[Do we have to monitor foetal heart rate during general anesthesia?]. / Faut-il monitorer le rythme cardiaque foetal au cours d'une anesthésie générale?

We present a case of an emergency Caesarean section due to misinterpretation of the cardiotocography (CTG) trace during general anaesthesia for treatment of dental abscess. Following failure of the dental abscess treatment under local anaesthesia, a 29-year-old female in the 36th week of a twin pregnancy was to undergo general anaesthesia. Foetal well-being was monitored with ultrasonographic evaluations of foetal heart rate. During surgery, senior obstetrician recorded a lack of beat-to-beat variability of the cardiotocography trace. The CTG pattern was interpreted as foetal distress and an emergency Caesarean section was performed under general anaesthesia. That was probably due to general anaesthesia. Then, two infants were extracted without neonatal distress necessitating intubation. This case report underlines the risk to misread an intraoperative CTG monitoring and if the CTG monitoring is normal before anaesthesia, reduced foetal beat-to-beat variability with a normal baseline heart rate during general anaesthesia is probably normal.

Target concentrations of remifentanil with propofol to blunt coughing during intubation, cuff inflation, and tracheal suctioning.

BACKGROUND: The target blood concentrations of propofol and remifentanil, when used in combination, required to blunt the cough response to tracheal intubation, cuff inflation, and tracheal suctioning without neuromuscular blocking agents are not known. METHODS: In a randomized prospective study, 81 patients were enrolled to determine which of three target remifentanil blood concentrations was required to blunt coughing during intubation, cuff inflation, and tracheal suctioning. Anaesthesia was achieved with propofol at a steady effect-site concentration of 3.5 microg ml(-1). The target blood remifentanil concentrations were 5, 10, or 15 ng ml(-1). These concentrations were maintained for 12 min before intubation. RESULTS: There was no cough response to intubation in more than 74% of patients and no significant difference in the incidence of coughing with intubation between the three groups. Significant difference in coughing, diminishing with increasing remifentanil target concentration, was observed with cuff inflation (P=0.04) and tracheal suctioning (P=0.007). Bradycardia and hypotension was more frequent with the remifentanil target concentration of 15 ng ml(-1). Tracheal suctioning resulted in more coughing than intubation (P=0.01) or cuff inflation (P=0.004). CONCLUSION: Target remifentanil blood concentrations of 5, 10, and 15 ng ml(-1) associated with a 3.5 microg ml(-1) propofol target blood concentration provided good intubating conditions and absence of cough about 75% of the time. Higher target remifentanil concentrations were associated with less coughing during tracheal tube cuff inflation and tracheal suctioning.

[Opioid anesthetics (sufentanil and remifentanil) in neuro-anaesthesia]. / Les morphiniques (sufentanil et rémifentanil) en neuro-anesthésie.

Remifentanil is the latest available compound of the 4-anilidopiperidine derivatives. It is characterized by an ultrashort duration of action and a metabolism independent of both hepatic and renal functions. Its main drawback is a lack of residual analgesia and the risk of postoperative hyperalgesia. Since its introduction in clinical practice, this drug has been compared to other congeners in a few studies in the setting of neurosurgery. Cerebral hemodynamics, intracranial pressure and CO(2) reactivity are similar to the effects of fentanyl and sufentanil provided that systemic arterial pressure is maintained. Haemodynamics does not greatly vary according to the type of the opioid. Fentanyl and sufentanil require higher hypnotic dosage (halogenated agents, propofol) and remifentanil is accompanied by greater volumes of fluid infusion. A marked reduction in extubation times and superior level of consciousness are reported with remifentanil. Rescue analgesic has to be given faster but pain scores remain low. Morphine 0.08 mg/kg IV administered at bone replacement results in good postoperative analgesia without delayed recovery. In summary, remifentanil is appropriate when rapid recovery and neurological evaluation are desired. Conversely, sufentanil is more suitable and easier to administer when postoperative mechanical ventilation and postponed awakening are scheduled.

Influence of propofol concentrations on multipulse transcranial motor evoked potentials.

