The impact of prehospital ventilation on outcome after severe traumatic brain injury

Correlation Between EtCO2 and PCO2 in Patients Undergoing Critical Care Transport

OBJECTIVES

End-tidal carbon dioxide (EtCO2) monitoring is widely used as a surrogate for the partial pressure of carbon dioxide (PCO2) in critically ill patients receiving manual or mechanical ventilation in prehospital, emergency, and critical care settings. Specific targets for ETCO2 are a key component of Emergency Medical Services (EMS) protocols, especially for specific patient groups such as those with traumatic brain injury. However, the correlation between EtCO2 and venous or arterial PCO2 is uncertain. We aimed to assess the correlation between EtCO2 and PCO2 in intubated patients undergoing critical care transport (CCT), and in specific subgroups of patients.

METHODS

We performed a retrospective review of patients undergoing emergency transport by a multi-state CCT agency. Patients were included if they had an advanced airway and both an EtCO2 and PCO2 reading within 5 min of each other. We obtained data on patient demographics, transport characteristics, medical categories, vital signs, lab values, and specific interventions. We performed univariable and multivariable binary logistic regression to assess the association between delta PCO2 and these characteristics.

RESULTS

We included 6,459 patients (mean age 58.4 years [SD 18.5], 57.1% male), of which a subset of 551 patients had multiple EtCO2-PCO2 measurements within 5 min. The median (IQR) initial delta PCO2 was 12.9 mmHg (7.1, 21.9). 3,967 (61.4%) patients had a delta PCO2 >10 mmHg and 1,843 (28.5%) had a delta PCO2 >20 mmHg. We identified an independent association between delta PCO2 >10 mmHg and age, male sex, interfacility transport, venous sampling site, respiratory rate, hypotension, hypoxia, and thoracostomy. In patients with multiple blood gas measurements, 76% had delta PCO2 >10 mmHg over the duration of the transport.

CONCLUSIONS

We identified substantial differences between EtCO2 and PCO2 across patients with medical and traumatic conditions undergoing critical care transport. The PCO2 assessment should be strongly considered as part of ventilatory management in patients encountered in emergency and critical care settings.

Novel High-tech, Low-cost Ventilation for Military Use, Mass Casualty Incidents, Stockpiling, and Underserved Communities

INTRODUCTION

Despite the significant need for mechanical ventilation in- and out-of-hospital, mechanical ventilators remain inaccessible in many instances because of cost or size constraints. Mechanical ventilation is especially critical in trauma scenarios, but the impractical size and weight of standard mechanical ventilators restrict first responders from carrying them in medical aid bags, leading to reliance on imprecise manual bag-mask ventilation. This is particularly important in combat-related injury, where airway compromise and respiratory failure are leading causes of preventable death, but medics are left without necessary mechanical ventilation. To address the serious gaps in mechanical ventilation accessibility, we are developing an Autonomous, Modular, and Portable Ventilation platform (AMP-Vent) suitable for austere environments, prolonged critical care, surgical applications, mass casualty incidents, and stockpiling. The core system is remarkably compact, weighing <2.3 kg, and can fit inside a shoebox (23.4 cm × 17.8 cm × 10.7 cm). Notably, this device is 65% lighter than standard transport ventilators and astoundingly 96% lighter than typical intensive care unit ventilators. Beyond its exceptional portability, AMP-Vent can be manufactured at less than one-tenth the cost of conventional ventilators. Despite its reduced size and cost, the system's functionality is uncompromised. The core system is equipped with closed-loop sensors and advanced modes of ventilation (pressure-control, volume-control, and synchronized intermittent mandatory ventilation), enabling quality care in a portable form factor. The current prototype has undergone preliminary preclinical testing and optimization through trials using a breathing simulator (ASL 5000) and in a large animal model (swine). This report aims to introduce a novel ventilation system and substantiate its promising performance through evidence gathered from preclinical studies.

MATERIALS AND METHODS

Lung simulator testing was performed using the ASL 5000, in accordance with table 201.105 "pressure-control inflation-type testing" from ISO 80601-2-12:2020. Following simulations, AMP-Vent was tested in healthy 10-kg female domestic piglets. The Children's Hospital of Philadelphia Institutional Animal Care and Use Committee approved all animal procedures. Swine received 4-min blocks of alternating ventilation, where AMP-Vent and a conventional anesthesia ventilator (GE AISYS CS2) were used to titrate to varied end-tidal carbon dioxide (EtCO2) goals with the initial ventilator switching for each ascending target (35, 40, 45, 50, 55 mmHg).

RESULTS

During ASL 5000 simulations, AMP-Vent exhibited consistent performance under varied conditions, maintaining a coefficient of variation of 2% or less within each test. In a large animal study, AMP-Vent maintained EtCO2 and SpO2 targets with comparable performance to a conventional anesthesia ventilator (GE AISYS CS2). Furthermore, the comparison of minute ventilation (Ve) distributions between the conventional anesthesia ventilator and AMP-Vent at several EtCO2 goals (35, 40, 45, 50, and 55 mmHg) revealed no statistically significant differences (p = 0.46 using the Kruskal-Wallis rank sum test).

CONCLUSIONS

Preclinical results from this study highlight AMP-Vent's core functionality and consistent performance across varied scenarios. AMP-Vent sets a benchmark for portability with its remarkably compact design, positioning it to revolutionize trauma care in previously inaccessible medical scenarios.

Evidence-based management of adult traumatic brain injury with raised intracranial pressure in intensive critical care unit at resource-limited settings: a literature review

Background

In underdeveloped countries, there is a greater incidence of mortality and morbidity arising from trauma, with traumatic brain injury (TBI) accounting for 50% of all trauma-related deaths. The occurrence of elevated intracranial pressure (ICP), which is a common pathophysiological phenomenon in cases of TBI, acts as a contributing factor to unfavorable outcomes. The aim of this systematic review is to analyze the existing literature regarding the management of adult TBI with raised ICP in an intensive critical care unit, despite limited resources.

Methods

This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis protocol. Search engines such as PubMed, the Cochrane database, and Google Scholar were utilized to locate high-level evidence that would facilitate the formation of sound conclusions.

Result

A total of 11 715 articles were identified and individually assessed to determine their eligibility for inclusion or exclusion based on predetermined criteria and outcome variables. The methodological quality of each study was evaluated using recommended criteria. Ultimately, the review consisted of 51 articles.

Conclusion

Physical examination results and noninvasive assessments of the optic nerve sheath diameter (ONSD) via sonography are positively associated with elevated ICP, and are employed as diagnostic and monitoring tools for elevated ICP in resource-limited settings. Management of elevated ICP necessitates an algorithmic approach that utilizes prophylactic measures and acute intervention treatments to mitigate the risk of secondary brain injury.

