The role of pre-hospital blood gas analysis in trauma resuscitation

Utilization of Multi-Parameter Blood Gas Analysis in Prehospital Emergency Medicine-A Scoping Review

BACKGROUND

Prehospital blood gas analysis (BGA) is an evolving field that offers the potential for early identification and management of critically ill patients. However, the utility and accuracy of prehospital BGA are subjects of ongoing debate.

OBJECTIVES

We aimed to provide a comprehensive summary of the current literature on prehospital BGA, including its indications, methods, and feasibility.

METHODS

We performed a scoping review of prehospital BGA. A thorough search of the PubMed, Embase, and Web of Science databases was conducted to identify relevant studies focusing on prehospital BGA in adult patients.

RESULTS

Fifteen studies met the inclusion criteria. Prehospital BGA was most frequently performed in patients in out-of-hospital cardiac arrest, followed by traumatic and nontraumatic cases. The parameters most commonly analyzed were pH, pCO2, pO2, and lactate. Various sampling methods, including arterial, venous, and intraosseous, were reported for prehospital BGA. While prehospital BGA shows promise in facilitating early identification of critical patients and guiding resuscitation efforts, logistical challenges are to be considered. The handling of preclinical BGA is described as feasible and useful in most of the included studies.

CONCLUSION

Prehospital BGA holds significant potential for enhancing patient care in the prehospital setting, though technical challenges need to be considered. However, further research is required to establish optimal indications and demonstrate the benefits for prehospital BGA in specific clinical contexts.

Arterial Blood Gases and Arterial Lines in the Prehospital Setting: A Systematic Literature Review and Survey of Current United Kingdom Helicopter Emergency Medical Services

OBJECTIVE

Prehospital guidelines state that monitoring should match in-hospital standards, but consensus on the use of arterial blood gases (ABGs) and arterial lines remains unclear. The aim was to perform a systematic literature review and survey of UK helicopter emergency medical services (HEMS) use and perceptions of ABGs and arterial lines.

METHODS

A systematic literature review was conducted for arterial lines and ABGs and prehospital care. Additionally, two questionnaires were distributed to all UK HEMS (questionnaire 1: current clinical practice and questionnaire 2: clinicians' opinions).

RESULTS

From 1,028 results, 13 studies (10 ABGs and 3 arterial lines) were included, demonstrating it is feasible to obtain ABGs and place arterial lines in the prehospital setting. There were concerns about practical difficulties for ABGs and the time taken for arterial lines. Survey responses were obtained from all UK HEMS (N = 22). Six services carry equipment for performing ABGs and nine services for arterial lines. Clinicians expressed concerns relating to the time taken to perform both procedures, but most believed it would allow better monitoring and more targeted treatment.

CONCLUSION

The evidence of benefit for both procedures remains poor. Overall, there may be clinical benefits, but these are likely to be patient specific and require further investigation.

Randomised controlled trials in pre-hospital trauma: a systematic mapping review

BACKGROUND

Trauma is a leading cause of morbidity and mortality worldwide with about 5.8 million deaths globally and the leading cause of death in those aged 45 and younger. The pre-hospital phase of traumatic injury is particularly important as care received during this phase has effects on survival. The need for high quality clinical trials in this area has been recognised for several years as a key priority to improve the evidence base and, ultimately, clinical care in prehospital trauma. We aimed to systematically map the existing evidence base for pre-hospital trauma trials, to identify knowledge gaps and inform decisions about the future research agenda.

METHODS

A systematic mapping review was conducted first employing a search of key databases (MEDLINE, CINAHL, EMBASE, and Cochrane Library from inception to March 23rd 2020) to identify randomised controlled trials within the pre-hospital trauma and injury setting. The evidence 'map' identified and described the characteristics of included studies and compared these studies against existing priorities for research. Narrative description of studies informed by analysis of relevant data using descriptive statistics was completed.

RESULTS

Twenty-three eligible studies, including 10,405 participants across 14 countries, were identified and included in the systematic map. No clear temporal or geographical trends in publications were identified. Studies were categorised into six broad categories based on intervention type with evaluations of fluid therapy and analgesia making up 60% of the included trials. Overall, studies were heterogenous with regard to individual interventions within categories and outcomes reported. There was poor reporting across several studies. No studies reported patient involvement in the design or conduct of the trials.

