Prehospital Surgical Cricothyrotomy in a Ground-Based 9-1-1 EMS System: A Retrospective Review.

BACKGROUND: Airway management is a cornerstone in the prehospital care of critically ill or injured patients. Surgical cricothyrotomy offers a rapid and effective solution when oxygenation and ventilation fail using less-invasive techniques. However, the exact indications, incidence, and success of prehospital surgical cricothyrotomy are unknown, with variable rates reported in the literature. This study aimed to examine prehospital indications and success rates for surgical cricothyrotomy within a large, suburban, ground-based Emergency Medical Services (EMS) system. METHODS: This is a retrospective analysis of 31 patients who underwent paramedic performed surgical cricothyrotomy from 2012 through 2022. Key demographic parameters were analyzed, including the incidence of cardiac arrest, call type (trauma versus medical), initial airway management attempts, number of endotracheal intubation (ETI) attempts before surgical airway, and average time to the establishment of a surgical airway in relation to the number of ETI attempts. Surgical cricothyrotomy success was defined as the acquisition of four-phase end-tidal capnography reading. The primary data sources were the EMS electronic medical records, and descriptive statistics were calculated. RESULTS: A total of 31 patients were included in the final analysis. Of those who received a surgical cricothyrotomy, 42% (13/31) occurred in the trauma setting, while 58% (18/31) were medical calls. In all patients who underwent surgical cricothyrotomy, the median (IQR) time to the procedure was 17 minutes (IQR = 11-24). In trauma patients, the median time to surgical cricothyrotomy was 12 minutes (IQR = 9-19) versus 19 minutes (IQR = 14-33) in medical patients. End-tidal carbon dioxide (ETCO2) detection and placement success was confirmed in 94% (29/31) of patients. Endotracheal intubation was attempted in 55% (17/31) before subsequent surgical cricothyrotomy, with 29% (9/31) receiving more than one ETI attempt. The median time to surgical cricothyrotomy when multiple prior intubation attempts occurred was 33 minutes (IQR = 23-36) compared to 14.5 minutes (IQR = 6-19) in patients without a preceding intubation attempt. CONCLUSION: Prehospital surgical airway can be performed by paramedics with a high degree of success. Identification of the need for surgical cricothyrotomy should be determined as soon as possible to allow for rapid securement of the airway and to ensure adequate oxygenation and ventilation.

Clinical evaluation of a fully electronic microfluidic white blood cell analyzer.

The White Blood Cell (WBC) count is one of the key parameters signaling the health of the immune system. Abnormal WBC counts often signal a systemic insult to the body such as an underlying infection or an adverse side effect to medication. Typically, the blood collected is sent to a central lab for testing, and results come back within hours, which is often inconvenient and may delay time-sensitive diagnosis or treatment. Here, we present the CytoTracker, a fully electronic, microfluidic based instant WBC analyzer with the potential to be used at point-of-care. The CytoTracker is a lightweight, portable, affordable platform capable of quantifying WBCs within minutes using only 50 µl of blood (approximately one drop of blood). In this study, we clinically evaluated the accuracy and performance of CytoTracker in measuring WBC and granulocyte counts. A total of 210 adult patients were recruited in the study. We validated the CytoTracker against a standard benchtop analyzer (Horiba Point of Care Hematology Analyzer, ABX Micros 60). Linear dynamic ranges of 2.5 k/µl- 35 k/µl and 0.6 k/µl- 26 k/µl were achieved for total WBC count and granulocyte count with correlation coefficients of 0.97 and 0.98. In addition, we verified CytoTracker's capability of identifying abnormal blood counts with above 90% sensitivity and specificity. The promising results of this clinical validation study demonstrate the potential for the use of the CytoTracker as a reliable and accurate point-of-care WBC analyzer.

Safety of prehospital intravenous bolus dose nitroglycerin in patients with acute pulmonary edema: A 4-year review.

