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Biomedical subjects

F Bonnet

Publications and source records attributed to F Bonnet.

At least 19 recordsLinked to original sources

Usefulness of consensus conferences: the case of albumin.

The usefulness of consensus conferences has been questioned. We have assessed the impact of a 1989 consensus conference about the treatment of hypovolaemia on prescribing practice at our hospital. Data available from the blood bank enabled us to follow albumin use and costs by department between 1987 and 1991. Medical journals, direct mail, and meetings were used to disseminate the recommendations of the consensus conference, which were that the only indications for albumin are massive haemorrhage, plasmapheresis, massive hypoalbuminaemia, and volume expansion in pregnancy; for hypovolaemia caused by septic shock or vasoplegia, fluid gelatins and crystalloids should be used. In the year after the conference, and in subsequent years, albumin use and costs were 40% lower than before the conference, even though total medical expenditure continued to rise and numbers of patients admitted did not change. We believe that consensus conferences can be a useful means of improving medical practice. The features that ensured success in this programme were the small number of prescribers, the homogeneous setting, and the frequent restatement of the recommendations.

Consensus Statements as Topic

Characterization of a human seminal plasma glycosaminoglycan-bearing polypeptide.

A glycosaminoglycan-bearing polypeptide (S.GP), present in human seminal plasma, was purified to homogeneity by a combination of CsCl density-gradient centrifugation, f.p.l.c. ion-exchange chromatography on a Mono Q HR column and Superose 6 gel filtration. The observed polydispersity of S.GP was attributed to the heterogeneity of its glycosaminoglycan content. Enzymic deglycosylation experiments and N-terminal amino-acid sequence determination indicate that it consists of a polypeptide (apparent molecular mass approx. 18 kDa) bearing both chondroitin and heparan sulphate chains. Evidence is given that S.GP contains a glycosaminoglycan-linkage domain of a so far uncharacterized gene product, proteolytically processed in the genital tract.

Amino Acid Sequence

Test of 20 similar intensive care ventilators in daily use conditions--evaluation of accuracy and performances.

Infrequent control, aging of components, may compromise the accuracy of ICU ventilators. In order to assess the reliability of ventilators during their clinical use, we bench tested a group of 20 CPU1 ventilators (Ohmeda) sampled at random in several ICU units. We found major leaks in 5 ventilators, attributable to the disposable tubings used in these systems. Mean error in expired tidal volume and corresponding standard deviation (precision) were greater than 100 ml in two. Positive end expiratory pressure measurement comprised a mean error higher than 2 cm H2O in 40% of the ventilators tested. The valve opening pressure threshold was correlated to the inspiratory flow (r = 0.81) contrary to the valve opening delay (average 138 +/- 40 ms). These two parameters did not correlate with the age of the ventilator. Our study addresses the need for periodic control of ventilator performance in order to minimize the risks of errors and malfunctions.

Age Factors

Clinical and pharmacokinetic aspects of the combination of meperidine and prilocaine for spinal anaesthesia.

The aim of this study was to determine whether the addition of a small dose of prilocaine could augment the spinal block induced by meperidine and affect intrathecal meperidine pharmacokinetic behaviour. Spinal anaesthesia was performed in 60 men scheduled for endoscopic resection of a prostatic adenoma or bladder tumour under spinal anaesthesia. They were allocated randomly to receive either 1 mg.kg-1 meperidine (Group 1, n = 30), or 1 mg.kg-1 meperidine plus 0.5 mg.kg-1 prilocaine (Group 2, n = 30). Blood samples were collected prior to and for 24 hr after spinal injection in 24 patients (12 in each group). Plasma meperidine levels were assayed by gas chromatography. Complete motor block was achieved in all Group 2 patients, but was incomplete in seven of Group 1 (P less than 0.05). The onset of both motor and sensory blocks was shorter (P less than 0.01) in Group 2 and the duration was longer (P less than 0.05). Coadministration of prilocaine modifies meperidine pharmacokinetic behaviour. The area under curve was 48% greater (P less than 0.01) and Cmax was higher in Group 2 than in Group 1, 145.8 +/- 42.2 vs 107 +/- 20.5 ng.ml-1 (P less than 0.001). No evidence of respiratory depression was noted in any of the patients. Despite the increase in plasma meperidine concentrations, no side effects were observed. The plasma concentrations remained at one third to one sixth the levels reported to induce a respiratory depression. It is concluded that the addition of prilocaine to meperidine improves motor and sensory block during surgery and alters meperidine kinetics without producing major side effects.

