[ICU acquired neuromyopathy]. / La neuromyopathie acquise en réanimation.

ICU acquired neuromyopathy (IANM) is the most frequent neurological pathology observed in ICU. Nerve and muscle defects are merged with neuromuscular junction abnormalities. Its physiopathology is complex. The aim is probably the redistribution of nutriments and metabolism towards defense against sepsis. The main risk factors are sepsis, its severity and its duration of evolution. IANM is usually diagnosed in view of difficulties in weaning from mechanical ventilation, but electrophysiology may allow an earlier diagnosis. There is no curative therapy, but early treatment of sepsis, glycemic control as well as early physiotherapy may decrease its incidence. The outcomes of IANM are an increase in morbi-mortality and possibly long-lasting neuromuscular abnormalities as far as tetraplegia.

[Comparison between ETCO2 values measured by the Smart Capnoline™ and the PACO2 in intubated then extubated postoperative cardiac surgery patients]. / Comparaison de la mesure de la PETCO(2) obtenue avec le Smart Capnoline™ avec la PaCO(2) en postopératoire de chirurgie cardiaque chez des patients intubés puis extubés.

OBJECTIVE: To compare the PaCO(2) with the ETCO(2) obtained with the Smart Capnoline™ in the postoperative setting of cardiac surgery during ventilation and after extubation TYPE OF STUDY: Prospective, observational. PATIENTS: Twenty patients after cardiac surgery. METHODS: In the intensive care unit, arterial blood gases were measured concomitantly with ETCO(2), and difference between PaCO(2) and ETCO(2) were calculated. Three CO(2) sensors were utilized: Filterline H set for intubated patients, Smart Capnoline HO(2) (nasal version) and Smart Capnoline O(2) (bucconasal version) after extubation. Data were compared with Wilconson test and the intraclass correlation coefficient was calculated. RESULTS: The difference PaCO(2) - ETCO(2) was significantly larger in extubated patients compared to intubated patients, which is also confirmed for the bucconasal sensor (intubated patients: 6.6 ± 4.3 mmHg, nasal sensor: 9.3 ± 3.5 mmHg, bucconasal sensor: 15,4 ± 12.9 mmHg). CONCLUSION: In the postoperative setting of cardiac surgery, ETCO(2) measurements allow a reliable estimation of PaCO(2) in intubated patients in contrast to measurements in extubated patients. The bucconasal CO(2) sensor does not show more reliable measurements compared to nasal sensors in the postoperative setting of cardiac surgery.

[Benchmark of a high-frequency jet ventilator, the Monsoon™]. / Étude d'un respirateur de jet-ventilation, le Monsoon™, sur banc d'essais.

OBJECTIVE: To test a high-frequency jet ventilator, the Monsoon™ (Acutronic laboratory) on a lung model with regard to delivered tidal volume and tracheal pressure measured through the injector. STUDY DESIGN: Benchmark study. MATERIAL AND METHODS: The jet ventilator was tested with seven commercially available catheters associated with their connecting line. Recorded data were: the injected volume per minute, the pressure measured in the connecting line between the ventilator and the injector and the difference between the end expiratory pressures (EEP) measured by the ventilator through the injector and the tracheal pressure. Measurements were performed by varying the driving pressure (P(w): 1 to 3 bar), inspiratory time/ventilatory cycle duration ratio (I/T: 0.25 to 0.35 %) and respiratory rate (RR 60 to 300 c/min). RESULTS: Whatever the injection catheter used, minute volume increased proportionally with P(w). For each injector and for a given P(w) and I/T, it was possible to determine a RR threshold upon tracheal pressure and EPP gradient largely increased: RR less than 3Hz for I/T less than 0.35 % and P(w) of 3 bar with adult catheters except for Leadercath(®) (RR 2Hz). All the paediatric catheters could be used at a P(w) less than 2 bar, a RR 120 c/min and I/T less than 0.35 %. CONCLUSION: Use of a dedicated injector line and a range of settings (RR and I/T rapport) are required to measure an actual EPP through the injector.

[Guide for the use of jet-ventilation during ENT and oral surgery]. / Guide d'utilisation de la jet-ventilation en chirurgie ORL, trachéale et maxillo-faciale.

The aim of this synthesis was to give recommendations on the use of jet-ventilation during ENT surgical and endoscopy procedures. Literature was collected from PUBMED and analysed by the members of French association of anaesthesiologists in ENT surgery, all skilled in this field. Presentation of these recommendations was given during the general assembly held in Reims, the 15th May 2009. Jet-ventilation is especially indicated during upper airway endoscopy and laryngeal invasive endoscopic surgery. Furthermore, transtracheal jet ventilation is included on most of difficult oxygenation and difficult intubation algorithm. The main risk of jet-ventilation is pulmonary barotrauma when expiration of injected gas is impeded by an upper airway obstruction. Failure and complications of tracheal puncture are rare when performed by experimented operators. Clinical use of jet ventilation requires a dedicated device. Practice of jet ventilation without intubation may be dangerous when applied without control of driving pressure and end expiratory tracheal pressure. Every anaesthetist should be familiar with transtracheal ventilation since they may face a "cannot ventilate cannot intubate" situation. Upper airway endoscopy and laryngeal surgery are the ideal field for training jet ventilation, even more so as this technique offers perfect operative conditions. To apply this project, jet ventilation should be used more frequently in routine practice. To maintain skill, regular use of these techniques is required.

Sodium channel Na(V)1.5 expression is enhanced in cultured adult rat skeletal muscle fibers.

This study analyzes changes in the distribution, electrophysiological properties, and proteic composition of voltage-gated sodium channels (Na(V)) in cultured adult rat skeletal muscle fibers. Patch clamp and molecular biology techniques were carried out in flexor digitorum brevis (FDB) adult rat skeletal muscle fibers maintained in vitro after cell dissociation with collagenase. After 4 days of culture, an increase of the Na(V)1.5 channel type was observed. This was confirmed by an increase in TTX-resistant channels and by Western blot test. These channels exhibited increased activation time constant (tau(m)) and reduced conductance, similar to what has been observed in denervated muscles in vivo, where the density of Na(V)1.5 was increasing progressively after denervation. By real-time polymerase chain reaction, we found that the expression of beta subunits was also modified, but only after 7 days of culture: increase in beta(1) without beta(4) modifications. beta(1) subunit is known to induce a negative shift of the inactivation curve, thus reducing current amplitude and duration. At day 7, tau(h) was back to normal and tau(m) still increased, in agreement with a decrease in sodium current and conductance at day 4 and normalization at day 7. Our model is a useful tool to study the effects of denervation in adult muscle fibers in vitro and the expression of sodium channels. Our data evidenced an increase in Na(V)1.5 channels and the involvement of beta subunits in the regulation of sodium current and fiber excitability.

Assessment of a cardiac output device using arterial pulse waveform analysis, Vigileo, in cardiac surgery compared to pulmonary arterial thermodilution.

Many devices are available to assess cardiac output (CO) in critically ill patients and in the operating room. Classical CO monitoring via a pulmonary artery catheter involves continuous cardiac output (CCO) measurement. The second generation of Flotrac/Vigileo monitors propose an analysis of peripheral arterial pulse waves to calculate CO (APCO) without calibration. The aim of our study was to compare the CO between the Swan Ganz catheter and the VigileoT. In this observational study, nine patients undergoing coronary artery bypass grafting were prospectively included. APCO, mean (CCO) and instantaneous CO (ICO) were measured. Perioperative and postoperative assessments were performed up to 24 hours post-surgery. Measurements were recorded every minute, resulting in the collection of 6492 data pairs. Comparison of APCO and ICO showed a limited bias of -0.1 l/min but an important percentage error of 48%. Corresponding values were -0.1 l/min and 46% for the APCO versus CCO comparison, and 0 and 17% for ICO versus CCO comparison. Large inter-individual variability does exist. During cardiac surgery and after leaving the operating room, Vigileo is not clinically equivalent to continuous thermodilution by pulmonary artery catheter Nevertheless, the connection between CCO and ICO relates the difference between APCO and CCO more to the different algorithms used. Further efforts should be concentrated on assessing the ability of this device to track changes in cardiac output.

Diabetic critical ischemia of lower limbs: distal arterial revascularisation.

