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.

Treatment of Presumed Hyperkalemia in the Prehospital Setting.

INTRODUCTION: Hyperkalemia (HK) is common and potentially a life-threatening condition. If untreated, HK can progress to ventricular arrhythmia and cardiac arrest. Early treatment reduces mortality in HK. This study evaluates a novel protocol for identification and empiric management of presumed HK in the prehospital setting. METHODS: This was a retrospective, observational chart review of a single, large, suburban Emergency Medical Services (EMS) system. Patients treated for presumed HK, with both a clinical concern for HK and electrocardiogram (ECG) changes consistent with HK, from February 2018 through February 2021 were eligible for inclusion. Patients were excluded if found to be in cardiac arrest on EMS arrival. Empiric treatment of HK included administration of calcium, sodium bicarbonate, and albuterol. Post-treatment, patients were placed on cardiac monitoring and adverse events recorded enroute to receiving hospital. Protocol compliance was assessed by two independent reviewers. Serum potassium (K) level was obtained from hospital medical records. RESULTS: A total of 582 patients were treated for HK, of which 533 patients were excluded due to cardiac arrest prior to EMS arrival. The remaining 48 patients included in the analysis had a mean age of 56 (SD = 20) years and were 60.4% (n = 29) male with 77.1% (n = 37) Caucasian, 10.4% (n = 5) African American, and 12.5% (n = 6) Hispanic. Initial blood draw at the receiving facilities showed K >5.0mEq/L in 22 (45.8%), K of 3.5-5.0mEq/L in 23 (47.9%), and K <3.5mEq/L in three patients (6.3%). Independent review of the EMS ECG found the presence of hyperkalemic-related change in 43 (89.6%) cases, and five (10.4%) patients did not meet criteria for treatment due to lack of either appropriate ECG findings or clinical suspicion. No episodes of unstable tachyarrhythmia or cardiac arrest occurred during EMS treatment or transport. CONCLUSION: The study evaluated a novel protocol for detecting and managing HK in the prehospital setting. It is feasible for EMS crews to administer this protocol, although a larger study is needed to make the results generalizable.

Feasibility of prehospital esmolol for refractory ventricular fibrillation.

Background: Esmolol may increase survival for patients with refractory ventricular fibrillation (RVF); however, information related to esmolol use in the prehospital environment is limited. We aimed to assess the feasibility of prehospital bolus dose esmolol for patients with RVF treated by a high-volume, ground-based emergency medical services (EMS) agency. Methods:  Esmolol (0.5 mg/kg single bolus) was added to the RVF protocol on December 10, 2018. Feasibility was defined as esmolol administration in >75% of RVF cases. Secondarily, we compared the proportion of patients with prehospital return of spontaneous circulation (ROSC), 24-hour survival, and survival to hospital discharge during the intervention period (December 10, 2018-June 10, 2020) to a historical control period (June 10, 2017-December 9, 2018) using chi-square tests. Results: Before the protocol change, 63 patients with RVF were identified. After esmolol was added, 70 patients with RVF were identified and 61 (87%) received esmolol. Prehospital ROSC was higher in the esmolol group compared to the historical control group, though statistical significance was not reached (38% versus 24%, P = 0.09). Overall, few patients survived to 24 hours (esmolol n = 15, pre-esmolol n = 16) and fewer survived to hospital discharge (esmolol n = 5, pre-esmolol n = 5), precluding stable statistical comparisons. Conclusion: Collectively, these findings suggest that EMS clinicians are able to accurately identify RVF and administer esmolol in the prehospital setting and that ROSC may be increased. Further large-scale studies are needed to determine the effect of prehospital esmolol for RVF as it relates to neurologically intact hospital discharge.

Prehospital Sinus Node Dysfunction and Asystole in a Previously Healthy Patient with COVID-19.

We report a case of a previously healthy 47-year-old female with syncope due to multiple episodes of nodal dysfunction and asystole. During these brief episodes, she was hypoxic in the mid-80's as a result of COVID-19 pneumonia. The patient was admitted and treated for viral pneumonia and found to have normal electrocardiograms (ECG's), normal troponin levels and a normal echocardiogram during her hospital stay. As she recovered from COVID-19, no further episodes of bradycardia or bradyarrhythmia were noted. This case highlights a growing body of evidence that arrhythmias, specifically bradycardia, should be anticipated by prehospital providers as a potential cardiac complication of SARS-CoV-2 infection.

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.

Motor vehicle crash fatalities among Hispanics in rural North Carolina.

OBJECTIVES: Deaths from motor vehicle crashes (MVCs) have decreased significantly over the past three decades. Unfortunately, few data have been collected regarding death rates for MVCs in minority populations. The purpose of this study was to compare the death rate of whites versus Hispanics for MVCs in a rural environment. METHODS: This study examined one rural county in North Carolina from January 1, 1999, to December 31, 1999. A retrospective cohort study was performed using the North Carolina State Highway Patrol computerized database of MVCs. Data regarding the total number of MVCs, fatalities, alcohol-related deaths, seatbelt usage, and cause of the collision were analyzed for both whites and Hispanics. Census information regarding population in this region also was obtained from the U.S. Bureau of Census. Data were analyzed using a chi-square test, with an alpha value of 0.05 used to establish statistical significance. RESULTS: During the study period, whites were involved in 2,689 MVCs, compared with 158 MVCs for Hispanics. Whites were involved in ten fatal MVCs, compared with seven fatal MVCs involving Hispanics. The percent of fatal MVCs for whites was 0.3%, or 10 deaths per 2,689 MVCs. In contrast, the percent of fatal MVCs for Hispanics was 4.4%, or 7 deaths per 158 MVCs; odds ratio (OR) = 12.4, 95% CI = 4.7 to 33.1. The 2000 Census Report for Pitt County noted a white population of 81,613 and a Hispanic population of 4,216. Based on these population data, the death rate for MVCs per 100,000 population was 12.3 for whites versus 166.0 for Hispanics, OR = 13.6, 95% CI = 5.2 to 35.6. Although the cause for this disparity was not determined, previous studies suggest that alcohol and decreased seatbelt usage are contributing factors. CONCLUSIONS: In this study, the death rates among Hispanics for rural MVCs were significantly higher than for whites. The causes of this disparity are not clear but are important to define. Only by understanding this disparity can we begin to develop appropriate interventions that may prevent these deaths.