Biomedical subjects

Gilles Perrin

Publications and source records attributed to Gilles Perrin.

6 recordsLinked to original sources

PubMed2006

Neuromuscular blocking agents decrease inflammatory response in patients presenting with acute respiratory distress syndrome.

OBJECTIVE: To evaluate the effects of neuromuscular blocking agents (NMBAs) on pulmonary and systemic inflammation in patients with acute respiratory distress syndrome ventilated with a lung-protective strategy. DESIGN: Multiple-center, prospective, controlled, and randomized trial. SETTING: One medical and two medical-surgical intensive care units. PATIENTS: A total of 36 patients with acute respiratory distress syndrome (Pao2/Fio2 ratio of < or =200 at a positive end-expiratory pressure of > or =5 cm H2O) were included within 48 hrs of acute respiratory distress syndrome onset. INTERVENTIONS: Patients were randomized to receive conventional therapy plus placebo (n = 18) or conventional therapy plus NMBAs (n = 18) for 48 hrs. Both groups were ventilated with a lung-protective strategy (tidal volume between 4 and 8 mL/kg ideal body weight, plateau pressure of < or =30 cm H2O). MEASUREMENTS AND MAIN RESULTS: Bronchoalveolar lavages and blood samples were performed, before randomization and at 48 hrs, to determine the concentrations of tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6, and IL-8. Pao2/Fio2 ratio was evaluated before randomization and at 24, 48, 72, 96, and 120 hrs. A decrease over time in IL-8 concentrations (p = .034) was observed in the pulmonary compartment of the NMBA group. At 48 hrs after randomization, pulmonary concentrations of IL-1beta (p = .005), IL-6 (p = .038), and IL-8 (p = .017) were lower in the NMBA group as compared with the control group. A decrease over time in IL-6 (p = .05) and IL-8 (p = .003) serum concentrations was observed in the NMBA group. At 48 hrs after randomization, serum concentrations of IL-1beta (p = .037) and IL-6 (p = .041) were lower in the NMBA group as compared with the control group. A sustained improvement in Pao2/Fio2 ratio was observed and was reinforced in the NMBA group (p < .001). CONCLUSION: Early use of NMBAs decrease the proinflammatory response associated with acute respiratory distress syndrome and mechanical ventilation.

Cytokines↗

PubMed2006

Inhaled nitric oxide does not prevent pulmonary edema after lung transplantation measured by lung water content: a randomized clinical study.

STUDY OBJECTIVE: In order to assess the effects of inhaled nitric oxide (iNO) in preventing early-onset lung edema from occurring after lung transplantation, we measured extravascular lung water (EVLW) in a group of lung transplant recipients who were at high risk for developing ischemia-reperfusion-induced lung injury. DESIGN: Prospective, randomized study. SETTINGS: Surgical ICU in a teaching hospital. PATIENTS: Thirty double-lung transplant recipients. INTERVENTIONS: Patients were randomized to receive or not receive 20 ppm iNO at the time of reperfusion (ie, before any occurrence of lung edema). In the NO group, iNO was then administered for a 12-h period. A double-dilution technique was used for the serial assessment of EVLW, intrathoracic blood volume, and cardiac index. Standard hemodynamic and pulmonary parameters were also recorded during the first 3 postoperative days. MEASUREMENTS AND RESULTS: Patients who received iNO did not have a different lung water content compared to control subjects (p = 0.61 [by analysis of variance (ANOVA)]). Blood oxygenation (ie, Pao(2)/fraction of inspired oxygen [Fio(2)] ratio) did not differ between the two groups (p = 0.61 [by ANOVA]). In both groups, EVLW and Pao(2)/Fio(2) ratio dropped significantly over time, regardless of the use of iNO (p < 0.01 [by ANOVA]). CONCLUSIONS: In the population studied, prophylactic iNO that was administered at 20 ppm had no effect on pulmonary edema formation and resolution following lung transplantation.

Administration, Inhalation↗

PubMed2005

Quantitative anatomic evaluation of cervical lateral mass fixation with a comparison of the Roy-Camille and the Magerl screw techniques.

