Hemodynamic collapse in multi-trauma patients with severe traumatic brain injury (TBI) poses both a diagnostic and therapeutic challenge for prehospital clinicians. Brain injury associated shock (BIAS), likely resulting from catecholamine storm, can cause both ventricular dysfunction and vasoplegia but may present clinically in a manner similar to hemorrhagic shock. Despite different treatment strategies, few studies exist describing this phenomenon in the early post-injury phase. This retrospective observational study aimed to describe the frequency of shock in isolated TBI in prehospital trauma patients and to compare their clinical characteristics to those patients with hemorrhagic shock and TBI without shock.

All prehospital trauma patients intubated by prehospital medical teams from New South Wales Ambulance Aeromedical Operations (NSWA-AO) with an initial Glasgow Coma Scale (GCS) of 12 or less were investigated. Shock was defined as a pre-intubation systolic blood pressure under 90mmHg and the administration of blood products or vasopressors. Injuries were classified from in-hospital computed tomography (CT) reports. From this, three study groups were derived: BIAS, hemorrhagic shock, and isolated TBI without shock. Descriptive statistics were then produced for clinical and treatment variables.

Of 1,292 intubated patients, 423 had an initial GCS of 12 or less, 24 patients (5.7% of the original cohort) had shock with an isolated TBI, and 39 patients had hemorrhagic shock. The hemodynamic parameters were similar amongst these groups, including values of tachycardia, hypotension, and elevated shock index. Prehospital clinical interventions including blood transfusion and total fluids administered were also similar, suggesting they were indistinguishable to prehospital clinicians.

Hemodynamic compromise in the setting of isolated severe TBI is a rare clinical entity. Current prehospital physiological data available to clinicians do not allow for easy delineation between these patients from those with hemorrhagic shock.

Hypoxia is a frequently reported complication during the intubation procedure in the emergency department (ED) and may cause bad outcomes. Therefore, oxygenation plays an important role in emergency airway management. The efficacy of oxygenation with high-flow nasal cannula (HFNC) in the ED has been studied, though the evidence is limited. The study aim was to compare two methods of preoxygenation in patients undergoing rapid sequence intubation (RSI) in the ED: (1) HFNC and (2) bag-valve mask (BVM) oxygenation.

This is a single-center, prospective, randomized controlled trial (RCT) in adult ED patients requiring RSI. Patients were randomized to receive preoxygenation with either HFNC or BVM. While HFNC therapy was continued during the intubation procedure, BVM oxygenation was interrupted for laryngoscopy. The primary outcome was the lowest peripheral oxygen saturation (SpO2) level during intubation. Secondary outcomes were incidence of desaturation (SpO2<90%) and severe hypoxemia (SpO2<80%) throughout the procedure, intubation time, rate of failed intubation, and 30-day survival rates.

A total of 135 patients were randomized into two groups (HFNC n = 68; BVM n = 67). The median lowest SpO2 value measured during intubation was 96% (88.8%-99.0%) in the HFNC group and 92% (86.0%-97.5%) in the BVM group (P = .161). During the intubation procedure, severe hypoxemia occurred in 13.2% (n = 9) of patients in the HFNC group and 8.9% (n = 6) in the BVM group, while mild hypoxemia was observed in 35.8% (n = 24) of the BVM group and 26.5% (n = 18) of the HFNC group. However, there was no statistically significant difference between the groups in terms of hypoxemia development (P = .429 and P = .241, respectively). No significant difference was reported in the rate of failed intubation between the groups. Thirty-day mortality was observed in 73.1% of the BVM group and 57.4% of the HFNC group, with a borderline statistically significant difference (difference 15.7; 95% CI of the difference: −0.4 to 30.7; P = .054).

The use of HFNC for preoxygenation, when compared to standard care with BVM oxygenation, did not improve the lowest SpO2 levels during intubation. Also, the use of HFNC during intubation did not provide benefits in reducing the incidence of severe hypoxemia. However, the 30-day survival rates were slightly better in the HFNC group compared to the BVM group.

Structured review of video laryngoscopy recordings from physician team prehospital rapid sequence intubations (RSIs) may provide new insights into why prehospital intubations are difficult. The aim was to use laryngoscope video recordings to give information on timings, observed features of the airway, laryngoscopy technique, and laryngoscope performance. This was to both describe prehospital airways and to investigate which factors were associated with increased time taken to intubate.

Sydney Helicopter Emergency Medical Service (HEMS; the aeromedical wing of New South Wales Ambulance, Australia) has a database recording all intubations. The database comprises free-text case detail, airway dataset, scanned case sheet, and uploaded laryngoscope video. The teams of critical care paramedic and doctor use protocol-led intubations with a C-MAC Macintosh size four laryngoscope and intubation adjunct. First-pass intubation rate is approximately 97%. Available video recordings and their database entries were retrospectively analyzed for pre-specified qualitative and quantitative factors.