Higher Oxygenation Is Associated with Improved Survival in Severe Traumatic Brain Injury but Not Traumatic Shock

Pre-hospital resuscitation of critically injured patients traditionally includes supplemental oxygen therapy to address potential hypoxemia. The objective of this study was to explore the association between pre-hospital hypoxemia, hyperoxemia, and mortality in patients with traumatic brain injury (TBI) and traumatic shock. We hypothesized that both hypoxemia and hyperoxemia would be associated with increased mortality. We used the Resuscitation Outcomes Consortium Prospective Observational Prehospital and Hospital Registry for Trauma (ROC PROPHET) database of critically injured patients to identify a severe TBI cohort (pre-hospital Glasgow Coma Scale [GCS] 3-8) and a traumatic shock cohort (systolic blood pressure ≤90 mm Hg and pre-hospital GCS >8). Arterial blood gas (ABG) obtained within 30 min of hospital arrival was required for inclusion. Patients with hypoxemia (PaO₂ <80 mm Hg) and hyperoxemia (PaO₂ >400 mm Hg) were compared to those with normoxemia (PaO₂ 80-400 mm Hg) with regard to the primary outcome measure of in-hospital mortality in both the TBI and traumatic shock cohorts. Multiple logistic regression was used to calculate odds ratios (ORs) after adjustment for multiple covariables. In addition, regression spline curves were generated to estimate the risk of death as a continuous function of PaO₂ levels. A total of 1248 TBI patients were included, of whom 396 (32%) died before hospital discharge. Associations between hypoxemia and increased mortality (OR, 1.8; 95% confidence interval [CI], 1.2-2.8; p = 0.008) and between hyperoxemia and decreased mortality (OR, 0.6; 95% CI, 0.4-0.9; p = 0.018) were observed. A total of 582 traumatic shock patients were included, of whom 52 (9%) died before hospital discharge. No statistically significant associations were observed between in-hospital mortality and either hypoxemia (OR, 1.0; 95% CI, 0.4-2.4; p = 0.987) or hyperoxemia (OR, 1.9; 95% CI, 0.6-5.7; p = 0.269). Among patients with severe TBI but not traumatic shock, hypoxemia was associated with an increase of in-hospital mortality and hyperoxemia was associated with a decrease of in-hospital mortality.

A systematic review of the timing of intubation in patients with traumatic brain injury: pre-hospital versus in-hospital intubation

PURPOSE

The objective of this systematic review was to examine current evidence on the risks versus benefit of pre-hospital intubation when compared with in-hospital intubation in adult patients with traumatic brain injuries.

METHODS

We conducted electronic searches of PubMed, Medline, Embase, CIANHL and the Cochrane library up to March 2021. Data extracted compared mortality, length of hospital and intensive care stay, pneumonia and functional outcomes in traumatic brain injured patients undergoing pre-hospital intubation versus in-hospital intubation. The risk of bias was assessed using the Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

Ten studies including 25,766 patients were analysed. Seven were retrospective studies, two prospective cohort studies and one randomised control study. The mean mortality rate in patients who underwent pre-hospital intubation was 44.5% and 31.98% for in-hospital intubation. The odds ratio for an effect of pre-hospital intubation on mortality ranged from 0.31 (favouring in-hospital intubation) to 3.99 (favouring pre-hospital). The overall quality of evidence is low; however, the only randomised control study showed an improved functional outcome for pre-hospital intubation at 6 months.

CONCLUSIONS

The existing evidence does not support widespread pre-hospital intubation in all traumatic brain injured patients. This does not, however, contradict the need for the intervention when there is severe airway compromise; instead, it must be assessed by experienced personnel if a time critical transfer to hospital is more advantageous. Favourable neurological outcomes highlighted by the randomised control trial favours pre-hospital intubation, but further research is required in this field.

Use of intraoperative mild hyperventilation to decrease the incidence of postoperative shoulder pain after laparoscopic gastric sleeve surgery: A prospective randomised controlled study

BACKGROUND AND AIMS

Post-laparoscopic shoulder pain (PLSP) is a common problem. It is a referred type of pain resulting from irritation of phrenic nerve endings. Multiple manoeuvres were used to decrease its incidence with varying success rates. In this study, we tested the use of mild intraoperative hyperventilation to reduce PLSP in patients undergoing laparoscopic sleeve gastrectomy surgery (LSG).

METHODS

Consenting American Society of Anesthesiologists-I and II patients undergoing LSG under general anaesthesia were randomly assigned to two groups. Group A (53 patients) received intraoperative mild hyperventilation with target end-tidal carbon dioxide (ETCO2) of 30-32 mmHg. Group B (51 patients) received conventional ventilation (ETCO2 of 35-40 mmHg). Incidence and severity of PLSP, cumulative analgesic requirements and incidence of nausea and vomiting were recorded at 12 and 24 hours postoperatively and then followed up after discharge over the phone at 48 hours, 1 week, 1 month and 3 months. Statistical significance of differences between the two groups was defined at P < 0.05.

RESULTS

Incidence of PLSP was comparable between the two groups in the first 24 hours. The intervention group had a significantly lower incidence of PLSP throughout the remaining assessment points (56.6% vs. 80.4%, 30.2% vs. 78.4%, 15.1% vs. 70.6%, 3.8% vs. 35.3% at 36 hours, 48 hours, 1 week and 1 month, respectively, P < 0.05). The average PLSP pain score was significantly lower in the mild hyperventilation group at all assessment time points. Nausea and vomiting were non-significantly lower in the mild hyperventilation group.

CONCLUSION

Mild intraoperative hyperventilation could be beneficial in reducing the incidence and severity of PLSP after LSG surgery.

Optimal Targets of the First 24-h Partial Pressure of Carbon Dioxide in Patients with Cerebral Injury: Data from the MIMIC-III and IV Database

BACKGROUND

It is generally believed that hypercapnia and hypocapnia will cause secondary injury to patients with craniocerebral diseases, but a small number of studies have shown that they may have potential benefits. We assessed the impact of partial pressure of arterial carbon dioxide (PaCO₂) on in-hospital mortality of patients with craniocerebral diseases. The hypothesis of this research was that there is a nonlinear correlation between PaCO₂ and in-hospital mortality in patients with craniocerebral diseases and that mortality rate is the lowest when PaCO₂ is in a normal range.

METHODS

We identified patients with craniocerebral diseases from Medical Information Mart for Intensive Care third and fourth edition databases. Cox regression analysis and restricted cubic splines were used to examine the association between PaCO₂ and in-hospital mortality.

RESULTS

Nine thousand six hundred and sixty patients were identified. A U-shaped association was found between the first 24-h PaCO₂ and in-hospital mortality in all participants. The nadir for in-hospital mortality risk was estimated to be at 39.5 mm Hg (p for nonlinearity < 0.001). In the subsequent subgroup analysis, similar results were found in patients with traumatic brain injury, metabolic or toxic encephalopathy, subarachnoid hemorrhage, cerebral infarction, and other encephalopathies. Besides, the mortality risk reached a nadir at PaCO₂ in the range of 35-45 mm Hg. The restricted cubic splines showed a U-shaped association between the first 24-h PaCO₂ and in-hospital mortality in patients with other intracerebral hemorrhage and cerebral tumor. Nonetheless, nonlinearity tests were not statistically significant. In addition, Cox regression analysis showed that PaCO₂ ranging 35-45 mm Hg had the lowest death risk in most patients. For patients with hypoxic-ischemic encephalopathy and intracranial infections, the first 24-h PaCO₂ and in-hospital mortality did not seem to be correlated.