Background: Intravenous nitrates are a primary therapy for hypertensive congestive heart failure (CHF) with acute pulmonary edema (APE) in the hospital setting. Historically, sublingual nitrates are the mainstay of emergency medical services (EMS) pharmacologic therapy for these patients. We aimed to evaluate the safety of prehospital bolus dose intravenous nitroglycerin in patients with APE. Methods: This is a retrospective evaluation of EMS data between March 15, 2018, and March 15, 2022, where CHF with APE was suspected and bolus-dose intravenous nitroglycerin was administered. Protocol inclusion criteria were hypertension (systolic blood pressure [SBP] >160 mmHg) and acute respiratory distress, with a presumption of decompensated CHF with APE. These patients received 1 mg intravenous nitroglycerin, with the option to repeat once for ongoing distress if the SBP remained >160 mmHg. The primary outcomes were adverse events, defined as hypotension (SBP <90 mmHg), syncope, vomiting, or dysrhythmia. Results: The final analysis included 235 patients. In patients receiving intravenous bolus nitroglycerin, the median (interquartile range [IQR]) initial and final EMS SBP values decreased from 198 mmHg (180-218) to 168 (148-187), respectively. The median (IQR) pulse decreased from 108 (92-125) to 103 (86-119), and the median oxygen saturation increased from 89% (82-95) to 98% (96-99). Three episodes (1.3%) of asymptomatic hypotension occurred, and none required intervention. Conclusion: This study supports a favorable safety profile for prehospital bolus-dose intravenous nitroglycerin for decompensated CHF with APE. Blood pressure, heart rate, and oxygen saturation improvements are also demonstrated. Further, prospective studies are needed to confirm these findings.

Prehospital Treatment of Benzodiazepine-Resistant Pediatric Status Epilepticus with Parenteral Ketamine: A Case Series.

We report the initial six pediatric patients treated with ketamine for benzodiazepine-resistant status epilepticus in an urban, ground-based emergency medical services (EMS) system. Evidence for ketamine as a second-line agent for both adult and pediatric refractory seizure activity in the hospital setting has increased over the past decade. The availability of an inexpensive and familiar second-line prehospital anti-epileptic drug option is extremely desirable. We believe these initial data demonstrate promising seizure control effects without significant respiratory depression, indicating a potential role for ketamine in the EMS treatment of pediatric benzodiazepine-refractory seizures.

QT interval and short-term outcome in acute heart failure.

OBJECTIVE: To investigate the association of corrected QT (QTc) interval duration and short-term outcomes in patients with acute heart failure (AHF). METHODS: We analyzed AHF patients enrolled in 11 Spanish emergency departments (ED) for whom an ECG with QTc measurement was available. Patients with pace-maker rhythm were excluded. Primary outcome was 30-day all-cause mortality and secondary outcomes were need of hospitalization, in-hospital mortality and prolonged hospitalization (> 7 days). Association between QTc and outcomes was explored by restricted cubic spline (RCS) curves. Results were expressed as odds ratios (OR) and 95%CI adjusted by patients baseline and decompensation characteristics, using a QTc = 450 ms as reference. RESULTS: Of 1800 patients meeting entry criteria (median age 84 years (IQR = 77-89), 56% female), their median QTc was 453 ms (IQR = 422-483). The 30-day mortality was 9.7%, while need of hospitalization, in-hospital mortality and prolonged hospitalization were 77.8%, 9.0% and 50.0%, respectively. RCS curves found longer QTc was associated with 30-day mortality if > 561 ms, OR = 1.86 (1.00-3.45), and increased up to OR = 10.5 (2.25-49.1), for QTc = 674 ms. A similar pattern was observed for in-hospital mortality; OR = 2.64 (1.04-6.69), for QTc = 588 ms, and increasing up to OR = 8.02 (1.30-49.3), for QTc = 674 ms. Conversely, the need of hospitalization had a U-shaped relationship: being increased in patients with shorter QTc [OR = 1.45 (1.00-2.09) for QTc = 381 ms, OR = 5.88 (1.25-27.6) for the shortest QTc of 200 ms], and also increasing for prolonged QTc [OR = 1.06 (1.00-1.13), for QTc = 459 ms, and reaching OR = 2.15 (1.00-4.62) for QTc = 588 ms]. QTc was not associated with prolonged hospitalization. CONCLUSION: In ED AHF patients, initial QTc provides independent short-term prognostic information, with increasing QTc associated with increasing mortality, while both, shortened and prolonged QTc are associated with need of hospitalization.

