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Biomedical subjects

M V Shah

Publications and source records attributed to M V Shah.

At least 19 recordsLinked to original sources
PubMed2000

Cardiovascular responses to pulmonary artery catheterization.

This study compares prospectively the cardiovascular and catecholamine responses to central venous and pulmonary artery catheterization before and after induction of general anaesthesia. Twenty patients for elective coronary artery surgery were randomized into two groups. One group had central venous and pulmonary artery catheterization performed awake using local anaesthesia. The other group had these catheters inserted following induction of general anesthesia. In all patients heart rate, arterial blood pressure, ST segment analysis and epinephrine and norepinephrine levels were measured prior to central venous cannulation and at 2-min intervals until placement of the lines was achieved. There were no statistically significant changes in any cardiovascular or catecholamine variable with time compared with the base-line measurements. There were no statistically significant differences in plasma catecholamine levels between the awake and the anaesthetized groups.

Blood Pressure↗
PubMed2000

Presentation and patterns of late recurrence of olfactory groove meningiomas.

The objective of this article is to present the recurrence pattern of olfactory groove meningiomas after surgical resection. Four patients, one female and three males, with surgically resected olfactory groove meningiomas presented with tumor recurrence. All patients underwent resection of an olfactory groove meningioma and later presented with recurrent tumors. The mean age at initial diagnosis was 47 years. All presented initially with vision changes, anosmia, memory dysfunction, and personality changes. Three patients had a preoperative MRI scan. All patients had a craniotomy, with gross total resection achieved in three, and 90% tumor removal achieved in the fourth. Involved dura was coagulated, but not resected, in all cases. Three patients were followed with routine head CT scans postoperatively, and none was followed with MRI scan. The mean time to recurrence was 6 years. Three patients presented with recurrent visual deterioration, and one presented with symptoms of nasal obstruction. Postoperative CT scans failed to document early tumor recurrence, whereas MRI documented tumor recurrence in all patients. Tumor resection and optic nerve decompression improved vision in two patients and stabilized vision in two. Complete resection was not possible because of extensive bony involvement around the anterior clinoid and inferior to the anterior cranial fossa in all cases. Evaluation of four patients with recurrent growth of olfactory groove meningiomas showed the epicenter of recurrence to be inferior to the anterior cranial fossa, with posterior extension involving the optic canals, leading to visual deterioration. This location led to a delay in diagnosis in patients who were followed only with routine CT scans. Initial surgical procedures should include removal of involved dura and bone, and follow-up evaluation should include formal ophthalmologic evaluations and routine head MRI scans.

Journal Article↗
PubMed2000

Clinical comparison of 'single agent' anaesthesia with sevoflurane versus target controlled infusion of propofol.

The introduction of total intravenous anaesthesia (TIVA) and the use of volatile induction/maintenance anaesthesia (VIMA) has led to the rediscovery of 'single agent' anaesthesia, eliminating the transition phase from induction to maintenance. We compared quality, patient acceptability and cost of TIVA using target control infusion (TCI) with propofol and VIMA with sevoflurane. Forty patients undergoing spinal surgery of 1-3 h were assigned to one of two groups. Group I received propofol-air-oxygen for induction followed by propofol-air-oxygen for maintenance. Group II received 8% sevoflurane-oxygen for induction and sevoflurane-oxygen-nitrous oxide for maintenance. Propofol had a significantly faster mean (SD) induction time (67 (20) s) than sevoflurane (97 (38) s) but was associated with double the incidence of involuntary movements. Although not significant, twice the number of interventions by the anaesthetist were required to maintain an adequate level of anaesthesia in the sevoflurane group. Emergence times, characteristics, postoperative nausea, vomiting and pain were unaffected by the anaesthetic technique. However, a more predictable emergence time was found following sevoflurane. Cardiovascular stability was good and comparable in both groups. The majority of patients found either technique acceptable and would choose the same anaesthetic again. Induction and maintenance was substantially cheaper with sevoflurane (28.06 Pounds) compared with propofol (41.43 Pounds).

Adult↗
PubMed2000

Indications for treatment of symptomatic atherosclerotic carotid artery disease.