CONCLUSIONS

Both hypercapnia and hypocapnia are harmful to most patients with craniocerebral diseases. Keeping the first 24-h PaCO₂ in the normal range (35-45 mm Hg) is associated with lower death risk.

Association of Ventilation during Initial Trauma Resuscitation for Traumatic Brain Injury and Post-Traumatic Outcomes: A Systematic Review

OBJECTIVES

In the absence of evidence of acute cerebral herniation, normal ventilation is recommended for patients with traumatic brain injury (TBI). Despite this recommendation, ventilation strategies vary during the initial management of patients with TBI and may impact outcome. The goal of this systematic review was to define the best evidence-based practice of ventilation management during the initial resuscitation period.

METHODS

A literature search of PubMed, CINAHL, and SCOPUS identified studies from 2009 through 2019 addressing the effects of ventilation during the initial post-trauma resuscitation on patient outcomes.

RESULTS

The initial search yielded 899 articles, from which 13 were relevant and selected for full-text review. Six of the 13 articles met the inclusion criteria, all of which reported on patients with TBI. Either end-tidal carbon dioxide (ETCO2) or partial pressure carbon dioxide (PCO2) were the independent variables associated with mortality. Decreased rates of mortality were reported in patients with normal PCO2 or ETCO2.

CONCLUSIONS

Normoventilation, as measured by ETCO2 or PCO2, is associated with decreased mortality in patients with TBI. Preventing hyperventilation or hypoventilation in patients with TBI during the early resuscitation phase could improve outcome after TBI.

Multiple trauma management in mountain environments - a scoping review : Evidence based guidelines of the International Commission for Mountain Emergency Medicine (ICAR MedCom). Intended for physicians and other advanced life support personnel

BACKGROUND

Multiple trauma in mountain environments may be associated with increased morbidity and mortality compared to urban environments.

OBJECTIVE

To provide evidence based guidance to assist rescuers in multiple trauma management in mountain environments.

ELIGIBILITY CRITERIA

All articles published on or before September 30th 2019, in all languages, were included. Articles were searched with predefined search terms.

SOURCES OF EVIDENCE

PubMed, Cochrane Database of Systematic Reviews and hand searching of relevant studies from the reference list of included articles.

CHARTING METHODS

Evidence was searched according to clinically relevant topics and PICO questions.

RESULTS

Two-hundred forty-seven articles met the inclusion criteria. Recommendations were developed and graded according to the evidence-grading system of the American College of Chest Physicians. The manuscript was initially written and discussed by the coauthors. Then it was presented to ICAR MedCom in draft and again in final form for discussion and internal peer review. Finally, in a face-to-face discussion within ICAR MedCom consensus was reached on October 11th 2019, at the ICAR fall meeting in Zakopane, Poland.

CONCLUSIONS

Multiple trauma management in mountain environments can be demanding. Safety of the rescuers and the victim has priority. A crABCDE approach, with haemorrhage control first, is central, followed by basic first aid, splinting, immobilisation, analgesia, and insulation. Time for on-site medical treatment must be balanced against the need for rapid transfer to a trauma centre and should be as short as possible. Reduced on-scene times may be achieved with helicopter rescue. Advanced diagnostics (e.g. ultrasound) may be used and treatment continued during transport.

The effects of arterial CO2 on the injured brain: Two faces of the same coin

Serum levels of carbon dioxide (CO₂) closely regulate cerebral blood flow (CBF) and actively participate in different aspects of brain physiology such as hemodynamics, oxygenation, and metabolism. Fluctuations in the partial pressure of arterial CO₂ (PaCO₂) modify the aforementioned variables, and at the same time influence physiologic parameters in organs such as the lungs, heart, kidneys, and the gastrointestinal tract. In general, during acute brain injury (ABI), maintaining normal PaCO₂ is the target to be achieved. Both hypercapnia and hypocapnia may comprise secondary insults and should be avoided during ABI. The risks of hypocapnia mostly outweigh the potential benefits. Therefore, its therapeutic applicability is limited to transient and second-stage control of intracranial hypertension. On the other hand, inducing hypercapnia could be beneficial when certain specific situations require increasing CBF. The evidence supporting this claim is very weak. This review attempts providing an update on the physiology of CO₂, its risks, benefits, and potential utility in the neurocritical care setting.

Mechanical Ventilation of Severe Traumatic Brain Injury Patients in the Prehospital Setting

OBJECTIVE

Suboptimal ventilation may impact outcomes in patients with traumatic brain injury (TBI). This study compares the incidence of eucapnia between manually and mechanically ventilated patients with severe TBI during helicopter transport.

METHODS

This retrospective chart review included consecutive intubated adults with severe TBI (Glasgow Coma Scale score < 9) transported by helicopter from the scene of injury to a level 1 trauma center between 2009 and 2015. The primary outcome was the first venous partial pressure of carbon dioxide obtained in the emergency department. Hypocapnia, eucapnia, and hypercapnia were defined based on the normal range for the testing instrument. The Fisher exact test was used to compare groups.

RESULTS

Of 1,070 trauma patients intubated and transported, 93 met the inclusion criteria with full data. The mean age was 43 years, 81 of 93 were white, and 70 of 93 were men. The mean Injury Severity Score was 29, and 26 of 93 were mechanically ventilated. Hypocapnia occurred in 4 of 93 and hypercapnia in 56 of 93. There was no difference in the rate of eucapnia in manually ventilated compared with mechanically ventilated patients (36% vs. 35%, P = 1.00).

CONCLUSION

Eucapnia at emergency department arrival occurred in 36% of patients and was unaffected by whether ventilation was manually or mechanically controlled. Few patients were hypocapnic, indicating a low incidence of hyperventilation during helicopter transport.

Tracheal intubation in traumatic brain injury: a multicentre prospective observational study

BACKGROUND

We aimed to study the associations between pre- and in-hospital tracheal intubation and outcomes in traumatic brain injury (TBI), and whether the association varied according to injury severity.

METHODS

Data from the international prospective pan-European cohort study, Collaborative European NeuroTrauma Effectiveness Research for TBI (CENTER-TBI), were used (n=4509). For prehospital intubation, we excluded self-presenters. For in-hospital intubation, patients whose tracheas were intubated on-scene were excluded. The association between intubation and outcome was analysed with ordinal regression with adjustment for the International Mission for Prognosis and Analysis of Clinical Trials in TBI variables and extracranial injury. We assessed whether the effect of intubation varied by injury severity by testing the added value of an interaction term with likelihood ratio tests.

RESULTS

In the prehospital analysis, 890/3736 (24%) patients had their tracheas intubated at scene. In the in-hospital analysis, 460/2930 (16%) patients had their tracheas intubated in the emergency department. There was no adjusted overall effect on functional outcome of prehospital intubation (odds ratio=1.01; 95% confidence interval, 0.79-1.28; P=0.96), and the adjusted overall effect of in-hospital intubation was not significant (odds ratio=0.86; 95% confidence interval, 0.65-1.13; P=0.28). However, prehospital intubation was associated with better functional outcome in patients with higher thorax and abdominal Abbreviated Injury Scale scores (P=0.009 and P=0.02, respectively), whereas in-hospital intubation was associated with better outcome in patients with lower Glasgow Coma Scale scores (P=0.01): in-hospital intubation was associated with better functional outcome in patients with Glasgow Coma Scale scores of 10 or lower.

