Optimizing Physiology During Prehospital Airway Management: An NAEMSP Position Statement and Resource Document.

Airway management is a critical component of resuscitation but also carries the potential to disrupt perfusion, oxygenation, and ventilation as a consequence of airway insertion efforts, the use of medications, and the conversion to positive-pressure ventilation. NAEMSP recommends:Airway management should be approached as an organized system of care, incorporating principles of teamwork and operational awareness.EMS clinicians should prevent or correct hypoxemia and hypotension prior to advanced airway insertion attempts.Continuous physiological monitoring must be used during airway management to guide the timing of, limit the duration of, and inform decision making during advanced airway insertion attempts.Initial and ongoing confirmation of advanced airway placement must be performed using waveform capnography. Airway devices must be secured using a reliable method.Perfusion, oxygenation, and ventilation should be optimized before, during, and after advanced airway insertion.To mitigate aspiration after advanced airway insertion, EMS clinicians should consider placing a patient in a semi-upright position.When appropriate, patients undergoing advanced airway placement should receive suitable pharmacologic anxiolysis, amnesia, and analgesia. In select cases, the use of neuromuscular blocking agents may be appropriate.

The Use of Ketamine for Air Medical Rapid Sequence Intubation Was Not Associated With a Decrease in Hypotension or Cardiopulmonary Arrest.

OBJECTIVE: Rapid sequence intubation (RSI) is associated with a number of complications that can increase morbidity and mortality. Among RSI agents used to blunt awareness of the procedure and produce amnesia, ketamine is unique in its classification as a dissociative agent rather than a central nervous system depressant. Thus, ketamine should have a lower risk of peri-RSI hypotension because of the minimal sympatholysis compared with other agents. Recent recommendations include the use of ketamine for RSI in hemodynamically unstable patients. The main goal of this analysis was to explore the incidence of hypotension and/or cardiopulmonary arrest in patients receiving ketamine, etomidate, midazolam, and fentanyl during air medical RSI. We hypothesized that ketamine would be associated with a lower risk of hemodynamic complications, particularly after adjusting for covariables reflecting patient acuity. In addition, we anticipated that an increased prevalence of ketamine use would be associated with a decreased incidence of peri-RSI hypotension and/or arrest. METHODS: This was a retrospective, observational study using a large air medical airway database. A waiver of informed consent was granted by our institutional review board. Descriptive statistics were used to present demographic and clinical data. The incidence rates of hypotension and cardiopulmonary arrest were calculated for each sedative/dissociative agent. Multivariable logistic regression was used to calculate the odds ratios of both hypotension and arrest for each of the sedative/dissociative agents. The prevalence of use for each agent and the incidence of hemodynamic complications (hypotension and arrest) were determined over time. RESULTS: A total of 7,466 RSI patients were included in this analysis. The use of ketamine increased over the duration of the study. Ketamine was associated with a higher incidence of both hypotension and arrest compared with other agents, even after adjustment for multiple covariables. The overall incidence of hypotension, desaturation, and cardiopulmonary arrest did not change over the study period. CONCLUSIONS: Although the incidence of hemodynamic complications was higher in patients receiving ketamine, this may reflect a selection bias toward more hemodynamically unstable patients in the ketamine cohort. The incidence of hypotension and arrest did not change over time despite an increase in the prevalence of ketamine use for air medical RSI. These data do not support a safer hemodynamic profile for ketamine.

Intracranial migration of intraocular silicone oil following repetitive head trauma.

Intraocular injection of silicone oil as a tamponade agent is a commonly used technique for the treatment of retinal detachment. An incompletely understood phenomenon which can occur after injection is the migration of silicone oil from the vitreous chamber to the intracranial space. Because the appearance of silicone oil can mimic hemorrhage or other pathologies on CT and MRI, careful comparison with prior studies is necessary to avoid unnecessary follow-up studies. We report a case of intracranial migration of intraocular silicone oil following repetitive head trauma.

The HEAVEN criteria predict laryngoscopic view and intubation success for both direct and video laryngoscopy: a cohort analysis.

