PubMed Health⌕ Search

Biomedical subjects

S J Howell

Publications and source records attributed to S J Howell.

18 recordsLinked to original sources
PubMed1995

Effects of propofol and thiopentone, and benzodiazepine premedication on heart rate variability measured by spectral analysis.

We studied the effects of temazepam premedication and induction of anaesthesia with thiopentone or propofol on the heart rate power spectrum in 47 patients undergoing elective minor surgery. Eighteen patients received temazepam 20 mg orally as premedication. There was a significant reduction in high frequency power and total power, and an increase in the ratio of low to high frequency power after induction of anaesthesia with either propofol or thiopentone. Patients who had received temazepam premedication had significantly greater low frequency, high frequency and total power than those who were not premedicated. There was no significant difference between premedicated and unpremedicated patients in the ratio of low to ventilatory frequency power.

Adult↗
PubMed1994

Case report: metastatic renal cell carcinoma presenting as intracerebral haemorrhage.

Cerebral haemorrhage is a well-established, albeit rare, complication of intracranial tumours. An autopsy series of 461 cerebral tumours revealed haemorrhage into only 2%. A case is described of intracerebral haemorrhage which complicated a metastatic renal cell carcinoma. There are four previous cases reported in the literature with this presentation, but this case differs in that the diagnosis was by cerebral angiography and at a site distant to the original haemorrhage.

Brain Neoplasms↗
PubMed1994

Resistant hypertension and preoperative silent myocardial ischaemia in surgical patients.

We studied 325 patients undergoing elective noncardiac surgery who had preoperative ambulatory ECG monitoring performed for a duration of 5130 h (range 8-24 h; mean 15.8 h). Sixty-four subjects (20%) had one or more episodes of ST segment depression consistent with myocardial ischaemia. Of all preoperative cardiovascular variables measured, the presence of elevated arterial pressure, despite patients being maintained on long term antihypertensive therapy, was the only factor associated significantly with the presence of preoperative silent myocardial ischaemia (P < 0.002). This correlation was confirmed when arterial hypertension was defined in four separate ways. The incidence of silent ischaemia in these patients was 33-55%. We suggest that admission arterial pressure may therefore be a useful screening test to identify patients at risk of preoperative myocardial ischaemia.

Adult↗
PubMed1994

Spinal cord compression immediately following, but unrelated to, epidural analgesia.

A patient developed spinal cord compression following epidural analgesia. The diagnosis was made difficult by the presence of epidural analgesia, although the compression was not in fact related to the analgesic technique employed. This case highlights the need for close observation of patients in whom epidural analgesia is, or has recently been, employed and the need to consider alternative reasons for neurological deficit.

Adult↗
PubMed1994

Bilirubin, ferritin, D-dimers and erythrophages in the cerebrospinal fluid of patients with suspected subarachnoid haemorrhage but negative computed tomography scans.

AIM: To assess the diagnostic value of cerebrospinal fluid (CSF) spectrophotometry, cytology, ferritin, and D-dimer measurements in the investigation of suspected subarachnoid haemorrhage in patients with negative or equivocal computed tomography (CT) scans. METHODS: CSF specimens submitted for assessment of xanthochromia were examined for erythrophages using a cytospin preparation stained with Wright's stain, for ferritin using the Ciba-Corning Magic IRMA assay, D-dimers using the Dimertest 2 latex agglutination slide test, and for bilirubin by scanning spectrophotometry. The patients were divided into three groups for data analysis and the results compared with the existing methods, CT, and angiogram results. Final diagnoses were reviewed by a consultant neurologist. RESULTS: Thirty six patients were recruited. In those patients with confirmed subarachnoid haemorrhage CSF cytology had a low sensitivity and there were false negative results with both the D-dimer and ferritin assays. Eleven patients with a negative or equivocal CT scan underwent angiography, but only one aneurysm and no arterio-venous malformations or bleeding points were identified. In the patient with the aneurysm there was no laboratory evidence of subarachnoid haemorrhage. Six patients had CSF abnormalities detected by the special tests only and in none of these cases was subarachnoid haemorrhage confirmed. All results were normal in four out of five cases of traumatic tap. CONCLUSIONS: This is a small study, but it shows that, depending on the timing of the lumbar puncture, false negative results can occur with both ferritin and D-dimer measurements. It suggests that neither of these tests adds significantly to the information provided by CT, visualisation of CSF, and spectrophotometry and confirms that, despite the use of spectrophotometry, D-dimer and ferritin assays in selecting patients for angiography, the proportion of patients with negative CT scans and colourless CSF with demonstrable vascular lesions remains low.

