Three-dimensional modeling system for unilateral mandibular bone distraction: a clinical case.

Facial hemiatrophies are anomalies of the first branchial arch and affect one in 4000-5000 newborns. Bone distraction is the technique of choice for the treatment of these dysmorphoses. Mandibular osteodistraction requires prior determination of the characteristics of the distraction vector whose three components will serve to activate the distractor. The patient, aged 5 years, presented with a right facial hemiatrophy, Grade IB according to the classification of Pruzansky. Tomodensitometric acquisition was obtained with a CT scanner. Software specifically designed for this application allows segmentation of the anatomical elements by a region-growing algorithm. The 3D representation of each element is added to a 3D scene, in which are placed the built-up landmarks necessary for the surgical simulation after 3D cephalometric analysis. The surgical cleavage plane is oriented according to the surgeon's requirements while preserving the predominant anatomical elements. The software allows performance of rotations and translations of the bone segments rendered independently from the cleavage plane. The distances and angles covered during the virtual movement are measured at its conclusion. The aim of moving the bone segments is to render the mandibular occlusion plane parallel to the reference occlusion plane. The vertical growth of the maxilla is realized by secondary recuperation. The distractor used was of an external multidirectional type allowing elongation of the mandibular ramus and mandibular corpus, closure of the goniac angle, and lateralization or medialization of the ramus. On the 15th day, the mandibular angle was reduced by 10 degrees, which allowed closure of the anterior gap and recentering of the incisive areas by a half-cuspid. The patient presented with a complex bone deficit in the three spatial directions, which allowed the development of software for modeling the distraction. Other clinical cases will be necessary to validate this 3D imaging-based technique.     

Nitrous oxide fraction in the carbon dioxide pneumoperitoneum during laparoscopy under general inhaled anesthesia in pigs

During prolonged laparoscopy, the diffusion of other gases in the carbon dioxide (CO(2)) pneumoperitoneum may lessen its safety. Nitrous oxide (N(2)O)/CO(2) gas mixtures may become hazardous with regard to gas embolization and fire risk. We therefore evaluated the kinetics of pneumoperitoneal intrusion of N(2)O. In five anesthetized domestic pigs, controlled ventilation, with an initial fraction of inspired oxygen = 1.0, was adjusted to keep ETCO(2) pressure between 35 and 45 mm Hg. The peritoneum was insufflated with CO(2) to a pressure of 12 mm Hg, which was maintained throughout the procedure. T0 was defined as the time when N(2)O was introduced in the breathing circuit (N(2)O end-tidal fraction = 66%). Gas samples (10 mL) from the pneumoperitoneum were analyzed every 10 min after T0. The N(2)O concentration was measured by using capillary gas chromatography coupled with mass spectrometry. Percentages of N(2)O in the CO(2) increased with time (t) according to the ideal equation: N(2)O((t)) = 66 (1 - exp(-0.005t)). In the peritoneal cavity, <2 h were required for the N(2)O to reach the concentration of 29%, which can support combustion. Eight hours to 10 h after T0, the intraperitoneal N(2)O fraction approaches the level of the N(2)O end-tidal fraction. Options to prevent accumulation of N(2)O are suggested. IMPLICATIONS: Pig models were used to evaluate the time course of nitrous oxide (N(2)O) diffusion in the pneumoperitoneum during nitrous oxide/oxygen anesthesia. Although peritoneal N(2)O concentration approaches the end-expiratory value after 8-10 h, it reaches 29% within 2 h. At this level, N(2)O is known to support combustion. This N(2)O pollution should be prevented.     

Peripartum dilated cardiomyopathies: is there a correlation with sexually transmitted diseases?

A revue of litérature about peripartum cardiomyopathy; a disease of unknown pathogenesis. Some retrospective studies suggest a relation with sexually transmitted diseases. Other risk factors were observed. Diuretics and digoxin are used in the treatment. Cardiac transplantation is the final solution but the affection could appear again. A database must be started with epidemiologic information to understand this disorder and its correlation with sexually transmitted diseases.     

