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Biomedical subjects

C Flamens

Publications and source records attributed to C Flamens.

At least 19 recordsLinked to original sources
PubMed2006

[Impact of the guidelines on clinical practice of artificial nutrition in intensive care unit after cardiovascular and thoracic surgery].

OBJECTIVE: To analyze the impact of an artificial nutrition program in post-anaesthesia intensive care unit. STUDY DESIGN: Observational study. PATIENTS AND METHODS: Patients with length of stay greater than 8 days after cardiovascular and thoracic surgery: Group 1: 34 patients (4-month period in 2000); group 2: 15 patients (2-month period in 2001); group 3: 40 patients (4-month period in 2003). Between these 3 periods, informations of physicians and written protocol in order to improve their nutritional knowledge. After analysis of variance (P<0.05). Newman-Keuls tests to compare themselves each groups. RESULTS: Anthropometric, demographic and clinical parameters were similar in the 3 groups. Energic intakes were less than 80% of basal energetic expenditures in 33%, 33 and 22% of patient, respectively (NS). Caloric and nitrogen intakes were less than recommended, respectively 19+/-6 (mean+/-SD), 21+/-7 and 21+/-8 kcal/kg/24 h and 102+/-32, 111+/-31 and 92+/-40 mg/kg/24 h (NS). However enteral nutrition was administered in 49, 40 and 100% of patients respectively (P<0.001). The glucid/lipid ratio improved from 0.47 in group 1 up to 0.68 in group 3 (P<0.0001). Vitamins, oligoelements and clinical and biological monitoring of artificial nutrition improved (P<0.001). CONCLUSION: A clinical audit demonstrated an improvement in artificial nutrition parameters but no significant change in others.

Aged↗
PubMed2003

Evaluation of the estimation of midazolam concentrations and pharmacokinetic parameters in intensive care patients using a bayesian pharmacokinetic software (PKS) according to sparse sampling approach.

The aim of the study was to assess the performance of a bayesian program (PKS System, Abbott) for predicting midazolam concentrations and pharmacokinetic parameters in intensive care patients by comparing the pharmacokinetic parameters estimated by PKS to those calculated according to rich data. The study involved 42 patients receiving midazolam infusion for two hours or for several days. The program was used to predict plasma midazolam concentrations after feedback of 1, 2 or 3 concentrations. High correlation between observed and estimated concentrations was shown (r(2) > 0.992). Mean prediction error, mean absolute prediction error and root mean squared error were low for the patients of the reference and validation groups. From two or three feedback concentrations, midazolam pharmacokinetic parameters estimated by PKS were statistically comparable with those obtained using a rich pharmacokinetic analysis (P > 0.05 paired Wilcoxon test). Thus, PKS is useful for predicting midazolam concentrations and pharmacokinetic parameters when at least two feedback concentrations are known. This software seems to be appropriate for providing significant help to the clinician for midazolam dosage adjustment, according to midazolam concentrations and clinical sedation.

Area Under Curve↗
PubMed2002

[Sedation induced by midazolam in intensive care: pharmacologic and pharmacokinetic aspects].

OBJECTIVE: Review on midazolam in order to optimize drug utilisation and therapeutic monitoring. DATA SOURCES: Research of English or French articles published until August 2001, using Medline database. The key words were: midazolam, pharmacokinetics, pharmacodynamic, sedation, drug interaction. STUDY SELECTION: Original articles, clinical cases and letters to the Editor were selected. Animal studies were excluded. DATA EXTRACTION: The articles were analysed according to their interest in midazolam clinical practice. DATA SYNTHESIS: Midazolam is a benzodiazepine widely used in intensive care unit, as a sedative, anxiety-relieving, and amnesic drug. Midazolam could be used in patients with cardiac, or respiratory failure, and in neurosurgery. A great interindividual variability on pharmacokinetic and pharmacodynamic response was observed. In intensive care patients, elimination half-life is known to be widely increased. Midazolam is metabolised by hepatic microsomes. The major metabolite is the 1-hydroxymidazolam, which is pharmacologically active. A prolonged sedation due to an accumulation of conjugated metabolite was observed in renal failure patients. Enzymatic inductors or inhibitors could influence pharmacokinetics and pharmacodynamic effects of midazolam. CONCLUSION: According to midazolam pharmacokinetic and pharmacodynamic variability, an individual dosage adjustment is essential for long-term sedation. Target controlled sedation could be a mean to limit the variability and to reach quickly the pharmacodynamic effect.