Aged

[Patient-controlled analgesia: effect of adding continuous infusion of morphine].

This double blind study aimed to assess the effects of a continuous intravenous (i.v.) infusion of morphine added to an intermittent bolus patient controlled analgesia on morphine demand and related side-effects. Patients scheduled for abdominal and thoracic surgery (ASA 2 or 3) were randomly allocated postoperatively to three groups (n = 10 each): group 1 were given i.v. boluses of 2 mg of morphine (lockout interval = 15 min); the other two groups were given the same boluses as well as a continuous i.v. infusion of either 1 mg.kg-1 of morphine (group 2) or 2 mg.kg-1 (group 3). Pain was assessed with a visual analog scale before starting analgesia, and after 1, 2, 3, 4, 8, 16, 24 and 36 h. Total and bolus morphine doses were recorded at the same time. Breathing rate and the level of sedation were measured every hour and blood gases every time 40 mg of morphine had been consumed. Morphine administration was stopped if breathing rate decreased to less than 10 c.min-1, the patient became too sedated, or PaCO2 rose to more than 45 mmHg. Pain scores were similar in the three groups. Total amounts of morphine were higher in groups 2 (56.8 +/- 23.8 mg) and 3 (116.2 +/- 41.8 mg) compared with group 1 (38.2 +/- 17.8 mg) (p < 0.05). Morphine administration was stopped in 5 patients in group 3 and in 1 in group 2 because PaCO2 had risen to more than 45 mmHg. Therefore, a continuous i.v. infusion is not required in patients receiving PCA, all the more so as this has deleterious respiratory effects.

Aged

[A study of 11 ventilators for anesthesia: laboratory testing].

Eleven anaesthesia ventilators were instrumentally tested under various conditions. They included: Excel and Modulus II Plus (Ohmeda); 710 and Servo anaesthesia circle 985 (Siemens); Jollytronic (Soxil) and Elsa (Engström); SA2 and Cicero (Dräger); ABT 4,300 (Kontron); Monnal A and the prototype Alys (Taema). The test circuit comprised a two compartment model lung, a pneumotachograph, a pressure gauge in the "airway". The volume was calculated as the integral of flow rate. Each machine was calibrated by the firms' technicians. Before each test, the pneumotachograph was calibrated using a 11 air syringe and the pressure gauge with a 5 cm water column. Each machine ventilated the model lung for 30 min before starting the tests. There were five tests: 1) reliability of the machine's spirometer, 2) reliability of the ventilation rate, 3) reliability of pressure measurements, 4) effect of increasing fresh gas flow on spirometry, 5) effect of increasing downstream resistances. In usual simulated ventilatory conditions, all the machines accurately delivered the setted ventilation and spirometric measurements were with minimal error only. Several ventilators (SA2, Excel, 710, Elsa, ABT 4,300) did not succeed in maintaining their performances when compliance was strongly decreased or resistance of the test lung notably increased. Resistance in the circuit during simulated spontaneous ventilation was < 3.6 cmH2O.l-1.s-1. Increasing fresh gas flow raised the minute volume delivered in six ventilators. It is concluded that, during extreme ventilatory conditions, the inspired volume must be adjusted so as to maintain the inspired tidal volume. However, ventilators which increase inspiratory time in response to an increased mechanical load cannot be adjusted by this way.

Anesthesia, Closed-Circuit

[Carotid artery injury: value of Doppler screening in head injured patients].

A case is reported of a patient with a traumatic aneurysm of the intracranial part of the carotid artery occurring after a traffic accident. The patient was admitted in coma (Glasgow score 5), and presented with a depressed fracture of the frontal and parietal bones, a fracture of the left petrous pyramid and of the left anterior clinoid process, as well as of the right tympanic bone and temporomandibular joint. The borders of the left carotid canal seemed unaltered. Despite the lack of localised neurological signs, cervical and transcranial Doppler ultrasonography was carried out. Intracranial carotid blood flow was found to be altered on both sides. Angiography showed a false carotid aneurysm on the left side (carotid siphon portion C3), and a moderate irregular stenosis of the C2 part on the right. There were no brain lesions on the CT scan. Prophylactic treatment with heparin was started. The patient recovered normal consciousness within a fortnight. The false aneurysm increased in volume and was treated by embolisation. Flow speeds in the carotid siphons also returned to normal. The usefulness of routine screening of patients with petrous bone fractures with Doppler ultrasound is discussed.

Adult

Risk factors for oxygen desaturation during sleep, after abdominal surgery.

The postoperative period after major abdominal surgery is known to be a period of increased episodic oxygen desaturation. In order to assess the risk factors for episodic desaturation, we have studied 29 surgical patients using pulse oximetry during the preoperative night (Npre) when they received benzodiazepine premedication and breathed air, and also during the first three nights after operation when they received nasal oxygen supplementation. Modal oxygen saturation (SpO2) exceeded 95% during all nights studied. The time spent at less than 90% (t90) and 85% (t85) SpO2 and the average SpO2 nadir (SpO2, nadir) did not differ each night. Heart rate was greater (mean 90.1 (SD 16.6) vs 68.2 (12.0) beat min-1, P < 0.001) during the second night after operation (N2) than during Npre. Before operation, the number of desaturations, t90 and t85 correlated with pharyngeal hypertrophy (P = 0.003, P = 0.002, P = 0.001, respectively). At the same time, t90 and t85 correlated with body mass index (P = 0.02 and P = 0.05, respectively). During N2, t90 correlated with radiological lung consolidation (P = 0.05) and SpO2, nadir correlated with FEV1 (P = 0.03). We conclude that there are several mechanisms responsible for oxygen desaturation and that these mechanisms differ before and after surgery.

Abdomen

A dose-range study of intrathecal meperidine combined with bupivacaine.

Twenty-one patients were included in a randomized study to receive either 10 mg of 0.5% hyperbaric bupivacaine alone or combined with 0.05, 0.1, 0.2, 0.3, 0.4 or 0.5 mg.kg-1 meperidine for spinal anaesthesia. Sensory blockade was assessed by pin prick, motor blockade by the Bromage scale, and postoperative analgesia by VAS scores and by the time before the first demand for analgesia. Spinal meperidine did not change the duration of sensory blockade, but induced a dose-related increase in postoperative efficient analgesia. Spinal meperidine might be considered as a means to obtain postoperative analgesia in the hours immediately following surgery.

Aged

Effects of epinephrine and clonidine on plasma concentrations of spinal bupivacaine.

ASA II-III patients, scheduled for peripheral vascular surgery, were included in a study designed to assess the effect of spinal epinephrine and clonidine on plasma concentrations of spinally administered 0.5% glucose-free bupivacaine. Patients were allocated randomly to three groups to receive via a spinal catheter 22.5 mg (4.5 ml) of bupivacaine alone (Group B, 9 patients) or combined with 0.3 mg epinephrine (Group BE, 10 patients) or 0.15 mg clonidine (Group BC, 10 patients). Sensory blockade was assessed by pin-prick and motor blockade on the Bromage scale. Bupivacaine plasma concentrations were measured by gas chromatography. A trend to prolongation of local anaesthetic blockade was documented in patients receiving bupivacaine plus epinephrine or clonidine. (Time to regression of sensory blockade to L2: 170 +/- 75 min in Group B, 230 +/- 50 min in Group BE, 232 +/- 64 min in Group BC.) The maximum peak concentration (Cmax), the time to reach Cmax (Tmax) and the time-concentration curve from 0-180 min (AUC) were not different for the three groups (Cmax 228 +/- 112 ng.ml-1 in Group B, 215 +/- 103 ng.ml-1 in Group BE, 234 +/- 159 ng.ml-1 in Group BC; Tmax 41 +/- 34 min in Group B, 59 +/- 31 min in Group BE, 68 +/- 32 min in Group BC; AUC 31.0 +/- 1.7 mg.ml-1.min-1 in Group B, 27.3 +/- 1.1 mg.ml-1.min-1 in Group BE, 27.0 +/- 1.1 mg.ml-1.min-1 in Group BC). The results of this study suggest that epinephrine and clonidine do not decrease blood resorption of spinal bupivacaine.

Aged

Effect of thoracic epidural anesthesia combined with general anesthesia on segmental wall motion assessed by transesophageal echocardiography.

Patients scheduled for vascular surgery are considered at risk for perioperative cardiac complications. Choice of anesthetic in such patients is guided by a desire not to adversely affect myocardial function. On the basis of data from laboratory studies, thoracic epidural anesthesia (TEA) has been advocated to prevent myocardial ischemia. The aim of this study was to assess whether TEA combined with general anesthesia has any effect on segmental wall motion (SWM) monitored by transesophageal echocardiography in these patients. Patients received alfentanil, midazolam, vecuronium, and 50% N2O in oxygen, and ventilation was controlled after orotracheal intubation; 12.5 mL of 2% lidocaine HCl was injected through an epidural catheter placed at T6-7 or T7-8. Hemodynamic measurements and transesophageal echocardiographic recordings were obtained before and 10, 20, 30, 40, and 60 min after lidocaine injection. Segmental wall motion was graded a posteriori by two independent experts on a predetermined scale (from 1 = normal to 5 = dyskinesia). A decrease greater than or equal to 2 grades was considered an SWM abnormality indicative of ischemia. Thoracic epidural anesthesia induced a decrease in systemic arterial blood pressure, heart rate, and cardiac index. The SWM score decreased slightly from 1.34 +/- 0.68 to 1.27 +/- 0.64 (mean +/- SD) (at 10 and 20 min, respectively) (P less than 0.05). Patients were a posteriori analyzed according to whether they had documented coronary artery disease or not. The SWM score before TEA was significantly higher in patients with documented coronary artery disease (1.51 +/- 0.88 vs 1.17 +/- 0.51, respectively; P less than 0.05) and did not change significantly after TEA.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Effect of preoperative normovolemic hemodilution on left ventricular segmental wall motion during abdominal aortic surgery.

Preoperative normovolemic hemodilution (PNH) has been proposed for patients scheduled to undergo aortic surgery. Coronary artery disease is frequent in these patients. The aim of the study was to assess the effect of PNH on hemodynamics and segmental wall motion (SWM) evaluated by transesophageal echocardiography in such patients. Twenty patients with coronary artery disease were allocated randomly to either PNH or no PNH; PNH was performed after anesthetic induction using dextran 60,000. Patients were operated on under general anesthesia and monitored intraoperatively with electrocardiographic lead CM5, radial and pulmonary artery catheters, and transesophageal echocardiography positioned to obtain a short-axis view. Hemodynamic and transesophageal echocardiographic data were collected after anesthetic induction and after PNH, before and 5 min after aortic clamping, after unclamping, and at the end of surgery. Aortic clamping induced a significant increase in systemic vascular resistance and arteriovenous difference in oxygen and a decrease in cardiac index (P < 0.05), but the effect of aortic clamping was inversely related to hemodilution. The SWM score (graded from 1 = normal to 5 = dyskinesia) was significantly increased after aortic clamping, mainly in the anterior segment (P < 0.05). Four patients in the control (no PNH) group and one in the PNH group developed new SWM abnormalities indicative of myocardial ischemia during surgery (P = NS). This study suggests that PNH may improve hemodynamic tolerance to aortic clamping in patients with coronary artery disease. The observed changes in SWM indicate that PNH may not worsen myocardial ischemia in patients scheduled to undergo aortic surgery.

