was 14.33 ± 5.3. BE changes in both groups of patients, based on Hb primary division, showed a significant difference (P ≤ 0.05). The results showed that there was no significant relation between the measured ISS and the changes in base values (P ≥ 0.05).

Conclusions

According to our results, the infusion of one liter normal saline will cause a statistically significant decrease only in BD, after one hour, in patients with moderate to severe ISS. The changes in SBP, PR, CVP and also pH, HCO₃ and Hb were not statistically remarkable.

Impact of common crystalloid solutions on resuscitation markers following Class I hemorrhage: A randomized control trial

BACKGROUND

Resuscitation after hemorrhage with crystalloid solutions can lead to marked acidosis and iatrogenically worsen the lethal triad. The effect of differing solutions on base deficit and lactate has been sparsely prospectively studied in humans. We sought to quantify the effect of normal saline (NS) and lactated Ringer's (LR) resuscitation in voluntary blood donors as a model for Class I hemorrhage.

METHODS

A prospective randomized control trial was conducted in conjunction with blood drives. Donors were randomized to receive no intravenous fluid (noIVF), 2-L NS, or 2-L LR after blood donation of 500 mL. Lactate and base deficit were measured before and after fluid administration using an iSTAT. The mean laboratory values were compared between groups first using a global test followed by pairwise testing between groups using the Wilcoxon rank-sum and Kruskal-Wallis tests. The Bonferroni correction was used and a statistical significance of p < 0.0167 was set.

RESULTS

A total of 157 patients completed the study. The mean (SD) age was 39.2 (12.7), and 65.0% were female. Patients in each group lost equivalent amounts of total blood volume, and a similar amount was replaced in the crystalloid group (p > 0.0167). Donors had comparable increases in lactate and base deficit after donation regardless of the group (p > 0.0167). After resuscitation with 2-L crystalloid, the lactate level increased higher in the LR group than in the noIVF or the NS group (1.36 mmol/L vs. 1.00 mmol/L vs. 1.54 mmol/L, p < 0.0001). In addition, the resuscitation base deficit increased in the NS group more than in the noIVF or LR group (-0.65 vs. -3.06 vs. -0.34, p < 0.0001).

CONCLUSION

This study is one of the first human studies to prospectively demonstrate quantifiable differences in base deficit and lactate by type of crystalloid resuscitation. LR resuscitation elevated lactate levels, and NS negatively affected the base deficit. These findings are critical to the interpretation of trauma patient resuscitation with crystalloid solutions.

LEVEL OF EVIDENCE

Therapeutic study, level II.

Base deficit and serum lactate concentration in patients with post traumatic convulsion

Introduction:

Traumatic brain injury is a major cause of morbidity and mortality worldwide, and has been reported to be one of the risk factors for epileptic seizures. Abnormal blood lactate (LAC) and base deficit (BD) reflects hypoperfusion and could be used as metabolic markers to predict the outcome. The aim of this study is to assess the prognostic value of BD and LAC levels for post traumatic convulsion (PTC) in head injury patients.

Materials and Methods:

All head injury patients with PTC were studied for the demographics profile, mechanism of injury, initial vital signs, and injury severity score (ISS), respiratory rates, CT scan findings, and other laboratory investigations. The data were obtained from the trauma registry and medical records. Statistical analysis was done using SPSS software.

Results:

Amongst 3082 trauma patients, 1584 were admitted to the hospital. Of them, 401 patients had head injury. PTC was observed in 5.4% (22/401) patients. Out of the 22 head injury patients, 10 were presented with the head injury alone, whereas 12 patients had other associated injuries. The average age of the patients was 25 years, comprising predominantly of male patients (77%). Neither glasgow coma scale nor ISS had correlation with BD or LAC in the study groups. The mean level of BD and LAC was not statistically different in PTC group compared to controls. However, BD was significantly higher in patients with associated injuries than the isolated head injury group. Furthermore, there was no significant correlation amongst the two groups as far as LAC levels are concerned.

Conclusion:

Base deficit but not lactic acid concentration was significantly higher in head injury patients with associated injuries. Early resuscitation by pre-hospital personnel and in the trauma room might have impact in minimizing the effect of post traumatic convulsion on BD and LAC.