CONCLUSION

The benefits and harms of tracheal intubation should be carefully evaluated in patients with TBI to optimise benefit. This study suggests that extracranial injury should influence the decision in the prehospital setting, and level of consciousness in the in-hospital setting.

CLINICAL TRIAL REGISTRATION

NCT02210221.

Hyperventilation in neurological patients: from physiology to outcome evidence

Hyperventilation is commonly used in neurological patients to decrease elevated intracranial pressure (ICP) or relax a tense brain. However, the potentially deleterious effects of hyperventilation may limit its clinical application. The aim of this review is to summarize the physiological and outcome evidence related to hyperventilation in neurological patients.

Postponing intubation in spontaneously breathing major trauma patients upon emergency room admission does not impair outcome

Background

Pre-hospital emergency anaesthesia and tracheal intubation are life-saving interventions in trauma patients. However, there is evidence suggesting that the risks associated with both procedures outweigh the benefits. Thus, we assessed whether induction of anaesthesia and tracheal intubation of trauma patients can be postponed in spontaneously breathing patients until emergency room (ER) admission without increasing mortality.

Methods

Retrospective analysis of major trauma patients either intubated on-scene by an emergency medical service (EMS) physician (pre-hospital intubation, PHI) or within the first 10 min after admission at a level 1 trauma centre (emergency room intubation, ERI). Data was extracted from the German Trauma Registry, hospital patient data management and electronic clinical information system.

Results

From a total of 946 major trauma cases documented between 2010 and 2017, 294 patients matched the study inclusion criteria. Mortality rate of PHI (N = 258) vs. ERI (N = 36) patients was 26.4% vs. 16.7% (p = 0.3). After exclusion of patients with severe traumatic brain injury and/or pre-hospital cardiac arrest, mortality rate of PHI (N = 100) vs. ERI patients (N = 29) was 6% vs. 17.2%, (p = 0.07). Median on-scene time was significantly (p < 0.01) longer in PHI (30 min; IQR: 21–40) vs. ERI patients (20 min; IQR: 15–28).

Conclusions

There was no statistical difference in mortality rates of spontaneously breathing trauma patients intubated on-scene when compared with patients intubated immediately after hospital admission. Due to the retrospective study design and small case number, further studies evaluating the impact of airway management timing in sufficiently breathing trauma patients are warranted.

Airway management in pre-hospital critical care: a review of the evidence for a 'top five' research priority

The conduct and benefit of pre-hospital advanced airway management and pre-hospital emergency anaesthesia have been widely debated for many years. In 2011, prehospital advanced airway management was identified as a ‘top five’ in physician-provided pre-hospital critical care. This article summarises the evidence for and against this intervention since 2011 and attempts to address some of the more controversial areas of this topic.

Association of Hypercapnia and Hypercapnic Acidosis With Clinical Outcomes in Mechanically Ventilated Patients With Cerebral Injury

IMPORTANCE

Clinical studies investigating the effects of hypercapnia and hypercapnic acidosis in acute cerebral injury are limited. The studies performed so far have mainly focused on the outcomes in relation to the changes in partial pressure of carbon dioxide and pH in isolation and have not evaluated the effects of partial pressure of carbon dioxide and pH in conjunction.

OBJECTIVE

To review the association of compensated hypercapnia and hypercapnic acidosis during the first 24 hours of intensive care unit admission on hospital mortality in adult mechanically ventilated patients with cerebral injury.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, binational retrospective review of patients with cerebral injury (traumatic brain injury, cardiac arrest, and stroke) admitted to 167 intensive care units in Australia and New Zealand between January 2000 and December 2015. Patients were classified into 3 groups based on combination of arterial pH and arterial carbon dioxide (normocapnia and normal pH, compensated hypercapnia, and hypercapnic acidosis) during the first 24 hours of intensive care unit stay.

MAIN OUTCOMES AND MEASURES

Hospital mortality.

RESULTS

A total of 30 742 patients (mean age, 55 years; 21 827 men [71%]) were included. Unadjusted hospital mortality rates were highest in patients with hypercapnic acidosis. Multivariable logistic regression analysis and Cox proportional hazards analysis in 3 diagnostic categories showed increased odds of hospital mortality (cardiac arrest odds ratio [OR], 1.51; 95% CI, 1.34-1.71; stroke OR, 1.43; 95% CI, 1.27-1.6; and traumatic brain injury OR, 1.22; 95% CI, 1.06-1.42; P <.001) and hazard ratios (HR) (cardiac arrest HR, 1.23; 95% CI, 1.14-1.34; stroke HR, 1.3; 95% CI, 1.21-1.4; traumatic brain injury HR, 1.13; 95% CI, 1-1.27), in patients with hypercapnic acidosis compared with normocapnia and normal pH. There was no difference in mortality between patients who had compensated hypercapnia compared with patients who had normocapnia and normal pH. In patients with hypercapnic acidosis, the adjusted OR of hospital mortality increased with increasing partial pressure of carbon dioxide, while no such increase was noted in patients with compensated hypercapnia.

CONCLUSIONS AND RELEVANCE

Hypercapnic acidosis was associated with increased risk of hospital mortality in patients with cerebral injury. Hypercapnia, when compensated to normal pH during the first 24 hours of intensive care unit admission, may not be harmful in mechanically ventilated patients with cerebral injury.

Efficacy of pre-hospital rapid sequence intubation in paediatric traumatic brain injury: A 9-year observational study

INTRODUCTION

Prehospital airway management of the paediatric patient with traumatic brain injury (TBI) is controversial. Endotracheal intubation of children in the field requires specific skills and has potential benefits but also carries potentially serious complications. We aimed to compare mortality and functional outcomes after six months between children with TBI who either underwent prehospital rapid sequence intubation (RSI) by trained Intensive Care paramedics (ICP) or received no intubation.

METHODS

We conducted a retrospective study of patients aged ≤14 years with suspected TBI in Victoria, Australia. Patients were either transported via helicopter and received RSI by an ICP (2005-2013) or via road ambulance and received no intubation (2006-2013). Prehospital data was linked to hospital and 6-month follow-up data to assess mortality and functional outcome.

RESULTS

A total of 106 patients were included in the study of which 87 received RSI by paramedics and 19 did not receive intubation. Overall, the intubation success rate was 99% (86/87), with a first-pass success rate of 93% (81/87). In total, 67% of patients (n = 41) receiving RSI had a favourable functional outcome, compared with 54% of non-intubated patients (n = 7) (p = 0.36). In the 75 children with major trauma, prehospital RSI was associated with a significant decrease in length of hospital stay (523 h vs. 1939 h, p = 0.03). In the 53 children in this subgroup with available six months data the difference in favourable functional outcome increased to 66% (n = 31)vs. 17% (n = 1) (p = 0.06).

DISCUSSION

Prehospital RSI in paediatric patients with TBI can safely be performed by highly trained paramedics. Overall, we observed more favourable long-term outcomes in patients who received prehospital intubation than those who did not, however our study is not powered to detect a significant difference. Intubation prior to transport might be beneficial for major trauma patients.

