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Biomedical subjects

V Muralidhar

Publications and source records attributed to V Muralidhar.

10 recordsLinked to original sources
PubMed2001

Analysis and characterization of photo-plethysmographic signal.

Qualitative assessment of the overall clinical status of the subject and characterization of complex cardiovascular dynamics from digital blood volume pulsations measured noninvasively using a photo-plethysmographic device is addressed. A novel concept is employed to detect the dominant nonsinusoidal periodicity embedded in the data series and to extract the associated periodic component. The detection and the extraction of periodic component is performed with moving window to accommodate the variations of the physiological oscillations. The covariance matrix formed by the gradually varying pattern is used as a simple measure of qualitative assessment. Further, the characterization of the underlying system in the light of nonlinear dynamical analysis is also presented. The stable subjects are shown to behave as a low-dimensional system whereas the diseased subjects exhibit comparatively high dimensional activity.

Adult↗
PubMedDate not supplied

Over-the-needle versus microcatheter-through-needle technique for continuous spinal anesthesia: a preliminary study.

BACKGROUND AND OBJECTIVES: A new catheter-over-needle design (Spinocath, B. Braun) has been developed to minimize problems and complications of continuous spinal anesthesia with microcatheters, which include difficult catheter insertion, failure of insertion, breakage, inadequate anesthesia, postdural puncture headache, and, rarely, development of cauda equina syndrome. METHODS: A comparative evaluation of this new catheter (22-gauge Spinocath) to the microcatheter (28-gauge Portex) was performed to study the problems of insertion, complications, quality of anesthesia, and postoperative analgesia in a prospective, randomized manner. Patients were allocated to two groups of 10 each: catheter-over-the-needle group (group I) and microcatheter-through-the needle (group II). Postoperative protocol consisted of an infusion of 0.125% isobaric bupivacaine delivered with a syringe infusion pump for 24 hours. RESULTS: The two groups were comparable in relation to age, sex, type of surgery, median height of the block, and the time taken for catheter insertion and surgery. Spontaneous backflow of cerebrospinal fluid (CSF) through the catheter with the needle in position was possible only in the spinocath group (8/10 cases). Initial introduction of the catheter into the subarachnoid space (8 vs 3: chi-square = 5.05; P = .03) and threading of the catheter were easier (8 vs 3 cases: chi-square = 5.05; P = .03) in group I. Aspiration of CSF was easy in group I in all ( 10 vs 2: chi-square = 13.33; P = .004). Complications such as resistance to drug injection, kinking (P < .05), inadequate anesthesia, and supplementation with general anesthesia were seen only in group II. Postoperative pain relief was comparable in both groups (P > .05). Both groups were comparable hemodynamically in the intra- and postoperative periods. CONCLUSIONS: Insertion, maintenance, and clinical effects were better achieved with the catheter-over-the needle design compared to the microcatheter. These preliminary findings need to be confirmed by a larger study.

Adult↗
PubMedDate not supplied

Diazepam induced delirium.

In Ophthalmic practice diazepam is often used a a premedicant. We report a case where administration of diazepam led to a state of acute delirium because of which surgery had to be postponed. The possible mechanisms for this reaction and the treatment is discussed. This side effect of diazepam should be kept in mind while dealing with delirium in the geriatric age group.

Aged↗
PubMedDate not supplied

Laryngeal changes following long-term stenting with polyvinyl chloride tubes.

BACKGROUND: To treat tracheal stenosis and permit wound healing to occur an inert stent is required which resists the contraction process and prevents re-stenosis. The newer stents of polyvinyl chloride are not readily available in India and endotracheal tubes are used in many centres. In our centre polyvinyl chloride tubes are used nasotracheally for prolonged periods. We prospectively studied the pattern of laryngeal changes that occur because of prolonged nasotracheal stenting with polyvinyl chloride tubes. METHODS: The incidence and pattern of laryngeal changes due to stents was prospectively studied at the time of removal of stents, using an operating microscope. Twenty-nine patients underwent tracheal reconstructive surgery for tracheal stenosis (post-intubation or post-tracheostomy) and tracheal injuries. RESULTS: Twelve different lesions were noted and their pattern was related to the period of stenting. Fibrosis, fibrous band formation and webs were noted after four weeks. A high incidence of laryngeal changes was seen in all age groups with an overall incidence of 79% (males 79%; females 88%; adults 82%, children 75%). The mean (SD) duration of stenting was 50 (33) days. Patients with laryngeal changes had a significantly (p < 0.05) longer duration of stenting [56 (34) days] compared to those without any lesion [29 (15) days]. CONCLUSIONS: After four weeks of stenting the severity and incidence of laryngeal changes increase. We recommend restriction of the use of polyvinyl chloride stents to less than four weeks to prevent permanent laryngeal damage.

Adolescent↗
PubMedDate not supplied

A profile of nutritional practices and its cost in an intensive care in India.

In a retrospective study fifty patients admitted to a combined medical and surgical intensive care unit were surveyed to see the pattern of nutritional support. The routine practices of initial assessment and monitoring of the nutritional state, ordering and technique of feeding, routes of administration and complications were noted over a 3 week period. This gives an idea of the pattern of care and problems associated with nutritional support of the critically ill in this part of the world. The average cost of parenteral nutrition for three weeks was approximately Rs. 25,960 ($865 approx.) per patient.

Adolescent↗
PubMedDate not supplied

Carcinoid crisis during a partial hepatic resection; lack of essential drugs: a cause for concern in the tropics.

We report a patient of carcinoid syndrome with hepatic metastasis (primary lesion in the ileum) who was posted for a right hepatic lobe resection and excision of the primary lesion. The patient developed carcinoid crisis with excessive blood loss due to vasodilation and severe hypotension during surgery. This case highlights the lack of essential drugs in the management of an intraoperative carcinoid crisis in this part of the world.

Anesthesia, General↗