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Biomedical subjects

L Knight

Publications and source records attributed to L Knight.

At least 19 recordsLinked to original sources

Modification of an aerosol mask to provide high concentrations of oxygen in the inspired air. Comparison to a nonrebreathing mask.

With a few simple modifications, an aerosol mask was adapted to deliver high concentrations of oxygen. We compared the delivery of high concentrations of oxygen by this modified aerosol mask (MAM) with that of a nonrebreathing mask (NRM) in five normal volunteers and six patients with respiratory failure. Besides improved oxygenation, the MAM also permitted the following: humidification of the inspired oxygen, nebulization of bronchodilators, oropharyngeal suctioning, and performance of fiberoptic bronchoscopy. In lieu of intubation and mechanical ventilation, MAM may be a better alternative to a NRM for maintaining adequate oxygenation until the clinical situation improves.

Adult

The dangers resulting from inaccurate computer-based operative records.

The accuracy of a computer-based recording system of operative procedures was audited at a major district general hospital. The system is supposed to provide accurate records of theatre activity, to allow for improved nursing resource allocation and provide surgeons with a basic record of their operations. Mistakes were present in the details of 27% of the cases entered. Such inaccuracies highlight a major danger to surgeons with regard to their accountability for operations attributed to them. Mistakes can only cause further problems with regard to audit and future resource allocation.

Documentation

Functional health pattern assessment: a seasonal migrant farmworker community.

A broad-based needs assessment of a migrant farmworker community was conducted using the community functional health pattern tool (Gikow & Kucharski, 1987) and Porter's (1987) factor-isolating theory of population group diagnosis. Data analysis revealed numerous health needs in all 10 functional health patterns and an urgent need for accessible primary prevention programs. A mobile outreach program to the migrant camps was seen as the most effective way to provide education, screening, and health care.

Adult

A comparison of the effect of ipratropium and albuterol in the treatment of chronic obstructive airway disease.

Twenty-five subjects with moderate to severe chronic obstructive airway disease were studied to compare the effect of ipratropium bromide, albuterol, and placebo on the forced expiratory volume in 1 s, (FEV1), forced vital capacity, heart rate, and blood pressure during six hours. Ipratropium produced a significantly greater improvement than albuterol in the FEV1 at 30 minutes and at 3, 4, and 5 hours and in the forced vital capacity at one through six hours. Fifteen subjects did not demonstrate a 15% improvement and at least a 200-mL increase in the FEV1, 15 minutes after metaproterenol sulfate aerosol. All 15 did improve after ipratropium therapy during the study. Ipratropium was effective significantly longer than albuterol. Subjects with better peak responses to ipratropium had a lower FEV1 percent predicted and a greater pack-year smoking history. In patients with chronic obstructive airway disease, ipratropium produces a longer duration of action than albuterol. It is more effective than albuterol in treating severely obstructed individuals and those not responding to metaproterenol. It is equally effective in treating others.

Administration, Inhalation

Endobronchial granulocytic sarcoma causing acute respiratory failure in acute myelogenous leukemia.

Infiltration by leukemic cells may occur in many organs. When localized masses caused by myeloid leukemic infiltration occur, they are called granulocytic sarcomas. Such tumors may be mistaken for primary carcinomas. In this report, we describe a 63-yr-old man with acute myelogenous leukemia who developed progressive atelectasis of the left lower lobe of the lung. Bronchoscopy revealed a fungating endobronchial tumor completely obstructing the left lower lobe bronchus and partially occluding the left upper lobe bronchus. Biopsies from this lesion showed an endobronchial granulocytic sarcoma. Despite chemotherapy, the patient developed progressive hypoxemia and died.

Bronchial Neoplasms

Pulmonary artery banding: long-term results in 63 patients.

Sixty-three patients who underwent banding of the pulmonary artery between 1968 and 1975 were studied. Mortality among patients who underwent the banding procedure was 22%, and among those with ventricular septal defect it was 7%. Thirty-eight of the 49 survivors of the banding procedure were investigated for abnormalities of the pulmonary outflow tract caused by the band. Seventy-one percent of these 38 patients had an identifiable abnormality of the pulmonary valve or artery. These complications occurred more frequently in patients banded at a very young age (less than 2 months old) and in patients in whom the band was in place more than two years. Corrective operations have been performed in 24 of the 49 patients who survived banding. Seventy-six percent of the patients with ventricular septal defect survived corrective operation, while only 29% of the patients with more complex lesions survived.