BACKGROUND: Existing difficult airway prediction tools are not practical for emergency intubation and do not incorporate physiological data. The HEAVEN criteria (Hypoxaemia, Extremes of size, Anatomic challenges, Vomit/blood/fluid, Exsanguination, Neck mobility) may be more relevant for emergency rapid sequence intubation (RSI). METHODS: A retrospective analysis included air medical RSI patients. A checklist was used to assess HEAVEN criteria prior to RSI, and Cormack-Lehane (CL) laryngoscopic view was recorded for the first intubation attempt. The incidence of a difficult (CL III/IV) laryngoscopic view as well as failure to intubate on first attempt with and without oxygen desaturation were determined for each of the HEAVEN criteria and total number of HEAVEN criteria. In addition, the association between HEAVEN criteria and both laryngoscopic view and intubation performance were quantified using multivariate logistic regression for direct laryngoscopy (DL) and video laryngoscopy (VL) configured with a Macintosh #4 non-hyperangulated blade. RESULTS: A total of 5137 RSI patients over 24 months were included. Overall intubation success was 97%. A CL III/IV laryngoscopic view was reported in 25% of DL attempts and 15% of VL attempts. Each of the HEAVEN criteria and total number of HEAVEN criteria were associated with both CL III/IV laryngoscopic view and failure to intubate on the first attempt with and without oxygen desaturation for both DL and VL. These associations persisted after adjustment for multiple co-variables including the other HEAVEN criteria. CONCLUSION: The HEAVEN criteria may be useful to predict laryngoscopic view and intubation performance for DL and VL during emergency RSI.

Vital sign patterns before shock-related cardiopulmonary arrest.

OBJECTIVE: Traditional vital sign thresholds reflect an increased risk of mortality, which may occur hours, days, or weeks following illness/injury, limiting immediate clinical significance to guide rescue therapy to avoid arrest. Our objective is to explore vital sign patterns prior to arrest due to shock. DESIGN: This retrospective observational analysis utilized physiological data from adult helicopter patients suffering provider-witnessed arrest. Pre-arrest values for systolic blood pressure (SBP), mean arterial pressure (MAP), heart rate (HR), shock index, and end-tidal carbon dioxide (EtCO2) were modeled against time using polynomial linear regression. The "terminal inflection point" beyond which arrest was imminent was identified where slope equals 1.0 (shock index) or -1.0 (SBP, MAP, HR, EtCO2) and was then compared to initial values. SETTING: Air ambulance services. PATIENTS: 70 helicopter patients over age fourteen suffering cardiac arrest. RESULTS: SBP and MAP demonstrated a gentle decline followed by acceleration beyond the inflection point (SBP 80.7 mmHg, MAP 61.9 mmHg). HR demonstrated an increase followed by a terminal drop, but inflection point values fell within normal range. Shock index increased gradually from a mean of 0.9 to the inflection point of 1.1. Initial EtCO2 values declined gradually from normal (34.4 mmHg) to the inflection point (24.7 mmHg), then dropped precipitously into arrest. All inflection points occurred 2-5 min prior to arrest. CONCLUSIONS: Vital sign patterns were defined for SBP, MAP, HR, shock index, and EtCO2 with clear inflection points identified 2-5 min prior to arrest. These patterns may help guide therapy to reverse deterioration and prevent arrest.

Bipartite patella separation and partial quadriceps tendon rupture in the setting of trauma.

Normal development of the patella typically involves fusion of secondary ossification centers into a single bone during adolescence, with failure of fusion resulting in bipartite and tripartite patellae. In such variants, injury to incomplete ossification center fusion, though uncommon, has been reported to occur in the setting of traumatic quadriceps tendon rupture. The authors present a rare and complex case of traumatic bipartite fragment separation, patellar avulsion, and a complex partial quadriceps tendon tear confirmed surgically in a 36-year-old male. In this case, a tear in the lateral aspect of the quadriceps tendon attached to the nonfused patellar ossification center resulted in retraction of the band containing the bipartite fragment and separation of the patellar fragments, with superior displacement of the smaller bony avulsion likely due to complex attachments from the medial aspect of the quadriceps tendon. Knowledge of the classical locations of a bipartite and tripartite patella can aid in the differentiation of the anatomic variant versus patellar avulsion. Additionally, knowledge of the variable and complex nature of the quadriceps tendon aids in understanding the process of patellar avulsions and various tears, leading to the appropriate orthopedic management.

Acute carotid thrombosis and ischemic stroke following overdose of the synthetic cannabinoid K2 in a previously healthy young adult male.

With the popularity of synthetic cannabinoid street drugs such as "K2 and Spice," a number of serious neurologic adverse events are coming to light. This case is a 36-year-old African American man, with no significant medical history, who presented with extensive left cervical and intracranial internal carotid artery occlusion and subsequent ischemic stroke. The patient endorsed smoking K2-a synthetic cannabinoid (SC) with structural similarity to cannabis. The mechanism by which SC abuse induces a prothrombotic state leading to ischemic neurovascular sequelae is currently unclear, although a temporal association in the absence of other stroke risk factors suggests a causal relationship. Our case highlights the need for emergent neuroimaging upon suspected SC overdose. Practitioners should be vigilant in recognizing that ischemic stroke and unexplained neurologic deficit can arise after SC abuse, especially in younger populations with few stroke risk factors and who are prone to chronic cannabis use.

A Continuous Quality Improvement Airway Program Results in Sustained Increases in Intubation Success.