CONCLUSION

This mapping review has highlighted that evidence from trials in prehospital trauma is sparse and where trials have been completed, the reporting is generally poor and study designs sub-optimal. There is a continued need, and significant scope, for improvement in a setting where high quality evidence has great potential to make a demonstrable impact on care and outcomes.

Automatic real-time analysis and interpretation of arterial blood gas sample for Point-of-care testing: Clinical validation

Background

Point-of-care arterial blood gas (ABG) is a blood measurement test and a useful diagnostic tool that assists with treatment and therefore improves clinical outcomes. However, numerically reported test results make rapid interpretation difficult or open to interpretation. The arterial blood gas algorithm (ABG-a) is a new digital diagnostics solution that can provide clinicians with real-time interpretation of preliminary data on safety features, oxygenation, acid-base disturbances and renal profile. The main aim of this study was to clinically validate the algorithm against senior experienced clinicians, for acid-base interpretation, in a clinical context.

Methods

We conducted a prospective international multicentre observational cross-sectional study. 346 sample sets and 64 inpatients eligible for ABG met strict sampling criteria. Agreement was evaluated using Cohen’s kappa index, diagnostic accuracy was evaluated with sensitivity, specificity, efficiency or global accuracy and positive predictive values (PPV) and negative predictive values (NPV) for the prevalence in the study population.

Results

The concordance rates between the interpretations of the clinicians and the ABG-a for acid-base disorders were an observed global agreement of 84,3% with a Cohen’s kappa coefficient 0.81; 95% CI 0.77 to 0.86; p < 0.001. For detecting accuracy normal acid-base status the algorithm has a sensitivity of 90.0% (95% CI 79.9 to 95.3), a specificity 97.2% (95% CI 94.5 to 98.6) and a global accuracy of 95.9% (95% CI 93.3 to 97.6). For the four simple acid-base disorders, respiratory alkalosis: sensitivity of 91.2 (77.0 to 97.0), a specificity 100.0 (98.8 to 100.0) and global accuracy of 99.1 (97.5 to 99.7); respiratory acidosis: sensitivity of 61.1 (38.6 to 79.7), a specificity of 100.0 (98.8 to 100.0) and global accuracy of 98.0 (95.9 to 99.0); metabolic acidosis: sensitivity of 75.8 (59.0 to 87.2), a specificity of 99.7 (98.2 to 99.9) and a global accuracy of 97.4 (95.1 to 98.6); metabolic alkalosis sensitivity of 72.2 (56.0 to 84.2), a specificity of 95.5 (92.5 to 97.3) and a global accuracy of 93.0 (88.8 to 95.3); the four complex acid-base disorders, respiratory and metabolic alkalosis, respiratory and metabolic acidosis, respiratory alkalosis and metabolic acidosis, respiratory acidosis and metabolic alkalosis, the sensitivity, specificity and global accuracy was also high. For normal acid-base status the algorithm has PPV 87.1 (95% CI 76.6 to 93.3) %, and NPV 97.9 (95% CI 95.4 to 99.0) for a prevalence of 17.4 (95% CI 13.8 to 21.8). For the four-simple acid-base disorders and the four complex acid-base disorders the PPV and NPV were also statistically significant.

Conclusions

The ABG-a showed very high agreement and diagnostic accuracy with experienced senior clinicians in the acid-base disorders in a clinical context. The method also provides refinement and deep complex analysis at the point-of-care that a clinician could have at the bedside on a day-to-day basis. The ABG-a method could also have the potential to reduce human errors by checking for imminent life-threatening situations, analysing the internal consistency of the results, the oxygenation and renal status of the patient.

Relationship Between Initial Arterial Blood Gases and Coagulation Profiles - Analyzing the Prognosis and Outcomes in Patients with Multiple Injuries/Trauma

Purpose

Trauma is recognized as a significant health concern across the world. The increase in the mortality rate of multiple trauma (MT) patients serves as a major issue for health-care providers. The study investigates the relationship between the initial arterial blood gases and coagulation profiles among the multiple injured/trauma patients.