Prehospital RSI video recordings were available for 385 cases from January 2018 through July 2020. Timings revealed a median of 58 seconds of apnea from laryngoscope entering mouth to ventilations. Median time to intubate (laryngoscope passing lips until tracheal tube inserted) was 35 seconds, interquartile range 28-46 seconds. Suction was required prior to intubation in 29% of prehospital RSIs. Fogging of the camera lens at time of laryngoscopy occurred in 28%. Logistic regression revealed longer time to intubate was associated with airway soiling, Cormack-Lehane Grade 2 or 3, multiple bougie passes, or change of bougie.

Video recordings averaging 35 seconds for first-pass success prehospital RSI with an adjunct give bed-side “definitions of difficulty” of 30 seconds for no glottic view, 45 seconds for no bougie placement, and 60 seconds for no endotracheal tube placement. Awareness of apnea duration can help guide decision making for oxygenation. All emergency intubators need to be cognizant of the need for suctioning. Improving the management of bloodied airways and bougie usage may reduce laryngoscopy duration and be a focus for training. Video screen fogging and missed recordings from some patients may be something manufacturers can address in the future.

Airway management is a controversial topic in modern Emergency Medical Services (EMS) systems. Among many concerns regarding endotracheal intubation (ETI), unrecognized esophageal intubation and observations of unfavorable neurologic outcomes in some studies raise the question of whether alternative airway techniques should be first-line in EMS airway management protocols. Supraglottic airway devices (SADs) are simpler to use, provide reliable oxygenation and ventilation, and may thus be an alternative first-line airway device for paramedics. In 2019, Alachua County Fire Rescue (ACFR; Alachua, Florida USA) introduced a novel protocol for advanced airway management emphasizing first-line use of a second-generation SAD (i-gel) for patients requiring medication-facilitated airway management (referred to as “rapid sequence airway” [RSA] protocol).

This was a one-year quality assurance review of care provided under the RSA protocol looking at compliance and first-pass success rate of first-line SAD use.

Records were obtained from the agency’s electronic medical record (EMR), searching for the use of the RSA protocol, advanced airway devices, or either ketamine or rocuronium. If available, hospital follow-up data regarding patient condition and emergency department (ED) airway exchange were obtained.

During the first year, 33 advanced airway attempts were made under the protocol by 23 paramedics. Overall, compliance with the airway device sequence as specified in the protocol was 72.7%. When ETI was non-compliantly used as first-line airway device, the first-pass success rate was 44.4% compared to 87.5% with adherence to first-line SAD use. All prehospital SADs were exchanged in the ED in a delayed fashion and almost exclusively per physician preference alone. In no case was the SAD exchanged for suspected dislodgement evidenced by lack of capnography.

First-line use of a SAD was associated with a high first-pass attempt success rate in a real-life cohort of prehospital advanced airway encounters. No SAD required emergent exchange upon hospital arrival.

Use of ketamine in the prehospital setting may be advantageous due to its potent analgesic and sedative properties and favorable risk profile. Use in the military setting has demonstrated both efficacy and safety for pain relief. The purpose of this study was to assess ketamine training, use, and perceptions in the civilian setting among nationally certified paramedics (NRPs) in the United States.

A cross-sectional survey of NRPs was performed. The electronic questionnaire assessed paramedic training, authorization, use, and perceptions of ketamine. Included in the analysis were completed surveys of paramedics who held one or more state paramedic credentials, indicated “patient care provider” as their primary role, and worked in non-military settings. Descriptive statistics were calculated.

A total of 14,739 responses were obtained (response rate=23%), of which 10,737 (73%) met inclusion criteria and constituted the study cohort. Over one-half (53%) of paramedics reported learning about ketamine during their initial paramedic training. Meanwhile, 42% reported seeking ketamine-related education on their own. Of all respondents, only 33% (3,421/10,737) were authorized by protocol to use ketamine. Most commonly authorized uses included pain management (55%), rapid sequence intubation (RSI; 72%), and chemical restraint/sedation (72%). One-third of authorized providers (1,107/3,350) had never administered ketamine, with another 32% (1,070/3,350) having administered ketamine less than five times in their career. Ketamine was perceived to be safe and effective as the vast majority reported that they were comfortable with the use of ketamine (94%) and would, in similar situations (95%), use it again.

This was the first large, national survey to assess ketamine training, use, and perceptions among paramedics in the civilian prehospital setting. While training related to ketamine use was commonly reported among paramedics, few were authorized to administer the drug by their agency’s protocols. Of those authorized to use ketamine, most paramedics had limited experience administering the drug. Future research is needed to determine why the prevalence of ketamine use is low and to assess the safety and efficacy of ketamine use in the prehospital setting.

