Absence of salting out effects in forensic blood alcohol determination at various concentrations of sodium fluoride using semi-automated headspace gas chromatography.

Blood alcohol measurements determined by headspace gas chromatography have been challenged on the grounds that the presence of the preservative sodium fluoride in blood samples artificially increases headspace alcohol concentrations due to a salting out effect. Blood samples containing varying amounts of ethanol and sodium fluoride were tested using semi-automated headspace gas chromatography with n-propyl alcohol as the internal standard to assess the validity of this challenge. We find, in fact, that under these test conditions the measured alcohol levels are systematically depressed as the amount of sodium fluoride in the blood sample increases. The challenge thus has no basis.

Efficacy of morphine sulfate-augmented hepatobiliary imaging in acute cholecystitis.

OBJECTIVE: A review of the English language literature was performed to determine the sensitivity and specificity of morphine sulfate-augmented hepatobiliary imaging for acute cholecystitis. Twenty publications, involving 914 patients, were reviewed from journals published between 1984 and 1999. The analysis of these patients has resulted in the largest combined review study to date. The sensitivity and specificity of morphine-augmented hepatobiliary imaging were calculated to be 96.1% and 88.6%, respectively. After reading this paper, the nuclear medicine technologist should be able to: (a) discuss the clinical use of morphine augmentation during hepatobiliary imaging; and (b) state the sensitivity and specificity of morphine sulfate-augmented hepatobiliary imaging.

Efficacy of syrup of ipecac-induced emesis for emptying gastric contents.

Syrup of ipecac (SOI) is a commonly used emetic for toxic ingestions. A preliminary study was undertaken to quantify the efficacy of SOI-induced emesis. Three groups of adult subjects fasted overnight before ingestion of 1 mCi of Tc-99m human serum albumin-sucralfate. Sucralfate is minimally absorbed from the gastrointestinal tract and has a gastric clearance half-time of 90 minutes, approximately equal to that of solid foods. At 5, 30, and 60 minutes after ingestion of radiolabeled sucralfate (RSC), subjects were given a standard dose of 30 ml SOI and 240 ml of water. Gastrointestinal tract images were obtained both at the time of ingestion of RSC and 60 minutes after ingestion of SOI. Regions-of-interest were drawn and activity measured over the stomach and small bowel with correction for physical decay. Those subjects (N = 10) treated at 5 minutes after ingestion retained a mean value of 17% of the administered RSC by 60 minutes. The group (N = 5) treated at 30 minutes after ingestion retained a mean value of 41%, while those (N = 5) treated at 60 minutes retained a mean value of 56%. The results tend to confirm the efficacy of SOI-induced emesis when SOI is given promptly (i.e., 5 minutes) following ingestion, and generally support efforts to assure widespread immediate availability of SOI for toxic ingestions.

Perfusion scan findings understate the severity of angiographic and hemodynamic compromise in chronic thromboembolic pulmonary hypertension.

Major vessel chronic thromboembolic pulmonary hypertension is potentially remediable by thromboendarterectomy. The diagnosis often has been delayed because a lung perfusion scan demonstrated modest defects thought to be incompatible with severe vascular obstruction. To define the relationships between perfusion scan abnormalities, angiographic findings, and hemodynamic data, we analyzed 25 consecutive patients with chronic major vessel thromboembolic pulmonary hypertension who subsequently underwent thromboendarterectomy. We found that the perfusion lung scan consistently caused us to underestimate the severity of pulmonary arterial obstruction as defined by pulmonary angiography. Furthermore, there was no significant correlation between the severity of hemodynamic compromise and the extent of obstruction defined by perfusion scan or angiogram. These findings suggest that, when pulmonary hypertension is known or suspected, the diagnosis of correctable, chronic major vessel obstruction should be pursued by angiography and hemodynamic assessment even though the perfusion scan may demonstrate only two segmental defects.

Intravenous administration of morphine sulfate in hepatobiliary imaging for acute cholecystitis: a review of clinical efficacy.

Morphine sulfate has been used by several investigators in the cholescintigraphic diagnosis of acute cholecystitis. A review of the available literature indicates that morphine sulfate significantly reduces the total time required for the hepatobiliary examination, while retaining both high sensitivity (98.8%) and specificity (88.9%).

Clinical efficacy of intravenous morphine administration in hepatobiliary imaging for acute cholecystitis.