Intraoperative Secondary Insults During Orthopedic Surgery in Traumatic Brain Injury

BACKGROUND

Secondary insults worsen outcomes after traumatic brain injury (TBI). However, data on intraoperative secondary insults are sparse. The primary aim of this study was to examine the prevalence of intraoperative secondary insults during orthopedic surgery after moderate-severe TBI. We also examined the impact of intraoperative secondary insults on postoperative head computed tomographic scan, intracranial pressure (ICP), and escalation of care within 24 hours of surgery.

MATERIALS AND METHODS

We reviewed medical records of TBI patients 18 years and above with Glasgow Coma Scale score <13 who underwent single orthopedic surgery within 2 weeks of TBI. Secondary insults examined were: systemic hypotension (systolic blood pressure<90 mm Hg), intracranial hypertension (ICP>20 mm Hg), cerebral hypotension (cerebral perfusion pressure<50 mm Hg), hypercarbia (end-tidal CO2>40 mm Hg), hypocarbia (end-tidal CO2<30 mm Hg in absence of intracranial hypertension), hyperglycemia (glucose>200 mg/dL), hypoglycemia (glucose<60 mg/dL), and hyperthermia (temperature >38°C).

RESULTS

A total of 78 patients (41 [18 to 81] y, 68% male) met the inclusion criteria. The most common intraoperative secondary insults were systemic hypotension (60%), intracranial hypertension and cerebral hypotension (50% and 45%, respectively, in patients with ICP monitoring), hypercarbia (32%), and hypocarbia (29%). Intraoperative secondary insults were associated with worsening of head computed tomography, postoperative decrease of Glasgow Coma Scale score by ≥2, and escalation of care. After Bonferroni correction, association between cerebral hypotension and postoperative escalation of care remained significant (P<0.001).

CONCLUSIONS

Intraoperative secondary insults were common during orthopedic surgery in patients with TBI and were associated with postoperative escalation of care. Strategies to minimize intraoperative secondary insults are needed.

Hyperoxia and Hypocapnia During Pediatric Extracorporeal Membrane Oxygenation: Associations With Complications, Mortality, and Functional Status Among Survivors

OBJECTIVES

To determine the frequency of hyperoxia and hypocapnia during pediatric extracorporeal membrane oxygenation and their relationships to complications, mortality, and functional status among survivors.

DESIGN

Secondary analysis of data collected prospectively by the Collaborative Pediatric Critical Care Research Network.

SETTING

Eight Collaborative Pediatric Critical Care Research Network-affiliated hospitals.

PATIENTS

Age less than 19 years and treated with extracorporeal membrane oxygenation.

INTERVENTIONS

Hyperoxia was defined as highest PaO2 greater than 200 Torr (27 kPa) and hypocapnia as lowest PaCO2 less than 30 Torr (3.9 kPa) during the first 48 hours of extracorporeal membrane oxygenation. Functional status at hospital discharge was evaluated among survivors using the Functional Status Scale.

MEASUREMENTS AND MAIN RESULTS

Of 484 patients, 420 (86.7%) had venoarterial extracorporeal membrane oxygenation and 64 (13.2%) venovenous; 69 (14.2%) had extracorporeal membrane oxygenation initiated during cardiopulmonary resuscitation. Hyperoxia occurred in 331 (68.4%) and hypocapnia in 98 (20.2%). Hyperoxic patients had higher mortality than patients without hyperoxia (167 [50.5%] vs 48 [31.4%]; p < 0.001), but no difference in functional status among survivors. Hypocapnic patients were more likely to have a neurologic event (49 [50.0%] vs 143 (37.0%]; p = 0.021) or hepatic dysfunction (49 [50.0%] vs 121 [31.3%]; p < 0.001) than patients without hypocapnia, but no difference in mortality or functional status among survivors. On multivariable analysis, factors independently associated with increased mortality included highest PaO2 and highest blood lactate concentration in the first 48 hours of extracorporeal membrane oxygenation, congenital diaphragmatic hernia, and being a preterm neonate. Factors independently associated with lower mortality included meconium aspiration syndrome.

CONCLUSIONS

Hyperoxia is common during pediatric extracorporeal membrane oxygenation and associated with mortality. Hypocapnia appears to occur less often and although associated with complications, an association with mortality was not observed.

Prehospital intubation for isolated severe blunt traumatic brain injury: worse outcomes and higher mortality

PURPOSE

Prehospital endotracheal intubation (ETI) for traumatic brain injury (TBI) is a controversial issue. The aim of this study was to investigate the effect of prehospital ETI in patients with TBI.

METHODS

Cohort-matched study using the US National Trauma Data Bank (NTDB) 2008-2012. Patients with isolated severe blunt TBI (AIS head ≥3, AIS chest/abdomen <3) and a field GCS ≤8 were extracted from NTDB. A 1:1 matching of patients with and without prehospital ETI was performed. Matching criteria were sex, age, exact field GCS, exact AIS head, field hypotension, field cardiac arrest, and the brain injury type (according PREDOT-code). The matched cohorts were compared with univariable and multivariable regression analysis.

RESULTS

A total of 27,714 patients were included. Matching resulted in 8139 cases with and 8139 cases without prehospital ETI. Prehospital ETI was associated with significantly longer scene (median 9 vs. 8 min, p < 0.001) and transport times (median 26 vs. 19 min, p < 0.001), lower Emergency Department (ED) GCS scores (in patients without sedation; mean 3.7 vs. 3.9, p = 0.026), more ventilator days (mean 7.3 vs. 6.9, p = 0.006), longer ICU (median 6.0 vs. 5.0 days, p < 0.001) and total hospital length of stay (median 10.0 vs. 9.0 days, p < 0.001), and higher in-hospital mortality (31.4 vs. 27.5 %, p < 0.001). In regression analysis prehospital ETI was independently associated with lower ED GCS scores (RC -4.213, CI -4.562/-3.864, p < 0.001) and higher in-hospital mortality (OR 1.399, CI 1.205/1.624, p < 0.001).

CONCLUSION

In this large cohort-matched analysis, prehospital ETI in patients with isolated severe blunt TBI was independently associated with lower ED GCS scores and higher mortality.

Traumatic brain injury: It is all about definition

BACKGROUND

TBI may be defined by different methods. Some may be most useful for immediate clinical purposes, however less optimal for epidemiologic research. Other methods, such as the Abbreviated Injury Score (AIS), may prove more beneficial for this task, if the cut-off-points for their categories are defined correctly.

OBJECTIVE

To reveal the optimal cut-off-points for AIS in definition of severity of TBI in order to ensure uniformity between future studies of TBI.

RESULTS

Mortality of patients with TBI AIS 3, 4 was 1.9% and 2.9% respectively, comparing with 31.1% among TBI AIS 5+. Predictive discrimination ability of the model with cut-off-points of 5+ for TBI AIS (in comparison with other cut-off-points) was better. Patients with missing Glasgow Coma Scale (GCS) in the ED had an in-hospital mortality rate of 11.5%. In this group, 25% had critical TBI according to AIS. Normal GCS didn't indicate an absence of head injury, as, among patients with GCS 15 in the ED, 26% had serious/critical TBI injury. Moreover, 7% of patients with multiple injury and GCS 3-8 had another reason than head injury for unconsciousness.