OBJECTIVES: To evaluate the outcomes of ischemic diabetic foot lesions for which distal arterial bypass grafting was considered as the first-line vascular procedure. PATIENTS AND METHODS: Between November 2004 and November 2006, 19 lower limbs of 17 diabetic patients with lower limb critical ischemia were operated in our department. The bypass grafts included five femoro-popliteal bypass grafts below knee and 14 distal bypass grafts. The 14 distal bypass grafts included; seven venous grafts on the dorsalis pedis artery, four femorotibial PTFE grafts and three femoroperoneal grafts. Arterio-venous fistula was applied to the distal anastomosis site in three limbs. RESULTS: At the time of discharge, the graft patency rate was 93.75%. The mean follow up period was 24 months. The primary cumulative patency rate was 63% at 2 year. The corresponding secondary patency rate was 87%. Among six ischemic ulcers, four ulcers healed within 2 to 12 months (66.6%). At 24 months, the cumulative rate of limb salvage was 76% and that of survival was 74%. CONCLUSION: Distal arterial bypass in diabetic lower limb ischemia improves blood circulation that accelerates foot ulcer healing. It can also avoid amputation or lower its level, and thus improving the patient's quality of life.

[Vision loss after spine surgery: a case report]. / Cécité bilatérale en postopératoire d'une chirurgie du rachis.

We report the case of a 36-year-old man who underwent neurosurgery for a T9 spine fracture consecutive to a fall. The patient had complete postoperative blindness which did not totally recover during the hospital stay. Decreased visual acuity and postoperative vision loss are not uncommon in spine surgery. Such postoperative complications in spine surgery are severe. To avoid them, it is mandatory to identify the contributing factors and set up a preventive strategy.

[Peribulbar anesthesia: efficacy of a single injection with a limited local anesthetic volume]. / Anesthésie péribulbaire: efficacité d'une seule injection et d'un volume d'anesthésiques locaux limité.

INTRODUCTION: Cataract surgery can be performed with peribulbar anesthesia. The classical technique consists of two injections of local anesthetics. The purpose of our study was to assess peribulbar anesthesia with a single injection and a limited volume of local anesthetics. MATERIAL AND METHOD: After local ethics committee agreement and oral consent, patients scheduled for cataract surgery using peribulbar anesthesia were prospectively included. The lower temporal puncture was performed with a peribulbar needle with propofol sedation. The mixture of local anesthetics was administered with tactile control of orbital pressure. The puncture was followed by a 10-min compression of the ocular globe. Akinesia, analgesia, complications, and surgical conditions were noted. RESULTS: A total of 101 successive patients were included. We administered 1.2 mg/kg of propofol. The volume of local anesthetics administered was 5.0 +/- 0.9 ml. Ninety patients had akinesia at 10 min and 6.7% moderate chemosis. No puncture complication occurred. At the end of surgery, the pain noted by the patients was 0.4 +/- 2.1 out of 100 (range, 0-10). Surgical conditions were good for all patients. CONCLUSION: Peribulbar anesthesia performed with a single injection and a limited volume of local anesthetics allows cataract surgery in good conditions for the surgeon with very good analgesia for the patient.

Comparison of cardiac output measurements between NICO and the pulmonary artery catheter during repeat surgery for total hip replacement.

OBJECTIVE: The aim of this study was to compare cardiac output measurements of the non-invasive cardiac output and the pulmonary artery catheter during repeat surgery for hip replacement. METHODS: In this prospective observational study, patients undergoing repeat hip surgery who needed a pulmonary artery catheter were included. A standard protocol was followed for induction, endotracheal intubation and maintenance of anaesthesia (sufentanil, etomidate, sevoflurane, cisatracurium). After endotracheal intubation, the non-invasive cardiac output was connected and a pulmonary artery catheter was inserted. Data were collected every 3 min until patients were extubated. RESULTS: Ten patients were included and 2455 points of comparison recorded. Cardiac output from the pulmonary artery catheter varied from 1.7 to 8.9 L min(-1) (mean 4.1 L min(-1)) and the non-invasive cardiac output (using averaging mode) from 1.7 to 8.0 L min(-1) (mean 3.7 L min(-1)). There was a significant correlation between them (P < 0.01; bias 0.3 L min(-1); limits of agreement +1.9 and -2.5 L min(-1)), although these differed between patients. CONCLUSION: The perioperative bias was small and the non-invasive cardiac output slightly underestimated cardiac output intraoperatively compared to the pulmonary artery catheter. The bias was smaller when mean cardiac output was below 3 L min(-1). Core temperature between 34.4 degrees C and 37.6 degrees C had no influence on the differences.

