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Biomedical subjects

N Soni

Publications and source records attributed to N Soni.

At least 37 records · Page 2Linked to original sources
PubMed2000

Central venous blood culture: a useful test for catheter colonisation?

OBJECTIVE: To evaluate the widespread practice of using qualitative culture of venous blood taken through central venous catheters (CVCs) as a means of diagnosing catheter colonisation in situ. DESIGN: A prospective clinical study. PATIENTS: Three hundred fifty-one CVCs were inserted into 228 critically ill patients. INTERVENTIONS: Prior to CVC removal, blood was taken for qualitative culture from the CVC and a peripheral site. All catheter tips underwent semi-quantitative analysis of bacterial colony count [1]. MEASUREMENTS AND RESULTS: One hundred eighteen (33.6%) CVCs were found to be colonised on removal. A positive central blood culture had a sensitivity and specificity of 50.8% and 78.9% when compared with the 'gold standard' of catheter tip culture. This gives a positive predictive value of 47.7% and a negative predictive value of 76.5%. The sensitivity and specificity of a positive peripheral blood culture were 41.5% and 77.7% with positive and negative predictive values of 48.8% and 72.9%, respectively. When only those catheters removed because of systemic sepsis (n = 139) were considered, a positive central blood culture had a sensitivity of 58.8% and a specificity of 69.3%. CONCLUSION: Our results indicate that the use of central blood culture confers a small advantage in sensitivity compared with peripheral blood culture. This advantage was further improved by only considering the catheters removed because of systemic sepsis but at the cost of a loss of specificity. Qualitative blood culture is a poor tool for the diagnosis of in-situ CVC colonisation.

Adult↗
PubMed2000

Risk factors for pressure sores in the critically ill.

Pressure sore development in the critically ill is a well-recognised problem and several risk factors have been put forward as being relevant; however, none has been proved valid in this population. This study examines the effects of specific risk factors for the development of pressure sores in the critically ill. Data on 22 specific risk factors were recorded every 8 h. Of 286 patients who were identified as having a minimum set of three predetermined risk factors, 77 developed pressure sores. Using univariate regression analysis, 18 of the 22 specific factors were identified as being significant (p < 0.05) in the development of pressure sores. Multivariate analysis identified five of these 18 specific risk factors as being independently significant (p < 0.05) in pressure sore development. These five factors were norepinephrine infusion, APACHE II score, faecal incontinence, anaemia and length of stay.

Critical Care↗
PubMed2000

Multidrug-resistant typhoid fever.

One hundred children (consecutive) with positive blood culture for Salmonella typhi were studied for clinical profile and complications. The common clinical features were fever (100%), vomiting (58%), abdominal pain (48%), cough (22%) and loose stools (14%) and the Widal test was positive in 75% patients. Eighty per cent of the salmonella isolates were resistant to amoxycillin, chloramphenicol and co-trimoxazole drugs, but all were sensitive to ciprofloxacin and ceftriaxone. Forty patients developed complications: encephalopathy (18), melaena (12), haematemesis (10), epistaxis (4), hepatitis (4), acalculous cholecystitis (4), bowel perforation (3) and nephritis (2). Complications were more frequent in children with multidrug-resistant typhoid. The final antibiotic required to render the children afebrile included ciprofloxacin (80), ceftriaxone, amoxycillin (4), chloramphenicol (4), amoxycillin and gentamicin (4), amoxycillin with chloramphenicol (2), and furazolidone (2). The defervesence time was least with ceftriaxone and greatest with amoxycillin. All the affected children made a complete recovery.

Anti-Bacterial Agents↗
PubMed1999

ICU admission in patients infected with the human immunodeficiency virus - a multicentre survey.

We conducted a retrospective study to assess the reasons for admission to the intensive care unit, and subsequent outcome, in patients infected with the human immunodeficiency virus (HIV). Four hospitals in the south of England participated, all with specialist HIV units. Data were collected on 127 patients admitted to ICU on 133 separate occasions between June 1993 and October 1997. The mean age on admission was 38 years (range 23-60 years). Ninety-four patients (70.7%) were documented HIV-positive before admission and 36 (27%) were diagnosed HIV-positive for the first time during admission; 36.1% were admitted with Pneumocystis carinii pneumonia. Overall ICU mortality was 33%, in-hospital mortality was 56% and the eventual mortality at the end of follow-up (March 1998) was 72%. Survival was highest in those admitted with respiratory HIV-related disease or HIV-unrelated illness. Associations with poor outcome included a prior AIDS-defining illness, a CD4 cell count of less than 100 cells.ml-1 and admission secondary to sepsis.

AIDS-Related Opportunistic Infections↗
PubMed1999

Antiseptic-bonded central venous catheters and bacterial colonisation.