Critical Care↗
PubMed2002

[Use of midazolam in postoperative sedation of patients with multiple organ failure treated with hemodiafiltration. Clinical study and pharmacokinetics].

OBJECTIVES: Evaluate the risk of accumulation of midazolam and conjugated 1-hydroxy-midazolam in high-risk ICU patients treated by continuous veno-venous haemofiltration. STUDY DESIGN: A prospective pharmocokinetic and clinical evaluation in 11 patients, with hepatic and renal failure. METHODS: Midazolam and metabolites were dosed in plasma and ultratiltration liquid by chromatography. Sedation was assessed by a simplified Ramsay score (EDS) with 4 levels. RESULTS: The mean duration of continuous infusion was 11 +/- 6 days. Peak plasma levels were over 150 ng ml-1 during the first 3 days, but normalized after that, only by drug adjustment based on scoring and clinical observation. There was no progressive accumulation of OH-midazolam, in spite of high levels (> 1000 ng ml-1). The Sieving coefficient (S) was 0.11 +/- 0.10 and 0.44 +/- 0.15 for midazolam and conjugated OH-midazolam respectively. A significant clearance (9.6 +/- 1.9 ml min-1) was observed for the conjugated products. T 1/2 beta was 11 h and was correlated with the mean time of recovery. A significant correlation was found between sedation score and both midazolam (r = 0.47) and OH-midazolam (r = 0.32). CONCLUSION: OH-midazolam risk of accumulation and significant clearance by haemodiafiltration should be taken into account in the drug adjustment in patients treated by continuous veno-venous haemofiltration.

Adjuvants, Anesthesia↗
PubMed2001

Midazolam disposition in patients undergoing continuous venovenous hemodialysis.

The aim of the study was to investigate the pharmacokinetics and removal of midazolam and unconjugated and glucuronidated 1-hydroxy-midazolam in 4 intensive care patients on continuous venovenous hemodialysis. Plasma midazolam and its metabolites were assessed by HPLC from blood samples collected during continuous infusion and after the end of infusion. Additional samples from the arterial and venous bloodlines and ultrafiltrate were drawn to calculate sieving coefficient and clearance of ultrafiltration. The elimination half-life of midazolam ranged from 7.6 to 22.8 hours. The clearance of ultrafiltration was between 0.13 and 4.7 ml/min and reached approximately 11% of the total clearance. The range of sieving coefficient was from 0.006 to 0.26, with an average fraction removal of 0.2%. 1-Hydroxy-midazolam glucuronide was removed by continuous hemodialysis (sieving 0.36 to 0.63), with a clearance of ultrafiltration ranging from 7.8 to 12.0 ml/min. These preliminary results showed that midazolam is not removed efficiently, and approximately half of the 1-hydroxy-midazolam glucuronide was removed by dialysis.

Aged↗
PubMed2000

Relative importance of flow versus pressure in splanchnic perfusion during cardiopulmonary bypass in rabbits.

BACKGROUND: Decreased gastrointestinal perfusion has been reported during cardiopulmonary bypass (CPB). Conflicting results have been published concerning thresholds of pressure and flow to avoid splanchnic ischemia during CPB. This study compared splanchnic perfusion during independent and randomized variations of CPB pump flow or arterial pressure. METHODS: Ten rabbits were studied during mild hypothermic (36 degrees C) nonpulsatile CPB using neonatal oxygenators. Simultaneous measurements of tissue blood flow in four different splanchnic areas (gastric, jejunum, ileum, and liver) were performed by laser Doppler flowmetry (LDF) before CPB (T0) and during a 4-step factorial experimental block design. Pressure and flow were alternatively high or low in random order. RESULTS: Laser Doppler flowmetry was significantly lower than pre-CPB value but was better preserved (analysis of covariance) in all organs, except liver, when CPB flow was high, whatever the pressure. Splanchnic LDF values in the low- versus high-flow groups expressed as perfusion unit were (mean +/- SD): stomach, 94+/-66 versus 137+/-75; jejunum, 118+/-78 versus 172+/-75; ileum, 95+/-72 versus 146+/-83; and liver, 79+/-72 versus 108+/-118. No significant difference of LDF was observed between the high- and low-pressure groups, whatever the flow, except for liver: stomach, 115+/-64 versus 117+/-83; jejunum, 141+/-80 versus 148+/-83; ileum, 127+/-87 versus 114+/-76; liver, 114+/-88 versus 73+/-70. CONCLUSION: Prevention of splanchnic ischemia during CPB should focus on preservation of high CPB blood flow rather than on high pressure.

