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Biomedical subjects

K S Channer

Publications and source records attributed to K S Channer.

At least 145 records · Page 8Linked to original sources
PubMed1985

Anxiety and depression in patients with chest pain referred for exercise testing.

Anxiety and depression were measured in 87 consecutive patients (65 males, 22 females) with chest pain before diagnostic exercise treadmill testing. Chest pain was assessed as typical or atypical of angina by an independent observer. Fifty exercise tests were positive; thirty-seven were negative (including nineteen submaximal). Patients with negative tests had significantly higher scores for anxiety and higher depression scores than those with positive tests. 12% of patients with positive tests were women compared with 43% with negative tests. 27 patients (73%) with negative tests had atypical pain compared with 6 (12%) with positive tests. Depressed patients walked for a significantly shorter time. The probability of a negative test in patients without anxiety or depression who had typical pain was 8% in males and 32% in females; the probability of a negative test in patients who were both anxious and depressed and had atypical pain was 97% in males and 99% in females. Diagnostic exercise testing in patients with both affective symptoms and atypical chest pain may be unhelpful, misleading, and uneconomical.

Adult↗
PubMed1985

Oesophageal function tests: are they of value?

Oesophageal function was assessed in 15 unselected control patients, eight patients with systemic sclerosis, 10 diabetics with autonomic neuropathy and 24 diabetic controls, by water bolus transit time derived from oesophageal scintigraphy, barium swallow and by timing the transit of a barium sulphate-filled capsule through the oesophagus. Water transit times and capsule transit times were significantly prolonged in patients with systemic sclerosis and diabetics with autonomic neuropathy, compared with controls. Barium swallow was abnormal in seven of eight patients with systemic sclerosis, whereas water transit time was abnormal in all eight and capsule transit time was abnormal in six of seven. Nine of 10 patients with diabetic autonomic neuropathy had abnormal barium swallows and water transit times but all 10 had prolonged capsule transit times. Eleven of 24 diabetic controls had abnormal barium swallows and water transit times, but 21 had abnormally prolonged capsule transit times. Six of 15 controls had abnormal barium swallows, four had abnormal water transit times and 12 had abnormal capsule transit times. In conclusion, water and capsule transit times are sensitive tests of oesophageal function and are as effective as barium swallow in detecting oesophageal motility disorders associated with systemic sclerosis and diabetic autonomic neuropathy. Capsule transit time is cheaper, involves a smaller radiation exposure than oesophageal scintigraphy and may be more sensitive.

Adult↗
PubMed1985

Effect of delayed esophageal transit on acetaminophen absorption.

Twenty patients awaiting cardiac catheterization swallowed a single tablet containing acetaminophen and barium sulfate. The first 11 subjects swallowed the tablet while supine; its progress down the esophagus was followed by fluoroscopy. In 10 of these subjects, transit of the tablet was delayed in the esophagus. The other nine subjects swallowed the tablet while standing; it entered the stomach immediately. The plasma concentration profile of acetaminophen was measured in all subjects. When there was delayed esophageal transit of tablets, the initial absorption of acetaminophen (measured as the AUC over the first 60 min) was lower than that after normal esophageal transit of tablets. The peak plasma acetaminophen concentration was also lower and occurred on average 70 min later when transit was delayed. These kinetic changes decrease the effectiveness of acetaminophen as an analgesic. We recommend that, to ensure rapid and complete drug absorption, patients be advised to swallow tablets with a large amount of water while standing.

Acetaminophen↗
PubMed1985

Oesophageal function in diabetes mellitus and its association with autonomic neuropathy.

We have evaluated oesophageal function in 34 diabetics and in 16 non-diabetic controls by a timed bolus transit method derived from dynamic oesophageal scintiscans (water transit time: WTT) and barium swallow. The diabetics were screened for autonomic neuropathy using standard cardiovascular responses and 10 patients were classified as abnormal. WTT was significantly prolonged in autonomic neuropaths compared with other diabetics (p less than 0.01) and controls (p less than 0.001). Abnormal peristalsis on barium swallow was seen more frequently in autonomic neuropaths (9/10) than in other diabetics (11/24, p less than 0.002). WTTs from all diabetic patients correlated with abnormal heart rate responses at rest (Rs = - 0.49, p less than 0.005), on deep inspiration (Rs = -0.48, p less than 0.005), and on standing (Rs = -0.39, p less than 0.025) but not with the Valsalva manoeuvre. A weaker correlation was found between the postural fall in blood pressure (Rs = 0.3, p less than 0.05). Diabetics with autonomic neuropathy frequently have asymptomatic oesophageal dysfunction which may result from a vagal neuropathy in view of its association with abnormalities of vagally mediated cardiovascular responses.

Adult↗
PubMed1985

The effect of formulation on oesophageal transit.

The oesophageal transit of barium sulphate in small or large, heavy or light capsules or film coated and plain oval tablets was measured during fluoroscopy in five separate studies involving 175 subjects. Transit of large, but not small capsules was significantly faster than plain oval tablets in both erect and supine subjects (P less than 0.05). Heavy large capsules entered the stomach in all subjects within 20 s, whereas in all other studies some subjects retained dosage forms in the oesophagus for over 5 min. The transit of heavy capsules was significantly faster than light capsules in erect subjects (P less than 0.0005). Light capsules tended to have faster transit times than heavy capsules in the supine position. Film coating significantly enhanced oval tablet transit in erect (P less than 0.00003) and supine subjects (P less than 0.05). When large capsules of equal weight but less dense than film coated oval tablets were directly compared, the tablet transit was significantly superior in the erect subjects (P less than 0.0001). In supine subjects the transit of the light capsule was significantly faster (P less than 0.005). It is concluded that different drug formulations can have significant effects on oesophageal transit, and hence on the development of drug induced oesophageal ulceration.