This study was undertaken to evaluate the impact of chlorhexidine/silver sulphadiazine-bonded catheters on the incidence of colonisation and catheter-related sepsis in critically ill patients. Threehundred and fifty-one catheters were inserted into 228 patients during the study period, 174chlorhexidine/silver sulphadiazine-bonded catheters and 177 standard catheters. Indications for catheter removal were: death, clinical redundancy and clinical evidence of local or systemic infection. All catheter tips were sent to the microbiology laboratory for semiquantitative analysis of bacterial colony count. Seventy-one (40.2%) of the standard catheters and 47 (27.2%) of the antiseptic-bonded catheters were found to be colonised on removal (p < 0.01). Eight cases (4.7%) of catheter-related sepsis were associated with standard catheters and three cases (1.7%) with antiseptic-bonded catheters, however, this reduction was not statistically significant. Our results indicate that the use of antiseptic-bonded catheters in critically ill patients significantly reduces the incidence of bacterial colonisation.

Adult↗
PubMed1998

The effects of low-dose dopamine infusions on haemodynamic and renal parameters in patients with septic shock requiring treatment with noradrenaline.

OBJECTIVE: To investigate whether low-dose dopamine (LDD) has a significant effect on systemic haemodynamic variables and renal function when used in conjunction with high-dose noradrenaline in optimally volume-resuscitated patients with septic shock. DESIGN: A prospective clinical study in which each patient acted as his/her own control. SETTING: Teaching hospital Intensive Care Unit. PATIENTS: Twenty-one patients with septic shock treated with high-dose noradrenaline were studied, 17 patients completed the study. INTERVENTIONS: Fluid loading to an optimal left ventricular stroke work index (LVSWI) whilst on more noradrenaline than 10 mcg/min and dopamine of 2.5 mcg/kg per min. Three study periods each of 2 h with LDD present, withdrawn and restarted. During each period a complete haemodynamic profile and measurement of urine flow rate, creatinine clearance and sodium excretion was performed. MEASUREMENT AND RESULTS: Removing and restarting LDD caused marked changes in cardiac index (CI, 17% fall, p < 0.01: 23% rise, p < 0.01), stroke volume (SV, 11% fall, p < 0.05: 14% rise, p < 0.05) and systolic blood pressure (SBP, 11% fall, p < 0.05: 14% rise, p < 0.05). Urine volume fell by 40% (p < 0.05) when dopamine was withdrawn. Significant reductions in sodium excretion (p < 0.05) and fractional sodium excretion (p < 0.05) also occurred on stopping LLD. Changes in creatinine clearance were not statistically significant. CONCLUSION: Low-dose dopamine causes significant increases in SBP SV, cardiac output and urine flow during treatment with noradrenaline.

Adrenergic alpha-Agonists↗
PubMed1998

Dopamine clearance in critically ill patients.

OBJECTIVE: To examine the validity of the low-dose "renal" dopamine regimen in critically ill patients by investigating the steady-state clearance of dopamine. DESIGN: A prospective clinical study. SETTING: Teaching hospital intensive care unit. PATIENTS: 48 haemodynamically stable patients receiving a dopamine infusion. INTERVENTIONS: Sampling of arterial blood and dopamine infusates. MEASUREMENT AND RESULTS: Plasma and infusate dopamine levels were measured by liquid chromatography with electrochemical detection. Steady-state clearance was determined by dividing the actual infusion rate by the steady-state plasma concentration. Dopamine clearance for the whole group was 46.4 +/- 35.9 ml/kg per min (mean +/- SD), which is significantly lower than 70 +/- 15.2 ml/kg per min reported for elective surgical patients (p = 0.01). Twelve patients with renal dysfunction had significantly lower dopamine clearances (36 +/- 16.6 ml/kg per min) than the remaining 36 patients (61 +/- 38.5 ml/kg per min, p = 0.022). There was a very poor correlation between plasma dopamine level and infusion rate for the group as a whole (r = 0.47), and this worsened (r = 0.31) when only those patients on a "renal" dose of 2-5 microg/kg per min were considered (n = 30). CONCLUSION: Plasma dopamine clearance is lower in critically ill patients and there is a large interindividual variation. It is therefore impossible to predict the plasma level from the infusion rate. Consequently, the concept of a selective renovascular low-dose dopamine infusion is invalid in critically ill patients.

Adult↗
PubMed1998

Serum albumin: touchstone or totem?

A decrease in serum albumin concentrations is an almost inevitable finding in disease states, and is primarily mediated in the acute phase by alterations in vascular permeability and redistribution. This change is not disease specific but marked changes that persist are generally associated with a poorer prognosis. Critical appraisal of long-standing practices and the availability of alternative colloid solutions have led to a reduction in albumin replacement therapy, and a widespread tolerance of lower albumin concentrations in patients. The factors determining serum albumin concentrations, their measurement and the implications of hypoalbuminaemia are reviewed. The clinical value of serum albumin measurement is discussed.

Acute-Phase Reaction↗