Video versus direct laryngoscopy by specialist paramedics in New South Wales: Preliminary results from a new airway registry.

OBJECTIVES: Video laryngoscopy (VL) is increasingly used as an alternative to direct laryngoscopy (DL) to improve airway visualisation and endotracheal intubation (ETI) success. Intensive Care Paramedics in New South Wales Ambulance, Australia started using VL in 2020, and recorded success in a new advanced airway registry. We used this registry to compare VL to DL. METHODS: The present study was a retrospective analysis of out-of-hospital data for ETI by specialist paramedics using an airway registry. We calculated overall and first-pass success for VL versus DL, and compared success using a Χ2 test. RESULTS: The DL overall success was 61 out of 78 (78.2%) and VL was 233 out of 246 (94.7%); difference of 16.5% (P < 0.001). First-pass for DL was successful for 49 out of 78 (62.8%) and for VL in 195 out of 246 (79.3%); difference of 16.5% (P = 0.003). There were five (1.6%) patients where both VL and DL were used and in all instances, DL was used first. CONCLUSIONS: This analysis of a new airway registry used by specialist paramedics in New South Wales shows a substantial increase in overall and first-pass intubation success with the use of VL when compared to DL.

The association of ketamine induction with blood pressure changes in paramedic rapid sequence intubation of out-of-hospital traumatic brain injury.

INTRODUCTION: Rapid sequence intubation (RSI) is used to secure the airway of traumatic brain injury (TBI) patients, with ketamine frequently used for induction. Studies show that ketamine-induction RSI might cause lower blood pressures when compared to etomidate. It is not clear if the results from that research can be extrapolated to systems that use different dosing regimens for ketamine RSI. Ambulance Victoria authorized the use of 1.5 mg/kg ketamine in January 2015 for head injury RSI induction by road-based paramedics. This study aims to examine whether systolic blood pressure changed when ketamine was introduced for prehospital head injury RSI. METHODS: This study was a retrospective analysis of out-of-hospital suspected TBI that received RSI by paramedics. Our analysis employs an interrupted time-series analysis (ITSA), which is a quasi-experimental method that tested whether hypotension and systolic blood pressures changed after the switch to ketamine induction in 2015. This ITSA utilized an ordinary least squares regression on complete observations using Newey-West standard errors. RESULTS: During the study period, paramedics performed RSI in 8,613 patients, and 1,759 (20.4%) had a TBI. Ketamine usage increased by 52.7% in January 2015 (p < 0.001) after road-based paramedics were authorized to use ketamine induction. This analysis found significant 5% increase in post-RSI hypotension (p = 0.046) after the introduction of ketamine, and thereafter the incidence of post-RSI hypotension increased steadily by 0.5% every 3 months (p = 0.004). Concurrently, changes in systolic blood pressure, as measured by the interval just before induction to the last measured on scene, show an average decrease of 7.8 mm Hg (p = 0.04) at the start of 2015 with the ketamine rollout. CONCLUSIONS: This ITSA shows that postinduction hypotension and also decreases in systolic blood pressures became evident after the introduction of ketamine. Further research to investigate the association between ketamine induction and survival is needed.

Association of blood pressure changes with survival after paramedic rapid sequence intubation in out-of-hospital patients with stroke.

OBJECTIVE: Rapid sequence intubation (RSI) is used to secure the airway of some patients with stroke. Recent observational studies suggest that RSI is associated with poorer survival, and that decreases in systolic blood pressure (BP) following RSI could be a cause of worse survival. The present study aims to find if decreased systolic BP after paramedic RSI is associated with poorer survival in stroke patients transported by ambulance. METHODS: The present study was a retrospective analysis of all stroke patients who received paramedic RSI attended by Ambulance Victoria, Australia. Logistic regression predicted the survival for strokes that had received RSI. The change in systolic BP during paramedic care was the main predictor. RESULTS: Of 43 831 patients with stroke, 882 (2%) received RSI. Almost 48% of RSI had a decline in systolic BP of more than 20% from baseline, and the decline in systolic BP after RSI was largest for intra-cerebral haemorrhage (-22.7 mmHg) compared to ischaemic strokes (-10.1 mmHg) or subarachnoid haemorrhage (-15.6 mmHg) (P = 0.001). Sixteen percent of the RSI group had an episode of hypotension anytime during the out-of-hospital care. For each 10 mmHg decrease in systolic BP with RSI for intra-cerebral haemorrhage an increase of 11% in the odds of survival is apparent (P = 0.04); for subarachnoid haemorrhage an increase of 17% (P = 0.02) and for ischaemic strokes a non-significant decrease of 7% (P = 0.26). CONCLUSIONS: Paramedic RSI-related decrease in systolic BP is associated with improved survival in those with intra-cerebral or subarachnoid haemorrhage but not ischaemic stroke.