The quest for a universal definition of polytrauma: a trauma registry-based validation study

BACKGROUND

A pilot validation recommended defining polytrauma as patients with an Abbreviated Injury Scale (AIS) score greater than 2 in at least two Injury Severity Score (ISS) body regions (2 × AIS score > 2). This study aimed to validate this definition on larger data set. We hypothesized that patients defined by the 2 × AIS score > 2 cutoff have worse outcomes and use more resources than those without 2 × AIS score > 2 and that this would therefore be a better definition of polytrauma.

METHODS

Patients injured between 2009 and 2011, with complete documentation of AIS by New South Wales Trauma Registry and 16 years and older were selected. Age and sex were obtained in addition to outcomes of ISS, hospital length of stay (LOS), intensive care unit (ICU) admission, ICU LOS, and mortality. We compared demographic characteristics and outcomes between patients with ISS greater than 15 who did and did not meet the 2 × AIS score > 2 definition. We then undertook regression analyses (logistic regression for binary outcomes [ICU admission and death] and linear regression for hospital and ICU LOS) to compare outcomes for patients with and without 2 × AIS score > 2, adjusting for sex and age categories.

RESULTS

In the adjusted analyses, patients with 2 × AIS score > 2 had twice the odds of being admitted to the ICU compared with those without 2 × AIS score > 2 (odds ratio, 2.5; 95% confidence interval [CI], 2.2-2.8) and 1.7 times the odds of dying (95% CI, 1.4-2.0; p < 0.001 for both models). Patients with 2 × AIS score > 2 also had a mean difference of 1.5 days longer stay in the hospital compared with those without 2 × AIS score > 2 (95% CI, 1.4-1.7) and 1.6 days longer ICU stay (95% CI, 1.4-1.8; p < 0.001 for all models).

CONCLUSION

Patients with 2 × AIS score > 2 had higher mortality, more frequent ICU admissions, and longer hospital and ICU stay than those without 2 × AIS score > 2 and represents a superior definition to the definitions for polytrauma currently in use.

LEVEL OF EVIDENCE

Diagnostic test/ criteria, level III.

A simple predictive formula for the blood requirement in patients with high-energy blunt injuries transferred within one hour post-trauma

Aims

To recognize patients who require massive transfusion at the early stage of blunt trauma, we retrospectively investigated patients with high-energy blunt injuries transferred within 1 h post-trauma.

Methods

Between August 2007 and July 2011, 233 trauma patients were: (i) injured by a high-energy blunt mechanism with Injury Severity Score ≥9; (ii) not dead on arrival; (iii) older than 9 years; and (iv) at our center within 1 h after injury. The findings for 113 of those patients were analyzed, including those produced by ultrasonography, computed tomography, and arterial blood gas analyses.

Results

Of 113 patients, 33 underwent massive transfusion (≥6 units) within 8 h of arrival. A logistic regression analysis revealed that an arterial lactate level ≥28 mg/dL (P < 0.001; odds ratio, 105.11; 95% confidence interval, 12.58-2,718.84) and a flat ratio of the inferior vena cava on computed tomography ≥3 (P < 0.001; odds ratio, 32.50; 95% confidence interval, 4.44-714.44) were significant independent predictors for a massive transfusion within 8 h. In a receiver operating curve analysis, the area under the curve of the need for massive transfusion was 0.956, with a sensitivity of 0.94 and a specificity of 0.90. A linear predictive formula for the probability (P) of receiving a massive transfusion was generated as P = 2 × lactate (mg/dL) + 15 × the flat ratio of inferior vena cava - 103. Using another 52 trauma patients, the formula was validated.

Conclusions

An elevated level of arterial lactate and the flat ratio of inferior vena cava were significant predictors for identifying the patients who would require a massive transfusion in the early stage after high-energy blunt trauma.

Rigid Intramedullary Nailing of Femoral Shaft Fractures in Skeletally Immature Patients Using a Lateral Trochanteric Entry Portal

Introduction

We describe rigid intramedullary nailing using a trochanteric entry for internal fixation of femoral shaft fractures in older children and adolescents.

