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Biomedical subjects

O Clark

Publications and source records attributed to O Clark.

8 recordsLinked to original sources
PubMed1997

Nausea and vomiting following thyroid and parathyroid surgery.

STUDY OBJECTIVES: To determine the incidence of postoperative nausea and vomiting (PONV) following thyroid and parathyroid surgery. To determine whether PONV is reduced when propofol is used for maintenance of anesthesia as compared to isoflurane and to evaluate the costs and resource consumption associated with these two anesthetic regimens. DESIGN: Randomized, prospective study. SETTING: University-affiliated hospital--a referral center for endocrinologic surgery. PATIENTS: 118 ASA physical status I and II patients, aged 18 years and older, undergoing elective thyroid or parathyroid surgery. INTERVENTIONS: Patients received either isoflurane (0.5 to 1.3% end-tidal) or propofol (50 to 200 micrograms/kg/min) for maintenance of anesthesia. All patients received propofol for induction of anesthesia, succinylcholine or vecuronium, nitrous oxide, and fentanyl. Prophylactic antiemetics were not administered. Postoperative pain was treated with ketorolac, fentanyl, or acetaminophen. MEASUREMENTS AND MAIN RESULTS: Signs and symptoms of nausea and vomiting were graded on a four point scale as 1 = no nausea; 2 = mild nausea; 3 = severe nausea; 4 = retching and/or vomiting. Grades 3 and 4 were grouped together as PONV. The combined incidence of PONV was 54% over the 24-hour postoperative evaluation period. PONV was significantly more common in patients receiving isoflurane than propofol for maintenance of anesthesia (64% vs. 44%). In women (n = 87), the incidence of PONV was significantly greater in those patients who received isoflurane than those who received propofol for maintenance (71% vs. 42%). However, in men (n = 31), there was no significant difference in PONV between anesthetic regimens (47% with isoflurane vs. 50% with propofol). There were no differences in the duration of stay in the postanesthesia care unit, time to discharge from the hospital, or local wound complications (hematomas) between groups. The use of propofol for maintenance of anesthesia was associated with an additional cost, relative to the isoflurane group, of $54.26 per patient. CONCLUSION: Patients undergoing thyroid or parathyroid surgery are at high risk for the development of PONV. Propofol for maintenance of anesthesia, although more expensive than isoflurane, reduces the rate of PONV in women.

Adult↗
PubMed1993

Clinical reactivation of herpes simplex virus type 2 infection in seropositive pregnant women with no history of genital herpes.

OBJECTIVE: To determine the risk for genital herpes and asymptomatic herpes simplex virus (HSV) shedding in late pregnancy and delivery in a population of HSV type 2 (HSV-2)-seropositive but previously asymptomatic pregnant women. DESIGN: A prospective inception cohort study. PARTICIPANTS: A total of 1355 pregnant women with no history of genital herpes referred from three private obstetrics practices between November 1985 and June 1988. MAIN OUTCOME MEASURES: Confidential questionnaires evaluated sexual risk factors in relation to HSV-2 serologic status as determined by Western blot analysis. Herpes simplex virus shedding was determined by viral culture of the cervix and vulva and of any suspicious lesions. RESULTS: Antibody to HSV-2 was detected in 439 of 1355 pregnant women (32%) with no history of genital herpes. Asymptomatic HSV shedding was detected in 5 of 1160 cultures (0.43%) obtained in late pregnancy and during delivery. A first episode of clinical genital herpes was recognized by 43 of 264 HSV-2-seropositive women (16%) during their pregnancy. CONCLUSIONS: Serologic evidence of unknown HSV-2 infection was common in pregnant women without a history of genital herpes. Asymptomatic viral shedding in these women occurred at a rate similar to that seen in women with symptomatic genital HSV-2 infection. To improve recognition of genital herpes near term, obstetricians should counsel pregnant women about the high prevalence and mild and diverse symptoms of genital HSV-2 infection.

Adult↗
PubMed1992

Set-point for parathyroid hormone release increases with postmaturational aging in the rat.

The plasma concentration of immunoreactive PTH (iPTH) increases with postmaturational aging in both humans and animals. In the present study we determined the basal, maximally stimulated, and maximally suppressed levels of iPTH and the concentration of whole blood ionized calcium sufficient to produce half-maximal suppression of the plasma concentration of iPTH (set-point for PTH release) in male Fischer 344 rats aged 3, 6, 12, 18, 24, and 28 months. Basal iPTH increased 2.3-fold from 3 to 28 months of age, whereas basal blood ionized calcium remained unchanged. The set-point for PTH release increased steadily and significantly (P < 0.001) from 1.19 +/- 0.09 mM at 3 months to 1.37 +/- 0.13 mM at 24 months and then declined slightly to 1.32 +/- 0.11 mM at 28 months of age. Basal iPTH correlated significantly with set-point. Neither maximally stimulated nor maximally suppressed iPTH levels showed any significant change with advancing age. These results suggest that the age-related increase in basal plasma iPTH in the rat may be in part a consequence of an increase in the set-point for PTH release.

Aging↗
PubMed1984

A new method with high sensitivity and specificity for localization of abnormal parathyroid glands.

A novel method for localization of abnormal parathyroid glands involving color-processing of nuclear scintigrams of the neck after injection of Thallium-201 and Technetium pertechnetate is presented with surgical correlation. Preoperative localization of single parathyroid adenomas was successful in 88% of previously unoperated patients and in 85.7% of those with adenomas not located at previous surgery. Eighty-three per cent of glands with secondary hyperplasia, 66% of glands with primary hyperplasia, and one carcinoma were localized. No abnormal studies were seen in non-hyperparathyroid hypercalcemia, and no false positive studies were seen. Localization appeared related to larger adenomas (300-5000 mg), although one of 60 mg was localized. Color-comparison dual-isotype scintigraphy was useful for localization of parathyroid adenomas and hyperplastic glands and exceeded the reported sensitivity of either ultrasonography or computerized tomography. It deserves wider evaluation in preoperative management of at least hyperparathyroidism of the primary or persistent types.

Adenoma↗
PubMed1982

Successful treatment of adrenal metastases from large-cell carcinoma of the lung.

Although on a weight basis the adrenal gland is the most common site of extranodal spread from lung cancer, antemortem diagnosis and successful therapy of adrenal metastasis are rare. We have treated two patients with apparently solitary metastases in the adrenal gland from large-cell carcinomas of the lung using a combination of adrenalectomy and vigorous therapy to the primary site. Both patients experienced symptomatic relief, and, in contrast to the expected short survival in lung cancer with distant metastasis, they remain well six years and 14 years after treatment.

Adrenal Gland Neoplasms↗
PubMed1982

Localization of parathyroid adenoma by computed tomography.

Sixteen consecutive patients with the clinical diagnosis of hyperparathyroidism, nine with and seven without previous surgery, had computed tomography (CT) examinations preoperatively to evaluate the use of CT in localizing parathyroid adenomas. The patients were scanned at 5 mm intervals from the level of the hyoid bone to the lung apex. Scanning of the mediastinum was performed at 10 mm intervals from apex to lung base. Computed tomography correctly identified prospectively the site of the adenoma in 10 of 13 patients (77%), with surgically proven adenomas. In retrospect, all 13 adenomas could be identified. One false positive diagnosis of adenoma was made. Our study suggests that CT may be beneficial in the preoperative localization of parathyroid tumors, particularly in ectopic locations.

Adenoma↗