The prehospital use of nitroglycerin according to standing medical orders in an urban EMS system

Adverse events after prehospital nitroglycerin administration in a nationwide registry analysis

OBJECTIVE

Nitroglycerin (NTG) is a vasodilator used in the prehospital setting with chest pain patients. Potential adverse effects include hypotension, bradycardia or tachycardia, and mental status change. However, it is unclear which factors, if any, are associated with patients having an adverse event after receiving NTG. The objective of this study was to determine demographic and clinical factors associated with adverse events after prehospital NTG administration.

METHODS

The ESO Data Collaborative (Austin, TX), containing records from 1322 EMS agencies, was queried for 911 encounters where NTG was administered to patients ≥18 years old by EMS. Adverse event outcomes were defined as a new systolic blood pressure (SBP) < 90, heart rate (HR) < 50 or > 120, mean arterial pressure (MAP) < 65, or change in mental status following NTG administration. Descriptive statistics and logistic regression models adjusting for age, sex, race, ethnicity, intravenous (IV) access, and initial vital signs were used to assess for adverse event-related factors.

RESULTS

Among 80,760 encounters, the mean age was 61 (IQR 50-72), with 52% males, 71% white race, and 7% Hispanic ethnicity. Adverse events occurred in 7% of encounters. Adverse events were found to be less common among Black patients (OR = 0.74, 95%CI:0.69-0.80). IV access obtained prior to NTG administration was associated with fewer adverse events (OR = 0.92, 95%CI:0.85-0.99). Increasing age (OR = 1.02, 95%CI:1.01-1.02) and HR (OR = 1.03, 95%CI:1.02-1.03) were associated with increased odds of adverse events while SBP (OR = 0.99, 95%CI:0.98-0.99) was inversely associated.

CONCLUSIONS

Adverse events following prehospital NTG administration were rare, especially in patients with an SBP > 110 and a HR < 100, and less frequent in those with existing IV access. Demographics were not found to be clinically significant.

Is pre-hospital treatment of chest pain optimal in acute coronary syndrome? The relief of both pain and anxiety is needed

BACKGROUND

Many patients who suffer from acute chest pain are transported by ambulance. It is not known how often treatment prior to hospital admission is optimal and how optimal pain-relieving treatment is defined. It is often difficult to delineate pain from anxiety.

AIM

To describe various aspects of chest pain in the pre-hospital setting with the emphasis on a) treatment and b) presumed acute coronary syndrome.

METHODS

In the literature search, we used PubMed and the appropriate key words. We included randomised clinical trials and observational studies.

RESULTS

Four types of drug appear to be preferred: 1) narcotic analgesics, 2) nitrates, 3) beta-blockers and 4) benzodiazepines. Among narcotic analgesics, morphine has been associated with the relief of pain at the expense of side-effects. Alfentanil was reported to produce more rapid pain relief. Nitrates have been associated with the relief of pain with few side-effects. Beta-blockers have been reported to increase the relief of pain when added to morphine. The combination of beta-blockers and morphine has been reported to be as effective as beta-blockers alone in pain relief, but this combination therapy was associated with more side-effects. Experience from anxiety-relieving drugs such as benzodiazepines is limited. It is not known how these 4 drugs should be combined. The results indicate that various pain-relieving treatments might modify the disease.

CONCLUSION

Our knowledge of the optimal treatment of chest pain and associated anxiety in the pre-hospital setting is insufficient. Recommendations from existing guidelines are limited. Large randomised clinical trials are warranted.

Influence of sex on the out-of-hospital management of chest pain

BACKGROUND

Sex disparities in the diagnosis and treatment of chest pain or suspected angina have been demonstrated in multiple clinical settings. Out-of-hospital (OOH) care for chest pain is protocol-driven and may be less likely to demonstrate differences between men and women.

OBJECTIVES

The objectives were to investigate the relationship between sex and the OOH treatment of patients with chest pain. The authors sought to test the hypothesis that OOH care for chest pain patients would differ by sex.