Although the incidence of stroke and stroke mortality have declined during the past few decades, stroke still ranks third as a cause of death and a primary cause of long-term disability in most industrialized societies. Atherosclerotic disease at the carotid bifurcation accounts for approximately 20% to 30% of all ischemic strokes. In this article, the indications for treatment of symptomatic internal carotid artery stenosis are reviewed.

Aged↗
PubMed1999

Radiographic incidence of multicentric malignant gliomas.

BACKGROUND: Multicentric malignant gliomas are interesting yet uncommon clinical entities with an unknown rate of occurrence. METHODS: We reviewed the computed tomography (CT) and magnetic resonance (MR) images of 100 consecutive patients with malignant gliomas to determine the incidence of multicentricity in malignant glial neoplasms. RESULTS: Five patients had multiple lesions on their initial radiographic study (synchronous lesions) and in four patients multiplicity developed after initial diagnosis (metachronous lesions). MR imaging demonstrated one lesion not seen on CT. CONCLUSIONS: Because synchronous or metachronous multicentricity was found in 9% of patients with malignant gliomas, treatment delivery should not be based on radiographic imaging without attempting to obtain an accurate diagnosis of the ongoing intracranial process.

Adult↗
PubMed1998

Medical and surgical management of intracerebral hemorrhage.

Intracerebral hemorrhage accounts for about 10% of all strokes. The diagnosis of this stroke subtype has been revolutionized by the use the computed tomography scanner. Therapeutic intervention in the form of medical and surgical management is reviewed. The critical management issues center on identifying the etiology of hemorrhage, controlling blood pressure, and controlling intracranial pressure.

Brain Neoplasms↗
PubMed1996

Comparison of predicted with measured creatinine clearance in cardiac surgical patients.

OBJECTIVE: To determine whether creatinine clearance can be determined from a single plasma creatinine measurement in patients up to 5 days after cardiac surgery. DESIGN: Observational longitudinal study. SETTING: Cardiac intensive care unit in a tertiary referral center for cardiothoracic surgery. PATIENTS: Seventy-five patients (54 men, 21 women) scheduled for elective coronary artery surgery (93 postoperative patient days). INTERVENTIONS: Creatinine clearance measurement using a 4-hour urine collection and a single arterial blood sample. MEASUREMENTS AND MAIN RESULTS: There was significant agreement (Deming analysis r = 0.63-0.84, correlation r = 0.76-0.95, p < 0.05) between the predicted creatinine clearance and the measured creatinine clearance on each of the postoperative days. This was maintained even if the patients required inotrope or vasoconstrictor therapy, were receiving parenteral nutrition, or had changing renal function (Deming analysis r = 0.67-0.7; correlation r = 0.8-0.93, p < 0.001) but does not apply to patients with preexisting renal dysfunction (Deming analysis r = 0.36; correlation r = 0.57, p = 0.002). CONCLUSIONS: In cardiac surgical patients with normal preoperative renal function, predicted creatinine clearance is as reliable as measured creatinine clearance up to the fifth postoperative day.

Cardiac Surgical Procedures↗
PubMed1996

Effect of antagonism of mivacurium on recovery of extraocular muscle function.

We have measured extraocular muscle function in 41 patients who received neuromuscular block with mivacurium 0.2 mg kg-1 during anaesthesia with propofol, ketorolac, fentanyl and isoflurane in nitrous oxide and oxygen, which was antagonized at the end of surgery with neostigmine 0.05 mg kg-1 and glycopyrronium 0.01 mg kg-1 in 21 of these patients. Extraocular muscle function was measured before and after surgery in each group with the Maddox Wing apparatus and compared with a control group (n = 20) who breathed spontaneously the same gaseous anaesthetic mixture via a reinforced laryngeal mask airway. In patients where the action of mivacurium was antagonized, extraocular muscle function was improved significantly 20 min after antagonism (P < 0.001) compared with those who received no antagonism. At 60 min after antagonism, there were no differences between the groups. There were no differences between patients who received no neuromuscular blockers and those who received blocker and antagonist.