The most urgent diagnosis addressed by cholescintigraphy is acute cholecystitis. By administering low-dose intravenous morphine sulfate to patients undergoing cholescintigraphy (who demonstrate visualization of both the common bile duct and intestine and nonvisualization of the gallbladder), the time required to complete the study has been reduced to a maximum of 90 minutes. One hundred twenty-eight patients underwent cholescintigraphy for clinically suspected acute cholecystitis. Forty patients received intravenous morphine sulfate during the procedure. In patients who received morphine sulfate during the examination, the sensitivity of cholescintigraphy for the diagnosis of acute cholecystitis was 100%; the specificity was 85%.

Indium 111-labeled white blood cell scans after vascular prosthetic reconstruction.

The clinical value of indium 111-labeled white blood cell (WBC) scanning done after vascular graft procedures was investigated to differentiate noninfectious postoperative inflammation associated with graft incorporation from early prosthetic graft infection. Indium 111-labeled WBC scans were initially obtained in 30 patients before discharge from the hospital and during the subsequent follow-up period (334 days). Fourteen of 30 patients (47%) had normal predischarge scans that included all 10 patients who had grafts confined to the abdomen and 4 of 20 patients (20%) who had grafts arising or terminating at the femoral arteries (p less than 0.05). Sixteen of 30 patients (53%) discharged with abnormal initial indium 111 WBC scans underwent serial scanning until the scan normalized or a graft complication developed. All of the 16 patients had grafts involving the groin region. Abnormal indium 111 uptake in the femoral region continued for a mean 114 days without the development of prosthetic graft infections. The sensitivity of indium 111-labeled WBC scans for detecting wound complications was 100%, whereas the specificity was 50%. Thus, the accuracy of the test was only 53%. We conclude that (1) abnormal indium 111 WBC scans are common after graft operations involving the groin region but are unusual after vascular procedures confined to the abdomen, and (2) in the absence of clinical suspicion, the indium 111-labeled WBC scan does not reliably predict prosthetic graft infection because of the low specificity of the test in the early postoperative period.

Space medicine--a review of current concepts.

Space medicine deals with the branch of research involved with the adaptation of humans to the unique environment of space. More than 100 people have traveled in space. The day will come when some human beings will spend all their time in space. Medical problems encountered in space, such as motion sickness, negative nitrogen and calcium balance, anemia and radiation exposure, are issues that already affect medical practice outside aerospace medicine.

Radiolabeled sucralfate: a review of clinical efficacy.

Radiolabeled sucralfate has been utilized by several investigators to evaluate peptic ulcer, active inflammatory bowel disease, esophageal ulcer, and gastric cancer. A review of the available literature indicates that radiolabeled sucralfate has been used to evaluate peptic ulcer and active inflammatory bowel diseases with high sensitivity and specificity. Other possible uses of radiolabeled sucralfate which have been less thoroughly studied and for which data are inadequate to accurately determine sensitivity and specificity include the detection of gastric cancer and esophageal ulceration.

Fungal splenic abscesses in the immunosuppressed patient. Correlation of imaging modalities.

A patient with fungal splenic abscesses is presented in whom multiple noninvasive diagnostic imaging modalities were available for correlation. Of the five imaging modalities, three (Gallium-67, ultrasound and computed tomography) were diagnostically useful, while two (liver-spleen scan and In-111 white blood cell scan) were not as useful. This case also stresses the use of repeated studies correlating with clinical impressions to obtain an accurate diagnosis in a potentially life-threatening condition such as splenic abscess.

False-negative bone image with radiographically evident osteoblastic lesions in prostatic carcinoma.

A unique case of documented prostatic carcinoma with radiographically evident osteoblastic lesions and a false-negative bone image is presented.

Intraoperative osteoscintigraphy as an aid to bone biopsy.

A new use for intraoperative bone imaging is described. The technique allowed accurate localization of bone pathology for biopsy where plain radiographs and bone morphology were otherwise normal. The technique should increase diagnostic accuracy and eliminate false-negative biopsy results.

Work in progress. Gastrointestinal ulcerations: detection using a technetium-99m-labeled ulcer-avid agent.

Technetium-99m-labeled sucralfate, an ulcer-avid material, was shown in preliminary animal and human studies to be stable in vivo with good sensitivity. Eight experimentally produced discrete gastric ulcers in three rabbits were visualized using this material. Of seven human studies, four studies were true-positive and three were true-negative. It is suggested that Tc-99m-labeled sucralfate may prove to have significant clinical advantages for the evaluation of gastrointestinal ulcer disease and other diseases that are associated with loss of mucosal integrity. The method for labeling sucralfate with Tc-99m was developed by the authors.