Aged

Can portable chest x-ray examination accurately diagnose lung consolidation after major abdominal surgery? A comparison with computed tomography scan.

PURPOSE: To prospectively quantify the degree of accuracy of portable chest x-ray film examination in the detection of postoperative lung consolidations. STUDY: Nineteen patients had a chest x-ray film and computed tomography (CT) scan the day before and 48 h following elective abdominal aortic replacement. RESULTS: The diagnosis of lung consolidations by x-ray film examination showed sensitivity of between 0.33 and 1.00, depending on the lung zone considered (lower at the lung bases). Specificity always was greater than 0.79. Radiologic lung volume decreased 16 percent postoperatively (p < 0.01) on average and noninflated parenchyma increased by a factor of 3 (p < 0.0001). Postoperatively, PaO2 correlated with the amount of condensed lung by CT scan (p < 0.002). CONCLUSION: In postoperative conditions, x-ray film examination is a method which presents good specificity but poor sensitivity in the diagnosis of lung consolidations.

Abdomen

Expression of the serglycin gene in human leukemic cell lines.

The expression of the human serglycin gene was determined in nine human leukemic cell lines, representing a spectrum of erythrocytic, megakaryocytic, monocytic, granulocytic, and lymphocytic potentialities. By Northern blot analysis, a 1.4 kb transcript was characterized in some of these cell lines, using a cDNA probe coding for human serglycin. Five of these cell lines, HEL, U-937, HL-60, K-562, and KU-812 were treated with phorbol myristic acetate to induce differentiation. Under these conditions the expression of the serglycin gene was modulated compared to the non-induced cells. HL-60, K-562, and KU-812 were also induced with dimethyl sulfoxide and retinoic acid; variations in serglycin transcript level were also observed. The present investigation establishes, at the nucleic acid level, the ability of various cells mimicking different stages in the developmental pathways of the haemopoietic lineage to synthesize proteoglycans belonging to the serglycin family. The results reported here led us to conclude that serglycin expression is closely associated with the haemopoietic cell differentiation pathway. The putative functions of serglycin in the haemopoietic system are briefly discussed.

Blotting, Northern

[Multiple localization and lymphatic involvement of papillary micro-carcinoma of the thyroid. Results of total thyroidectomy with bilateral lymph node excision. Apropos of 38 patients].

This study involved 38 patients with occult papillary carcinoma of the thyroid gland treated by total thyroidectomy and bilateral prophylactic neck dissection. The histological results show the glandular multicentricity on either side, both in single nodule (65%) and in multinodular goiter (73.3%). High risk of cervical spreading clearly appears in papillary carcinoma (18.4% of the patients) even in these small foci (lower than 10 mm). Topography of involvement brings into prominence two main territories: paratracheal, mid and lower jugularly nodes (involved in 92.8% of the positive dissections).

Adolescent

[Plexus nerve blocks for postoperative analgesia after orthopedic surgery of the lower limbs].

In our institution, plexus nerves blocks have been performed in seventy patients after lower limb surgery. The technique is considered as simple and reliable. The administration of a 0.375 per cent bupivacaine epinephrine containing solution allows to obtain analgesia longer than 15 hours in 45 p. 100 of the patients, devoided of side effects. Lower limb plexus nerves blocks appear as an efficient technique for postoperative analgesia following orthopaedic surgery.

Adult