CONCLUSIONS

This study recommends the adoption of an AIS cut-off ≥ 5 as a valid definition of severe TBI in epidemiological studies, while AIS 3-4 may be defined as 'moderate' TBI and AIS 1-2 as 'mild'.

Are prehospital airway management resources compatible with difficult airway algorithms? A nationwide cross-sectional study of helicopter emergency medical services in Japan

Purpose

Immediate access to the equipment required for difficult airway management (DAM) is vital. However, in Japan, data are scarce regarding the availability of DAM resources in prehospital settings. The purpose of this study was to determine whether Japanese helicopter emergency medical services (HEMS) are adequately equipped to comply with the DAM algorithms of Japanese and American professional anesthesiology societies.

Methods

This nationwide cross-sectional study was conducted in May 2015. Base hospitals of HEMS were mailed a questionnaire about their airway management equipment and back-up personnel. Outcome measures were (1) call for help, (2) supraglottic airway device (SGA) insertion, (3) verification of tube placement using capnometry, and (4) the establishment of surgical airways, all of which have been endorsed in various airway management guidelines. The criteria defining feasibility were the availability of (1) more than one physician, (2) SGA, (3) capnometry, and (4) a surgical airway device in the prehospital setting.

Results

Of the 45 HEMS base hospitals questioned, 42 (93.3 %) returned completed questionnaires. A surgical airway was practicable by all HEMS. However, in the prehospital setting, back-up assistance was available in 14.3 %, SGA in 16.7 %, and capnometry in 66.7 %. No HEMS was capable of all four steps.

Conclusion

In Japan, compliance with standard airway management algorithms in prehospital settings remains difficult because of the limited availability of alternative ventilation equipment and back-up personnel. Prehospital health care providers need to consider the risks and benefits of performing endotracheal intubation in environments not conducive to the success of this procedure.

Electronic supplementary material

The online version of this article (doi:10.1007/s00540-015-2124-7) contains supplementary material, which is available to authorized users.

Airway management of patients with traumatic brain injury/C-spine injury

Traumatic brain injury (TBI) is usually combined with cervical spine (C-spine) injury. The possibility of C-spine injury is always considered when performing endotracheal intubation in these patients. Rapid sequence intubation is recommended with adequate sedative or analgesics and a muscle relaxant to prevent an increase in intracranial pressure during intubation in TBI patients. Normocapnia and mild hyperoxemia should be maintained to prevent secondary brain injury. The manual-in-line-stabilization (MILS) technique effectively lessens C-spine movement during intubation. However, the MILS technique can reduce mouth opening and lead to a poor laryngoscopic view. The newly introduced video laryngoscope can manage these problems. The AirWay Scope® (AWS) and AirTraq laryngoscope decreased the extension movement of C-spines at the occiput-C1 and C2-C4 levels, improving intubation conditions and shortening the time to complete tracheal intubation compared with a direct laryngoscope. The Glidescope® also decreased cervical movement in the C2-C5 levels during intubation and improved vocal cord visualization, but a longer duration was required to complete intubation compared with other devices. A lightwand also reduced cervical motion across all segments. A fiberoptic bronchoscope-guided nasal intubation is the best method to reduce cervical movement, but a skilled operator is required. In conclusion, a video laryngoscope assists airway management in TBI patients with C-spine injury.

Comparison of tracheal intubation and alternative airway techniques performed in the prehospital setting by paramedics: a systematic review

This systematic review included controlled clinical trials comparing tracheal intubation (TI) with alternative airway techniques (AAT) (bag-mask ventilation and use of extraglottic devices) performed by paramedics in the prehospital setting. A priori outcomes to be assessed were survival, neurologic outcome, airway management success rates and complications. We identified trials using EMBASE, MEDLINE, CINAHL, The Cochrane Library, Web of Science, author contacts and hand searching. We included 5 trials enrolling a total of 1559 patients. No individual study showed any statistical difference in outcomes between the TI and AAT groups. Because of study heterogeneity, we did not pool the data. This is the most comprehensive review to date on paramedic trials. Owing to the heterogeneity of prehospital systems, administrators of each system must individually consider their airway management protocols.

Effects of PaCO2 derangements on clinical outcomes after cerebral injury: A systematic review

OBJECTIVE

Partial pressure of arterial carbon dioxide (PaCO2) is a major regulator of cerebral blood flow (CBF). Derangements in PaCO2 have been thought to worsen clinical outcomes after many forms of cerebral injury by altering CBF. Our aim was to systematically analyze the biomedical literature to determine the effects of PaCO2 derangements on clinical outcomes after cerebral injury.

METHODS

We performed a search of Cochrane Library, PUBMED, CINHAL, conference proceedings, and other sources using a comprehensive strategy. Study inclusion criteria were (1) human subjects; (2) cerebral injury; (3) mechanical ventilation post-injury; (4) measurement of PaCO2; and (5) comparison of a clinical outcome measure (e.g. mortality) between different PaCO2 exposures. We performed a qualitative analysis to collate and summarize effects of PaCO2 derangements according to the recommended methodology from the Cochrane Handbook.

RESULTS

Seventeen studies involving different etiologies of cerebral injury (six traumatic brain injury, six post-cardiac arrest syndrome, two cerebral vascular accident, three neonatal ischemic encephalopathy) met all inclusion and no exclusion criteria. Three randomized control trials were identified and only one was considered a high quality study as per the Cochrane criteria for assessing risk of bias. In 13/17 (76%) studies examining hypocapnia, and 7/10 (70%) studies examining hypercapnia, the exposed group (hypercapnia or hypocapnia) was associated with poor clinical outcome.

CONCLUSION

The majority of studies in this report found exposure to hypocapnia and hypercapnia after cerebral injury to be associated with poor clinical outcome. However, the optimal PaCO2 range associated with good clinical outcome remains unclear.

Evidence-based assessment of severe pediatric traumatic brain injury and emergent neurocritical care

Pediatric traumatic brain injury accounts for approximately 474,000 emergency department visits, 37,000 hospitalizations, and 3,000 deaths in children 14 years and younger annually in the United States. Acute neurocritical care in children has advanced with specialized pediatric trauma centers and emergency medical services. This article reviews pediatric-specific diagnosis, management, and medical decision making related to the neurocritical care of severe traumatic brain injury.

Preliminary report of a mathematical model of ventilation and intrathoracic pressure applied to prehospital patients with severe traumatic brain injury

BACKGROUND

Inadvertent hyperventilation is associated with poor outcomes from traumatic brain injury (TBI). Hypocapnic cerebral vasoconstriction is well described and causes an immediate and profound decrease in cerebral perfusion. The hemodynamic effects of positive-pressure ventilation (PPV) remain incompletely understood but may be equally important, particularly in the hypovolemic patient with TBI.

OBJECTIVE

Preliminary report on the application of a previously described mathematical model of perfusion and ventilation to prehospital data to predict intrathoracic pressure.