Patients and Methods

A retrospective study design was used, and 137 acute trauma patients' data were included from the King Abdullah University Hospital (KAUH) from 1 January 2014 to 1 October 2017.

Results

The results showed that patients were mainly male (79.6%) and had RTA (71.5%). They had a normal pH (50.4%) and pCO2 (68.6%) while decreasing HCO3 (51.1%). An increasing level of pCO2 (45%) along with PT (28%), PTT (17%) and INR (23%) is observed. It also showed a decreasing level of platelets (39%). The overall findings showed a close association of the blood gases and coagulation indicators.

Conclusion

The study concludes that to control the coagulation markers, the blood gases of the patients should be screened and monitored.

Retrospective study on pattern and outcome of management of sigmoid volvulus at district hospital in Ethiopia

Background

Sigmoid volvulus is the commonest cause of large bowel obstruction in many regions of the world. Its prevalence varies greatly geographically. In Ethiopia, the disease is the commonest cause of emergency admissions due to intestinal obstruction. However, few studies have been conducted discussing the management outcome in Ethiopia and Africa. This research was conducted to assess the pattern & management outcome of acute sigmoid volvulus at a district hospital in South-west Ethiopia.

Methods

A facility based retrospective cross-sectional review of surgical records was done to identify patients who had acute sigmoid volvulus. Data was collected using structured questionnaire by three pre trained data collectors. The collected data was checked for its completeness, and then entered, edited, cleaned and analyzed using Statistical Package for the Social Sciences (SPSS) version 22.0. For all statistical significance tests the cut-off value set was P < 0.05.

Result

A total of 131 patients were managed for acute sigmoid volvulus. 108 (82.4%) were men with a male to female ratio of 4.7:1. The hospital prevalence of acute sigmoid volvulus was 27.9%. Majority (42%) of the patients were in the 6th decades of life. Abdominal pain, abdominal distention & inability to pass feces & flatus were the predominant presenting compliant while abdominal distention was the dominant physical finding in all of the patients. Ninety-seven patients (74%) had viable bowel obstruction of which 29 patients had successful rectal tube deflation. The remaining 68 patients were managed operatively by either primary resection & anastomosis (62 patients) or derotation alone (6 patients). Thirty-four patients had gangrenous bowel obstruction and were managed by either primary resection and anastomosis (16 patients) or Hartman’s colostomy (18 patients). Six patients died of which 5 had primary resection and anastomosis (2 for viable and 3 for gangrenous bowel obstruction).The predominant postoperative complication was wound infection in 11(10.7%) patients. Factors associated with unfavorable outcome were female sex, primary resection & end to end anastomosis and presentation of illness more than 24 h.

Conclusion

The most common management was primary resection and anastomosis. The overall mortality rate was 4.5% and the mortality rate related to primary resection and end to end anastomosis was 6.4%. Mortality rate was higher in those patients who had resection and anastomosis for gangrenous bowel compared to those who had viable bowel (19% vs 3%). Generally factors associated with poor outcome were duration of illness, primary resection and anastomosis and being female.

Diagnostic value of prehospital arterial blood gas measurements - a randomised controlled trial

Background

Arterial blood gas analysis is an important diagnostic tool in managing critically ill patients within the hospital. Whether prehospital application of this diagnostic modality contributes to more exact diagnoses and treatments in critically ill prehospital patients is unknown. The aim of this study was to establish whether access to arterial blood gas analysis increased the prehospital diagnostic accuracy of prehospital anaesthesiologists. Furthermore, we investigated whether prehospital blood gas analysis resulted in therapeutic interventions that would not have been carried out if the arterial blood gas analyser had not been available.

Methods

In a prospective randomised study, two groups of prehospital adult patients with acute critical illness were compared. All patients received standard prehospital care. In the intervention group, an arterial blood gas sample was analysed prehospitally. The primary outcome was the impact of blood gas analysis on the accuracy of prehospital diagnoses. Furthermore, we registered any therapeutic interventions that were carried out as a direct result of the blood gas analysis.

