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D Chassard

Publications and source records attributed to D Chassard.

At least 55 records · Page 3Linked to original sources
PubMed1999

Clinical impact of rapid oxacillin susceptibility testing using a PCR assay in Staphylococcus aureus bactaeremia.

OBJECTIVES: The aim of this work was to establish the clinical impact of rapid oxacillin susceptibility testing in nosocomial Staphylococcus aureus bacteraemia. METHODS: This study was performed in 145 critically ill patients infected by S. aureus. Patients were randomly assigned to one of two groups: patients for whom susceptibility testing was performed using a rapid same day multiplex PCR assay for detection of the staphylococcal mecA (mean delay of response: 6 h) and those for whom testing was accomplished using traditional overnight techniques (21 h). RESULTS: The results of this study showed no significant difference between the two groups in terms of age, Simplified Acute Physiologic Score, severity of infection, severity of underlying disease and clinical outcome (control vs. PCR): unfavourable outcome of infection, 12.32 vs. 12.5%; 95% CI for the difference = -11.49 to 11.09 (P = 0.975); unfavourable general outcome, 16.43 vs. 20.83%; 95% CI for the difference = -17.35 to 8.50 (P = 0.497). For the oxacillin-susceptible S. aureus bactaeraemia, results were: unfavourable outcome of infection = 13.04 vs. 11.11%; 95% CI for the difference = -11.38 to 16.18 (P = 0.767); unfavourable general outcome = 13.04 vs. 20.37%; 95% CI for the difference = -22.12 to 8.07 (P = 0.331). CONCLUSION: This study seemed to demonstrate that rapid oxacillin susceptibility testing using a PCR assay did not have a major impact on the care and outcome of patients with S. aureus bactaeremia.

Adult↗
PubMed1999

[Acute pernicious malaria treated with exchange transfusion].

A 53-year-old patient, after return from a short visit to the Ivory Coast, was admitted for suspicion of hepatic encephalopathy. An acute pernicious malaria was diagnosed with associating altered consciousness, hyperthermia, icterus, hepatomegaly, and oliguria. Blood tests showed acute renal failure, pancytopenia, disseminated intravascular coagulation, metabolic acidosis and parasitaemia at 12%. An intravenous therapy with quinine and doxycycline was started without delay. One day later, an exchange blood transfusion including a erythrapheresis and plasmapheresis was undertaken. The patient's general condition improved, and he was discharged from the ICU 22 days later. The indications for exchange blood transfusion in acute pernicious malaria are discussed.

Acute Disease↗
PubMed1999

Measurements of systolic time intervals using a transoesophageal pulsed echo-Doppler.

Measurement of systolic time intervals (STI), an index of left ventricular (LV) systolic function, is usually labour intensive and requires considerable expertise to perform accurately. We have evaluated the accuracy of an automated, continuous and non-invasive STI measurement technique using a descending aortic blood velocity Doppler signal obtained using a transoesophageal echo-Doppler system (TEDS) and an ECG signal. STI were measured in adult pigs using a transoesophageal probe (4 x 4 mm pulsed wave Doppler transducer, 5-MHz frequency and a 3 x 3 mm echo transducer, 10-MHz frequency) associated with an ECG recorder. Measurements were performed at baseline and after injection of esmolol and dobutamine. TEDS data were compared with those obtained by one-line recordings of the electrocardiogram and the central aortic arterial pressure wave. Similar mean values were observed for pre-ejection period (PEPI), LV ejection time (LVET) and PEP/LVET with the two methods. Agreement between the methods (Bland and Altman's test) was excellent with 95% confidence intervals for PEP, LVET and PEP/LVET of -7.17 to +1.37 ms, -12.64 to +0.24 ms and -0.033 to +0.028, respectively. We conclude that the combination of descending aorta blood velocity Doppler and ECG signal is an alternative technique for non-invasive and objective measurement of STI, allowing continuous monitoring of LV systolic function.

Animals↗
PubMed1999

Gram stain of bronchoalveolar lavage fluid in the early diagnosis of ventilator-associated pneumonia.

To assess the usefulness of the Gram stain in the early diagnosis of ventilator-associated pneumonia (VAP), we performed 146 protected specimen brushings (PSB) and bronchoalveolar lavages (BAL) in 118 patients suspected of having nosocomial pneumonia. Gram stain and counts of infected cells were performed in all samples from BAL fluid. A final diagnosis of pneumonia was established in 51 patients and there was no infection in 95 cases. A threshold of 2% of infected cells was used to distinguish between VAP and the group without VAP (sensitivity 86.3%, specificity 78.9%, positive predictive value 68.7% and negative predictive value 91.4%); there was good agreement with the final diagnosis (kappa statistic 0.616; concordance 81.5%). Regarding detection of bacteria using the Gram stain, we found a sensitivity of 90.2%, specificity 73.7%, positive predictive value 64.8% and negative predictive value 93.3%; there was moderate agreement with the final diagnosis (kappa statistic 0.586; concordance 79.4%). In the VAP group, we analysed the degree of qualitative agreement between Gram stain and PSB quantitative cultures: the correlation was complete in 51% (26 of 51 VAP), partial in 39.2% (20 of 51 VAP) and there was no correlation in 9.8% (five of 51 VAP). We conclude that the Gram stain is useful for rapid diagnosis of VAP but unreliable for early adaptation of empiric therapy.

Adolescent↗
PubMed1999

Pharmacokinetics of isepamicin during continuous venovenous hemodiafiltration.