Age Factors

Lidocaine plasma concentrations during and after endoscopic procedures.

Plasma lidocaine concentrations were intermittently measured in 8 upper gastrointestinal endoscopy and 12 bronchoscopy patients. The highest individual concentration was 0.98 microgram/ml in the upper gastrointestinal endoscopy patients and 3.79 microgram/ml in the bronchoscopy patients. Highest concentrations were reached at 15 minutes in the gastrointestinal endoscopy patients and at 30 or 60 minutes in the bronchoscopy patients. Thus, since lidocaine does not produce toxic effects at concentrations inferior to 6 microgram/ml, doses of this topical anaesthetic up to 16 mg/kg can be safely given during endoscopic procedures to patients with normal hepatic and cardiovascular functions. However, patients with liver metastases should be considered at high risk even if their liver function tests are normal. Patients at high risk of developing lidocaine toxicity should receive lower doses and be closely watched for at least 60 minutes after the end of the procedure.

Anesthetics, Local

Late hemodynamic and angiographic findings after ascending aorta--pulmonary artery anastomosis.

Ascending aorta-pulmonary artery (Waterston) anastomosis was performed in 75 children, 51 of whom were younger than 1 month of age and 36 younger than 1 week of age at the time of operation. There were 21 operative and eight late deaths. Operative deaths occurred more frequently in infants with complex cardiac conditions and severe hypoxemia and acidosis preoperatively. The postoperative status of the pulmonary arteries or arterioles could not be correlate with the degree of cardiomegaly, the pulmonary vascular markings, or characteristics of the shunt murmur. Sixty-four percent of the patients catheterized had one or more postoperative structural abnormalities of the pulmonary arteries following the operation, most frequently kinking or narrowing of a pulmonary artery. Occlusion of a pulmonary artery occurred in five of 33 patients studied by angiography. Pulmonary vascular disease may also develop. Therefore, patients should be catheterized 1 year postoperatively to evaluate the level of pulmonary vascular resistance and the pulmonary arteries.

Aorta

Three year experience with percutaneous introduction of inferior vena cava filter.

Fifteen patients with recurrent pulmonary embolism were treated with a Mobin-Uddin umbrella filter (UF) introduced percutaneously via femoral vein. There were not technical difficulties, bleeding, or migration of the UF. The incidence of lower extremity edema or phlebitis was not higher than in patients with transjugular application of the UF or in patients with surgical inferior vena cava clipping. Two patients had fatal recurrent pulmonary embolism: in one of them the UF was positioned correctly in the vicinityof the renal veins; in the second the UF was placed too low and a large clot may have formed proximal to the UF. The transfemoral approach of the UF insetion represents a significant simplication of the inferior vena caval interruption, but it can only be used if thrombi are excluded by venography in the iliac vein and inferior vena cava. The UF should be placed as close as possible to the orifices of the renal veins to prevent a thrombus formation proximal to the filter.

Adolescent

Peripheral angiograph enhancement by long leg pneumatic boots.

In patients with arterial occlusive disease it is virtually impossible to predict the speed of blood flow due to the presence of stenoses, occlusions, and collaterals. Repeated exposures and injections can be avoided by the use of pneumatic boots which increase peripheral blood flow by reactive hyperemia, are well tolerated by patients, and decreases the pain associated with injection of contrast material.

Angiography

The effect of valium on myocardial blood flow.

The effect of Valium on coronary blood flow was studied. In 18 patients undergoing coronary angiography, total and regional myocardial blood flow was determined by the 133Xe wash-out technique. A total of 39 pre- and 39 post-Valium injection wash-out curves were constructed. Results indicate (99% confidence) that intravenous Valium injection (0.1 mg/kg body weight) decreases myocardial blood flow 12--15%.

Angiography