Results

A total of 310 patients were included in the study. Eighty-eight of these patients were subsequently excluded, primarily due to difficulties in obtaining post hoc consent or venous sampling or other technical difficulties. A total of 102 patients was analysed in the arterial blood gas group (ABG group), while 120 patients were analysed in the standard care group (noABG group). In 78 of the 102 patients in the ABG group, the prehospital physician reported that ABG analysis increased their perceived diagnostic precision. In 81 cases in the noABG group, the lack of arterial blood gas analysis was perceived to have decreased diagnostic accuracy. The claim that ABG analysis increased diagnostic accuracy could, however, not be substantiated as there was no difference in the number of un-specific diagnoses between the groups.

Blood gas analysis increased the probability of targeting specific prehospital therapeutic interventions and led to 159 interventions, including intubation, ventilation and/or upgrading the level of urgency, in 71 ABG-group patients (p < 0.001).

Conclusion

Although prehospital arterial blood gas analysis did not improve the accuracy of the prehospital diagnoses assigned to patients, it significantly increased the quality of treatment provided to patients with acute critical illness.

Trial registration

ClinicalTrials.gov, NCT03006692, retrospectively registered six months after first patient entry.

The utility of abnormal initial arterial blood gas values in determining clinical futility of trauma cases with severe hemorrhage

BACKGROUND

Patients who experience trauma with severe hemorrhage requiring immediate surgery and massive blood transfusion often present with markedly abnormal laboratory values. These cases require valuable resources; however, little is known regarding prognostic factors that correlate with mortality. The purpose of this study was to determine whether abnormal initial arterial blood gas (ABG) pH, a marker for severe blood loss, could serve as a prognostic indicator for these patients.

METHODS

An IRB approved retrospective study was performed at LAC+USC Medical Center Level I Trauma Center. Data was collected from trauma patients with severe hemorrhage admitted between June 2015 and April 2016 who were immediately admitted to the OR following entry into the ER. Baseline variables of age, sex and mechanism of trauma were collected. The pH readings from the initial three ABG data were obtained, and mortality was determined for each patient.

RESULTS

We identified 247 patients, 84.2% of which were male. Ages ranged from 1 to 91years (average=38.4). Overall mortality was 13.8%. The average initial pH value for non-survivors (7.10±0.13) was significantly lower than for survivors (7.34±0.07) [p<0.001]. Among patients whose initial three ABG pH values averaged ≤7.15, the survival rate was 8.7%. Ten patients had any single recorded pH value≤6.91. The mortality rate among these patients was 90%.

CONCLUSIONS

Consideration should be given to initial pH values when resuscitating "red blanket" patients. However, the pH values alone cannot reliably be used to determine clinical futility in individual patients in the early period after injury.

The effectiveness of prehospital hypertonic saline for hypotensive trauma patients: a systematic review and meta-analysis

Background

The optimal prehospital fluid for the treatment of hypotension is unknown. Hypertonic fluids may increase circulatory volume and mute the pro-inflammatory response of the body to injury and illness. The purpose of this systematic review is to determine whether in patients presenting with hypotension in the prehospital setting (population), the administration of hypertonic saline (intervention), compared to an isotonic fluid (control), improves survival to hospital discharge (outcome).

Methods

Searches were conducted in Medline, Embase, CINAHL, and CENTRAL from the date of database inception to November, 2016, and included all languages. Two reviewers independently selected randomized control trials of hypotensive human participants administered hypertonic saline in the prehospital setting. The comparison was isotonic fluid, which included normal saline, and near isotonic fluids such as Ringer’s Lactate. Assessment of study quality was done using the Cochrane Collaborations’ risk of bias tool and a fixed effect meta-analysis was conducted to determine the pooled relative risk of survival to hospital discharge. Secondary outcomes were reported for fluid requirements, multi-organ failure, adverse events, length of hospital stay, long term survival and disability.