METHODS

A 1-year retrospective cohort study of 683 emergency medical services (EMS) patients with a complaint of chest pain was conducted. Included were patients taken to any one of three hospitals (all cardiac referral centers) by a single municipal EMS system. Excluded were patients transported by basic life support (BLS) units, those younger than 30 years, and patients with known contraindications to any of the outcome measures. Multivariable regression was used to adjust for potential confounders. The main outcome was adherence to state EMS protocols for treatment of patients over age 30 years with undifferentiated chest pain. Rates of administration of aspirin, nitroglycerin, and oxygen; establishment of intravenous (IV) access; and cardiac monitoring were measured.

RESULTS

A total of 342 women and 341 men were included. Women were less likely than men to receive aspirin (relative risk [RR] = 0.76; 95% confidence interval [CI] = 0.59 to 0.96), nitroglycerin (RR = 0.76; 95% CI = 0.60 to 0.96), or an IV (RR 0.86; 95% CI = 0.77 to 0.96). These differences persisted after adjustment for demographics and emergency department (ED) evaluation for acute coronary syndrome (ACS) as a blunt marker for cardiac risk. Women were also less likely to receive these treatments among the small subgroup of patients who were later diagnosed with acute myocardial infarction (AMI).

CONCLUSIONS

For OOH patients with chest pain, sex disparities in treatment are significant and do not appear to be explained by differences in patient age, race, or underlying cardiac risk.

Errors of omission in the treatment of prehospital chest pain patients

OBJECTIVE

Despite the widespread use of standard treatment protocols, there are few published data regarding paramedic protocol adherence. In this descriptive study, the authors sought to assess the frequency and nature of deviations from a standardized treatment protocol for the chief complaint of chest pain. They also sought to quantify any time delays in treatment of potential ischemic cardiac chest pain.

METHODS

A retrospective review of written documentation obtained from four ambulance services in a mid-Atlantic state was completed. A convenience sample of consecutive emergency medical services (EMS) records was obtained from January 2001 to May 2002, and 75 calls were selected from each service (N = 300).

RESULTS

Neither the median scene times nor the response times varied among the four services in the study. However, the suburban ambulance service (service 1) did have a significantly longer transport time (19 minutes) than the rural (14 minutes) and the urban (11 and 10 minutes) services (p < 0.05). Documentation of history and physical characteristics varied widely for each service. The patient took aspirin 10% of the time prior to EMS arrival, yet paramedics gave it additionally 50% of the time, while nitroglycerin was given in 73% of cases of suspected cardiac ischemia. Posttreatment vital signs for nitroglycerin were documented 30% of the time for three of the four services, while the other service documented these 75% of the time. Medical command contact varied by agency (80-100%), as did the receipt and completion of medical orders.

CONCLUSIONS

Paramedics may delay transport of patients with potential cardiac ischemia. Deviations from protocol occur frequently and the care documented for prehospital patients with chest pain is variable. The expected care described by written protocols does not correlate with the treatment documented.

Evaluation and management of acutely decompensated chronic heart failure in the emergency department

A wide range of patients with symptomatic heart failure seek treatment in the emergency department. While there is no single approach to the diversity of patients with acutely decompensated heart failure, certain overarching principles apply. For patients with acute pulmonary edema or cardiogenic shock, the first priority must be rapid stabilization and treatment of reversible problems. For patients with less dramatic presentations, a more systematic search for precipitating factors may be required. Therapy, in general, is directed at reversing dyspnea and/or hypoxemia caused by pulmonary edema, improving systemic perfusion, and reducing myocardial oxygen demand. While morphine and diuretics still have their traditional roles, vasodilators and inotropic agents play an increasingly important part in the modern pharmacologic approach to decompensated heart failure in the emergency department. After evaluation and stabilization in the emergency department, most patients will require hospital admission, although a subset of low-risk patients may be appropriate for discharge to home following a period of observation. Strategies to optimize emergency department care are likely to have an impact upon patient outcomes and upon resource utilization. (c)2001 by CHF, Inc.