Adolescent↗
PubMed1985

Recurrent idiopathic pneumomediastinum.

A case is described of the rare syndrome of recurrent idiopathic pneumomediastinum which had been mistakenly diagnosed as recurrent spontaneous perforation of the oesophagus. The case illustrates the importance of distinguishing between pneumomediastinum and oesophageal rupture because of their markedly differing prognosis and management.

Adult↗
PubMed1984

Antipyrine absorption after delayed oesophageal capsule transit.

Twenty fasted patients were given hard gelatin capsules containing antipyrine and barium, and in ten patients the capsule arrested and disintegrated in the oesophagus. Plasma antipyrine was assayed at 10 min intervals for 1 h, then 30 min intervals for a further 3 h. The plasma concentration-time curves for the patients in whom the capsule entered the stomach rapidly, and for those in whom the capsule lodged in the oesophagus, were compared. The absorption in the first hour was calculated from the area under the plasma concentration-time curve and found to be significantly lower if the capsule disintegrated in the oesophagus (P less than 0.0005). The time to peak plasma concentration was delayed by an average of 46 min (P less than 0.01) and the peak plasma concentration was significantly lower (P less than 0.05) if delayed capsule transit occurred. Delayed capsule transit through the oesophagus significantly changed the pharmacokinetic profile of antipyrine.

Absorption↗
PubMed1984

The effect of posture at the time of administration on the central depressant effects of the new hypnotic zopiclone.

Nine healthy volunteers swallowed 7.5 mg zopiclone in the standing and lying positions on different occasions. Plasma concentrations of zopiclone and psychometric tests, including simple and complex reaction time, and critical flicker fusion threshold, were performed at regular intervals after drug administration. The results show that when the drug was swallowed in the supine position, there was a significant delay in the onset of the impairment of psychomotor function, with prolongation in time to peak impairment by 30-40 min (P less than 0.02). The overall impairment in psychomotor performance was found to be significantly less after administration of the drug in the supine position (P less than 0.005). Pharmacokinetic analysis revealed a prolongation in lag time of greater than 20 min before absorption began (P less than 0.002) after supine drug administration, with a significantly lower rate constant of absorption (P less than 0.02). Area under the plasma concentration-time curve extrapolated to infinity and rate constant of elimination were not significantly different between the two modes of administration. We conclude that to obtain a rapid and complete effect from the hypnotic zopiclone, the tablet should be swallowed in the standing position.

Adult↗
PubMed1984

Effect of left atrial size on the oesophageal transit of capsules.

The oesophageal transit time of barium sulphate capsules was measured using X ray fluoroscopy in 20 patients with mitral valve disease and 12 control patients in the erect and supine positions when swallowed with both 15 ml and 60 ml of water. An erect barium swallow was performed, and from a lateral radiograph the area of indentation of the oesophagus caused by the cardiac impression was measured. Left atrial diameter was derived from M mode echocardiography. In 19 patients with mitral valve disease one or more capsules remained in the oesophagus for five minutes and disintegrated there, whereas this occurred in only six control patients. Capsule transit time was significantly slower in the study patients than in the control patients in the supine position with 15 ml water. There was a significant correlation between the area of indentation and mean capsule transit time and supine 15 ml transit time. The area of indentation closely correlated with the left atrial diameter. When capsules were delayed in the oesophagus, this occurred mainly at the level of the left atrial impression in the study patients and at the lower oesophageal sphincter in the control patients. Patients with mitral valve disease are more likely than control patients to have delayed oesophageal transit of capsules because of the anatomical deformity caused by enlargement of the left atrium.

Adult↗
PubMed1983

The effect of hyoscine butylbromide on the swallowing of capsules.

Hyoscine butylbromide (20 mg) given intravenously to 48 patients with normal oesophageal motility significantly reduced oesophageal transit of hard gelatin capsules when swallowed in the erect and supine positions with 15 ml and 60 ml water when compared to an age/sex matched group. Delayed capsule transit and possible failed or slowed drug absorption occurring as a consequence of anti-cholinergic drugs on the oesophagus, constitutes a new drug interaction.

Adult↗
PubMed1983

The effect of glucagon on the swallowing of capsules.

Glucagon (0.3 mg) given intravenously to 45 patients with normal oesophageal motility significantly reduced oesophageal transit of hard gelatin capsules when swallowed in the supine position with 15 ml water, compared to an age/sex matched group. This is taken to represent an effect on oesophageal peristalsis which has not previously been recognised.

Adult↗
PubMed1983

Persistent visual hallucinations secondary to chronic solvent encephalopathy: case report and review of the literature.

A case of solvent encephalopathy presenting with persistent visual hallucinations, and characterised by a diffusely abnormal EEG and delayed visually evoked responses to checkerboard pattern reversal (VERs), is described. Abnormalities in the EEG and VERs showed minimal improvement over many months of abstinence from glue sniffing. The literature on the neurological sequelae of solvent abuse is reviewed.

Adolescent↗