Effect of a subanesthetic dose of ketamine on memory and conscious awareness in healthy volunteers

RATIONALE: Ketamine is an NMDA receptor antagonist with psychotogenic and cognitive effects in healthy volunteers and schizophrenic patients which has been proposed to be a useful tool to investigate neurobiological basis of schizophrenia. OBJECTIVE: The present study characterized the effects of a subanesthetic dose of ketamine on memory and related subjective states of awareness in healthy volunteers. METHODS: Twenty-six subjects were given either a 60-min ketamine (0.5 mg/kg per hour) or a placebo infusion. To obtain constant plasma ketamine throughout the experiment, ketamine was administered using a computer-controlled infusion system. Subjects carried out episodic memory tasks involving words presented before and during infusion. Memory performance was assessed with recognition and free recall tasks. Subjective states of awareness were assessed using an experiential approach. Levels of psychopathology were evaluated with BPRS. RESULTS: Ketamine impaired performance in free recall and recognition of words presented during, but not before, infusion. There were no differences between groups concerning states of awareness associated with recognition memory. Subjects under ketamine had higher BPRS total scores as well as BPRS negative and positive cluster scores than control subjects. CONCLUSIONS: Ketamine decreases episodic memory performance by impairing encoding, but not retrieval processes. It does not selectively impair subjective states of awareness associated with recognition memory as it has been seen in patients with schizophrenia. Ketamine might mimic the memory impairment associated with acute, but not chronic, forms of schizophrenia.     

Le dosage capillaire de la lactatémie en réanimation : avancées et perspectives

Capillary lactate micromethod assay brings up options about pre- and intra-hospital patient grading, goal-directed resuscitation, and vascular monitoring. Lactate is no longer considered as a metabolic waste only but it is recognized as an energetic substrate. The main advantage of capillary lactate assay in patient grading is the possibility to obtain a not delayed, non-invasive, bedside result, which represents a critical improvement when compared to conventional arterial assay. Capillary lactate assay is also relevant in goal-directed resuscitation protocols based on the lactate clearance concept. Compartmental lactate measurement in ischemic limbs is also a promising direction in the evaluation of the outcome after surgical revascularization.     

Principes généraux de la prise en charge hospitalière de la prééclampsie

The management of the PE patient requires admission in order to perform a meticulous assessment of the mothers’ and fetal state, distinguishing between the severe and the mild forms.     

Carotid Endarterectomy with Intermediate Cervical Plexus Block

During carotid endarterectomy, the use of locoregional anesthesia to achieve a combined superficial and deep cervical plexus block can cause cardiovascular, respiratory, and neurologic complications. Seeking to reduce risk and find an easier procedure, we applied locoregional anesthesia and an intermediate cervical plexus block in a series of patients who underwent carotid endarterectomy.From 2006 through 2007, 183 patients underwent primary carotid endarterectomy at our hospital. Mean age was 75.9 ± 9.9 yr; mean body mass index, 27.3 ± 6.7 kg/m²; and median American Society of Anesthesiologists physical status classification, P3 (range, P2–P4). All procedures combined an intermediate cervical plexus block with subcutaneous infiltration of the incision line. We inserted a 15-mm, 25G needle to its full length, perpendicular to the skin along the posterior border of the sternocleidomastoid muscle, midway between the mastoid process and the clavicle. We injected 10 mL of 0.75% ropivacaine solution for 3 to 5 minutes. This block was systematically combined with subcutaneous infiltration of the incision line with the ropivacaine (0.75%, 10 mL), and sometimes also with 2% topical lidocaine intraoperatively. If necessary, intraoperative sedation, analgesia, or both were given to patients to improve their compliance.Intraoperative topical lidocaine was required in 59 patients (32.2%), and intravenous midazolam, fentanyl, or both were required in 29 patients (15.8%). Two procedures were converted to general anesthesia (1.1%). No perioperative deaths or complications occurred. Postoperatively, 2 patients experienced strokes and 1 sustained a myocardial infarction (total rate, 1.6%).We found the intermediate cervical plexus block to be feasible, effective, and safe, with low perioperative and postoperative complication rates. Herein, we report our findings.Key words: Anesthesia/methods/utilization, cervical plexus, endarterectomy, carotid/adverse effects/methods, injections, intramuscular, nerve block/adverse effects/methods, safety, treatment outcomeGeneral anesthesia and locoregional anesthesia (LRA) are both suitable choices in carotid endarterectomy (CEA). Although today most surgeons use general anesthesia, the potential benefits of LRA techniques are well described.^1,2 If LRA is the choice, CEA is typically approached via a combined superficial and deep cervical plexus block. This technique requires specific skills and expertise, and it can potentially cause complications, such as respiratory depression, cardiac arrest, and vertebral artery or nerve injury.³ In 2003, experimenting on human cadavers, Pandit and colleagues⁴ showed that the deep cervical fascia is permeable, giving a possible explanation for the clinical efficacy of a purely superficial cervical plexus block in comparison with a deep or combined cervical plexus block. In 2004, Telford and Stoneham⁵ systematized the nomenclature of cervical plexus block, classifying “intermediate” block as the injection of local anesthetic between the superficial and deep cervical fascia. We contend that there is some confusion and misunderstanding in the literature regarding cervical plexus block: some authors define superficial block as a block deep in the investing layer of the deep cervical fascia that can spread to the deep areas of the neck. Moreover, there is no consensus in regard to the preferable LRA approach, and no clinical series appear to have dealt with intermediate cervical plexus block.To overcome the risks and technical difficulties of the combined cervical plexus block, we began in 2006 to approach CEA with an intermediate block. In our observational study, we sought to investigate this technique''s feasibility, efficacy, and safety for the patient. Herein, we report our findings.     