BucklandDM, CroweRP, CashRE, GondekS, MalusoP, SirajuddinS, SmithER, DangerfieldP, ShapiroG, WankaC, PanchalAR, SaraniB. Ketamine in the Prehospital Environment: A National Survey of Paramedics in the United States. Prehosp Disaster Med. 2018;33(1):23–28.

Optimal emergent management of traumatic hemorrhagic shock patients requires a better understanding of treatment provided in the prehospital/Emergency Medical Services (EMS) and emergency department (ED) settings.

Described in this research are the initial clinical status, airway management, fluid and blood infusions, and time course of severely-injured hemorrhagic shock patients in the EMS and ED settings from the diaspirin cross-linked hemoglobin (DCLHb) clinical trial.

Data were analyzed from 17 US trauma centers gathered during a randomized, controlled, single-blinded efficacy trial of a hemoglobin solution (DCLHb) as add-on therapy versus standard therapy.

Among the 98 randomized patients, the mean EMS Glasgow Coma Scale (GCS) was 10.6 (SD = 5.0), the mean EMS revised trauma score (RTS) was 6.3 (SD = 1.9), and the mean injury severity score (ISS) was 31 (SD = 17). Upon arrival to the ED, the GCS was 20% lower (7.8 (SD = 5.3) vs 9.7 (SD = 6.3)) and the RTS was 12% lower (5.3 (SD = 2.0) vs 6.0 (SD = 2.1)) than EMS values in blunt trauma patients (P < .001). By ED disposition, 80% of patients (78/98) were intubated. Rapid sequence intubation (RSI) was utilized in 77% (60/78), most often utilizing succinylcholine (65%) and midazolam (50%). The mean crystalloid volume infused was 4.2 L (SD = 3.4 L), 80% of which was infused within the ED. Emergency department blood transfusion occurred in 62% of patients, with an average transfused volume of 1.2 L (SD = 2.0 L). Blunt trauma patients received 2.1 times more total fluids (7.4 L vs 3.5 L, < .001) and 2.4 times more blood (2.4 L vs 1.0 L, P < .001). The mean time of patients taken from injury site to operating room (OR) was 113 minutes (SD = 87 minutes). Twenty-one (30%) of the 70 patients taken to the OR from the ED were sent within 60 minutes of the estimated injury time. Penetrating trauma patients were taken to the OR 52% sooner than blunt trauma patients (72 minutes vs 149 minutes, P < .001).

Both GCS and RTS decreased prior to ED arrival in blunt trauma patients. Intubation was performed using RSI, and crystalloid infusion of three times the estimated blood loss volume (L) and blood transfusion of the estimated blood loss volume (L) were provided in the EMS and ED settings. Surgical intervention for these trauma patients most often occurred more than one hour from the time of injury. Penetrating trauma patients received surgical intervention more rapidly than those with a blunt trauma mechanism.

SloanEP, KoenigsbergM, WeirWB, ClarkJM, O'ConnorR, OlingerM, CydulkaR. Emergency Resuscitation of Patients Enrolled in the US Diaspirin Cross-linked Hemoglobin (DCLHb) Clinical Efficacy Trial. Prehosp Disaster Med. 2015;30(1):1-8.

Hemodynamic instability following emergent endotracheal intubation (EETI) is a potentially life-threatening adverse event. The objectives of this systematic literature review were to document the incidence of postintubation hemodynamic instability (PIHI), to determine the definitions for PIHI used in the available literature, and to examine factors associated with PIHI in adult patients who require EETI.

Articles published in Medline (1966–August 2012).

This systematic review included adult, inhospital studies of EETIs. Studies with nonemergent or pediatric patient populations were excluded.

Two authors independently performed data abstraction. Disagreements were resolved by a third party. The methodological quality of included studies was assessed with the Newcastle-Ottawa Quality Assessment Scale for Cohort Studies.

We estimated the pooled prevalence of PIHI across studies using a random effects meta-analysis. Subgroups analyzed included study design, intubation setting, geographic location of the study, physician experience, medications used for sedation, neuromuscular blockade, and definition of PIHI. Eighteen studies were analyzed, with sample sizes from 84 to 2,833 patients. The incidence of PIHI ranged from 5 to 440 cases per 1,000 intubations, with a pooled estimate of 110 cases per 1,000 intubations (95% CI 65–167).

PIHI was found to occur in 110 cases per 1,000 in-hospital, emergent intubations. However, heterogeneity among the included studies limits the reliability of this summary estimate. Further investigation is warranted.

The optimal approach to airway management in penetrating neck injuries (PNIs) remains controversial. The primary objective of this study was to review the method of endotracheal intubation in PNI at a Canadian tertiary trauma centre. Secondarily, we sought to determine the incidence of PNI in our trauma population and to describe the epidemiologic elements of this population.