Review article: Emergency endotracheal intubation in non-traumatic brain pathologies: A systematic review and meta-analysis.

Endotracheal intubation is an advanced airway procedure performed in the ED and the out-of-hospital setting for acquired brain injuries that include non-traumatic brain pathologies such as stroke, encephalopathies, seizures and toxidromes. Controlled trial evidence supports intubation in traumatic brain injuries, but it is not clear that this evidence can be applied to non-traumatic brain pathologies. We sought to analyse the impact of emergency intubation on survival in non-traumatic brain pathologies and also to quantify the prevalence of intubation in these pathologies. We conducted a systematic literature search of Medline, Embase and the Cochrane Library. Eligibility, data extraction and assessment of risk of bias were assessed independently by two reviewers. A bias-adjusted meta-analysis using a quality-effects model pooled prevalence of intubation in non-traumatic brain pathologies. Forty-six studies were included in this systematic review. No studies were suitable for meta-analysis the primary outcome of survival. Thirty-nine studies reported the prevalence of intubation in non-traumatic brain pathologies and a meta-analysis showed that emergency intubation was used in 12% (95% CI 0-33) of pathologies. Endotracheal intubation was used commonly in haemorrhagic stroke 79% (95% CI 47-100) and to a lesser extent for seizures 18% (95% CI 10-27) and toxidromes 25% (95% CI 6-48). This systematic review shows that there is no high-quality clinical evidence to support or refute emergency intubation in non-traumatic brain pathologies. Our analysis shows that intubation is commonly used in non-traumatic brain pathologies, and the need for rigorous evidence is apparent.

Flight Versus Ground Out-of-hospital Rapid Sequence Intubation Success: a Systematic Review and Meta-analysis.

INTRODUCTION: Endotracheal intubation (ETI) is a critical procedure performed by both air medical and ground based emergency medical services (EMS). Previous work has suggested that ETI success rates are greater for air medical providers. However, air medical providers may have greater airway experience, enhanced airway education, and access to alternative ETI options such as rapid sequence intubation (RSI). We sought to analyze the impact of the type of EMS on RSI success. METHODS: A systematic literature search of Medline, Embase, and the Cochrane Library was conducted and eligibility, data extraction, and assessment of risk of bias were assessed independently by two reviewers. A bias-adjusted meta-analysis using a quality-effects model was conducted for the primary outcomes of overall intubation success and first-pass intubation success. RESULTS: Forty-nine studies were included in the meta-analysis. There was no difference in the overall success between flight and ground based EMS; 97% (95% CI 96-98) vs. 98% (95% CI 91-100), and no difference in first-pass success for flight compared to ground based RSI; 82% (95% CI 73-89) vs. 82% (95% CI 70-93). Compared to flight non-physicians, flight physicians have higher overall success 99% (95% CI 98-100) vs. 96% (95% CI 94-97) and first-pass success 89% (95% CI 77-98) vs. 71% (95% CI 57-84). Ground-based physicians and non-physicians have a similar overall success 98% (95% CI 88-100) vs. 98% (95% CI 95-100), but no analysis for physician ground first pass was possible. CONCLUSIONS: Both overall and first-pass success of RSI did not differ between flight and road based EMS. Flight physicians have a higher overall and first-pass success compared to flight non-physicians and all ground based EMS, but no such differences are seen for ground EMS. Our results suggest that ground EMS can use RSI with similar outcomes compared to their flight counterparts.

Nonphysician Out-of-Hospital Rapid Sequence Intubation Success and Adverse Events: A Systematic Review and Meta-Analysis.