Results

Of the 1160 non-duplicate citations screened, thirty-eight articles underwent full-text review, and five trials were included in the systematic review. All studies administered a fixed 250 ml dose of 7.5% hypertonic saline, except one that administered 300 ml. Two studies used normal saline, two Ringer’s Lactate, and one Ringer’s Acetate as control. Routine care co-interventions included isotonic fluids and colloids. Five studies were included in the meta-analysis (n = 1162 injured patients) with minimal statistical heterogeneity (I² = 0%). The pooled relative risk of survival to hospital discharge with hypertonic saline was 1.02 times that of patients who received isotonic fluids (95% Confidence Interval: 0.95, 1.10). There were no consistent statistically significant differences in secondary outcomes.

Conclusions

There was no significant difference in important clinical outcomes for hypotensive injured patients administered hypertonic saline compared to isotonic fluid in the prehospital setting. Hypertonic saline cannot be recommended for use in prehospital clinical practice for the management of hypotensive injured patients based on the available data.

PROSPERO registration # CRD42016053385.

A Case of Strongyloidiasis: An Immigrant Healthcare Worker Presenting with Fatigue and Weight Loss

BACKGROUND

Strongyloides stercoralis is an intestinal nematode parasite classified as a soil-transmitted helminth, endemic in tropical and subtropical regions. Strongyloides stercoralis can remain dormant for decades after the initial infection.

CASE

We describe a patient who was diagnosed with Strongyloides stercoralis infection three weeks after a left inguinal hernia repair and discuss approaches to prevention, diagnosis, and treatment.

CONCLUSIONS

Physicians in the United States often miss opportunities to identify patients with chronic strongyloidiasis. Symptoms may be vague and screening tests have limitations. We review current strategies for diagnosis and treatment of chronic intestinal strongyloidiasis in immigrant patients who have significant travel history to tropical regions and discuss the clinical features and management of the infection.

Point of care blood gases with electrolytes and lactates in adult emergencies

Point-of-care testing (POCT) is one of the formidable concept introduce in the field of critical care settings to deliver decentralized, patient-centric health care to the patients. Rapid provision of blood measurements, particularly blood gases and electrolytes, may translate into improved clinical outcomes. Studies shows that POCT carries advantages of providing reduced therapeutic turnaround time (TTAT), shorter door-to-clinical-decision time, rapid data availability, reduced preanalytic and postanalytic testing errors, self-contained user-friendly instruments, small sample volume requirements, and frequent serial whole-blood testing. However, still there is a noticeable debate that exists among the laboratorians, clinicians, and administrators over concerns regarding analyzer inaccuracy, imprecision and performance (interfering substances), poorly trained non-laboratorians, high cost of tests, operator-dependent quality of testing, and difficulty in integrating test results with hospital information system (HIS). On search of literature using Medline/Pubmed and Embase using the key phrases "ppoint-of-care test," "central laboratory testing," "electrolytes," "blood gas analysis," "lactate," "emergency department," "intensive care unit," we found that POCT of blood gases and selected electrolytes may not entirely replace centralized laboratory testing but may transfigure the clinical practice paradigm of emergency and critical care physicians. We infer that further comprehensive, meaningful and rigorous evaluations are required to determine outcomes which are more quantifiable, closely related to testing events and are associated with effective cost benefits.

Evaluation of gasometric parameters in trauma patients during mobile prehospital care

OBJECTIVE

To evaluate gasometric differences of severe trauma patients requiring intubation in prehospital care.

METHODS

Patients requiring airway management were submitted to collection of arterial blood samples at the beginning of pre-hospital care and at arrival at the Emergency Room. We analyzed: Glasgow Coma Scale, respiratory rate, arterial pH, arterial partial pressure of CO2 (PaCO2), arterial partial pressure of O2 (PaO2), base excess (BE), hemoglobin O2 saturation (SpO2) and the relation of PaO2 and inspired O2 (PaO2/FiO2).

RESULTS

There was statistical significance of the mean differences between the data collected at the site of the accident and at the entrance of the ER as for respiratory rate (p = 0.0181), Glasgow Coma Scale (p = 0.0084), PaO2 (p <0.0001) and SpO2 (p = 0.0018).

