title: Aspects on the intensity and the relief of pain in the prehospital phase of acute coronary syndrome: experiences from a randomized clinical trial.
abstract: The primary aim of this study was to evaluate the pain relief and tolerability of two pain-relieving strategies in the prehospital phase of presumed acute coronary syndrome (ACS), and the secondary aim was to assess the relationship between the intensity and relief of pain and heart rate, blood pressure, and ST deviation. Patients with chest pain judged as caused by ACS were randomized (open) to either metoprolol 5 mg intravenously (i.v.) three times at 2-min intervals (n = 84; metoprolol group) or morphine 5 mg i.v. followed by metoprolol 5 mg three times i.v (n = 80; morphine group). Pain was assessed on a 10-grade scale before randomization and 10, 20, and 30 min thereafter. The mean pain score decreased from 6.5 at randomization to 2.8 30 min later, with no significant difference between groups. The percentages with complete pain relief (pain score < or = 1) after 10, 20, and 30 min were 11, 16, and 21%, respectively, with no difference between groups. Hypotension was less frequent in the metoprolol group compared with the morphine group (0 vs. 6.3%; P=0.03), as was nausea/vomiting (7.2 vs. 24.0%; P=0.004). At randomization intensity of pain was associated with degree of ST elevation (P=0.009). The degree of pain relief over 30 min was associated with decrease in heart rate (P=0.03) and decrease in ST elevation (P=0.01).In conclusion, in the prehospital phase of presumed ACS, neither a pain-relieving strategy including an anti-ischemic agent alone nor an analgesic plus anti-ischemic strategy in combination resulted in complete pain relief. Fewer side effects were found with the former strategy. Other pain-relieving strategies need to be evaluated.
authors.affiliation: Ambulance Department of Dalarna County, Falu Hospital, Falun, Sweden.
authors.forename: Crister
authors.initials: C
authors.lastname: Zedigh
authors.forename: Annika
authors.initials: A
authors.lastname: Alho
authors.forename: Elisabet
authors.initials: E
authors.lastname: Hammar
authors.forename: Thomas
authors.initials: T
authors.lastname: Karlsson
authors.forename: Thomas
authors.initials: T
authors.lastname: Kellerth
authors.forename: Leif
authors.initials: L
authors.lastname: Svensson
authors.forename: Eva
authors.initials: E
authors.lastname: Grimbrandt
authors.forename: Johan
authors.initials: J
authors.lastname: Herlitz
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage* / Q000009:adverse effects; D000368:Aged; D000369:Aged, 80 and over; D000698:Analgesia / Q000009:adverse effects / Q000379:methods*; D000700:Analgesics / Q000008:administration & dosage* / Q000009:adverse effects; D000787:Angina Pectoris / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D004562:Electrocardiography; D004632:Emergency Medical Services; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage* / Q000009:adverse effects; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage* / Q000009:adverse effects; D010147:Pain Measurement; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists; D000700:Analgesics; D009020:Morphine; D008790:Metoprolol