Bilirubin↗
PubMed1992

Acute bilateral ballism in a patient with intravascular dissemination of gastric carcinoma.

An 84-year-old woman presented with an acute onset of violent bilateral ballism-chorea. She was admitted to the local neurology unit, but not definite diagnosis could be made of the underlying condition, although she did appear to have bronchopneumonia. At autopsy the stomach wall was thickened, and the lesser curve lymph nodes were firm and enlarged. A single nodule was noted in the liver while the lungs appeared consolidated. Histology revealed a moderate-to-poorly differentiated gastric adenocarcinoma with extensive intravascular dissemination which included the central nervous system (CNS). Numerous small infarcts related to vessels occluded by tumour were present throughout the brain, and we feel that this was the underlying mechanism for the acute onset of ballism.

Adenocarcinoma↗
PubMed1989

Profiles of instant heart rate during partial seizures.

Instant heart rate (R-R intervals) can be readily studied during spontaneous seizures recorded with ambulatory cassette AEEG/AECG techniques. Ninety-three seizures were recorded in 32 patients with complex partial epilepsy. Instant R-R interval plots showed that 74% of seizures were associated with a dominant tachycardia, the most characteristic features of which were the initial steep acceleration phase at seizure onset and the wide fluctuations in heart rate ('exaggerated sinus arrhythmia') which occurred during and immediately after the seizure. Five percent of seizures were associated with a dominant but transient phase of heart rate slowing during or towards the end of the seizure. Nineteen percent of seizures showed equivocal or negative ictal effects on the heart rate and rhythm despite unequivocal AEEG seizure discharges. Conversely, other patients had characteristic heart rate changes despite equivocal AEEG abnormality. The heart rate profiles showed striking seizure-to-seizure similarities when multiple fits were recorded in the same patient. Ratemeter profiles may be clinically useful to locate epileptic seizures in long duration records; they can help to locate seizures which are either inaccurately timed or poorly identified by the event marker, or not clearly associated with definite AEEG changes. The secondary cardiac effects of epilepsy may be misdiagnosed if their primary cerebral origin is not suspected.

Adult↗
PubMed1989

Cardiac asystole associated with epileptic seizures: a case report with simultaneous EEG and ECG.

Cardiac arrhythmias occurring in association with epileptic seizures are a potential source of diagnostic confusion and a possible cause of sudden unexpected death in epilepsy. A case is described in which simultaneous ambulatory electroencephalography and electrocardiography revealed periods of asystole coinciding with epileptic seizures. The aystole appeared to precede obvious changes in the scalp recorded electroencephalogram (EEG), but clinical attacks and EEG seizure activity were not altered by pacemaker correction of the cardiac arrhythmias.

Arrhythmias, Cardiac↗
PubMed1989

Ictus emeticus.

Explore the source record for details and available documents.

Adult↗
PubMed1989

Pseudostatus epilepticus.

Thirteen patients with pseudostatus (simulated status epilepticus) have been compared to 13 patients with true status epilepticus seen at a regional neurological centre. Pseudostatus was common in patients with pseudoseizures and was often misdiagnosed as status epilepticus. Complications of this misdiagnosis included eight episodes of anticonvulsant-induced respiratory arrest. Patients with pseudostatus commonly had multiple episodes of 'status'. They usually also had a history of other unexplained illness and of deliberate self-poisoning. Management of these patients was difficult and emphasizes the need for specialist expertise for patients with epilepsy and apparent epilepsy.

Adolescent↗
PubMed1980

Ethanol affects the acquisition of information.

Two experiments were carried out on pigeons to assess the effects of acute ethanol (ETOH) administration on a delayed pair comparison procedure. ETOH disrupted performance at the two higher doses (1.0 and 2.0 g/kg, given orally). When the initial (zero delay) performance levels of treated and untreated birds were equated by (indirectly) varying the to-be-remembered stimulus' exposure duration, it was found that the impairment could, to a point, be overcome. This finding is interpreted in terms of hypothesis which suggests that ETOH affects the acquisition but not the subsequent storage of information.

Animals↗
PubMedDate not supplied

Preventive pain management in the postoperative hand surgery patient.

The purpose of this quasi-experimental clinical study was to investigate differences in postoperative pain management within the hand surgical population. The research question proposed: Is there a difference in the pain experience between postoperative patients who receive an analgesic upon onset of sensation and those who receive an analgesic upon onset of pain? The effectiveness of pain management was compared for two groups of randomly assigned, adult, orthopaedic patients who had undergone elective hand surgery using axillary block anesthesia. The results of this study concluded that more effective pain control was achieved when patients were medicated upon onset of sensation versus onset of pain.

Adult↗