This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.
Dr. Galla and I share similar concern about the effect of halothane on circulation. The only value that I can see in publishing Doctor Galla's communication of Feb. 12 to you, and this reply, is to emphasize the amount of information that needs to be obtained from published figures in these days of abbreviated communications. The example at point concerns cardiac output, which was listed at 5.17 ± 0.50 liters per minute. The standard error of the mean is equal to the standard deviation divided by the square root of N — 1. Ten subjects were measured, so N = 10. The square root of N — 1 therefore becomes 3. The standard deviation then will be 3 times 0.50, which equals 1.50; and 1.50 is 28% of 5.17. These values then state statistically that approximately one-third of the values will lie between the average (5.17) and 28% below that figure.
Virtue RW. Respiratory and Hemodynamic Measurements During Anesthesia-Reply. JAMA. 1962;180(6):510. doi:10.1001/jama.1962.03050190072018
Coronavirus Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: