PubMed Health⌕ Search

Biomedical subjects

G Gueret

Publications and source records attributed to G Gueret.

10 recordsLinked to original sources
PubMed2006

Fibre-optic intubation teaching in sedated patients with anticipated difficult intubation.

BACKGROUND AND OBJECTIVES: The objective of the study was to assess the safety of training fibre-optic intubation performed under propofol light general anaesthesia in patients with an anticipated difficult intubation. METHODS: Patients with ear, nose and throat cancer having at least two criteria for anticipated difficult intubation and scheduled for fibre-optic intubation were included prospectively. In 26 patients, intubation was performed by an anaesthesia resident (under senior supervision), whereas in 20 patients, it was performed by a senior anaesthesiologist. All patients received propofol light general anaesthesia adjusted to maintain both loss of consciousness and spontaneous ventilation. RESULTS: Of the 46 patients, 45 had successful fibre-optic intubation, and one needed a rescue procedure because of hypoxaemia. Residents failed to intubate four patients, who were easily intubated by the senior. Episodic hypoxaemia (SPO2 < 90%) occurred in three patients in each group. No statistically significant difference was found between junior and senior neither on the duration of the procedure (9.3 +/- 4.9 vs. 7.5 +/- 4.0 min) nor on the propofol consumption (197 +/- 130 vs. 193 +/- 103 mg) or the ETCO2 at the end of the procedure (36 +/- 6 vs. 38 +/- 6 mmHg), respectively. CONCLUSION: Teaching fibre-optic tracheal intubation in patients with anticipated difficult intubation and sedated with propofol did not increase morbidity significantly compared with an experienced anaesthesiologist. Fibre-optic intubation under propofol light general anaesthesia could be safely performed by a resident as long as a senior anaesthesiologist is permanently present, spontaneous ventilation is maintained and a rescue oxygenation technique is immediately available.

Airway Obstruction↗
PubMed2006

[Benchmark of a high-frequency jet ventilator, the Mistral].

OBJECTIVE: To test a high-frequency jet ventilator, the Mistral (Acutronic Laboratory) on a lung model. METHODS: The jet ventilator Mistral was tested with two connectors (7 and 20 ml) and four catheters. Pressure and flow measurements were performed by varying the driving pressure (1 to 3 bars), the I/T ratio (0.25, 0.35, 0.45) and the frequency (1 to 5 Hz). Recorded data were: the volume delivered by the ventilator, the pressure measured in the connecting line between the ventilator and the injector and the difference between the end expiratory pressure measured by the ventilator through the injector and the tracheal pressure. RESULTS: An increase in driving pressure induced a proportional increase in minute volume whatever the injection catheter used. After insufflation, when a Seldicath catheter was used, the pressure decrease was the slowest and the time constant the longest. Increase in frequency or I/T ratio, particularly beyond 0.35, was associated with an increase of the end expiratory pressure measured by the respirator. The gradient of pressure measured by the respirator and by an external sensor was lower with the 7 ml connector whatever the catheter used, and was larger with the Seldicath catheter. CONCLUSION: The use of a low volume connector should be preferred, because it allows the measurement of the end expiratory pressure for a larger range of driving pressure, expiratory time and catheters. The performances of the Seldicath catheter are below those of the other catheters studied.

High-Frequency Jet Ventilation↗
PubMed2006

[Right atrial rupture after abdominal blunt trauma].

If the cardiac injuries are frequent after closed chest traumatism, the cardiac injuries after abdominal closed traumatism are unusual but serious. We report the case of a right auricular rupture associated with a liver injury after a closed abdominal traumatism. The diagnosis was suspected on the TDM and confirmed by echocardiography. An emergency sternotomy was performed due to sudden haemodynamic instability. The initial clinical signs are often misleading. However the diagnosis must be made quickly and the treatment begun without delay.

Abdominal Injuries↗
PubMed2006

Cardiac output measurements in off-pump coronary surgery: comparison between NICO and the Swan-Ganz catheter.

BACKGROUND: The aim of this prospective study was to compare continuous cardiac output measurements of the non-invasive cardiac output system (NICO) with the pulmonary artery catheter during off-pump coronary bypass surgery. METHODS: Twenty-two patients enrolled for off-pump coronary surgery received both a pulmonary artery catheter and a non-invasive cardiac output system for measurement of cardiac output. Data were compared by the Bland-Altman method to calculate the degree of agreement and to analyse if a significant difference existed between the two methods of cardiac output measurements. RESULTS: Perioperatively, the non-invasive cardiac output underestimated cardiac output, but postoperatively overestimated it. The limits of agreement were larger during surgery compared to the postoperative period (-3.1; +2.5 vs. -1.4; +2.2 L min(-1)). Perioperatively, cardiac output measured with the pulmonary artery catheter varied from 0.5 to 7.5 L min(-1) (mean 3.6 L min(-1)) and with the non-invasive cardiac output from 0.5 to 8.4 L min(-1) (mean 3.9 L min(-1)). Postoperatively, these were 2.5-7.7 L min(-1) (mean 4.5 L min(-1)) and 2.3-8.4 L min(-1) (mean 4.9 L min(-1)), respectively. CONCLUSION: During off-pump cardiac surgery, the non-invasive cardiac output reliably measures cardiac output and does it more rapidly than a pulmonary artery catheter and may be more useful in order to detect rapid haemodynamic changes.

Aged↗
PubMed2004

Is muscle relaxant necessary for cardiac surgery?

The need for continuous and complete paralysis during the entire cardiac surgery has not yet been investigated and is still controversial. In a series of 87 patients undergoing cardiac surgery with normothermic cardiopulmonary bypass, we studied the delay of recovery, incidence of residual paralysis, unwanted patient movement, and difficult surgical conditions after a single dose of atracurium (0.5 mg/kg) or cisatracurium (0.15 mg/kg). Anesthesia was induced with etomidate and remifentanil followed by tracheal intubation. The delay to obtain a train-of-four ratio of >0.9 was longer with cisatracurium than with atracurium (86 +/- 18 versus 97 +/- 19 min). However, at the end of surgery, this ratio was >0.9 for all patients. The presence of unwanted patient movement, diaphragmatic contractions, and difficult surgical conditions were observed. Delay of extubation of the trachea was similar in both groups. We conclude that there is no need for continuous neuromuscular blockade during cardiac surgery. A single dose of either atracurium or cisatracurium is sufficient to provide efficient paralysis from the start of induction leading to quicker recovery from paralysis in fast-track cardiac surgery.

Aged↗
PubMed2002

[Coronary thrombosis on patient with the factor V Leiden mutation].

We report a documented observation of coronary thrombosis occurring in a 25-year-old patient with no risk factor, presenting a hereditary thrombophilia (facteur V Leiden) diagnosed a few months earlier in a context of venous thrombosis. This patient had a spread out anterior myocardial infarction with cardiac arrest due to a ventricular fibrillation; although he was quickly rescued by the mobile intensive Care Unit, the patient died 48 hours later, after cerebral anoxia. The mutation called factor V Leiden is a widely spread hereditary family thrombophilia (5 to 6% of the population) and is characterized by a resistance to activated C protein provoking a hypercoagulable state. The unexpected arterial thrombosis, very rare in that case, can be extremely serious and raises the question of a preventive medication such as antiplatelet agent or low-molecular-weight heparin as soon as the genetic abnormally has been proved to be symptomatic.

Adult↗
PubMed1999

Transcriptional activation of CYP2C, MxA and Fas in sudden infant death syndrome.

The expression of cytochrome P4502C has been shown to be upregulated in sudden infant death syndrome (SIDS) and could be linked to viral infection through the release of interferon alpha and interleukins. MxA is a reliable marker of IFNalpha release and its level was significantly enhanced in SIDS reflecting the release of IFNalpha in response to viral infection. Similarly, the concentration of Fas protein was increased in SIDS (2.6x control) and indicated a stimulation of the Fas gene expression. Accumulation of MxA and Fas proteins were visible in liver and to a lesser extent in lung and kidney. The amount of RNA encoding CYP2C9 (4.4x control), 2C8 (2.5x) and 2C18 (2.3x) was markedly higher in SIDS than in age-matched children and would suggest a transcriptional activation of CYP2C gene expression. Finally, CYP2C genes were shown to be adjacent to two IFN-inducible genes (IFI54 and IFI56) on chromosome 10. We conclude that in SIDS a viral infection leads to the release of IFNalpha which could activate a battery of IFN-inducible genes. This might modify the chromatin structure and facilitate the accessibility to promoter/regulatory sequences of CYP2C and Fas genes close to IFN-inducible gene on chromosome 10.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Developmental expression of CYP2C and CYP2C-dependent activities in the human liver: in-vivo/in-vitro correlation and inducibility.

Experiments were performed in vivo and in vitro to date the onset of hepatic CYP2C isoforms and CYP2C-dependent activities during the perinatal period in humans. Proteins were not detected by immunoblotting in fetal livers and developed in the first few weeks after birth, irrespective of the gestational age at birth. Similarly, the hydroxylation of tolbutamide, a marker for CYP2C9 was undetected in fetal liver microsomes and rose in the first month after birth. In adult liver preparations, the hydroxylation of diazepam correlated well with the CYP3 A content of microsomes (r = 0.858, p < 0.01) and with the 6 beta hydroxylation of testosterone (r = 0.830, p < 0.005), whereas demethylation was related to the bulk of CYP2C proteins (r = 0.865, p < 0.005). In fetal liver microsomes, hydroxylation and demethylation activities accounted for less than 5% of the adult activities and both increased immediately after birth to reach adult activities at 1 year of age. When diazepam was given for sedative purpose in neonates and infants, the in-vivo urinary excretion of desmethyl diazepam, temazepam and oxazepam was extremely low in 1-2 day newborns (less than 5 nmol metabolites excreted in 24 h per kg body weight) and developed in the first week after birth. In newborns, barbiturates and to a lesser extent steroids, acted as inducers of CYP2C isoforms and increased tolbutamide hydroxylation, diazepam demethylation and diazepam hydroxylation by 2 to 10-fold. The surge of CYP2C proteins was caused by an accumulation of RNAs occurring in the first week after birth. The hepatic content in CYP2C8, 2C9 and 2C18 RNA displayed the same profile of evolution, which suggested a coregulation of their synthesis during the neonatal period. Taken together, these biochemical and clinical data enable dating of the onset of CYP2C proteins to the first weeks after birth, which is of considerable clinical importance in pediatric pharmacology.

Adult↗
PubMedDate not supplied

Multi-detector row computed tomography angiography: an alternative imaging method for surgical strategy in lower extremity arterial occlusive disease.

In order to show the value of CT angiography in the pretherapeutic assessment of lower leg ischemia, we studied 93 CT angiographies in 85 patients. Two groups were defined according to the level of revascularization: 52 angioscanner were made prior to suprainguinal revascularization and 41 prior to infrainguinal reconstruction. Two decision attitudes were chosen by two different physicians, a radiologist and vascular surgeon, members of the same team. The attitudes where then compared in order to evaluate the value of CT angiography. The first attitude was a pragmatic strategy based on the images as interpreted by the first physician and on the intraoperative information including surgical treatment and, if necessary, angiography. This indicates that the results of this attitude cover the performed revascularizations. The second attitude determined a virtual strategy and was chosen by the second physician a posteriori, based solely on the medical file with the same CT angiography images. These two strategies were compared in order to assess the agreement on the level of the lesion and the choice of revascularization. In 84 CT angiographies (90.3%), the analysis of the lesions and the choice of lesions to be treated were identical. In 9.6% of scans the strategies were not comparable because the lesions were interpreted differently or the scans were difficult to read. The sensitivity of CT angiography in detecting lesions and guiding the therapeutic strategy was 96% and its positive predictive value was 93%. Follow-up was reported according to the life-table method to assess the overall outcome and the results in both groups. The overall survival rate at 12 months for 85 patients was 90%. Secondary patency rates at 12 months in the group of patients who underwent a suprainguinal and infrainguinal revascularization were 98% and 71% respectively. Overall limb salvage at 12 months was 94%. In this setting, CT angiography allowed us to select adequate treatment in the majority of cases. These results obtained after a strategy based on CT angiography images are comparable with the results as published in the literature after the strategy based on conventional angiography.

Adult↗