CONCLUSION

tracheal intubation changes the parameters PaO2 and SpO2. There was no difference in metabolic parameters (pH, bicarbonate and base excess). In the analysis of blood gas parameters between survivors and non-survivors there was statistical difference between PaO2, hemoglobin oxygen saturation and base excess.

Point-of-Care Blood Gases, Electrolytes, Chemistries, Hemoglobin, and Hematocrit Measurement in Venous Samples from Pet Rabbits

Point-of-care testing is an attractive option in rabbit medicine, because it permits rapid analysis of a panel of electrolytes, chemistries, blood gases, hemoglobin, and hematocrit, requiring only 65 μL of blood. The purpose of this study was to evaluate the performance of a portable clinical analyzer for measurement of pH, partial pressure of CO2, Na, chloride, potassium, blood urea nitrogen, glucose, hematocrit, and hemoglobin in healthy and diseased rabbits. Blood samples obtained from 30 pet rabbits were analyzed immediately after collection by the portable clinical analyzer (PCA) and immediately thereafter (time &lt;20 sec) by a reference analyzer. Bland-Altman plots and Passing-Bablok regression analysis were used to compare the results. Limits of agreement were wide for all the variables studied, with the exception of pH. Most variables presented significant proportional and/or constant bias. The current study provides sufficient evidence that the PCA presents reliability for pH, although its low agreement with a reference analyzer for the other variables does not support their interchangeability. Limits of agreement provided for each variable allow researchers to evaluate if the PCA is reliable enough for their scope. To the authors’ knowledge, the present is the first report evaluating a PCA in the rabbit.

Trauma hemostasis and oxygenation research position paper on remote damage control resuscitation: definitions, current practice, and knowledge gaps

The Trauma Hemostasis and Oxygenation Research Network held its third annual Remote Damage Control Resuscitation Symposium in June 2013 in Bergen, Norway. The Trauma Hemostasis and Oxygenation Research Network is a multidisciplinary group of investigators with a common interest in improving outcomes and safety in patients with severe traumatic injury. The network's mission is to reduce the risk of morbidity and mortality from traumatic hemorrhagic shock, in the prehospital phase of resuscitation through research, education, and training. The concept of remote damage control resuscitation is in its infancy, and there is a significant amount of work that needs to be done to improve outcomes for patients with life-threatening bleeding secondary to injury. The prehospital phase of resuscitation is critical in these patients. If shock and coagulopathy can be rapidly identified and minimized before hospital admission, this will very likely reduce morbidity and mortality. This position statement begins to standardize the terms used, provides an acceptable range of therapeutic options, and identifies the major knowledge gaps in the field.

Polytrauma at the Emergency Department; can we relate arterial blood gas analysis to a shock classification?

OBJECTIVE

Shock is defined as a change of circulation which results in hypoxia at the tissue level. Lactate and base deficit (BD) are associated with a high risk of multiple organ dysfunction in trauma patients. In this study we evaluated the influence of early recognition of shock in trauma patients.

METHODS

In a retrospective study, relevant data were collected from the Radboud University Nijmegen Medical Centre (RUNMC) database between January 2009 and December 2010. Vital parameters were taken at the accident scene, and patients were divided into four shock classes. Arterial blood gas analysis was performed on arrival in the emergency department. Statistical analysis was performed with SPSS version 17.0. Statistical significance was assumed at p ≤ 0.05.

RESULTS

A total of 255 patients were included. Patients who suffered from prehospital shock, and those who were intubated prior to hospital admittance showed a bad outcome, presenting with a more severe metabolic acidosis, higher ISS and higher mortality. There was a significant difference for bicarbonate and BD between shockclass I + II and shockclass III + IV, respectively 22.7 vs. 19.7 and -3.4 vs. -6.9. Intubated patients had a decreased bicarbonate and BD compared to not intubated patients, respectively 21.81 vs. 23.24 and -5.08 vs. -2.38. Mortality and ISS were higher in patients in shock class III and IV. Significant differences in serum lactate levels were not found.

CONCLUSIONS

Prehospital shock influences patient outcome; outcome of patients is related to initial shock classification. Further validation of our shock classification, however, is necessary.