Nebulized Ketamine for Analgesia in the Prehospital Setting: A Case Series.

We report the initial seven patients treated with nebulized ketamine for moderate to severe pain, via breath-actuated nebulizer, in an urban, ground-based emergency medical services (EMS) system. Ketamine for analgesia in the emergency setting has become widespread over the past decade. The addition of a non-parenteral, inexpensive, and well-tolerated ketamine delivery option is extremely desirable. We believe these initial data demonstrate promising pain reduction coupled with minimal side effects, indicating a potential role for nebulized ketamine in EMS.

Metabolomics Profiling of Patients With A-ß+ Ketosis-Prone Diabetes During Diabetic Ketoacidosis.

When stable and near-normoglycemic, patients with "A-ß+" ketosis-prone diabetes (KPD) manifest accelerated leucine catabolism and blunted ketone oxidation, which may underlie their proclivity to develop diabetic ketoacidosis (DKA). To understand metabolic derangements in A-ß+ KPD patients during DKA, we compared serum metabolomics profiles of adults during acute hyperglycemic crises, without (n = 21) or with (n = 74) DKA, and healthy control subjects (n = 17). Based on 65 kDa GAD islet autoantibody status, C-peptide, and clinical features, 53 DKA patients were categorized as having KPD and 21 type 1 diabetes (T1D); 21 nonketotic patients were categorized as having type 2 diabetes (T2D). Patients with KPD and patients with T1D had higher counterregulatory hormones and lower insulin-to-glucagon ratio than patients with T2D and control subjects. Compared with patients withT2D and control subjects, patients with KPD and patients with T1D had lower free carnitine and higher long-chain acylcarnitines and acetylcarnitine (C2) but lower palmitoylcarnitine (C16)-to-C2 ratio; a positive relationship between C16 and C2 but negative relationship between carnitine and ß-hydroxybutyrate (BOHB); higher branched-chain amino acids (BCAAs) and their ketoacids but lower ketoisocaproate (KIC)-to-Leu, ketomethylvalerate (KMV)-to-Ile, ketoisovalerate (KIV)-to-Val, isovalerylcarnitine-to-KIC+KMV, propionylcarnitine-to-KIV+KMV, KIC+KMV-to-C2, and KIC-to-BOHB ratios; and lower glutamate and 3-methylhistidine. These data suggest that during DKA, patients with KPD resemble patients with T1D in having impaired BCAA catabolism and accelerated fatty acid flux to ketones-a reversal of their distinctive BCAA metabolic defect when stable. The natural history of A-ß+ KPD is marked by chronic but varying dysregulation of BCAA metabolism.

Prehospital Efficacy and Adverse Events Associated with Bolus Dose Epinephrine in Hypotensive Patients During Ground-Based EMS Transport.

BACKGROUND: The utility and efficacy of bolus dose vasopressors in hemodynamically unstable patients is well-established in the fields of general anesthesia and obstetrics. However, in the prehospital setting, minimal evidence for bolus dose vasopressor use exists and is primarily limited to critical care transport use. Hypotensive episodes, whether traumatic, peri-intubation-related, or septic, increase patient mortality. The purpose of this study is to assess the efficacy and adverse events associated with prehospital bolus dose epinephrine use in non-cardiac arrest, hypotensive patients treated by a single, high-volume, ground-based Emergency Medical Services (EMS) agency. METHODS: This is a retrospective, observational study of all non-cardiac arrest EMS patients treated for hypotension using bolus dose epinephrine from September 12, 2018 through September 12, 2019. Inclusion criteria for treatment with bolus dose epinephrine required a systolic blood pressure (SBP) measurement <90mmHg. A dose of 20mcg every two minutes, as needed, was allowed per protocol. The primary data source was the EMS electronic medical record. RESULTS: Forty-two patients were treated under the protocol with a median (IQR) initial SBP immediately prior to treatment of 78mmHg (65-86) and a median (IQR) initial mean arterial pressure (MAP) of 58mmHg (50-66). The post-bolus SBP and MAP increased to 93mmHg (75-111) and 69mmHg (59-83), respectively. The two most common patient presentations requiring protocol use were altered mental status (55%) and respiratory failure (31%). Over one-half of the patients treated required both advanced airway management (62%) and multiple bolus doses of vasopressor support (55%). A single episode of transient severe hypertension (SBP>180mmHg) occurred, but there were no episodes of unstable tachyarrhythmia or cardiac arrest while en route or upon arrival to the receiving hospitals. CONCLUSION: These preliminary data suggest that the administration of bolus dose epinephrine may be effective at rapidly augmenting hypotension in the prehospital setting with a minimal incidence of adverse events. Paramedic use of bolus dose epinephrine successfully increased SBP and MAP without clinically significant side effects. Prospective studies with larger sample sizes are needed to further investigate the effects of prehospital bolus dose epinephrine on patient morbidity and mortality.