Anaesthesia mode for caesarean section and mortality in very preterm infants: An epidemiologic study in the EPIPAGE cohort

BackgroundLittle is known about the influence of anaesthesia for caesarean section on outcome in very preterm infants.MethodsA prospective, population-based, cohort study (the EPIPAGE cohort) included all births before 33 weeks in nine French regions in 1997. Of 2360 infants live-born between 27 and 32 weeks, 1338 were delivered by caesarean section with general anaesthesia (n = 711, 53.1%), spinal anaesthesia (n = 419, 31.3%), or epidural anaesthesia (n = 208, 15.6%). Neonatal mortality was compared among these three groups using bi- (according to gestational age and to anaesthetic technique) and multivariate analyses.ResultsNeonatal mortality was 10.1% with general anaesthesia, 12.2% with spinal anaesthesia and 7.7% with epidural anaesthesia. After adjustment for gestational age and characteristics of pregnancy, delivery and neonate, spinal anaesthesia was associated with a higher risk of neonatal death than general anaesthesia (adjusted odds ratio, 1.7; 95% confidence interval 1.1 to 2.6).ConclusionIn this population-based study, spinal anaesthesia was associated with an increased risk of neonatal mortality in very preterm infants compared to general anaesthesia (and epidural anaesthesia), independently from gestational age and characteristics of the pregnancies, deliveries and neonates. Although this multivariate analysis does not prove a causal relationship, the results suggest it could exist, particularly if maternal haemodynamics are poorly controlled. With recent significant change in the conduct of spinal anaesthesia, further studies are needed to investigate potential harmful effects of anaesthesia on very preterm infants delivered by caesarean section.     

Ultrasonographic control of the puncture level for lumbar neuraxial block in obstetric anaesthesia

BACKGROUND: Errors in the judgement of puncture level during neuraxial anaesthesia can lead to significant complications. The aim of this study was to assess, in obstetric anaesthesia, the accuracy of clinical determination of the lumbar spinal interspace level, using surface ultrasound imaging as control. METHODS: At the anaesthesia follow-up visit, women who had received lumbar neuraxial anaesthesia during labour were prospectively included. The intervertebral level of needle insertion, located by the needle scar position, was identified by ultrasonography and compared with the clinical level reported on the chart by the anaesthetist who performed the block. RESULTS: Ninety-nine women were studied. The clinical puncture level was accurate in 36.4% of patients. Ultrasound examination showed the puncture level to be more cephalad than the level noted in the anaesthetic record in almost 50% of patients. In 15% of patients, the puncture level was more caudad than the anaesthetist had assessed. Factors including type of anaesthesia, indication, time period, level of anaesthetic experience, BMI, and spinal pathology did not seem to influence the frequency of errors. CONCLUSIONS: The observed differences between clinical and ultrasonic identification of spinal puncture level highlight the potential for serious complications associated with the performance of neuraxial blocks above the spinous process of L3 in the parturient. With the increase in popularity of techniques involving puncture of the dura mater for labour anaesthesia, we feel that awareness of this risk is important.