[Refractory hypoxemia treated early by HFO in a severe traumatic brain injury patient]. / Hypoxémie réfractaire traitée précocement par HFO chez un patient traumatisé crânien grave.

A 23-year-old man without previous medical history, was transferred to our surgical intensive care unit for management of a traumatic brain injury (Glasgow Coma Score of 3 on admission). He rapidly presented a refractory hypoxaemia essentially due to posterior alveolar collapse. Severe hypoxaemia and hypercarboxaemia didn't respond to conventional ventilation and complicated the management of the brain injury and the control of intracranial pressure. The introduction of high-frequency oscillatory ventilation permitted a respiratory improvement in 48 hours and a good neurological outcome.

[Evaluation of the renal function in cardiac surgery with CPB: role of the cystatin C and the calculated creatinine clearance]. / Evaluation de la fonction rénale périopératoire en chirurgie cardiaque: rôle de la cystatine C et de clairance de la créatinine calculée.

OBJECTIVES: The evaluation of the renal function in cardiac surgery is difficult. The gold standard remains the creatinine clearance in clinical practice. Cystatin C was recently proposed in order to evaluate the renal function. The aim of our study was to evaluate the cystatin C in cardiac surgery with CPB. PATIENTS AND METHODS: After informed consent and ethical committee agreement, 60 patients operated in cardiac surgery with CPB were prospectively included. Cystatin C,measured and calculated (Cockcroft and MDRD methods) creatinine were compared with the Student t-test and with the Bland and Altman method. p<0,05 was considered as a significant threshold. RESULTS: The reproducibility of the calculated creatinine clearance was better when the urinary collecting time was below 400 minutes. The estimation of the creatinine clearance by the Cockcroft and MDRD methods is better when the clearance is low. A significant correlation between the creatinine clearance and the cystatin C does exist, but the correlation coefficient was low. In case of acute renal dysfunction, the increase of the creatinine occurred earlier than the increase of the cystatin C. CONCLUSION: In cardiac surgery with CPB, the evaluation of the renal function was not improved by the cystatin C.

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.

[Metabolic acidosis after cardiac surgery with cardiopulmonary bypass revisited with the use of the Stewart acid-base approach]. / Evaluation de la théorie de Stewart lors de l'acidose métabolique survenant après chirurgie cardiaque sous circulation extracorporelle.

INTRODUCTION: According to the Stewart approach of acid-base regulation, chloride from either volume replacement or cardiopulmonary bypass (CPB) priming solution may induce metabolic acidosis. The alternative hypothesis stands in volume dilution with solutions free of bicarbonate. OBJECTIVES: Evaluate the acid-base status of patients undergoing cardiac surgery with CPB priming containing chloride and bicarbonate. MATERIAL AND METHODS: Prospective study. METHODS: Twenty-eight patients were prospectively included. Priming of CPB contained 47.4 mmol/l of bicarbonate and 97.7 mmol/l of chloride. Arterial blood samples were taken at 3 timings: prior (T1) and after (T2) CPB, and on arrival in the ICU (T3). Following measurements were performed: Na(+), K(+), Cl(-), Mg(++), Ca(++), phosphates, albumin, lactate and arterial blood gases. RESULTS: After CPB respiratory acidosis was observed. There was a significant increase of chloride with a decrease in apparent strong ion difference (SIDa). At the same time bicarbonate and base excess (BE) remained constant. A significant but weak correlation between BE and SIDa existed (r(2) = 0.06, p=0.024). On the contrary, no correlation was found between variations of BE and SIDa. However, the correlation was stronger between values and variations of bicarbonate and BE (respectively r(2)=0.605, p<0.0001 and r(2)=0.495, p<0.0001). CONCLUSION: No metabolic acidosis occurred after cardiac surgery when CPB was primed with bicarbonate. Therefore, it appears that chloride administration is not the main mechanism being involved in the acid-base regulation. This reinforces the hypothesis that metabolic acidosis during CPB may mainly be due to dilution of bicarbonate.

[Benchmark of a high-frequency jet ventilator, the Mistral]. / Etude d'un respirateur de jet ventilation, le Mistral, sur banc d'essai.

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.