Feasibility, Effectiveness and Safety of Prehospital Intravenous Bolus Dose Nitroglycerin in Patients with Acute Pulmonary Edema.

Introduction: The necessity of rapid preload and afterload reduction in patients with decompensated congestive heart failure (CHF) and acute pulmonary edema (APE) is well established. In the hospital setting, intravenous (IV) nitroglycerin demonstrates improved patient morbidity and mortality. However, prehospital treatment is typically limited to sublingual nitroglycerin at doses that often do not affect afterload. In this study, we assessed feasibility, safety and effectiveness of prehospital IV bolus nitroglycerin in decompensated CHF patients with APE. Methods: This was a retrospective chart review of all emergency medical services (EMS) and ED patient care records of subjects treated for presumed decompensated CHF with APE with bolus-dose IV nitroglycerin between March 15, 2018 and March 15, 2019 by a large, suburban, county-based EMS service in Texas. Inclusion criteria for treatment included both hypertension (systolic blood pressure [SBP] > 160 mmHg) and acute respiratory distress with a paramedic clinical impression of decompensated CHF with APE. Treatment consisted of a 1 mg nitroglycerin bolus, repeated in 5 minutes if SBP > 160 mmHg. Results: During the study period, 48 patients were treated with IV bolus nitroglycerin. Initially, the median (IQR) SBP was 211.0 mmHg (190.0-229.5), 5-minutes post IV NTG was 177.0 mmHg (155.0-199.0), and upon ED arrival was 181.5 mmHg (157.0-207.0). 5 minutes after IV nitroglycerin, the median pulse decreased from 113 (96-124) to 103 (85-117) beats per minute and the median oxygen saturation increased from 86% (74-89) to 98% (96-99). Based on hospital records review, 45/48 (94%) of patients treated with IV nitroglycerin were found to have CHF with APE. A single episode of transient hypotension, which resolved without treatment, did occur during EMS transport. Conclusion: This case series found that patients who were treated by paramedics with IV NTG had improved systolic blood pressure and oxygen saturation upon ED arrival as compared to their initial presentation. Over 90% of these patients were correctly identified by paramedics as having CHF with APE based on ED evaluation. Only one patient had an adverse event, which was transient hypotension that did not require intervention.

The high prevalence of pain in emergency medical care.

Although there is a widely held belief that pain is the number 1 complaint in emergency medical care, few studies have actually assessed the prevalence of pain in the emergency department (ED). We conducted an analysis of secondary data by using explicit data abstraction rules to determine the prevalence of pain in the ED and to classify the location, origin, and duration of the pain. This retrospective cross-sectional study was conducted at an urban teaching hospital in Indianapolis, IN. Charts from 1,665 consecutive ED visits during a 7-day period were reviewed. Pain was defined as the word pain or a pain equivalent word (including aching, burning, and discomfort) recorded on the chart. Of the 1,665 visits, 61.2% had pain documented anywhere on the chart, 34.1% did not have pain, and 4.7% were procedures. Pain was a chief complaint for 52.2% of the visits. This high prevalence of pain has important implications for the allocation of resources as well as educational and research efforts in emergency medical care.