BACKGROUND: Motor evoked potentials can be affected by propofol anaesthesia. We studied how increasing target concentrations of propofol altered transcranial motor evoked potentials (tcMEP) during scoliosis surgery. METHODS: Fifteen patients undergoing surgery for scoliosis were anaesthetized with remifentanil and propofol without nitrous oxide or neuromuscular blocking agents (BIS<60). tcMEP were elicited by transcranial electric multipulse stimulation of the motor cortex and recording of compound action potentials from the anterior tibialis muscle. tcMEP were obtained before surgery with propofol target values set from 4 to 8 mg litre(-1), and then during surgery. Arterial propofol concentrations were measured for each tcMEP recording. RESULTS: Before surgery, increasing propofol reduced tcMEP amplitude in a dose-dependent manner, with no effect on latency. During surgery, at equivalent propofol concentrations, tcMEP were not statistically different from those obtained before surgery. In all except one patient, tcMEP signals were present during the entire procedure. In this patient the loss of tcMEP was unfortunately related to an anterior spinal cord lesion, which was confirmed by a wake-up test. CONCLUSION: We found that, although propofol had a dose-dependent effect on tcMEP amplitude, anaesthesia could be maintained with remifentanil and propofol to allow recording and interpretation of tcMEP signals.

Target concentration of propofol required to insert the laryngeal mask airway in children.

BACKGROUND: The aim of this prospective study was to determine the target concentration (CPRED) curves for laryngeal mask airway (LMA) insertion in children. METHODS: The CPRED of propofol required for insertion of the LMA was determined in 72 unpremedicated children, aged 3-10 years, ASA physical status I. CPRED was reached in 2 min according to a sequential allocation. LMA insertion was then performed by an experienced anaesthetist who was unaware of the concentration. Insertion conditions were noted as satisfactory (jaw relaxed, no coughing, gagging, swallowing or laryngeal spasm, minimal limb movement), excellent (no movement at all) or unacceptable if otherwise. RESULTS: The CPRED50 and CPRED90 were 7.86 microg.ml(-l)[95% confidence interval (CI) 6.46-9.26] and 10.71 microg.ml(-l) (95% CI 9.31-12.12), respectively, in the satisfactory group and 10.86 microg.ml(-l) (95% CI 10.14-11.57) and 13.71 microg.ml(-l) (95% CI 12.99-14.42) in the excellent group when calculations were based on Kataria's pharmacokinetics. These figures were increased 1.5-fold when calculations were based on Marsh's pharmacokinetics. With Schüttler's pharmacokinetics, CPRED50 were 4.62 microg.ml(-l) and 13.66 microg.ml(-l) for satisfactory and excellent groups, respectively. CONCLUSIONS: The target-controlled infusion technique for anaesthesia induction and insertion of the LMA was a safe and effective technique in our study.

Target-controlled sedation-analgesia using propofol and remifentanil in women undergoing late termination of pregnancy.

Twenty-one women undergoing termination of pregnancy for severe fetal abnormality received remifentanil and propofol using a target-controlled infusion system and were studied prospectively. Target concentrations were initially set at 1 ng.mL(-1) for remifentanil and 0.8 microg.mL(-1) for propofol. Remifentanil concentration was adjusted to obtain visual analog scores <50 mm with preservation of ventilation. Visual analog scores assessed by the patients and physiologic data were recorded every 15 min until delivery. The median duration of administration was 150 min [10th-90th centiles: 42-282 min). Visual analog scores decreased within the first 5 min (P < 0.05) and remained under 50 mm for 91.7% of time. The median rate of infusion of remifentanil was 0.056 microg.kg(-1) min(-1) [10th-90th centiles: 0.037-0.15 ng.mL(-1)]. At delivery, the median target concentration was 2.2 ng.mL(-1) [10th-90th centiles: 1.25-4 ng.mL(-1)] for remifentanil and 0.8 microg.mL(-1) [10th-90th centiles: 0.32-1.12 microg.mL(-1)] for propofol. Remifentanil requirements were statistically correlated to gestational age, parity and duration of labor. No episodes of ventilatory depression, nausea, vomiting or pruritus were noted. Patients scored analgesia as excellent in 12 cases, good in 7 cases and moderate in 2 cases. Further studies are required to determine the place and the best regimen of remifentanil infusion for pain management in labor in those cases when epidural analgesia is contraindicated.

Complications of endoscopic sphincterotomy: results from a single tertiary referral center.