Step 1 Preparation Prior to Incision

Appropriate preparation prior to the operation is key to minimizing intraoperative and postoperative complications.

Step 2 Perform Incision and Exposure

A well-positioned incision will facilitate and reduce difficulty with ideal guidewire placement.

Step 3 Place and Overream the Guide Pin

Ensure that the guide pin is properly positioned on the greater trochanter, while avoiding the piriformis fossa.

Step 4 Place the Guidewire and Reduce the Fracture

Prepare the definitive guidewire. Insert the guidewire into the proximal fragment via the trochanteric portal. While maintaining the fracture reduction, advance the guidewire into the distal fragment.

Step 5 Measure Nail Length and Begin Overreaming

Pay careful attention to the amount of reaming as well as distraction across the fracture site to provide the best fit for the nail.

Step 6 Insert the Nail

Be sure to maintain the reduction while advancing the nail across the fracture site. Reconfirm that traction has been reduced to avoid distraction at the fracture site.

Step 7 Insert Proximal and Distal Interlocks

Use the interlocking screws to secure the proper rotational alignment.

Step 8 Make Final Images and Close the Wound

Confirm the reduction and adequate fixation before closure.

Results

In our original study, a cohort of 246 femoral shaft fractures among 241 skeletally immature patients treated with trochanteric entry rigid intramedullary nailing was retrospectively reviewed.IndicationsContraindicationsPitfalls & Challenges.

Identifying the bleeding trauma patient: predictive factors for massive transfusion in an Australasian trauma population

BACKGROUND

Military and civilian data would suggest that hemostatic resuscitation results in improved outcomes for exsanguinating patients. However, identification of those patients who are at risk of significant hemorrhage is not clearly defined. We attempted to identify factors that would predict the need for massive transfusion (MT) in an Australasian trauma population, by comparing those trauma patients who did receive massive transfusion with those who did not.

METHODS

Between 1985 and 2010, 1,686 trauma patients receiving at least 1 U of packed red blood cells were identified from our prospectively maintained trauma registry. Demographic, physiologic, laboratory, injury, and outcome variables were reviewed. Univariate analysis determined significant factors between those who received MT and those who did not. A predictive multivariate logistic regression model with backward conditional stepwise elimination was used for MT risk. Statistical analysis was performed using SPSS PASW.

RESULTS

MT patients had a higher pulse rate, lower Glasgow Coma Scale (GCS) score, lower systolic blood pressure, lower hemoglobin level, higher Injury Severity Score (ISS), higher international normalized ratio (INR), and longer stay. Initial logistic regression identified base deficit (BD), INR, and hemoperitoneum at laparotomy as independent predictive variables. After assigning cutoff points of BD being greater than 5 and an INR of 1.5 or greater, a further model was created. A BD greater than 5 and either INR of 1.5 or greater or hemoperitoneum was associated with 51 times increase in MT risk (odds ratio, 51.6; 95% confidence interval, 24.9-95.8). The area under the receiver operating characteristic curve for the model was 0.859.

CONCLUSION

From this study, a combination of BD, INR, and hemoperitoneum has demonstrated good predictability for MT. This tool may assist in the determination of those patients who might benefit from hemostatic resuscitation.

LEVEL OF EVIDENCE

Prognostic study, level III.

Timing of orthopaedic surgery in multiple trauma patients: development of a protocol for early appropriate care

OBJECTIVES

The purpose was to define which clinical conditions warrant delay of definitive fixation for pelvis, femur, acetabulum, and spine fractures. A model was developed to predict the complications.

DESIGN

Statistical modeling based on retrospective database.

SETTING

Level 1 trauma center.

PATIENTS

A total of 1443 adults with pelvis (n = 291), acetabulum (n = 399), spine (n = 102), and/or proximal or diaphyseal femur (n = 851) fractures.

INTERVENTION

All fractures were treated surgically.

MAIN OUTCOME MEASUREMENTS

Univariate and multivariate analysis of variance assessed associations of parameters with complications. Logistic predictive models were developed with the incorporation of multiple fixed and random effect covariates. Odds ratios, F tests, and receiver operating characteristic curves were calculated.