STUDY DESIGN: An anatomic and computed tomography (CT) study of the Roy-Camille and the Magerl techniques with quantitative comparison of the safety zones of the two surgical techniques. OBJECT: The purpose of this study was to compare quantitatively the safety zones of the Roy-Camille and the Magerl techniques as a function of the vertebral level from C3-C6. SUMMARY OF BACKGROUND DATA: The two most popular techniques for lateral mass screws are the Roy-Camille and the Magerl technique. Nerve roots, vertebral artery, facet joints, and the spinal cord are at risk during the placement of lateral mass screws. Several anatomic studies are reported, but there is no comparative and quantitative evaluation. The influence of the vertebral level was never reported. METHODS: Lateral mass screws were first implanted on four cervical spines according to the two surgical techniques. Screws were then extracted and their cavities filled with a blue casting medium. To determine the precise limits of each safety zone in the sagittal plane, the specimens were sectioned according to the sagittal angulation of the two screwing techniques. The correlations between the anatomic landmarks on the specimen and the anatomic landmarks on the CT scan were established. One hundred and sixty lateral mass screws were then implanted in 20 cervical spines from C3-C6. A CT was done before and after placing lateral mass screws. On the morphologic CT scan, we measured the sagittal safety angle (SSA) for each surgical technique and also performed a morphometry of lateral masses. On the control CT scan, we analyzed screws placement in relation to the sagittal safety zone. RESULTS: The mean SSA was 15.8 +/- 6.3 degrees for the Roy-Camille technique and 18.7 +/- 3.8 degrees for the Magerl technique, P < 0.005. With respect to the vertebral level, the Roy-Camille safety zone decreased from C3-C6 with a greater angulation at C3-C4 (20.4 +/- 4.7 degrees ) than at C5-C6 (11.6 +/- 4.3 degrees ), P < 0.001. Such variations were not observed for the Magerl technique, the SSA of which was 19.4 +/- 3.6 degrees at C5-C6 and 17.9 +/- 4 degrees at C3-C4, P < 0.01. Lateral masses became more elongated and thinner at the lower segment of the cervical spine with a C3-C4 height/thickness ratio = 1.1 +/- 0.3 and a C5-C6 height/thickness ratio = 1.3 +/- 0.2, P < 0.005. Roy-Camille screws (19%) were found out of the safety zone at C3-C4 whereas 37.5% were found outside at C5-C6, P < 0.05. We observed opposite results for Magerl screws with 38% screws out of the safety zone at C3-C4 and only 17.5% outside at C5-C6, P < 0.05. CONCLUSION: The Roy-Camille technique demonstrated a progressive decrease of its safety zone from C3-C6. At C5 and C6 there is a great probability to have a transarticular screw with a Roy-Camille screw. A similar variation was not observed for the Magerl technique. These anatomic results seem to be in relation with the morphologic variability of lateral masses from C3-C6 as demonstrated by an increase of the height/thickness ratio at the lower part of the cervical spine. According to these anatomic considerations and previously published biomechanical data, Roy-Camille technique appears to be the best option at C3 and C4. On the opposite at C5 and C6, the choice is more difficult considering that there is no biomechanical difference between the two techniques and that the Magerl technique is safer but a more demanding procedure.

Biomechanical Phenomena↗

PubMed2005

NH2 terminal pro-brain natriuretic peptide plasma level as an early marker of prognosis and cardiac dysfunction in septic shock patients.

OBJECTIVE: To investigate N-terminal pro-brain natriuretic peptide (NT-proBNP) level as a prognostic factor and a marker of myocardial dysfunction in patients with septic shock. DESIGN: Prospective observational study. SETTING: Intensive care unit. SUBJECTS: A total of 39 patients diagnosed with septic shock and requiring mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: Demographic, hemodynamic, respiratory, and biological data (notably NT-proBNP, lactate, and cardiac troponin I) were collected at inclusion and every 12 hrs. The independent factors for death were higher Sequential Organ Failure Assessment score in the 24-hr period after inclusion (odds ratio, 4.7; 95% confidence interval, 1.15-19.3) and the highest NT-proBNP level in the 24-hr period after inclusion (odds ratio, 1.12 per 1000 pg/mL increase; 95% confidence interval, 1.05-1.26). An NT-proBNP of >13,600 pg/mL predicted intensive care unit mortality with an accuracy of 77%. Area under the receiver operating characteristic curve was 0.8 (p = .002; 95% confidence interval, 0.66-0.93). NT-proBNP levels were over the accepted normal range in all patients. Values were highest between 24 and 36 hrs after onset of septic shock and were significantly higher in nonsurvivors at each time between inclusion and day 7. The lowest left ventricular stroke work index of the first 24-hr period after inclusion was the only factor that independently influenced higher NT-proBNP levels at the same time (odds ratio, 0.91; 95% confidence interval, 0.84-0.98). CONCLUSION: NT-proBNP seems to be an early factor of prognosis and myocardial dysfunction in patients with septic shock.