INTRODUCTION: Airway management is a critical skill for air medical providers, including the use of rapid sequence intubation (RSI) medications. Mediocre success rates and a high incidence of complications has challenged air medical providers to improve training and performance improvement efforts to improve clinical performance. OBJECTIVES: The aim of this research was to describe the experience with a novel, integrated advanced airway management program across a large air medical company and explore the impact of the program on improvement in RSI success. METHODS: The Helicopter Advanced Resuscitation Training (HeART) program was implemented across 160 bases in 2015. The HeART program includes a novel conceptual framework based on thorough understanding of physiology, critical thinking using a novel algorithm, difficult airway predictive tools, training in the optimal use of specific airway techniques and devices, and integrated performance improvement efforts to address opportunities for improvement. The C-MAC video/direct laryngoscope and high-fidelity human patient simulation laboratories were implemented during the study period. Chi-square test for trend was used to evaluate for improvements in airway management and RSI success (overall intubation success, first-attempt success, first-attempt success without desaturation) over the 25-month study period following HeART implementation. RESULTS: A total of 5,132 patients underwent RSI during the study period. Improvements in first-attempt intubation success (85% to 95%, p < 0.01) and first-attempt success without desaturation (84% to 94%, p < 0.01) were observed. Overall intubation success increased from 95% to 99% over the study period, but the trend was not statistically significant (p = 0.311). CONCLUSIONS: An integrated advanced airway management program was successful in improving RSI intubation performance in a large air medical company.

Systolic Blood Pressure Threshold for HEMS-Witnessed Arrests.

OBJECTIVE: Defining vital sign thresholds has focused on mortality, which may be delayed for hours, days, or weeks after injury. This limits the immediate clinical significance in guiding therapy to avoid arrest. The aim of this study was to identify a systolic blood pressure (SBP) threshold indicating imminent cardiopulmonary arrest. METHODS: This was a retrospective, observational study analyzing physiological data from air medical patients suffering witnessed arrest. We limited the analysis to a subgroup of adult (> 14 years) patients with hypoperfusion-related arrest. Prearrest SBP values were plotted over time, with arrest defined as "time zero." Multiple linear regression was used to define a best fit curve to identify an inflection point beyond which arrest was imminent. RESULTS: A total of 53 eligible patients were identified; 33 (62%) were trauma victims. A fifth-degree equation showed appropriate goodness of fit (r = -.66, P < .0001). An inflection point was identified at an SBP of 78 mm Hg, with arrest occurring approximately 3 minutes later. CONCLUSION: An inflection point below SBP 80 mm Hg was identified, suggesting a predictable physiological pattern for perfusion-related deterioration. This may help guide therapy to reverse deterioration and prevent arrest.

A Novel Difficult-Airway Prediction Tool for Emergency Airway Management: Validation of the HEAVEN Criteria in a Large Air Medical Cohort.

BACKGROUND: Difficult-airway prediction tools help identify optimal airway techniques, but were derived in elective surgery patients and may not be applicable to emergency rapid sequence intubation (RSI). The HEAVEN criteria (Hypoxemia, Extremes of size, Anatomic abnormalities, Vomit/blood/fluid, Exsanguination, Neck mobility issues) may be more relevant to emergency RSI patients. OBJECTIVE: To validate the HEAVEN criteria for difficult-airway prediction in emergency RSI using a large air medical cohort. METHODS: This was a retrospective analysis using a large air medical airway registry using data from 160 bases over a 1-year period. Standard test characteristics (sensitivity, specificity, positive predictive value, negative predictive value [NPV]) for the HEAVEN criteria were calculated for overall intubation success, first-attempt success, and first-attempt success without desaturation. In addition, multivariable logistic regression was used to quantify the independent association between each of the HEAVEN criteria, as well as the total number of criteria present and intubation success after adjusting for age, gender, and clinical category (burn, medical, trauma, nontraumatic shock). RESULTS: A total of 2419 patients undergoing air medical RSI were included. Excellent NPV was observed (97% for each of the HEAVEN criteria except "Exsanguination," which had an NPV of 87% but specificity of 99%). First-attempt success was lower for each of the HEAVEN criteria, with an inverse relationship observed between total HEAVEN criteria and intubation success (first-attempt success with no criteria = 94% and with 5 + criteria = 43%). Multivariable logistic regression revealed independent associations between each of the HEAVEN criteria, as well as total number of criteria and intubation success. CONCLUSIONS: The HEAVEN criteria seem to be a useful tool to predict difficult airways in emergency RSI.

Esophageal pneumatosis in the setting of small bowel ileus with acute resolution after nasogastric tube decompression.