The objective of this study was to analyze the pharmacokinetics of isepamicin during continuous venovenous hemodiafiltration. Six patients received 15 mg of isepamicin per kg of body weight. The mean isepamicin concentration peak in serum was 62.88 +/- 18.20 mg/liter 0.5 h after the infusion. The elimination half-life was 7. 91 +/- 0.83 h. The mean total body clearance was 1.75 +/- 0.28 liters/h, and dialysate outlet (DO) clearance was 2.76 +/- 0.59 liters/h. The mean volume of distribution was 19.83 +/- 2.95 liters. The elimination half-life, DO clearance, and volume of distribution were almost constant. In this group of patients, the initial dosage of 15 mg/kg appeared to be adequate, but the dosage interval should be determined by monitoring residual isepamicin concentrations in plasma.

Aged↗
PubMed1998

Lower oesophageal sphincter tone increases after induction of anaesthesia in pigs with full stomach.

PURPOSE: The lower oesophageal sphincter (LOS) is the man mechanism that prevents gastro-oesophageal regurgitation during anaesthesia. The aim of this study was to assess the effect on lower oesophageal sphincter pressure (LOSP) of rapid sequence induction in pigs with full stomachs. METHODS: Lower oesophageal sphincter pressure and oesophageal barrier pressure (BrP = LOSP minus gastric pressure) were measured using a water-perfused manometric catheter method in 12 pigs after gastric filling with 500 ml of liquid nutrient mixture. Six pigs were randomly allocated to receive 5 mg.kg-1 propofol and 3 mg.kg-1 succinylcholine i.v. and six pigs received 8 mg.kg-1 thiopentone and 3 mg.kg-1 succinylcholine i.v. RESULTS: After induction, mean LOSP increased during the period with fasciculations from 19 +/- 4 mmHg to 28 +/- 5 mmHg in the propofol-succinylcholine group and from 23 +/- 6 mmHg to 36 +/- 7 mmHg in the thiopentone-succinylcholine group. The LOSP remained elevated after the fasciculations. LOSP and BrP were not different between the groups. CONCLUSIONS: Induction of anaesthesia with propofol-succinylcholine or thiopentone-succinylcholine increases LOSP and, consequently, BrP in pigs with a full stomach. This increase begins before fasciculations and remains elevated for the period when intubation would occur.

Anesthesia↗
PubMed1997

Overestimation of low cardiac output measured by thermodilution.

We have investigated the influence of a cold water bolus (CWB) injection on overestimation of cardiac output (CO) in low CO states in anaesthetized dogs. CO was measured using three methods: (1) thermodilution (TD), (2) electromagnetic (EM) flow meter placed on the pulmonary artery and (3) transoesophageal echo-Doppler (OD) placed on the descending aorta. Measurements of CO were obtained before (steady state) and after induction of a low CO state with thiopentone 5 mg kg-1 i.v. After CWB injection, mean CO measured by EM and OD increased by 26% and 27%, respectively (P < 0.05) during steady state, and by 85% and 75% (P < 0.05) during the low CO state. This transient increase was produced by an increase in stroke volume, while heart rate did not change. Frank Starling's law may explain this variation by a sudden increase in preload produced by CWB injection. These results indicate that thermodilution overestimated CO during low CO states when CWB injection was used.

Animals↗
PubMed1997

Cricoid cartilage pressure decreases lower esophageal sphincter tone.

BACKGROUND: Cricoid cartilage pressure induced to prevent pulmonary aspiration from regurgitation of gastric contents has been recommended, and its efficacy requires a force greater than 40 Newtons. For regurgitation to occur, both an increase in gastric pressure and relaxation of the lower esophageal sphincter (LES) are necessary. However, the effect of cricoid cartilage pressure on the LES is unknown. This study evaluated the effects of cricoid cartilage pressure on LES in human volunteers. METHODS: Lower esophageal sphincter and esophageal barrier pressures (which equals LES pressure-gastric pressure) were measured using a manometric method in eight unanesthetized volunteers (4 men, 4 women) classified as American Society of Anesthesiologists physical status 1. The force applied to the cricoid cartilage was measured continuously, and LES pressure was recorded at a cricoid force of 20 and 40 Newtons. RESULTS: Cricoid pressure decreased LES pressure from 24 +/- 3 mmHg to 15 +/- 4 mmHg at a force of 20 Newtons (P < 0.05) and to 12 +/- 4 mmHg with a force of 40 Newtons (P < 0.01). CONCLUSIONS: These findings may explain the occurrence of pulmonary aspiration before tracheal intubation despite application of cricoid cartilage pressure.

Adult↗
PubMed1996

[Alkalinization of local anesthetics: theoretically justified but clinically useless].

PURPOSE: In vitro studies have demonstrated the potential advantages of alkalinization on anaesthetic activity, by decreasing the ratio of ionized to nonionized molecules, there by permitting more rapid penetration of local anaesthetic through biological membranes, thus decreasing the onset time. The proportion of each form depends on the pKa of the agent and the ultimate pH of the solution. When NaHCO3 is mixed with local anaesthetics, CO2 is produced. Carbon dioxide has been reported to enhance local anaesthetic action by diffusion trapping of the cationic form in pH gradient combined with a direct depressant action of CO2. The purpose of this study was to examine if clinical studies confirmed the in vitro action of alkalinisation. SOURCE: The literature pertinent to alkalinization of local anaesthetics published in the major anaesthesia and pharmacology journals of North America and Europe. PRINCIPAL FINDINGS: While in vitro studies have demonstrated potential advantages for alkalinization on anaesthetic activity, clinical studies have shown that alkalinization of local anaesthetics produces inconsistent results. For bupivacaine and etidocaine, alkalinization of local anaesthetic solution can produce precipitation, thus limiting the feasibility of increasing the pH. CONCLUSIONS: On the basis of this review, routine alkalinization of local anaesthetics is not recommended.

Anesthetics, Local↗