Search PubMed⌕ Search

Biomedical subjects

P Chari

Publications and source records attributed to P Chari.

At least 37 records · Page 2Linked to original sources
PubMed1998

The effect of magnesium sulphate on hemodynamics and its efficacy in attenuating the response to endotracheal intubation in patients with coronary artery disease.

UNLABELLED: Laryngoscopy and endotracheal intubation may produce adverse hemodynamic effects. Magnesium has direct vasodilating properties on coronary arteries and inhibits catecholamine release, thus attenuating the hemodynamic effects during endotracheal intubation. We studied 36 patients with coronary artery disease (CAD) scheduled for elective coronary artery bypass grafting to evaluate the hemodynamic effects of magnesium and its efficacy in attenuating the response to endotracheal intubation. Patients received either 0.1 mL/kg (50%) magnesium sulfate (50 mg/kg) (Group A, n = 19) or isotonic sodium chloride solution (Group B, n = 17) before the induction of anesthesia and 0.05 mL/kg of isotonic sodium chloride solution (Group A) or lidocaine 2% (1 mg/kg) (Group B) before intubation. The hemodynamic variables were recorded before induction, after the trial drug, after induction, and after endotracheal intubation. Automatic ST segment analysis was performed throughout the study period. Magnesium sulfate administration was associated with increased cardiac index (P < 0.01), a minimal increase in heart rate, and a significant decrease in mean arterial pressure (MAP) and systemic vascular resistance (SVR) (P < 0.001). None of the patients in the magnesium group had significant ST depression compared with three patients in the control group. The magnesium group patients had a significantly lesser increase in MAP (P < 0.05) and SVR (P < 0.01) compared with the control group patients who received lidocaine before endotracheal intubation. Thus, magnesium is an useful adjuvant to attenuate endotracheal intubation response in patients with CAD. IMPLICATIONS: Endotracheal intubation produces adverse hemodynamic effects, which may be more detrimental in patients with coronary artery disease than in healthy patients. The present study shows that magnesium administered before endotracheal intubation can attenuate this response better than lidocaine.

Anesthetics, Local↗
PubMed1998

The effect of hyperventilation and hyperoxia on cerebral venous oxygen saturation in patients with traumatic brain injury.

UNLABELLED: Eighteen head-injured patients undergoing hyperventilation were studied for changes in jugular venous oxygen saturation (SjvO2) and arteriovenous oxygen content difference (AVDO2) in response to changes in PaO2 and PaCO2. SjvO2 decreased significantly from 66% +/- 3% to 56% +/- 3% (mean +/- SD) when PaCO2 decreased from 30 to 25 mm Hg at a PaO2 of 100-150 mm Hg. SjvO2 values returned to baseline (66% +/- 2%) when PaCO2 was restored to 30 mm Hg. Repetition of the study at a PaO2 of 200-250 mm Hg produced a similar pattern. However, SjvO2 values were significantly greater with PaO2 within the range of 200-250 mm Hg (77% +/- 4% and 64% +/- 3%) than SjvO2 measured at a PaO2 of 100-150 mm Hg at PaCO2 values of both 30 and 25 mm Hg. AVDO2 also improved with a PaO2 of 200-250 mm Hg at each PaCO2 (P < 0.001). In conclusion, decreases in SjvO2 associated with decreases in PaCO2 may be offset by increasing PaO2. IMPLICATIONS: The adequacy of cerebral oxygenation can be estimated in head-injured patients by monitoring jugular bulb oxygen saturation and the arteriovenous oxygenation content difference. Increasing the partial pressure of arterial oxygen above normal offset deleterious effects of hyperventilation on jugular bulb oxygen saturation and arteriovenous oxygenation content difference in head-injured patients.

Adolescent↗
PubMed1996

Pre-operative anxiety. Effect of early or late position on the operating list.

The influence of the relative position on the operating list on pre-operative anxiety was studied in 60 adult female ASA 1 patients undergoing major surgery. Thirty patients were placed first on the operating list (group 1) and 30 were given a time 4-5 h later (group 2). Each patient was visited on the evening prior to surgery and again on the morning of surgery. Anxiety was measured at each visit by objective criteria and part 1 of the State-Trait Anxiety Inventory questionnaire. The pulse rate, systolic blood pressure and the State-Trait Anxiety Inventory questionnaire scores were higher on the second visit than on the first (p < 0.001) in all patients. This increase was greater in group 2 than in group 1 (p < 0.05). The evening anxiety scores were not correlated with those on the morning visit and could not predict them.

Adult↗
PubMed1996

Respiratory variables during thoracotomy for PDA ligation.