Esophageal pneumatosis is a rare condition with diverse potential etiologies including traumatic, mechanical, ischemic, obstructive respiratory, autoimmune, immunodeficient, and infectious causes. Here, we present a case of esophageal pneumatosis in the setting of upper gastrointestinal and small bowel ileus, diagnosed on computed tomography (CT), with acute resolution after nasogastric tube decompression. A patient presented to the emergency department with epigastric discomfort. CT of the abdomen/pelvis demonstrated intramural air in the mid-to-distal esophagus, consistent with esophageal pneumatosis, and diffuse dilatation of the visualized esophagus, stomach, and small bowel, consistent with an ileus. Patient was managed with nasogastric tube decompression and bowel rest. Subsequent esophagram did not demonstrate any evidence of perforation and a repeat CT of the abdomen/pelvis, performed 11 hours after initial diagnostic CT, demonstrated interval resolution of patient's esophageal pneumatosis, and improvement of patient's ileus.

Spinal subarachnoid and subdural hematoma presenting as a Brown-Séquard-like myelopathy following minor trauma in a patient on dabigatran etexilate.

Dabigatran etexilate is a relatively new anticoagulant from the class of direct thrombin inhibitors which is administered orally and does not require routine blood work monitoring. Dabigatran may be attractive to both clinicians and patients because of both its convenience and efficacy; however, clinical complications are still being elucidated. Here, we present a previously unreported case of spinal subarachnoid and subdural hematoma presenting as a Brown-Séquard-like myelopathy in a patient after minor trauma in the setting of Dabigatran anticoagulation.

Dietary protein and protein-rich food in relation to severely depressed mood: A 10 year follow-up of a national cohort.

High-protein diets are advocated to facilitate weight loss, and improve cardiovascular risk factors, but data on psychiatric effects are lacking. We analyzed data from 1947 men and 2909 women aged 25-74 years when examined in 1971-1975 as the baseline of the National Health and Nutrition Examination Follow-Up Study. The amounts of macronutrients were obtained from a 24-hour recall, and frequencies of eating protein-rich foods were estimated using a 3-month food frequency questionnaire. Severely depressed mood (SDM) was defined as Center for Epidemiologic Studies Depression Scale score ≥ 22 or taking anti-depression medication after an average of 10.6 years of follow-up. A significant gender difference was observed in the prevalence of SDM and its association with protein intake. The weighted prevalence of SDM was 11.45 (SE = 0.96) % and 17.45(1.05) % respectively among men and women. Among men, the relative risk (RRs) of SDM were 1.00, 0.46 (95% CI = 0.22-0.99) and 0.38 (0.16-0.92) respectively for the lowest, middle and highest third protein intake (p for trend=0.0347). Among women, the RRs were 1.00, 1.93 (1.23-3.08) and 2.47 (1.24-4.90) respectively with lowest, middle and the highest third intakes (p for trend = 0.0023). These estimates were adjusted for cigarette smoking, alcohol consumption, BMI, socioeconomic status at baseline, and the history of cancer, stroke, heart attack and diabetes assessed at follow-up interview. The authors concluded that increased intake of protein demonstrated a protective effect among men but a deleterious effect among women.

Regionalized approach to emergency medical services training for the care of patients with mechanical assist devices.

Advances in mechanical circulatory assist device technology have allowed dozens of patients with different types of devices to live in any community in the United States. Some of the newer devices pump blood continuously, resulting in patients without pulses. The mechanical circulatory assist device teams and emergency medical services providers in the mid-Atlantic region wondered how best to prepare the community to respond appropriately to emergencies in patients with these mechanical devices.

Dietary linoleic and oleic fatty acids in relation to severe depressed mood: 10 years follow-up of a national cohort.

The influence of dietary fatty acids (FAs) other than omega-3 FAs on mood has been largely overlooked. The authors prospectively assessed the association between dietary linoleic and oleic FAs and the risk of severe depressed mood (SDM) among 4856 adults aged 25-74 years who were examined in 1971-1975 as a part of a national survey. Intakes of FAs were obtained at baseline from a 24-hour recall and categorized into thirds. SDM was defined as Center for Epidemiologic Studies Depression Scale scores at follow-up survey >or=22 or taking anti-depression medication. After an average of 10.6 years of follow-up, the proportion of individuals with SDM were 11.45 (SE=0.96) % and 17.45(1.05) % respectively among 1947 men and 2909 women. The odds ratios (ORs) were 1 (reference), 1.64(95% CI=1.06, 2.54) and 2.34 (1.41, 3.87) respectively for men with lowest, middle and highest third of linoleic FA intake (p for trend=0.001); the ORs were 1 (reference), 0.88 (0.56, 1.38) and 0.48 (0.25, 0.95) respectively for women with lowest, middle and highest third of oleic FA intake (p for trend=0.0347). No association was observed from saturated FA. These estimates were adjusted for fish consumption at baseline and major physical diseases at follow-up. The authors concluded that increased intake of oleic FA was associated with reduced risk among women while increased intake of linoleic FA was associated with increased risk of SDM among men.