RESULTS

Twelve percent had pulmonary complications, with 8.2% overall developing pneumonia. The pH and base excess values were lower (P < 0.0001) and the rate of improvement was also slower (all Ps < 0.007), with pneumonia or any pulmonary complication. Similarly, lactate values were greater with pulmonary complications (all Ps < 0.02), and lactate was the most specific predictor of complications. Chest injury was the strongest independent predictor of pulmonary complication. Initial lactate was a stronger predictor of pneumonia (P = 0.0006) than initial pH (P = 0.047) or the rate of improvement of pH over the first 8 hours (P = 0.0007). An uncomplicated course was associated with the absence of chest injury (P < 0.0001) and definitive fixation within 24 (P = 0.007) or 48 hours (P = 0.005). Models were developed to predict probability of complications with various injury combinations using specific laboratory parameters measuring residual acidosis.

CONCLUSIONS

Acidosis on presentation is associated with complications. Correction of pH within 8 hours to >7.25 was associated with fewer pulmonary complications. Presence and severity of chest injury, number of fractures, and timing of fixation are other significant variables to include in a predictive model and algorithm development for Early Appropriate Care. The goal is to minimize complications by definitive management of major skeletal injury once the patient has been adequately resuscitated.

Base excess as a predictor for injury severity in pediatric trauma patients

BACKGROUND

Base excess is considered a predictor of mortality and severity of injury in trauma patients. Base excess had been widely examined in different settings. Only few studies have examined the role of base excess in pediatric trauma patients.

OBJECTIVE

To evaluate the value of admission base excess in pediatric trauma patients with respect to intensive care unit (ICU) admission rate and length of hospital stay.

METHODS

A retrospective study of pediatric trauma patients was conducted at a Level II trauma center. All patients aged 0-16 years for which a trauma team was activated over the years 2006-2009 were included. Study database included admission base excess, mechanism of injury, location and nature of injury, injury severity score, length of hospital stay, and ICU admission.

RESULTS

The study group consisted of 359 patients. There was a weak linear correlation between admission base excess, length of stay in the hospital, and ICU admission. Base excess seemed to show a stronger correlation for the youngest age group (0-6 years) and no correlation for the middle age group. There was a positive but weak correlation (R Spearman = 0.26) between admission base excess and Injury Severity Score (ISS). However, 40% of the children with an ISS score >25 had normal admission base excess values. The area under the curve of the receiver operating characteristic curves of base excess for predicting ICU admission was 0.66.

CONCLUSIONS

The admission base excess in pediatric trauma patients seems to be a weak prognostic factor in our facility.

Admission base excess as a predictor of transfusion requirement and mortality in dogs with blunt trauma: 52 cases (2007-2009)

OBJECTIVE

To evaluate the ability of admission base excess (ABE) to predict blood transfusion requirement and mortality in dogs following blunt trauma.

DESIGN

Retrospective study 2007-2009.

SETTING

University Veterinary Teaching Hospital.

ANIMALS

Fifty-two dogs admitted to the intensive care unit for treatment following blunt trauma.

MEASUREMENTS AND MAIN RESULTS

Animals requiring red blood cell transfusion (N = 8) had significantly lower ABE than those not requiring transfusion (N = 44; median base excess [BE] = -8.4 versus -4.7, P = .0034), while there was no difference in admission packed cell volume (PCV) or age. Animals that died or were euthanized due to progression of signs (N = 5) had lower median ABE than those that survived (N = 47; median BE = -7.3 versus -4.9, P = 0.018). Admission PCV and age were not significantly different between survivors and nonsurvivors. Receiver operator characteristic curve analysis showed an ABE cutoff of -6.6 was 88% sensitive and 73% specific for transfusion requirement (P < 0.001), and a cutoff of -7.3 was 81% sensitive and 80% specific for survival (P < 0.001). Multivariate logistic regression analysis demonstrated that ABE was a predictor of transfusion requirement that was independent of overall severity of injury as measured by the Animal Triage Trauma (ATT) score, but a similar analysis showed that only ATT was an independent predictor of survival.

CONCLUSIONS

The ABE in dogs with blunt trauma was a predictor of mortality and blood transfusion requirement within 24 hours.