Ambulatory Surgical Procedures↗
PubMed1994

Right atrial electrocardiography: a technique for the placement of central venous catheters for chemotherapy or intravenous nutrition.

Central venous catheters used for chemotherapy are usually sited so that the catheter tip lies in the superior vena cava. This study evaluated right atrial electrocardiography as a method of accurately placing the catheter tip in 34 patients over a period of 22 months. An electrocardiograph adaptor was connected to the catheter and the tip advanced into a central vein until a biphasic P wave was identified. In 31 of 34 patients the characteristic P wave changes were observed and the position of the catheter tip confirmed by screening to be in the superior vena cava. Right atrial electrocardiography is an accurate, reliable and rapid method of positioning the tip of a central venous catheter, and avoids or reduces exposure to radiation.

Catheterization, Central Venous↗
PubMed1994

A comparison of the effect on gastric emptying of alfentanil or morphine given during anaesthesia for minor surgery.

Twenty patients, scheduled for minor gynaecological surgery, were studied. Anaesthesia was induced with propofol and maintained with oxygen, nitrous oxide and enflurane. Patients were randomly allocated to two groups: group 1 were given alfentanil 0.2 mg; group 2 were given morphine 5 mg. The rate of gastric emptying was measured indirectly by the paracetamol absorption technique. The results showed that morphine caused greater delay in gastric emptying compared with alfentanil (p < 0.05). The observed effect on gastric emptying rate may potentially affect the risk of peri-operative regurgitation and aspiration. This study provides further evidence that in short day-case procedures, when oral medication may be required postoperatively, alfentanil may be preferable to morphine as an intra-operative opioid.

Acetaminophen↗
PubMed1994

Mediastinitis and sepsis syndrome following intubation.

A patient developed sepsis syndrome with shock 7 h after an anaesthetic for a shoulder replacement. Tracheal intubation had been difficult and required the use of a stylet and gum-elastic bougies. A gastrografin swallow subsequently demonstrated an oesophageal perforation and mediastinitis was diagnosed at surgical exploration. She survived after a prolonged period of intensive care treatment.

Aged↗
PubMed1994

A comparison of the effect on gastric emptying of either enflurane or propofol given during maintenance of anaesthesia for minor surgery.

Twenty patients scheduled for minor gynaecological surgery were studied. Anaesthesia was induced with propofol and maintained either with enflurane/oxygen/nitrous oxide or propofol/oxygen/nitrous oxide. The rate of gastric emptying was measured indirectly by the paracetamol absorption model. The results showed that there was no significant difference in gastric emptying rate between the two groups. Recovery in the propofol group was more rapid in that paracetamol ingestion occurred earlier in the recovery period compared with the enflurane group.

Acetaminophen↗
PubMed1992

Gastroduodenal dysfunction as a cause of gastric bacterial overgrowth in patients undergoing mechanical ventilation of the lungs.

We have studied 15 patients undergoing mechanical ventilation of the lungs for evidence of a relationship between gastroduodenal dysfunction and gastric bacterial overgrowth. Duodenal reflux was detected by quantitative measurement of conjugated bilirubin in gastric aspirate specimens. The pH and bacterial content of these specimens were analysed. A minority of specimens with pH less than 3.5 contained measurable numbers of viable bacteria. The total bacterial count and the count of Gram negative bacteria correlated significantly with specimen pH in both cases (P less than 0.001, in both). In the 72 specimens of gastric aspirate with pH greater than 3.5, the presence of Gram negative bacteria was associated significantly with detectable bilirubin (P less than 0.001). The total bacterial count was greater also in specimens containing bilirubin (P = 0.009). These results suggest that gastroduodenal dysfunction may promote gastric bacterial overgrowth, contributing to the development of ventilator-associated pneumonia.

Adult↗
PubMed1992

Pediatric skull, skull base, and meningeal tumors.

Calvarial neoplastic and non-neoplastic tumors are routinely encountered by all neurosurgeons. Benign and malignant skull base and meningeal tumors are relatively rare lesions in children. Interdisciplinary approaches to those tumors more frequently encountered in the pediatric population in these locations are discussed. Unique aspects of the diagnosis, treatment, and prognosis for infants and children are discussed.

Child↗