[Point-of-care testing in preclinical emergency medicine]

BACKGROUND

Measurement of biological signals directly at the patient (point-of-care testing, POCT) is an established standard in emergency medicine when test results are needed quickly and within a reliable time frame or if external testing requires a disproportionate effort.

OBJECTIVES

Currently, the rapid test for β-HCG in urine and POCT measurement of lactate, blood gases, cardiac tropinin, haemoglobin, and hematocrit are well established in emergency medicine. POCT of copeptin, fatty acid-binding proteins (FABP), procalcitonin, coagulation values, natriuretic peptides, D-dimer, and toxicological substances are of future interest. In this article, the appropriate use of point-of-care testing in prehospital emergency medicine is discussed.

RESULTS

Application of POCT is dependent of the underlying conditions, the availability of appropriate devices, and of suitable reference methods in a central laboratory. In addition, economical and quality aspects play an important role.

CONCLUSION

In emergency departments, POCT is currently developing into a standard measuring method for a number of markers because hospital laboratories are increasingly being merged and consequently reduce their emergency-analytic services. In countries with a high density of hospitals, however, preclinical POCT should be reduced to the minimum necessary.

Fluid therapy in neurotrauma: basic and clinical concepts

The patient with head trauma is a challenge for the emergency physician and for the neurosurgeon. Currently traumatic brain injury constitutes a public health problem. Knowledge of the various therapeutic strategies to provide support in the prehospital and perioperative are essential for optimal care. Rapid infusion of large volumes of crystalloids to restore blood volume and blood pressure quickly is now the standard treatment for patients with combined TBI and HS The fluid in patients with brain and especially in the carrier of brain injury is a critical topic; we present a review of the literature about the history, physiology of current fluid preparations, and a discussion regard the use of fluid therapy in traumatic brain injury and decompressive craniectomy.

Intravenous Fluid Therapy in Traumatic Brain Injury and Decompressive Craniectomy

The patient with head trauma is a challenge for the emergency physician and for the neurosurgeon. Currently traumatic brain injury constitutes a public health problem. Knowledge of the various supportive therapeutic strategies in the pre-hospital and pre-operative stages is essential for optimal care. The immediate rapid infusion of large volumes of crystalloids to restore blood volume and blood pressure is now the standard treatment of patients with combined traumatic brain injury (TBI) and hemorrhagic shock (HS). The fluid in patients with brain trauma and especially in patients with brain injur y is a critical issue. In this context we present a review of the literature about the history, physiology of current fluid preparations, and a discussion regarding the use of fluid therapy in traumatic brain injury and decompressive craniectomy.

What's new in resuscitation strategies for the patient with multiple trauma?

The last decade has seen a sea change in the management of major haemorrhage following traumatic injury. Damage control resuscitation (DCR), a strategy combining the techniques of permissive hypotension, haemostatic resuscitation and damage control surgery has been widely adopted as the preferred method of resuscitation in patients with haemorrhagic shock. The over-riding goals of DCR are to mitigate metabolic acidosis, hypothermia and coagulopathy and stabilise the patient as early as possible in a critical care setting. This narrative review examines the background to these changes in resuscitation practice, discusses the central importance of traumatic coagulopathy in driving these changes particularly in relation to the use of high FFP:RBC ratio and explores methods of predicting, diagnosing and treating the coagulopathy with massive transfusion protocols as well as newer coagulation factor concentrates. We discuss other areas of trauma haemorrhage management including the role of hypertonic saline and interventional radiology. Throughout this review we specifically examine whether the available evidence supports these newer practices.

Temperature and time stability of whole blood lactate: implications for feasibility of pre-hospital measurement

Background

To determine the time and temperature stability of whole blood lactate using experimental conditions applicable to the out-of-hospital environment.

Findings

We performed a prospective, clinical laboratory-based study at an academic hospital. Whole blood lactate was obtained by venipuncture from five post-prandial, resting subjects. Blood was stored in lithium heparinized vacutainers in three temperature conditions: 1) room temperature (20°C), 2) wrapped in a portable, instant ice pack (0°C), or 3) wet ice (0°C). Lactate concentrations (mmol/L) were measured at 0, 5, 10, 20, and 30 minutes after sampling, and compared using repeated measures analysis of variance.