Lactate in Trauma: A Poor Predictor of Mortality in the Setting of Alcohol Ingestion

Resuscitation end point markers such as lactate and base deficit (BD) are used in trauma to identify and treat a state of compensated shock. Lactate and BD levels are also elevated by alcohol. In blunt trauma patients with positive blood alcohol levels, lactate may be a poor indicator of injury. Retrospective data were collected on 1083 blunt trauma patients with positive blood alcohol levels admitted a Level I trauma center between 2003 and 2006. Patients were stratified by Injury Severity Score, age, gender, and Glasgow Coma Score. Logistic regression analyses were used to assess lactate and BD as independent risk factors for mortality. Seventy-four per cent of patients had an abnormal lactate level compared with 28 per cent with abnormal BD levels. In patients with mild injury, lactate levels were abnormal in more than 70 per cent of patients compared with less than 20 per cent of patients with abnormal BD levels. Linear regression showed lactate is not a significant predictor of mortality. Regardless of Injury Severity Score, lactate appeared to be more often abnormal than BD in the setting of alcohol ingestion. Additionally, because BD, and not lactate, was shown to be an independent predictor of mortality, lactate may not be a reliable marker of end point resuscitation in this patient population.

Mismatch of arterial and central venous blood gas analysis during haemorrhage

BACKGROUND AND OBJECTIVE

Arterial base excess and lactate levels are key parameters in the assessment of critically ill patients. The use of venous blood gas analysis may be of clinical interest when no arterial blood is available initially.

METHODS

Twenty-four pigs underwent progressive normovolaemic haemodilution and subsequent progressive haemorrhage until the death of the animal. Base excess and lactate levels were determined from arterial and central venous blood after each step. In addition, base excess was calculated by the Van Slyke equation modified by Zander (BE(z)). Continuous variables were summarized as mean +/- SD and represent all measurements (n = 195).

RESULTS

Base excess according to National Committee for Clinical Laboratory Standards for arterial blood was 2.27 +/- 4.12 versus 2.48 +/- 4.33 mmol(-l) for central venous blood (P = 0.099) with a strong correlation (r(2) = 0.960, P < 0.001). Standard deviation of the differences between these parameters (SD-DIFBE) did not increase (P = 0.355) during haemorrhage as compared with haemodilution. Arterial lactate was 2.66 +/- 3.23 versus 2.71 +/- 2.80 mmol(-l) in central venous blood (P = 0.330) with a strong correlation (r(2) = 0.983, P < 0.001). SD-DIFLAC increased (P < 0.001) during haemorrhage. BE(z) for central venous blood was 2.22 +/- 4.62 mmol(-l) (P = 0.006 versus arterial base excess according to National Committee for Clinical Laboratory Standards) with strong correlation (r(2) = 0.942, P < 0.001). SD-DIFBE(z)/base excess increased (P < 0.024) during haemorrhage.

CONCLUSION

Central venous blood gas analysis is a good predictor for base excess and lactate in arterial blood in steady-state conditions. However, the variation between arterial and central venous lactate increases during haemorrhage. The modification of the Van Slyke equation by Zander did not improve the agreement between central venous and arterial base excess.

Does thoracic injury impair the predictive value of base deficit in trauma patients?