METHODS

Ventilation data from 108 TBI patients (76 ground transported, 32 helicopter transported) were used for this analysis. Ventilation rate (VR) and end-tidal carbon dioxide (PetCO2) values were used to estimate tidal volume (VT). The values for VR and estimated VT were then applied to a previously described mathematical model of perfusion and ventilation. This model allows input of various lung parameters to define a pressure-volume relationship, then derives mean intrathoracic pressure (MITP) for various VT and VR values. For this analysis, normal lung parameters were utilized. Separate analyses were performed assuming either fixed or variable PaCO2-PetCO2 differences. Ground and air medical patients were compared with regard to VR, PetCO2, estimated VT, and predicted MITP.

RESULTS

A total of 10,647 measurements were included from the 108 TBI patients, representing about 13 minutes of ventilation per patient. Mean VR values were higher for ground patients versus air patients (21.6 vs. 19.7 breaths/min; p < 0.01). Estimated VT values were similar for ground and air patients (399 mL vs. 392 mL; p = NS) in the fixed model but not the variable (636 vs. 688 mL, respectively; p < 0.01). Mean PetCO2 values were lower for ground versus air patients (30.6 vs. 33.8 mmHg; p < 0.01). Predicted MITP values were higher for ground versus air patients, assuming either fixed (9.0 vs. 8.1 mmHg; p < 0.01) or variable (10.9 vs. 9.7 mmHg; p < 0.01) PaCO2-PetCO2 differences.

CONCLUSIONS

Predicted MITP values increased with ventilation rates. Future studies to externally validate this model are warranted.

Evaluation of the impact of implementing the emergency medical services traumatic brain injury guidelines in Arizona: the Excellence in Prehospital Injury Care (EPIC) study methodology

Traumatic brain injury (TBI) exacts a great toll on society. Fortunately, there is growing evidence that the management of TBI in the early minutes after injury may significantly reduce morbidity and mortality. In response, evidence-based prehospital and in-hospital TBI treatment guidelines have been established by authoritative bodies. However, no large studies have yet evaluated the effectiveness of implementing these guidelines in the prehospital setting. This article describes the background, design, implementation, emergency medical services (EMS) treatment protocols, and statistical analysis of a prospective, controlled (before/after), statewide study designed to evaluate the effect of implementing the EMS TBI guidelines-the Excellence in Prehospital Injury Care (EPIC) study (NIH/NINDS R01NS071049, "EPIC"; and 3R01NS071049-S1, "EPIC4Kids"). The specific aim of the study is to test the hypothesis that statewide implementation of the international adult and pediatric EMS TBI guidelines will significantly reduce mortality and improve nonmortality outcomes in patients with moderate or severe TBI. Furthermore, it will specifically evaluate the effect of guideline implementation on outcomes in the subgroup of patients who are intubated in the field. Over the course of the entire study (~9 years), it is estimated that approximately 25,000 patients will be enrolled.

Prehospital intubation in patients with isolated severe traumatic brain injury: a 4-year observational study

Objectives. To study the effect of prehospital intubation (PHI) on survival of patients with isolated severe traumatic brain injury (ISTBI). Method. Retrospective analyses of all intubated patients with ISTBI between 2008 and 2011 were studied. Comparison was made between those who were intubated in the PHI versus in the trauma resuscitation unit (TRU). Results. Among 1665 TBI patients, 160 met the inclusion criteria (105 underwent PHI, and 55 patients were intubated in TRU). PHI group was younger in age and had lower median scene motor GCS (P = 0.001). Ventilator days and hospital length of stay (P = 0.01 and 0.006, resp.) were higher in TRUI group. Mean ISS, length of stay, initial blood pressure, pneumonia, and ARDS were comparable among the two groups. Mortality rate was higher in the PHI group (54% versus 31%, P = 0.005). On multivariate regression analysis, scene motor GCS (OR 0.55; 95% CI 0.41-0.73) was an independent predictor for mortality. Conclusion. PHI did not offer survival benefit in our group of patients with ISTBI based on the head AIS and the scene motor GCS. However, more studies are warranted to prove this finding and identify patients who may benefit from this intervention.

Standard operating procedure changed pre-hospital critical care anaesthesiologists' behaviour: a quality control study

Introduction

The ability of standard operating procedures to improve pre-hospital critical care by changing pre-hospital physician behaviour is uncertain. We report data from a prospective quality control study of the effect on pre-hospital critical care anaesthesiologists’ behaviour of implementing a standard operating procedure for pre-hospital controlled ventilation.

Materials and methods

Anaesthesiologists from eight pre-hospital critical care teams in the Central Denmark Region prospectively registered pre-hospital advanced airway-management data according to the Utstein-style template. We collected pre-intervention data from February 1^st 2011 to January 31^st 2012, implemented the standard operating procedure on February 1^st 2012 and collected post intervention data from February 1^st 2012 until October 31^st 2012. We included transported patients of all ages in need of controlled ventilation treated with pre-hospital endotracheal intubation or the insertion of a supraglottic airways device. The objective was to evaluate whether the development and implementation of a standard operating procedure for controlled ventilation during transport could change pre-hospital critical care anaesthesiologists’ behaviour and thereby increase the use of automated ventilators in these patients.

Results

The implementation of a standard operating procedure increased the overall prevalence of automated ventilator use in transported patients in need of controlled ventilation from 0.40 (0.34-0.47) to 0.74 (0.69-0.80) with a prevalence ratio of 1.85 (1.57-2.19) (p = 0.00). The prevalence of automated ventilator use in transported traumatic brain injury patients in need of controlled ventilation increased from 0.44 (0.26-0.62) to 0.85 (0.62-0.97) with a prevalence ratio of 1.94 (1.26-3.0) (p = 0.0039). The prevalence of automated ventilator use in patients transported after return of spontaneous circulation following pre-hospital cardiac arrest increased from 0.39 (0.26-0.48) to 0.69 (0.58-0.78) with a prevalence ratio of 1.79 (1.36-2.35) (p = 0.00).

Conclusion

We have shown that the implementation of a standard operating procedure for pre-hospital controlled ventilation can significantly change pre-hospital critical care anaesthesiologists’ behaviour.

Perioperative management of traumatic brain injury

Traumatic brain injury (TBI) is a major public health problem and the leading cause of death and disability worldwide. Despite the modern diagnosis and treatment, the prognosis for patients with TBI remains poor. While severity of primary injury is the major factor determining the outcomes, the secondary injury caused by physiological insults such as hypotension, hypoxemia, hypercarbia, hypocarbia, hyperglycemia and hypoglycemia, etc. that develop over time after the onset of the initial injury, causes further damage to brain tissue, worsening the outcome in TBI. Perioperative period may be particularly important in the course of TBI management. While surgery and anesthesia may predispose the patients to new onset secondary injuries which may contribute adversely to outcomes, the perioperative period is also an opportunity to detect and correct the undiagnosed pre-existing secondary insults, to prevent against new secondary insults and is a potential window to initiate interventions that may improve outcome of TBI. For this review, extensive Pubmed and Medline search on various aspects of perioperative management of TBI was performed, followed by review of research focusing on intraoperative and perioperative period. While the research focusing specifically on the intraoperative and immediate perioperative TBI management is limited, clinical management continues to be based largely on physiological optimization and recommendations of Brain Trauma Foundation guidelines. This review is focused on the perioperative management of TBI, with particular emphasis on recent developments.

Pro/con debate: should PaCO2 be tightly controlled in all patients with acute brain injuries?