Mean baseline lactate among resting subjects (N = 5) was 1.24 mmol/L (95%CI: 0.49,1.98 mmol/L). After 30 minutes, lactate concentration increased, on average, by 0.08 mmol/L (95%CI: 0.02,0.13 mmol/L), 0.18 mmol/L (95%CI: 0.07,0.28 mmol/L), and 0.36 mmol/L (95%CI: 0.24,0.47 mmol/L) when stored in wet ice, ice pack, and room temperature, respectively. The increase in lactate was similar in samples wrapped in portable ice pack or stored in wet ice at all time points (p > 0.05), and met criteria for equivalence at 30 minutes. However, lactate measurements from whole blood stored at room temperature were significantly greater, on average, than wet ice or portable ice pack within five and ten minutes, respectively (p < 0.05).

Conclusions

Whole blood lactate measurements using samples stored in a portable ice pack are similar to wet ice for up to 30 minutes. These conditions are applicable to the out-of-hospital environment, and should inform future studies of pre-hospital measurement of lactate.

Clinical and cellular effects of hypothermia, acidosis and coagulopathy in major injury

BACKGROUND

Hypothermia, acidosis and coagulopathy have long been considered critical combinations after severe injury. The aim of this review was to give a clinical update on this triad in severely injured patients.

METHODS

A non-systematic literature search on hypothermia, acidosis and coagulopathy after major injury was undertaken, with a focus on clinical data from the past 5 years.

RESULTS

Hypothermia (less than 35 °C) is reported in 1·6-13·3 per cent of injured patients. The occurrence of acidosis is difficult to estimate, but usually follows other physiological disturbances. Trauma-induced coagulopathy (TIC) has both endogenous and exogenous components. Endogenous acute traumatic coagulopathy is associated with shock and hypoperfusion. Exogenous effects of dilution from fluid resuscitation and consumption through bleeding and loss of coagulation factors further add to TIC. TIC is present in 10-34 per cent of injured patients, depending on injury severity, acidosis, hypothermia and hypoperfusion. More expedient detection of coagulopathy is needed. Thromboelastography may be a useful point-of-care measurement. Management of TIC is controversial, with conflicting reports on blood component therapy in terms of both outcome and ratios of blood products to other fluids, particularly in the context of civilian trauma.

CONCLUSION

The triad of hypothermia, acidosis and coagulopathy after severe trauma appears to be fairly rare but does carry a poor prognosis. Future research should define modes of early detection and targeted therapy.

The acute management of trauma hemorrhage: a systematic review of randomized controlled trials

Introduction

Worldwide, trauma is a leading cause of death and disability. Haemorrhage is responsible for up to 40% of trauma deaths. Recent strategies to improve mortality rates have focused on optimal methods of early hemorrhage control and correction of coagulopathy. We undertook a systematic review of randomized controlled trials (RCT) which evaluated trauma patients with hemorrhagic shock within the first 24 hours of injury and appraised how the interventions affected three outcomes: bleeding and/or transfusion requirements; correction of trauma induced coagulopathy and mortality.

Methods

Comprehensive searches were performed of MEDLINE, EMBASE, CENTRAL (The Cochrane Library Issue 7, 2010), Current Controlled Trials, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP) and the National Health Service Blood and Transplant Systematic Review Initiative (NHSBT SRI) RCT Handsearch Database.

Results

A total of 35 RCTs were identified which evaluated a wide range of clinical interventions in trauma hemorrhage. Many of the included studies were of low methodological quality and participant numbers were small. Bleeding outcomes were reported in 32 studies; 7 reported significantly reduced transfusion use following a variety of clinical interventions, but this was not accompanied by improved survival. Minimal information was found on traumatic coagulopathy across the identified RCTs. Overall survival was improved in only three RCTs: two small studies and a large study evaluating the use of tranexamic acid.

Conclusions

Despite 35 RCTs there has been little improvement in outcomes over the last few decades. No clear correlation has been demonstrated between transfusion requirements and mortality. The global trauma community should consider a coordinated and strategic approach to conduct well designed studies with pragmatic endpoints.