INTRODUCTION: Base deficit (BD) has been shown to be a valuable indicator to be predictive of complications and mortality after trauma. Arterial carbon dioxide (PaCO(2)) may be influenced by thoracic injuries, potentially diminishing the predictive value of BD. Therefore, the aim of this study was to assess the predictive value of admission BD for mortality and complications in trauma patients with thoracic injuries. METHODS: By a prospective database analysis of patients with an injury to the chest admitted to the University Medical Center Utrecht between 2000 and 2004 were studied. All patients with a blood gas analyses were included. Absolute BD was used for analyses. Clinical outcome parameters were recorded. RESULTS: The BD was higher in the non-surviving patients compared to the survivors (7.5 vs. 3.8, p<0.001). Mortality rate of patients with an admission BD of >/=6 was increased in thoracic trauma patients (BD<6 mortality rate 7%, BD>/=6 mortality rate 27%; p<0.001). In patients who required ICU admittance the BD was increased compared to patients without ICU admission (5.2 vs. 2.9, p<0.001). Within the subgroup of patients admitted to the ICU, the BD was higher in patients who required ventilation (3.8 vs. 5.5, p=0.025). Patients who developed chest related complications had increased BD compared with those without complications (4.9 vs. 4.0, p=0.025), the BD was particularly increased in patients who developed acute respiratory distress syndrome (ARDS) (4.1 vs. 6.4, p=0.004). Carbon dioxide (PaCO(2)) showed a predictive value for mortality (44 vs. 53, p<0.001), ICU admission (42 vs. 46, p=0.003) and hospital stay. CONCLUSION: Admission BD is a predictive factor in thoracic trauma patients for mortality and chest related complications. Furthermore it is a predictive factor for ICU admission, required ventilation and hospital stay. The use of BD in thoracic trauma patients can potentially identify patients who require additional monitoring or early aggressive therapy.

Initial base deficit as predictors for mortality and transfusion requirement in the severe pediatric trauma except brain injury

OBJECTIVE

The initial base deficit (BD) is an important indicator of shock in adult trauma patients, but its value is unclear in pediatric trauma patients. This study assessed the ability of the initial BD to predict mortality and blood transfusion requirements in children except severe brain injury patients.

METHODS

This study was a retrospective review of pediatric patients with severe trauma arriving at the emergency department of a university hospital from January 1998 to June 2005. Blood pressure, the initial BD, and the Injury Severity Score were assessed as independent predictors of mortality and the blood transfusion requirement using multiple regression analysis.

RESULTS

The study group constituted 102 patients. According to the multiple regression analysis results, the initial systolic blood pressure, Injury Severity Score, and blood transfusion requirement were not independent predictors of mortality (P = 0.104, 0.959, 0.386, respectively). By contrast, the initial BD was an independent predictor, with an odds ratio of 13.6 for BD of -8 mEq/L or less (confidence interval [CI], 3.51-35.23, P = 0.037), and systolic blood pressure and BD were independent predictors of blood transfusion requirement; the odds ratio for hypotension was 3.2 (CI, 0.51-8.32, P = 0.044), and the odds ratio was 15.3 for BD values of -8 or less (CI, 2.24-51.43, P = 0.003).

CONCLUSION

The initial BD in pediatric trauma patients except severe brain injury was an independent predictor of mortality and blood transfusion requirement within 24 hours. Mortality and blood transfusion requirement were significantly high when initial BD was less than -8 mEq/L.

A comparison of central venous and arterial base deficit as a predictor of survival in acute trauma

BACKGROUND

The arterial base deficit has been demonstrated to be a marker of shock and predictive of survival in injured patients. The venous blood, however, may better reflect tissue perfusion. Its usefulness in trauma is unknown. We compared central venous with arterial blood gas analysis to determine which was a better predictor of survival in injured patients.

METHODS

A prospective, nonrandomized series of acutely injured patients was investigated. Patients who had an arterial blood gas analysis for acid-base determination had a simultaneous central venous blood gas analysis and routine blood tests. Patient demographics, Injury Severity Score, and survival past 24 hours were recorded. Arterial and venous blood samples were analyzed for pH, PCO2, PO2, HCO3, hemoglobin-oxygen saturation, base deficit, and lactate.

RESULTS

One hundred patients were enrolled. There were 76 survivors and 24 nonsurvivors. Wilcoxon rank sum test and multivariate logistic regression were used for each recorded variable; only central venous base deficit was predictive of survival past 24 hours (P = .0081). Specifically, arterial base deficit was not predictive of survival past 24 hours.

CONCLUSION

In a prospective series of acutely injured patients, central venous base deficit, not arterial base deficit, was predictive of survival past 24 hours.

Identification and Resuscitation of the Trauma Patient in Shock

This article focuses on rapid diagnosis and treatment of the patient suffering from trauma-related shock, including early identification of patients at risk for occult hypoperfusion. Resuscitation strategies (delayed resuscitation, damage control resuscitation), end points of resuscitation, and the role of blood products and pro-coagulants for resuscitation are discussed.