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Biomedical subjects

D R Karnad

Publications and source records attributed to D R Karnad.

41 records · Page 3Linked to original sources

Human immunodeficiency virus type 1 infection in patients with severe falciparum malaria in urban India.

BACKGROUND: CD4+ T cells restrict parasitaemia during the first attack of falciparum malaria; humoral immunity, develops weeks later and protects against reinfection. HIV infection may affect severity of falciparum malaria and development of protective immunity. AIMS: To study the prevalence of HIV infection in Indian patients with severe falciparum malaria and its effect on severity of illness and recurrences of and mortality related to malarial infection. PATIENTS: Consecutive patients with severe falciparum malaria and voluntary blood donors. SETTING AND DESIGN: Prospective cohort study in a university hospital in Mumbai. RESULTS: Five (11.6%) of 43 patients and 521 (1.8%) of 28749 blood donors had HIV infection (OR 7.1, 95% CI = 2.8 to 18.2, p=0.001). Clinical features, APACHE II score, number of organs affected, parasite index and mortality in patients with and without HIV infection were comparable. CD4+ counts were < 500 cells/ microl in 2 patients and normal in 3. Opportunistic infections including pulmonary tuberculosis in one patient (CD4+ counts > 500 cells/ microl), and oral candidiasis in two (CD4+ counts 275 and 250 cells/ microl) were noted. One patient developed fatal Pneumocystis carinii pneumonia two weeks after recovering from malaria. P. falciparum infection recurred in 2 of the 4 HIV infected survivors and in none of 31 survivors without HIV infection (RR 38.8, 95% CI 2.2 to 671, p=0.01). CONCLUSIONS: HIV infection is associated with increased risk of severe malaria even with normal CD4+ counts; severity of disease and mortality are not increased. However, prior HIV infection impairs protective immune response to Plasmodium falciparum in residents of hypoendemic areas.

Adult↗

Effect of venous hypercarbia and hyperventilation on myocardial contractility in canine haemorrhagic shock.

To study the effect of venous hypercarbia on myocardial contractility, haemorrhagic shock was produced in six healthy mongrel dogs by ex-sanguination of 15 ml of blood/kg body weight every 20 minutes till a loss of 45 ml/kg was achieved. After recording haemodynamic and respiratory parameters, the dogs were hyperventilated by positive pressure ventilation for 30 minutes and haemodynamic and blood gas parameters reassessed. During haemorrhagic shock, mean cardiac output decreased from 4.23 l min to 0.98 l min (p < 0.01), stroke index from 2.25 to 0.35 ml/kg (p < 0.05) and left ventricular stroke work index from 3.72 to 0.19 g. m/kg. The mean mixed venous pCO2 increased from 35 mmHg to 56.7 mmHg (p < 0.05). During hypoventilation, mixed venous pCO2 decreased to 40 mmHg (p < 0.05) and without any volume replacement, mean cardiac output increased 2.5 l min (P < 0.05), stroke index to 1.13 ml/kg (p < 0.05) and left ventricular stroke work index, and index of myocardial contractility, increased to 0.78 g.m/kg (p < 0.05). Thus, although hypovolaemia is the major cause of low cardiac output in haemorrhagic shock, this study shows that venous hypercarbia (which probably indicates tissue respiratory acidosis) further worsens circulatory failure by decreasing myocardial contractility. Hyperventilation improves cardiac functions and increases output by relieving tissue hypercarbia in spite of persistent hypovolaemia.

Animals↗

Ascitic fluid filtration and intravenous infusion versus total-volume paracentesis with infusion of plasma expander in cirrhosis with tense or intractable ascites.

BACKGROUND: Patients with cirrhotic ascites have low serum albumin levels, and paracentesis of ascitic fluid could compromise them further. AIM: We compared the therapeutic efficacy of ascitic fluid filtration and concentrate infusion (AFI) versus total-volume paracentesis (TVP) with colloid infusion in control of tense or intractable cirrhotic ascites. METHODS: Ten patients underwent AFI; their ascitic fluid was filtered repeatedly through hollow-fiber hemodialyzer, and the concentrate reinfused intravenously. In ten patients TVP was done with simultaneous intravenous colloid infusion. Follow-up was done weekly and the study terminated if the patient needed diuretics or developed complications. RESULTS: Pre-study parameters were similar in the two groups. In the AFI and TVP groups, the duration of procedure was median 12 hours and 5.5 hours; fluid removed by paracentesis was 10.2 L and 8.0 L, respectively; and fluid infused intravenously was 0.5 L [with mean (SD) protein content 5.7 (1.3) g/dl] and 1.1 L, respectively. Glomerular filtration rates were lower than normal in the two groups but did not change significantly with the procedure; body weight remained significantly lower up to week 3 and week 2, respectively. The study was terminated at median week 3 (range 1-8) and week 2 (1-4), respectively. Fever was an accompaniment of AFI and one patient developed peritonitis. CONCLUSION: Patients undergoing AFI remained diuretic-free longer; the procedure is cost-effective but needs to be further evaluated to minimize the side-effects.

Ascites↗