The control of supplemental oxygen by oximetry

Volume 76 Number 2

SELECTED

previously for it was not until great enough to force the fluid The author then discusses other membranes: 1. The so-called stitution which may or infarction of the

ABSTRACTS

the onset of labor that between the membranes causes of amniotic fluid

45!) the intrauterine pressure and the decidua to the leakage with gross rupture

“high leak” or rupture of the amnioehorion arise secondary to the trauma of attempted membranes, or markedly elevated intrauterine

2. The “double” or “split” sae with the separation Fluid passes through the permeable amnion and drains the more friable chorion.

with subsequent recef~abortion, coitus, infectiorl, pressures.

of the amnion to the outside

from the via minor

LAURENCE

The Canadian Vol. 78, 19.58. Swyer, Paul IL, and Weight,

John:

Medical

Association

The Control

beeawe outsidr. of the

chorion. tears in

SONDERS

Journal

of Supplemental

Oxygen by Oximetry,

p. 231. This paper describes experience in the control of supplemental oxygen with the we of the diamagnetic oxygen analyzer and the Wood speetrophotometric ear osimeter in the assessment of arterial oxygen saturation. The 31 patients investigated were receiving supplemental oxygen on the clinical grounds of cyanosis of central origin or dyspnea or both. In 14 patients receiving supplemental oxygen on clinical grounds, the arterial oxygen saturation was above 95 per cent when they were removed from oxygen and tested in air. They were probably receiving oxygen unnecessarily. In 14 cases there was less than 95 per cent saturation at the first examination. A significant proportion of these patients required more than 46 per cent oxygen initially to achieve an approximately normal arterial oxygen saturation. The tendency was for the need for supplemental oxygen to drop progressively with the passage of time. So surviving infant required supplemental oxygen for longer than 5 days. It was felt that if an infant’s blood can be shown to be 95 to 98 per cent saturated oximetrically, the arterial oxygen tension is not likely to be at dangerous levels. With approximately 96 per cent arterial saturation measured by ear oximeter, the partial PVHsure of oxygen in arterial blood will remain close to the safe 100 mm. Hg level. Oximetry can be used to control administration of supplemental oxygen at the miuimum level necessary to secure oxygenation of arterial blood and avoid hyperoxia in infant,s in the weight groups susceptible to retrolental fibroplasia, and hypoxia due to adherenl*e to a rigid rule-of-thumb limitation of supplemental oxygen. JOHN 5. DETTLINI;

Douglas, R. G., Buchman, M. L., and MacDonald, I?. A.: in Gynecological and Obstetrical Practice, p. 1065.

Recent Trends

in Hysterectomy

Recent trends in hysterectomy were discussed as they occurred at the New York Lying-In Hospital between the years 1950 and 1956, when 3,233 hysterectomies were pcrformed. Of the operations performed, 74.9 per cent were total abdominal in type; 3.7 per cent were subtotal; 18.2 per cent were vaginal; and 3.2 per cent were radical procedures. After 1946, there was a rapid reversal from subtotal to total hysterectomy. The incidence of vaginal hysterectomy has almost doubled since 1959. The median age of the patients who had abdominal hysterectomies was 45.3 years: whereas for those who had vaginal hysterectomies it was 54.6 years. The anesthesia of choice was general anesthesia with thiopentone induction, followed by nitrous osideoxygen-ether or cyclopropane. Myomas were the most frequent indication for the abdominal operation, and prolapse of the uterus for the vaginal procedure. The technique employed in total abdominal