Physiological deadspace fraction of tidal volume (VD/VT), arterial to end-tidal carbon dioxide tension differences [P(a-E')CO2], arterial oxygen tension (PaO2) and respiratory system compliance were studied in twenty patients with patent ductus ateriosus scheduled for multiple ligation and transfixation through posterolateral thoracotomy under general anaesthesia with controlled ventilation. The study period was divided into six stages: stage 1--supine posture under anaesthesia, stage 2--lateral posture before start of surgery, stage 3--after chest opening before lung manipulation, stage 4--after ductus ligation and lung re-expansion before chest closure, stage 5--lateral posture, chest closed, stage 6--supine stage before reversal. There was a significant (P < 0.01) increase of VD/VT on attaining the lateral posture. The fraction decreased significantly (P < 0.05) on opening of the chest (stage 3) and subsequently increased at stage 4. There was no significant change in mean P(a-E')CO2 at various stages of thoracotomy. PaO2 fell significantly on opening of the chest and was lowest before chest closure (stage 4). PaO2 increased following chest closure but was still significantly lower than the pre-surgical supine stage. Respiratory system compliance was lowest at stage 4. Changes in deadspace fraction VD/VT do not correspond favourably to arterial oxygen tensions during posterolateral thoractomy.

Adolescent↗
PubMed1994

Phakomorphic glaucoma--an unusual cause of postoperative vomiting.

A 60-year-old female patient receiving epidural buprenorphine for postoperative analgesia developed intractable nausea and vomiting not responding to antiemetics. Ophthalmic consultation for congestion of the left eye was sought and the patient was diagnosed as having phakomorphic glaucoma. Extracapsular extraction of the left lens was performed after primary anti-oedema measures. Glaucoma as a cause of intractable postoperative nausea and vomiting should be considered in susceptible patients.

Analgesia, Epidural↗
PubMed1993

Aphasia in bilinguals.

The neurophysiological and the neurolinguistic basis of multilingualism is not yet fully elucidated. A study of the occurrence of aphasia in multilingual patients and the pattern of recovery may help to clarify some unsolved problems. For e.g. is the ability to use a second language stored in a different area of the left hemisphere and what is the extent of involvement of the right hemisphere in language skills? When recovery from aphasia occurs, what factors determine the rate of recovery of different languages and the priorities of recovery? To understand some of the problems, a study of aphasia in multilinguals was conducted in Madras, South India, where multilingualism is common. 88 patients were studied with 40 healthy controls, using standard protocols. It was found that the pattern of recovery was dispersed widely in time, rate, level, degree and between the languages known. No support was obtained for the notion that the patients' mother tongue recovers first, nor was support found for the importance of language proficiency viewed globally. Evidence was found that the languages in which routine thinking, mental calculations and praying were carried out were the ones most resistant to damage in brain insults. It is interesting that these functions are all highly overlearned, acquired early in life and used frequently over the course of many years. Another observation made was that the incidence of crossed aphasia was fairly high, in both uni- and multi-linguals, with the latter showing a slightly higher incidence.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Midazolam as an induction agent in mitral stenosis patients for closed mitral commissurotomy.

In 30 patients of rheumatic heart disease with mitral stenosis (MS) belonging to NYHA class II and III scheduled for closed mitral commissurotomy anaesthesia was induced with morphine 0.15 mg/kg followed by either thiopentone (group A, n = 15) or midazolam (group B, n = 15) titrated to produce sleep. Patients were intubated with pancuronium bromide in a dose of 0.12 mg/kg. Minimum mean arterial blood pressure following induction was significantly lower in thiopentone group (77 +/- 7 mm Hg) than midazolam group (85 +/- 6 mm Hg; P < 0.05). After intubation blood pressure was significantly higher in thiopentone group (99 +/- 8 mm Hg) than midazolam group patients (89 +/- 7 mm Hg). Heart rate was significantly higher in thiopentone treated patients both before and after endotracheal intubation. During surgery, three patients in group A had hypotensive episodes (mean arterial blood pressure 20% below basal at two successive readings 5 min apart) while one in group B had a hypotensive episode. Average duration of surgery was comparable between the two groups (102 +/- 15 and 95 +/- 18 min) and postoperatively there was no significant difference in sedation score and incidence of nausea and vomiting between the two groups.

Adult↗
PubMed1991

Cardio-vascular effects of vecuronium & pancuronium in patients undergoing elective closed mitral valvotomy.

Vecuronium, a monoquaternary analogue of pancuronium, the neuromuscular blocker, was compared with pancuronium in 50 patients undergoing elective closed mitral valvotomy. The patients were randomly divided into two groups of 25 each, and the muscle relaxants were administered in a dose of 0.1 mg/kg body weight. Both the agents produced identical intubating conditions at 3 min. Vecuronium showed a significantly shorter onset of action, as compared to pancuronium. The latter significantly increased the heart rate throughout the period of study whereas vecuronium significantly decreased the heart rate, 25 min after administration. There was significant increase in the mean arterial pressure (MAP) at tracheal intubation in both the groups, which persisted throughout the period of study in pancuronium group. There was a significant fall in MAP at 30 min after relaxant in vecuronium group. The incidence of arrythmias was similar and significant in both the groups. Vecuronium, thus showed a quicker onset of action with minimal haemodynamic effects, as compared to pancuronium in patients undergoing closed mitral valvotomy.