STUDY OBJECTIVE: Rapid sequence intubation performed by nonphysicians such as paramedics or nurses has become increasingly common in many countries; however, concerns have been stated in regard to the safe use and appropriateness of rapid sequence intubation when performed by these health care providers. The aim of our study is to compare rapid sequence intubation success and adverse events between nonphysician and physician in the out-of-hospital setting. METHODS: A systematic literature search of key databases including MEDLINE, EMBASE, and the Cochrane Library was conducted. Eligibility, data extraction, and assessment of risk of bias were assessed independently by 2 reviewers. A bias-adjusted meta-analysis using a quality-effects model was conducted for the primary outcomes of overall intubation success and first-pass intubation success and for adverse events when possible. RESULTS: Eighty-three studies were included in the meta-analysis. There was a 2% difference in successful intubation proportion for physicians versus nonphysicians, 99% (95% confidence interval [CI] 98% to 99%) versus 97% (95% CI 95% to 99%). A 10% difference in first-pass rapid sequence intubation success was noted between physicians versus nonphysicians, 88% (95% CI 83% to 93%) versus 78% (95% CI 65% to 89%). For airway trauma, bradycardia, cardiac arrest, endobronchial intubation, hypertension, and hypotension, lower prevalences of adverse events were noted for physicians. However, nonphysicians had a lower prevalence of hypoxia and esophageal intubations. Similar proportions were noted for pulmonary aspiration and emesis. Nine adverse events estimates lacked precision, except for endobronchial intubation, and 4 adverse event analyses showed evidence of possible publication bias. Consequently, no reliable evidence exists for differences between physicians and nonphysicians for adverse events. CONCLUSION: This analysis shows that physicians have a higher rapid sequence intubation first-pass and overall success, as well as mostly lower rates of adverse events for rapid sequence intubation in the out-of-hospital setting. Nevertheless, for all success and adverse events no firm conclusion for a difference could be drawn because of lack of precision of meta-analytic estimates or selective reporting. First-pass success could be an area in which to focus quality improvement strategies for nonphysicians.

Frequency of adjustment with comorbidity and illness severity scores and indices in cardiac arrest research.

BACKGROUND: Previous research demonstrates that results from observational research correlate well with results from clinical trials, and if the former are well designed these can guide clinical practice. Observational studies in cardiac arrest research are beset by confounding due to illness severity and comorbidity. We aimed to count the number of studies that utilize comorbidity and illness severity scores and indices, and to measure the change in results across analyses that adjust for scores and indices. METHODS: A systematic search of databases for cardiac arrest studies that report survival outcomes for 2015 and that utilize illness severity and comorbidity indices and scores was conducted. We quantified the proportion of studies and the change in magnitude of estimates when adjustment for indices and scores were used. RESULTS: Sixty (28%) of 213 cardiac arrest studies that report survival outcomes utilize illness severity or comorbidity indices and scores, of which 39 studies (65%) used risk scores and indices to account for the confounding effect of comorbidity or illness severity. A 14% change towards the null in the magnitude of effect sizes was apparent when models included illness severity or comorbidity adjustment (interquartile range -37.7 to 4.4). CONCLUSIONS: A small proportion of cardiac arrest studies account for illness severity and comorbidity with scores and indices, and such adjustment tend to drive estimates towards the null (no difference in groups being compared). Confounding by illness severity and comorbidity is a significant source of bias in non-randomized cardiac arrest studies.

Airways in out-of-hospital cardiac arrest: systematic review and meta-analysis.

OBJECTIVE: To determine the differences in survival for out-of-hospital advanced airway intervention (AAI) compared with basic airway intervention (BAI) in cardiac arrest. BACKGROUND: AAI is commonly utilized in cardiac arrest in the out-of-hospital setting as a means to secure the airway. Observational studies and clinical trials of AAI suggest that AAI is associated with worse outcomes in terms of survival. No controlled trials exist that compares AAI to BAI. METHODS: We conducted a bias-adjusted meta-analysis on 17 observational studies. The outcomes were survival, short-term (return of spontaneous circulation and to hospital admission), and longer-term (to discharge, to one month survival). We undertook sensitivity analyses by analyzing patients separately: those who were 16 years and older, nontrauma only, and attempted versus successful AAI. RESULTS: This meta-analysis included 388,878 patients. The short-term survival for AAI compared to BAI were overall OR 0.84(95% CI 0.62 to 1.13), for endotracheal intubation (ETI) OR 0.79 (95% CI 0.54 to 1.16), and for supraglottic airways (SGA) OR 0.59 (95% CI 0.39 to 0.89). Long-term survival for AAI were overall OR 0.49 (95% CI 0.37 to 0.65), for ETI OR 0.48 (95% CI 0.36 to 0.64), and for SGA OR 0.35 (95% CI 0.28 to 0.44). Sensitivity analyses shows that limiting analyses to adults, non-trauma victims, and instances where AAI was both attempted and successful did not alter results meaningfully. A third of all studies did not adjust for any other confounding factors that could impact on survival. CONCLUSIONS: This meta-analysis shows decreased survival for AAIs used out-of-hospital in cardiac arrest, but are likely biased due to confounding, especially confounding by indication. A properly conducted prospective study or a controlled trial is urgently needed and are possible to do.