Terence W. Sutton

Time of onset of chest pain in acute myocardial infarction

We studied the time of onset of chest pain in 1099 patients admitted to a coronary care unit with myocardial infarction using a statistical model. Statistical analysis demonstrated an excess of infarcts with time of onset of chest pain at 0700 hours (14%) and at midnight (11%), with the remaining infarct population (75%) forming a background distribution over the 24 hr.

Circadian variation in the frequency of onset of chest pain in acute myocardial infarction.

The time of onset of chest pain was studied prospectively in 1154 consecutive patients admitted to a coronary care unit with myocardial infarction during a five year period. Statistical analysis confirmed a previous finding in a retrospective study of a bimodal frequency distribution with peaks in the time of onset of chest pain between 2330 and 0030 hours and between 0630 and 0830 hours.

Acute myocardial infarction and day of the week

S everal studies investigated the relation between the incidence of acute myocardial infarction and the days of the week.le5 Most of these studies concerned mortality3-5 and found that the incidence is highest on Monday and Saturday. Furthermore, the World Health Organization Regional Office for Europe project of the Myocardial Infarction Community Registers2 also found the peak incidence of heart attacks on these days. There was significant deviation from the uniform distribution in only 1 of the 19 centers involved, although when the figures from all the centers were combined (n = 831 l), a statistically significant but small difference in the distribution from the uniform was seen. We studied the relation between the frequency of occurrence of myocardial infarction and the days of the week in 2,254 patients admitted to a coronary care unit during a lo-year period. Patients are admitted to the coronary care unit of Leicester General Hospital by the emergency ambulance service. The average delay between reporting onset of symptoms and admission to the unit is about 30 minutes. The 2 main coronary care units admit patients 7 days a week from all parts of the city of Leicester and its surroundings. The number of patients admitted at the hospital is approximately 50% of the total of those with suspected acute myocardial infarction, without geographic, sex or age bias. Since the inception of the coronary care unit in 1976 we have kept accurate records of patient characteristics, documenting the date and time of onset of chest pain, and admission to and discharge from the unit, together with electrocardiographic and cardiac enzyme changes, complications and therapy. We examined the records of all patients admitted to the unit between January I, 1979, and December 31, 1988. Of 8,881 admissions, 3,239 (36%) had an acute myocardial infarction, according to the Minnesota code criteria.

Nursing decision making in a coronary care unit

This study was designed as an approximate replication of a recent Canadian study on a sample of 20 nurses from the coronary care unit of a large teaching hospital in the U.K. Results from this study indicate that knowledge and experience are the two most important factors influencing rapid decision making, and nurses make many rapid decisions in emergency situations prior to seeking medical help. These results are in agreement with those of the original study.

Do indwelling cannulae on coronary care units need a heparin flush

Abstract One hundred and ninety six admissions to a coronary care unit who had intravenous (‘Venflon’) cannulae inserted were studied to see whether the addition of heparin to flushing solutions diminished clotting in cannulae, or reduced associated thrombophlebitis. Comparing 0.9% saline with a standard low dose dilution of heparin (10 units/ml) in a controlled trial, no differences were found in the incidence of inflammation, or of clotting in cannulae. Since heparin is more expensive than saline, may interact with other intravenous drugs, and might affect systemic anti-coagulation, routine use of it in coronary care units for flushing intravenous cannulae is not recommended.

A trial of povidone-iodine ointment for the prevention of cannula thrombophlebitis

The efficacy of povidone-iodine ointment in the prevention of cannula thrombophlebitis was assessed in a prospective controlled study of 100 consecutive patients. Thrombophlebitis was evaluated clinically, and in addition all cannulae were cultured, semi-quantitatively and by the conventional broth technique, to detect any bacterial colonization. The incidence of thrombophlebitis was slightly higher in the test than in the control group. It is concluded that the use of povidone-iodine ointment for prophylaxis does not reduce the incidence of cannula thrombophlebitis. There was no significant association between the incidence of thrombophlebitis and cannula colonization as measured by either the semi-quantitative technique or the conventional broth technique.