Adolescent↗
PubMed1991

Psychiatric symptoms in patients with non-organic chronic intractable pain.

Patients (200) with chronic intractable pain were evaluated to identify various psychiatric symptoms. Identifiable psychiatric illness, commonest being neurotic depression and anxiety states, was found in 72 per cent patients. The common symptoms reported on the present state examination (PSE) were worrying (77%), depression (40%), loss of interest (31.5%), hopelessness (16.5%), loss of weight (18%), and suicidal ideas (8%) and irritability (41.5%). Two thirds of patients had both anxiety and depression.

Adolescent↗
PubMed1990

Role of epidural analgesia on endocrine & metabolic responses to surgery.

Serum levels of cortisol, T3, T4 and blood levels of glucose, lactate and pyruvate were measured 15 min before anaesthesia, 15 and 60 min after skin incision and at 2 h after surgery, in 16 patients undergoing elective surgery on lower extremities either under epidural analgesia (group I) or general anaesthesia (group II). The results showed that as long as the effect of epidural analgesia persisted, it could inhibit the increases in cortisol and blood glucose and the decreases in T3 levels, observed under general anaesthesia. This is probably because of the blocking effect of epidural analgesia on the afferent neurogenic impulses from the area of surgery. T4, lactate and pyruvate levels were not affected to any significant extent. These observations could be of value in the operative management of patients with diabetes mellitus and others with a high surgical morbidity.

Adult↗
PubMed1989

Fluid deprivation before operation. The effect of a small drink.

The effect of oral fluids before operation, followed by intramuscular morphine, on gastric volume and pH was examined in 150 elective surgical patients, ASA physical status 1 and 2, who were randomly assigned to one of the three groups of 50 each. Group 1 (control) continued their overnight fast; patients in Groups 2 and 3 received 150 ml water 2 hours before the scheduled time of surgery. Patients in Group 3 received intramuscular morphine 0.15 mg/kg and promethazine 0.5 mg/kg one hour before operation. The residual gastric volume was obtained by suction and its volume and pH measured immediately after induction of anaesthesia. Statistically significant (p less than 0.05) decrease in residual gastric volume was observed in Groups 2 and 3 as compared to Group 1. However, the difference between these two groups was not statistically significant. There was no statistically significant difference in pH among the three groups. Overnight fluid fasting is not justified in elective surgical patients. Morphine can be safely given one hour before surgery in patients who have received water (150 ml) 2 hours before operation.

Adolescent↗
PubMed1988

Nifedipine and surgical removal of phaeochromocytoma.

The management of five patients with phaeochromocytoma undergoing surgical removal is described. Pre-operative preparation with phenoxybenzamine and nifedipine for 7 days before surgery prevented excessive fluctuations in cardiovascular parameters in the peri-operative period and resulted in an uneventful recovery.

Adrenal Gland Neoplasms↗
PubMed1987

Tyrosine phosphorylation of band 3 inhibits peripheral protein binding.

The cytoplasmic domain of band 3 (cdb3) of the human erythrocyte membrane is a good substrate of endogenous and exogenous protein-tyrosine kinases. Because one site of tyrosine phosphorylation is within the glycolytic enzyme/hemoglobin-binding region at the N terminus of the polypeptide, we have investigated whether tyrosine phosphorylation of cdb3 might influence its interaction with the above peripheral proteins. Using p40, a protein-tyrosine kinase isolated from bovine thymus, we demonstrate that aldolase binding to cdb3 linked to Affi-Gel 15 is significantly inhibited by phosphorylation of the immobilized band 3. Importantly, upon dephosphorylation of the gel with acid phosphatase, aldolase binding returns to prephosphorylated values. Similarly, cdb3 phosphorylation was found to inhibit glyceraldehyde-3-phosphate dehydrogenase, phosphofructokinase, and hemoglobin binding to immobilized cdb3. In the converse experiment, untreated soluble cdb3 was shown to bind to immobilized aldolase, whereas phosphorylated cdb3 (approximately equal to 1.8 mol of Pi/mol of cdb3) did not. Furthermore, phosphorylated cdb3 was unable to inhibit aldolase catalysis, whereas untreated cdb3, as shown previously by others, was a potent inhibitor. Taken together, these results demonstrate that phosphorylation of cdb3 on tyrosine residues inhibits peripheral protein binding at the polypeptide's N terminus. In view of the known effect of glycolytic enzyme binding to band 3 on catalytic activity, tyrosine phosphorylation of band 3 may modulate glycolysis in vivo.

Anion Exchange Protein 1, Erythrocyte↗