You are the attending intensivist in a neurointensive care unit caring for a woman five days post-rupture of a cerebral aneurysm (World Federation of Neurological Surgeons Grade 4 and Fisher Grade 3). She is intubated for airway protection and mild hypoxemia related to an aspiration event at the time of aneurysm rupture, but is breathing spontaneously on the ventilator. Your patient is spontaneously hyperventilating with high tidal volumes despite minimal support and has developed significant hypocapnia. She has not yet developed the acute respiratory distress syndrome. You debate whether to tightly control her partial pressure of arterial carbon dioxide, weighing the known risks of acute hypocapnia in other forms of brain injury against the potential loss of clinical neuromonitoring associated with deep sedation and neuromuscular blockade in this patient who is at high risk of delayed ischemia from vasospasm. You are also aware of the potential implications of tidal volume control if this patient were to develop the acute respiratory distress syndrome and the effect of permissive hypercapnia on her intracranial pressure. In this paper we provide a detailed and balanced examination of the issues pertaining to this clinical scenario, including suggestions for clinical management of ventilation, sedation and neuromonitoring. Until more definitive clinical trial evidence is available to guide practice, clinicians are forced to carefully weigh the potential benefits of tight carbon dioxide control against the potential risks in each individual patient based on the clinical issues at hand.

Prehospital non-drug assisted intubation for adult trauma patients with a Glasgow Coma Score less than 9

OBJECTIVES

Prehospital airway management for adult trauma patients remains controversial. We sought to review the frequency that paramedic non-drug assisted intubation or attempted intubation is performed for trauma patients in Ontario, Canada, and determine its association with mortality.

METHODS

We conducted a retrospective cohort study using the Ontario Trauma Registry's Comprehensive Data Set for 2002-2009. Eligible patients were greater than 16 years of age, had an initial Glasgow Coma Score of less than 9 and were cared for by ground-based non-critical care paramedics. The primary outcome was mortality. Outcomes were compared between patients undergoing prehospital intubation versus basic airway management. Logistic regression analyses were used to quantify the association between prehospital intubation and mortality.

RESULTS

Of the 2229 patients included in the analysis, 671 (30.1%) underwent prehospital intubation. Annual rates of prehospital intubation declined from 33.7% to 14.0% (ptrend<0.0001) over the study period. Unadjusted death rates were 66.0% versus 34.8% in the intubation and basic airway groups, respectively (p<0.0001). Intubation in the prehospital setting was associated with a heightened risk of mortality (adjusted OR 2.8, 95% CI 1.1 to 7.6).

CONCLUSIONS

Prehospital non-drug assisted intubation for trauma is being performed less frequently in Ontario, Canada. Within our study population, paramedic non-drug assisted intubation or attempted intubation was associated with a heightened risk of mortality.

[Emergency anesthesia, airway management and ventilation in major trauma. Background and key messages of the interdisciplinary S3 guidelines for major trauma patients]

Patients with multiple trauma presenting with apnea or a gasping breathing pattern (respiratory rate  < 6/min) require prehospital endotracheal intubation (ETI) and ventilation. Additional indications are hypoxia (S(p)O(2)  < 90% despite oxygen insufflation and after exclusion of tension pneumothorax), severe traumatic brain injury [Glasgow Coma Scale (GCS)  < 9], trauma-associated hemodynamic instability [systolic blood pressure (SBP)  < 90 mmHg] and severe chest trauma with respiratory insufficiency (respiratory rate  > 29/min). The induction of anesthesia after preoxygenation is conducted as rapid sequence induction (analgesic, hypnotic drug, neuromuscular blocking agent). With the availability of ketamine as a viable alternative, the use of etomidate is not encouraged due to its side effects on adrenal function. An electrocardiogram (ECG), blood pressure measurement and pulse oximetry are needed to monitor the emergency anesthesia and the secured airway. Capnography is absolutely mandatory to confirm correct placement of the endotracheal tube and to monitor tube dislocations as well as ventilation in the prehospital and hospital setting. Because airway management is often complicated in trauma patients, alternative devices need to be available preclinical and a fiber-optic endoscope should be available within the hospital. Use of these alternative measures for airway management and ventilation should be considered at the latest after a maximum of three unsuccessful endotracheal intubation attempts. Emergency medical service (EMS) physicians should to be trained in emergency anesthesia, ETI and alternative methods of airway management on a regular basis. Within hospitals ETI, emergency anesthesia and ventilation are to be conducted by trained and experienced anesthesiologists. When a difficult airway or induction of anesthesia is expected, endotracheal intubation should be supervised or conducted by an anesthesiologist. Normoventilation should be the goal of mechanical ventilation. After arrival in the resuscitation room the ventilation will be controlled and guided with the help of arterial blood gas analyses. After temporary removal of a cervical collar, the cervical spine needs to be immobilized by means of manual in-line stabilization when securing the airway.

Perioperative management of adult traumatic brain injury

This article presents an overview of the management of traumatic brain injury (TBI) as relevant to the practicing anesthesiologist. Key concepts surrounding the pathophysiology and anesthetic principles are used to describe potential ways to reduce secondary insults and improve outcomes after TBI.

[Emergency anesthesia, airway management and ventilation in major trauma. Background and key messages of the interdisciplinary S3 guidelines for major trauma patients]

Patients with multiple trauma presenting with apnea or a gasping breathing pattern (respiratory rate <6/min) require prehospital endotracheal intubation (ETI) and ventilation. Additional indications are hypoxia (S(p)O(2)<90% despite oxygen insufflation and after exclusion of tension pneumothorax), severe traumatic brain injury [Glasgow Coma Scale (GCS)<9], trauma-associated hemodynamic instability [systolic blood pressure (SBP)<90 mmHg] and severe chest trauma with respiratory insufficiency (respiratory rate >29/min). The induction of anesthesia after preoxygenation is conducted as rapid sequence induction (analgesic, hypnotic drug, neuromuscular blocking agent). With the availability of ketamine as a viable alternative, the use of etomidate is not encouraged due to its side effects on adrenal function. An electrocardiogram (ECG), blood pressure measurement and pulse oximetry are needed to monitor the emergency anesthesia and the secured airway. Capnography is absolutely mandatory to confirm correct placement of the endotracheal tube and to monitor tube dislocations as well as ventilation and oxygenation in the prehospital and hospital setting. Because airway management is often complicated in trauma patients, alternative devices and a fiber-optic endoscope need to be available within the hospital. Use of these alternative measures for airway management and ventilation should be considered at the latest after a maximum of three unsuccessful intubation attempts. Emergency medical service (EMS) physicians should to be trained in emergency anesthesia, ETI and alternative methods of airway management on a regular basis. Within hospitals ETI, emergency anesthesia and ventilation are to be conducted by trained and experienced anesthesiologists. When a difficult airway or induction of anesthesia is expected, endotracheal intubation should be supervised or conducted by an anesthesiologist. Normoventilation should be the goal of mechanical ventilation. After arrival in the resuscitation room the ventilation will be controlled and guided with the help of arterial blood gas analyses. After temporary removal of a cervical collar, the cervical spine needs to be immobilized by means of manual in-line stabilization when securing the airway.