Animals↗
PubMed1998

[Reversible graft dysfunction after cardiac transplantation].

The authors report 3 cases of major graft dysfunction after cardiac transplantation which recovered completely with biventricular mechanical assistance in 4 to 8 days. All three cases were primary biventricular graft failures in patients with normal preoperative pulmonary resistances. These early dysfunctions (with no signs of myocardial infarction on electro- or echocardiography and in the absence of abnormal increased peri-operative enzyme levels) associated with total functional recovery conforming to the definition of the phenomenon of myocardial stunning. These results argue in favour of aggressive management of primary graft dysfunction.

Echocardiography, Transesophageal↗
PubMed1997

Pharmacokinetics of acyclovir in patients undergoing continuous venovenous hemodialysis.

The pharmacokinetics of acyclovir in three patients undergoing continuous venovenous hemodialysis was investigated. Acyclovir was administered as an intravenous infusion over 1 hour at a dose of 5 mg/kg daily in one patient and 10 mg/kg every 48 hours in two patients. Samples from the arterial and venous blood lines and from ultrafiltrate were collected to calculate pharmacokinetic parameters, sieving coefficient and clearance of ultrafiltration. Plasma concentrations of acyclovir were assessed by high-performance liquid chromatography. Peak plasma concentrations were 9.3 mg/l for the patient receiving 5 mg/kg daily, 29.6 mg/l and 20.7 mg/l for the two patients with 10 mg/kg every 48 hours. The elimination half-life ranged from 8.8 to 11.2 hours and was approximately half those found in patients with renal impairment. The clearance by ultrafiltration was from 17.4 to 22.3 ml/minute and reached nearly 35% of the total clearance. The sieving coefficient ranged from 0.92 to 0.98 with an average rate of removal over the dosing interval ranging from 6.7 to 13.0 mg/hour. These data should be taken into account to optimize drug therapy in patients on continuous hemodialysis. Until formal guidelines are defined, acyclovir dosage should be adjusted according to monitoring of plasma drug concentrations.

Acyclovir↗
PubMed1996

[Aneurysms of the left ventricle without atheromatous coronary artery disease. Apropos of 2 cases].

Left ventricular aneurysms are usually secondary to myocardial infarction with atheromatous coronary artery disease. The authors report two rare cases of non-atheromatous left ventricular apical aneurysms. The first case was clearly post-traumatic but the diagnosis in the second case was more difficult. The authors discuss the aetiological diagnosis of these rare non-atheromatous aneurysms in adults and the therapeutic management with respect to these two cases and a review of the literature.

Coronary Angiography↗
PubMed1996

Intracardiac air clearing in valvular surgery guided by transesophageal echocardiography.

BACKGROUND AND AIMS OF THE STUDY: Air embolism during open heart surgery seems to be a common occurrence and may be responsible for neuropsychological deficit or myocardial damage. MATERIAL AND METHODS: Forty-two consecutive patients undergoing valvular surgery were studied using the long axis view of the heart by two dimensional transesophageal echocardiography (TEE). The patients were randomized into two groups of 21 each. In group 1, the routine air evacuation method was used. In group 2, the same air evacuation method was used and controlled with a Doppler ultrasonic probe adjusted around the root of the aorta. At the end of air evacuation, intracardiac microbubbles and retained air were analyzed with TEE and when air was founded, its location was communicated to the surgeons who tried to remove it by shaking the heart and tilting the operating table for 15 minutes. The patients were assessed for detection of cardiac or neurological postoperative complications. RESULTS: The incidences of microbubbles and retained air were 57% and 43% in group 1, and 62% and 38% in group 2 respectively (ns). The mean grade of microbubbles was lower in group 2: 1.4 +/- 0.8 vs. 2.2 +/- 0.9, p < 0.05. TEE allowed to significantly decrease (p < 0.05) retained air and mean grade of microbubbles to 14% and 1.3 +/- 0.8 in group 1, and to 10% and 0.8 +/- 0.8 in group 2, without statistical difference between the two groups. Despite the help of TEE, manual attempts to eradicate retained air were unsuccessful in five patients (three in group 1, two in group 2). CONCLUSIONS: The use of aortic ultrasonic probe allowed to reduce the amount of microbubbles. TEE was a useful tool not only for the detection of retained air but also for locating it, and guiding the procedure to eliminate it.

