Intrapulmonary gas distribution. A comparison of the helium mixing time and nitrogen single breath test in normal and diseased subjects.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to M Mitchell.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Median and posterior tibial somatosensory evoked potentials (SEPs) were studied on 25 patients with pathologically proven intraspinal neoplasms, and the results were compared and correlated with the details of clinical examination and the information derived from magnetic resonance imaging (MR). MR was abnormal in all cases and in 23 of 25 (92%) demonstrated an intraspinal expansile lesion. SEP was abnormal in 19 of 25 patients (76%). Abnormal SEPs were found in 18 of 19 patients (94%) with cervical or thoracic neoplasms but only in 1 of 6 patients (16%) with the tumor in the thoracolumbar or lumbar region. SEP-MR correlation was significant (P less than 0.05) for thoracic intraspinal neoplasms where all 9 had an abnormal SEP showing a similar pattern of normal median and abnormal posterior tibial study. Clinically, all 7 patients with posterior column sensory deficits had abnormal SEP (100%). Abnormal SEPs were seen in 7 of 11 (63%) patients with spinothalamic deficits and in 4 of 8 (50%) of those with normal sensory examinations. Four of 9 patients (44%) with a normal neurological examination or an examination disclosing ambiguous results indistinguishable from a peripheral pathology had an abnormal SEP strongly suggesting a central sensory disorder. Comparison of preoperative and postoperative SEPs did not disclose useful prognostic information pertaining to the functional recovery.
BACKGROUND: When ultrasonography is used to investigate deep-vein thrombosis, serial testing is recommended for those who test negative initially. Serial testing is inconvenient for patients and costly. We aimed to assess whether the calculation of pretest probability of deep-vein thrombosis, with a simple clinical model, could be used to improve the management of patients who present with suspected deep-vein thrombosis. METHODS: Consecutive outpatients with suspected deep-vein thrombosis had their pretest probability calculated with a clinical model. They then underwent compression ultrasound imaging of proximal veins of the legs. Patients at low pretest probability underwent a single ultrasound test. A negative ultrasound excluded the diagnosis of deep-vein thrombosis whereas a positive ultrasound was confirmed by venography. Patients at moderate pretest probability with a positive ultrasound were treated for deep-vein thrombosis whereas patients with an initial negative ultrasound underwent a single follow-up ultrasound 1 week later. Patients at high pretest probability with a positive ultrasound were treated whereas those with negative ultrasound underwent venography. All patients were followed up for 3 months for thromboembolic complications. FINDINGS: 95 (16.0%) of all 593 patients had deep-vein thrombosis; 3%, 17%, and 75% of the patients with low, moderate, and high pretest probability, respectively, had deep-vein thrombosis. Ten of 329 patients with low pretest probability had the diagnosis confirmed, nine at initial testing and one at follow-up. 32 of 193 patients with moderate pretest probability had deep-vein thrombosis, three diagnosed by the serial (1 week) test, and two during follow-up. 53 of 71 patients with high pretest probability had deep-vein thrombosis (49 by the initial ultrasound and four by venography). Only three (0.6%) of all 501 (95% CI 0.1-1.8) patients diagnosed as not having deep-vein thrombosis had events during the 3-month follow-up. Overall only 33 (5.6%) of 593 patients required venography and serial testing was limited to 166 (28%) of 593 patients. INTERPRETATION: Management of patients with suspected deep-vein thrombosis based on clinical probability and ultrasound of the proximal deep veins is safe and feasible. Our strategy reduced the need for serial ultrasound testing and reduced the rate of false-negative or false-positive ultrasound studies.
The technology of transesophageal echocardiography is now widely available and has proved extremely useful in evaluating cardiovascular anatomy and pathology. Unfortunately, the enhanced echocardiographic detail and multiple transesophageal imaging planes may sometimes be confusing and cause misinterpretations. The majority of these problems are simply the result of operator inexperience. To help prevent misdiagnoses, we have collected a series of the more common diagnostic and technical "pitfalls" of transesophageal echocardiography.
Four school superintendents with a shared commitment to students' needs were able to forge a coalition that brought positive change to an entire region. Helping students and their families was a rallying issue for all community agencies. Initially, the four districts joined to apply for grant funding to link schools and social services providers. This served as a model and catalyst for many other cooperative community efforts.
The difficulties experienced with the recruitment and retention of registered nurses has made it necessary for NHS trusts to review the traditional role of nurses and to transfer some of their duties to other groups of staff in order to maintain services. For example, in the operating department, operating department assistants and operating department practitioners (ODAs/ODPs) are undertaking some of the duties that were previously the responsibility of nurses. This article presents the findings of a survey to determine the extent to which ODAs/ODPs have access to controlled drugs in operating theatres. The survey was initially undertaken by the author in Welsh hospitals during 1998. The mixed responses generated discussion in the Duthie Review Committee (Committee Chairman, personal communication, Royal Pharmaceutical Society of Great Britain (RPSGB), 1999) and led to a collaborative exercise based on a random selection of NHS trust hospitals in England, Scotland and Northern Ireland to obtain a broader data across the UK. Despite a clear legal position concerning possession, the survey showed that practice varied widely and that some trusts may be contravening the Misuse of Drugs Regulations 1985 in order to keep the service running when registered nurses are not available.
Explore the source record for details and available documents.
The benefits of research being undertaken by more than one researcher cannot be underestimated. Having one researcher with intimate knowledge of the organisation and another who could provide a dispassionate view, paid dividends in this study into shared governance from an ethnographic perspective.
Surgical nursing is changing as the type of surgical procedures being performed are becoming more complex and the time for delivering nursing care is reducing. This has resulted in condensing the acute physical care required into a few hours, often to the detriment of other aspects of nursing intervention such as pre- and post-operative anxiety management. A pre-operative psychological care plan for use in a modern, dynamic, surgical arena is briefly outlined as no such strategy currently exists.
Three strains of Escherichia coli (ATCC 128, 10536, and 25922) and one strain of Bacillus subtilis (ATCC 3491) were compared as indicator microorganisms in microbial inhibition tests for their ability to detect fluoroquinolone residues. E. coli strains 128 and 10536 were most susceptible to fluoroquinolone residues, with detection limits of 35-50 micrograms/kg for enrofloxacin. Of the 2 strains, E. coli 10536 was slightly less susceptible. Ciprofloxacin was detected consistently by E. coli 128 at 30 micrograms/kg. Other fluoroquinolone drugs of veterinary interest detected by E. coli 128 were sarafloxacin and difloxacin at 100-250 micrograms/kg concentration. E. coli 25922 yielded 100% sensitivity in detection of enrofloxacin only at the 250 micrograms/kg concentration, and ciprofloxacin and sarafloxacin at 200 micrograms/kg. B. subtilis detected only enrofloxacin 100% of the time at 250 micrograms/kg. The E. coli strains tested were insensitive to other antibacterials commonly used in animals, with the exception of ceftiofur which was detected by E. coli 128 and 10536 at 500 micrograms/kg. The B. subtilis strain was not effective in detecting the fluoroquinolone drugs, whereas the E. coli strains were selective for the fluoroquinolones. E. coli 128 was 100% effective in detecting enrofloxacin and ciprofloxacin in spiked diaphragm homogenate samples at 50 micrograms/kg. Of the microorganisms tested, E. coli strain ATCC 128 was highly suitable as an indicator microorganism in a microbial inhibition assay for selective detection of fluoroquinolone antibacterial residues in animal tissues.