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Biomedical subjects

R A Sack

Publications and source records attributed to R A Sack.

At least 37 records · Page 2Linked to original sources
PubMed1986

Origin and composition of lipid deposits on soft contact lenses.

"Jelly bump" deposits, common to high-water-content hydrogel extended-wear contact lenses, were shown to be composed primarily of lipids, with calcium an optional minor component. Extraction, separation, and analysis of deposited versus nondeposited regions of the same lenses reveals that lipids were restricted to the deposited regions of the lens, with a composition of long and intermediate chain cholesterol esters (possibly waxy esters) and triglycerides. This composition is independent of deposit size or individual depositor. Except for an elevated triglyceride level, the composition mirrors that of the tear lipid layer. Analysis of tear films of heavy and nondepositors, combined with clinical evidence, reveals that many depositors have a relatively decreased tear flow with some exhibiting an elevated tear-lipid fraction. A mechanism of deposition is proposed to require the local depletion of the aqueous tear layer stranding lipid on the lens surface, thereby creating a hydrophobic region suitable for further deposition. Deposition does not mechanistically involve tear film proteins, calcium, or microorganisms although they can, at times, be associated with the lipid deposit.

Biomechanical Phenomena↗
PubMed1984

Hypokalemia of various etiologies complicating elective surgical procedures.

During a 12-month period, 7933 surgical procedures were performed in a suburban intercommunity hospital. Thirty scheduled procedures were cancelled preoperatively by the anesthesia department because the level of serum potassium was below 3.2 mEq/L. Hypokalemia compromised three patients intraoperatively, and two patients suffered severe and life-threatening complications postoperatively. A preoperative bowel preparation produced severe hypokalemia in one patient, thus bringing the routine use of this time-honored procedure into question. The suggestion is made that all patients who are over 50 years of age, and who are scheduled for elective operation, receive an admission evaluation of the level of serum potassium.

Adult↗
PubMed1982

Prolonged postoperative apnea complicating gynecologic surgery; atypical cholinesterase and myasthenia gravis.

Over a 10-year period 12,643 gynecologic surgical procedures were performed with the patients under general anesthesia. Succinylcholine was the muscle relaxant used in the majority of cases. Four of these patients developed prolonged postoperative apnea; the longest period of apnea was 6 hours. In one patient atypical cholinesterase was documented, and two of the patients were subsequently diagnosed as having myasthenia gravis. In the fourth case an etiology for the apnea was not demonstrated. A compilation of drugs in common clinical usage which interfere with neuromuscular transmission is included.

Adult↗
PubMed1980

The effect of utilization on health care costs.

This report analyzes the effect of utilization on health care costs. Two important aspects of utilization are examined: (1) the type of obstetric delivery utilized; (2) the extent of utilization of hospital facilities. A retrospective review of the type of delivery employed by five different physicians to deliver 494 primiparous patients revealed cesarean section rates varying from 16% to 40%. Average charges incurred by 100 patients who had undergone uncomplicated abdominal hysterectomies varied by as much as 26%. A simple formula to project cost is included.

California↗
PubMed1979

The value of intravenous urography prior to abdominal hysterectomy for gynecologic disease.

Negligence and failure to "test timely" are the two most common charges in obstetric and gynecologic malpractice suits. Both charges are often made in cases involving urinary tract injury during gynecologic surgery. These injuries occur most commonly during abdominal hysterectomy. This report is a 6 year study of 170 consecutive abdominal hysterectomies to ascertain the value of routine preoperative urography in preventing urinary tract injuries. As a control, 260 consecutive abdominal hysterectomies were performed without preoperative urography. There was one ureteral transection in the control group, but unrecognized urinary tract injuries did not occur in either the study or control group. The risks, costs, and benefits of urography are analyzed.

Adult↗
PubMed1978

The primary-care physician and cancer detection: the role of the Pap smear.

This is a retrospective 5 year study of cancer detection in the suburban office of a primary-care physician. There were 127 diagnoses of malignancy confirmed in 5,011 patients, 62 in the reproductive system and 62 in other organ systems. More than 9,000 Pap smears resulted in the final diagnosis of carcinoma of the cervix in only seven patients. 374 curettages yielded 37 cases of endometrial carcinoma. All of these patients had Class I Pap smears preoperatively.

Adult↗