Aged↗

PubMed2004

Accuracy of the double indicator method for measurement of extravascular lung water depends on the type of acute lung injury.

OBJECTIVE: The double indicator method is sensitive to alterations in the distribution of pulmonary blood flow. This distribution is influenced by the type of lung injury. The aim of this study was to compare measurements of lung water by the double indicator method with measurements obtained by gravimetry in a direct lung injury model induced by tracheal instillation of hydrochloric acid and in an indirect lung injury model induced by the intravenous injection of oleic acid. DESIGN: Prospective, randomized laboratory study. SETTING: Animal research laboratory. SUBJECTS: Forty-two female pigs (28+/-3 kg). INTERVENTIONS: Pigs were anesthetized and ventilated and were allocated into three groups: control (n = 6), hydrochloric acid (4 mL/kg intratracheally, n = 24), or oleic acid (0.1 mL/kg intravenously, n = 12). MEASUREMENTS AND MAIN RESULTS: Hydrochloric acid instillation or oleic acid injection resulted in a similar hypoxemia and induced a two- to three-fold increase in extravascular lung water (EVLW) by gravimetry (EVLWG) at 3 hrs compared with controls. In the oleic acid group, there was a significant correlation between EVLWG and EVLW by double indicator method (EVLWDI; r =.88, p <.0001). The bias for EVLWDI - EVLWG measurements was -5.2 mL/kg (95% confidence interval, -5.7 to -4.7 mL/kg) with 95% limits of agreement of -7 to -3.4 mL/kg. In the hydrochloric acid group, there was no significant correlation between EVLWDI and EVLWG values, and the double indicator method failed to detect pulmonary edema in 65% of the animals (EVLWDI <8 mL/kg). The bias was -7.9 mL/kg (95% confidence interval, -9.3 to -6.5 mL/kg) with 95% limits of agreement of -14.4 to -1.4 mL/kg. CONCLUSIONS: The double indicator method is useful for evaluation of pulmonary edema in indirect lung injury, as induced by oleic acid, but produces misleading values in direct lung injury, as produced by hydrochloric instillation.

Analysis of Variance↗

PubMed2004

Biomechanical evaluation of cervical lateral mass fixation: a comparison of the Roy-Camille and Magerl screw techniques.

OBJECT: The purpose of this study was to assess human cervical spine pullout force after lateral mass fixation involving two different techniques: the Roy-Camille and the Magerl techniques. Although such comparisons have been conducted previously, because of the heterogeneity of results and the importance of this procedure in clinical practice, it is essential to have data derived from a prospective and randomized biomechanical study involving a sufficient sample of human cervical spines. The authors also evaluated the influence of the sex, the vertebral level, the bone mineral density (BMD), the length of bone purchase, and the thickness of the anterior cortical purchase. METHODS: Twenty-one adult cervical spines were harvested from fresh human cadavers. Computerized tomography was performed before and after placing 3.5-mm titanium lateral mass screws from C-3 to C-6. Pullout forces were evaluated using a material testing machine. The load was applied until the pullout of the screw was observed. A total of 152 pullout tests were available, 76 for each type of screw fixation. The statistical analysis was mainly performed using the Kaplan-Meier survival method. The mean pullout force was 266 +/- 124 N for the Roy-Camille technique and 231 +/- 94 N for the Magerl technique (p < 0.025). For the C3-4 specimen group, Roy-Camille screws were demonstrated to exert a significantly higher resistance to pullout forces (299 +/- 114 N) compared with Magerl screws (242 +/- 97 N), whereas no difference was found between the two techniques for the C5-6 specimen group (Roy-Camille 236 +/- 122 N and Magerl 220 +/- 86 N). Independent of the procedure, pullout strengths were greater at the C3-4 level (271 +/- 114 N) than the C5-6 level (228 +/- 105 N) (p < 0.05). No significant correlation between the cancellous BMD, the thickness of the anterior cortical purchase, the length of bone purchase, and maximal pullout forces was found for either technique. CONCLUSIONS: The difference between pullout forces associated with the Roy-Camille and the Magerl techniques was not as significant as has been previously suggested in the literature. It was interesting to note the influence of the vertebral level: Roy-Camille screws demonstrated greater pullout strength (23%) at the C34 vertebral level than Magerl screws but no significant difference between the techniques was observed at C5-6.

Biomechanical Phenomena↗