Adolescent↗
PubMed1995

Valvular replacement for aortic stenosis on patients in NYHA class III and IV. Early and long term results.

From January 1972 to June 1990, 112 patients between 39 and 83 years old, divided into 68 NYHA class III (60.72%) and 44 NYHA class IV, underwent surgery for aortic stenosis. There were 67 male (59.82%) and 45 female (40.18%). Early mortality included 8 patients (7.14%). Actuarial survival (including early postoperative mortality) for all 112 patients was 88.39%, 77.67%, 67.85% and 65.7% t one year, five, ten and fifteen years respectively. Clinical criteria are subjective but they remain the best prognostic factor. Surgery is indicated at occurrence of first symptoms, but, even in advanced cases, aortic valvular replacement can significantly improve survival and functional status. Even if operative risk is increased and secondary cardiomyopathy often progresses after surgery, aortic valve replacement results seem better than those of medical treatment alone.

Adult↗
PubMed1993

[Plasma concentrations of diltiazem and its metabolites in coronary surgery: relation with preoperative treatment].

Preoperative oral administration of calcium channel blocking agents has been found ineffective to prevent perioperative myocardial ischaemia. Our hypothesis was that low plasma concentrations may account for this inefficiency. Twenty-three male patients, scheduled for surgical myocardial revascularisation, were administered their usual anti-anginal treatment, including 180 to 360 mg of diltiazem since more than one week. The usual dosage was given at 8.00 p.m. on the day before surgery. On the morning of surgery, after withdrawal of a first blood sample, 60 mg of diltiazem were administered per month before the induction of anaesthesia. The anaesthesia was obtained with fentanyl, midazolam or flunitrazepam, pancuronium and isoflurane as required. The cardiopulmonary bypass (CPB) was associated with total haemodilution with Ringer's Lactate and a membrane oxygenator. A second blood sample was withdrawn after CPB. Plasma concentrations of diltiazem and its two active metabolites, N-monodemethyldiltiazem (MA) and desacetyldiltiazem (M1), were assessed by HPLC. Plasma diltiazem concentrations decreased from 78 +/- 66 (mean +/- SD) to 51 +/- 42 micrograms.l-1 (p < 0.05) with wide individual variations. These concentrations were under therapeutic levels in 18 out of 23 patients before (p < 0.05) with wide individual variations. These concentrations were under therapeutic levels in 18 out of 23 patients before induction and in 22 patients after CPB. The metabolite/diltiazem ratios remained constant. A dosage-plasma concentration relationship was observed preoperatively with diltiazem and MA. It is concluded that plasma concentrations of diltiazem should be optimized preoperatively in order to prevent myocardial ischaemia.

Aged↗
PubMed1991

[Dopexamine: a new catecholamine used in the treatment of low cardiac output after heart surgery].

The value of dopexamine hydrochloride, a beta 2 agonist with dopamine-like and weak beta 1 effects, for the treatment of low cardiac output was investigated in twelve patients. All had undergone cardiac surgery (valve replacement, aorto-coronary bypass), and had a cardiac index (C1) less than 21.min-1.m-2, low urine output (17 +/- 23 ml.h-1), and poor peripheral perfusion (peripheral cyanosis, cold hands and feet). Systolic arterial blood pressure was decreased, but over 80 mmHg. Diastolic pulmonary arterial or wedge blood pressure was more than 15 mmHg. Usual haemodynamic monitoring was carried out using arterial and Swan-Ganz catheters. Dopexamine hydrochloride doses were increased every 15 min by increments of 1 microgram.kg-1.min-1, up to a maximum dose of 8 micrograms.kg-1.min-1, so as to determine the optimal dose for each patient. This dose was then given for a period of up to 48 h. During the initial titration phase, heart rate increased by 37% from control at a dose of 4 micrograms.kg-1.min-1, this increase becoming less important at higher doses (13% at 8 micrograms.kg-1.min-1). Mean arterial blood pressure increased by 13% at a dose of 2 micrograms.kg-1.min-1. Mean pulmonary arterial blood pressure did not change significantly, but wedge pressure fell by 25% at 4 micrograms.kg-1.min-1. Simultaneously, CI increased by 56%, and systemic vascular resistances decreased by 31% (p less than 0.005). During the continuous steady rate infusion period, heart rate fell to a level of about 100 b.min-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic Agonists↗