We conducted a review of patients with PNIs who were enrolled in the Nova Scotia Trauma Registry database. We included all patients 16 years of age or under who presented between April 1, 1994 and March 31, 2005 with penetrating injuries of the neck and an Injury Severity Score (ISS) of 9 or less or who underwent Trauma Team activation at our Tertiary Trauma Centre (regardless of ISS) and/or who were identified upon admission as a “major” trauma case. The variables of interest were patient age and sex, injury mechanism, injury location, place of intubation and method of intubation.

There were 19 people who met inclusion criteria and they were enrolled in our study. The injury mechanisms involved knife (n = 13) or gunshot (n = 5) wounds (one patient's injuries were categorized as “other”). Three patients (15.8%) were not intubated. The remaining 16 patients were intubated during prehospital care (n = 5), in the emergency department (n = 6) or in the operating room (n = 5). Of these, 8 patients (42.1%) underwent awake intubation and 8 (42.1%) underwent rapid sequence intubation.

There is clear variability of airway management in PNI. We believe that such patients represent a heterogeneous group where the attending physician must have a conservative yet varied approach to airway management based on the individual clinical scenario.

Our objective was to document and compare the views obtained at laryngoscopy during emergency department (ED) rapid sequence intubation (RSI) by anesthetists and emergency physicians of varying seniority and experience.

Data were prospectively collected on every intubation attempt in 7 urban Scottish EDs for 2 calendar years, commencing Jan. 11, 1999. Data included patient’s age, gender, grade and specialty of intubator, laryngoscopic grade, and number of intubation attempts. Quality of laryngoscopic visualization was graded using the Cormack–Lehane scale, with grades I and II considered good visualization. A descriptive analysis was performed, and key statistical comparisons made.

During the study period, 735 patients underwent RSI, and grade of intubation was documented in 672 cases (91%). In total, 68.2%, 23.4%, 6.1% and 2.4% of the intubations were classified as Cormack–Lehane grade I, II, III and IV respectively. Overall, anesthetists and anesthesia trainees achieved good laryngoscopic visualization in 94.0% of cases (95% confidence interval [CI], 90.8%–96.4%) and emergency physicians and emergency medicine trainees did so in 89.2% of cases (95% CI, 85.5%–92.3%; p = 0.027). Specialist registrars and senior house officers in anesthesia were more likely to obtain good visualization than their emergency medicine counterparts (p = 0.034 and 0.035 respectively). Consultants in emergency medicine were more likely to obtain good views than their anesthesia counterparts, but this difference was not statistically significant.

Anesthetic trainees obtain better laryngoscopic views than emergency medicine trainees, but these differences disappear with increasing emergency physician seniority, suggesting a training and experience effect. Emergency medicine trainees may benefit from additional focus on laryngoscopic visualization techniques early in their training period.

We conducted a qualitative systematic review to evaluate the efficacy and safety of propofol for direct current cardioversion (DCC), rapid sequence intubation (RSI) and procedural sedation in adult emergency department (ED) patients.

MEDLINE (1966 to September 2000), PubMed (to September 2000), EMBASE (1988 to September 2000), Database of Systematic Reviews (to September 2000), Best Evidence (1991 to September 2000) and Current Contents (1996 to September 2000) databases.

English-language, randomized, comparative evaluations of propofol for procedures routinely conducted in adults (>18 years) were included. Direct current cardioversion, RSI and procedural sedation were considered.

Efficacy and safety endpoints were evaluated for all trials. For DCC and procedural sedation trials, efficacy measures included induction and recovery times, as well as the association for successful procedure. For the RSI trials, optimal intubating conditions were evaluated as the primary efficacy endpoint. Safety measures included hemodynamic changes, apnea rates and adverse effects.

In the setting of DCC, efficacy and safety outcomes were similar for propofol, thiopental, etomidate and methohexital. All of these agents provided markedly shorter induction and recovery times than midazolam. Patients who were pre-medicated with fentanyl exhibited prolonged recovery times and greater decreases in blood pressure. When used for RSI, propofol administration was associated with satisfactory intubating conditions that were comparable to those seen with thiopental and etomidate. Blood pressure reductions were seen in both DCC and RSI studies. Apneic episodes (>30 seconds) occurred in 23% of propofol recipients, 28% of thiopental recipients and 7% of etomidate and midazolam recipients. Apart from the DCC studies described, no procedural sedation studies met our predefined review eligibility criteria.

The body of literature evaluating propofol for DCC and RSI in the ED is limited. There is evidence to support the use of propofol for DCC and RSI, but this evidence comes from stable patients in non-ED settings. Further ED-based randomized comparative trials should be conducted before propofol is adopted for widespread use in the ED.