BACKGROUND AND STUDY AIMS: Complications of endoscopic sphincterotomy (ES) have been assessed in recent multicenter studies. The aim of this series was to report and identify risk factors for complications of ES at a single tertiary referral center. PATIENTS AND METHODS: Between 1996 and 2000, 1159 consecutive endoscopic retrograde cholangiopancreatographies (ERCP) procedures were performed and their related complications were assessed. A total of 658 patients (57 %) underwent ES. All the clinical, radiological and biological data were carefully recorded within the 30 days following the procedure. Multivariate analysis was performed using a stepwise logistic model. RESULTS: The morbidity rate for ES was 7.7 %, being moderate to severe in 5 %. Morbidity included acute pancreatitis (3.5 %), perforations (1.8 %), sepsis (1.2 %) and bleeding (1.2 %). The 30-day mortality was 0.9 %. In the 1159 ERCP procedures, 231 patients underwent precut papillotomy (20 %) followed by sphincterotomy in 174 cases. Using logistic regression analysis, the risk factors for ES were precut papillotomy (relative risk, RR 2.76), confidence interval, (CI 1.39 - 5.49) and the presence of sphincter of Oddi dysfunction (RR, 7.72, CI 3.2 - 18.4). CONCLUSIONS: In this single-center series, we found a complication rate of ES in about 7 %, comparable to that in multicenter series. Precut papillotomy and sphincter of Oddi dysfunction were the main independent risk factors for ES.

The combination of a heat and moisture exchanger and a Booster: a clinical and bacteriological evaluation over 96 h.

OBJECTIVE: To determine whether the combination with a new device (Booster ) for active humidification improves the efficacy of a hydrophobic heat and moisture exchanger (HME). DESIGN AND SETTING: Prospective, interventional study in the ICU of a university hospital. PATIENTS: Consecutive patients requiring controlled mechanical ventilation INTERVENTIONS: Patients were ventilated with a HME, and a Booster was added for 96 h to the ventilatory circuit. MEASUREMENTS AND RESULTS: During the inspiration phase the following factors were measured: peak and mean airway pressures, maximal (beginning of inspiration), minimal (end of inspiration), and mean values of temperature of inspired gases, and relative and absolute humidity of inspired gases. Microbiological samples were obtained from the Booster, the ventilator side of the HME, and the tracheal secretions on days 1 and 4. Minimal and mean temperatures were increased as soon as the Booster was used and this increase was maintained for 96 h until the Booster was withdrawn. Then the temperature returned to baseline values. Absolute humidity values followed the same course. There was also some indirect evidence of very little, if any, changes in the HME resistance. The ventilatory side of the HMEs remained sterile in each patient, and the Booster was colonized by the same bacteria as those in the tracheal secretions. CONCLUSIONS: Adding the Booster to a hydrophobic HME improved the heat and water preservation of ventilatory gas.

[Target controlled infusion (TCI) anesthesia using propofol. Assessment of training and practice in the operating room]. / Anesthésie intraveineuse à objectif de concentration (Aivoc) avec le propofol. Evaluation des formations et pratiques au bloc opératoire.

OBJECTIVE: To evaluate overall awareness of TCI and the need for training in the TCI technique. To assess, among trained anaesthetists, the value of the session and the impact of TCI technique on their working practice. STUDY DESIGN: Two prospective domestic surveys during the first quarter of 1999. METHODS: Three hundred anaesthetists representative of French anaesthetists as a whole, and 336 anaesthetists who had taken part in a training course. RESULTS: The notoriety of TCI was high and greater in the public sector compared with the private sector. Almost 3/4 of anaesthetists believed that training was necessary but only four anaesthetists out of ten TCI users said they had taken part in training sessions. After the training session nine anaesthetists out of ten became TCI users and would have recommended the training course despite the low number and variety of anaesthetic procedures observed during the practical part of training. The main difficulties reported during initial use were the choice of target concentrations and the management of drug interactions. Familiarisation to the technique was rapid (less than 20 procedures). Despite the lack of long experience (< 6 months for more than 2/3 of them), TCI appeared to be more likely used for anaesthesia of average duration. CONCLUSIONS: TCI was perceived to be an innovative concept with a requirement of a specific training. This preliminary appraisal of training sessions was generally satisfactory but underline a need for future training sessions focused on practical aspects.

Measurement of tracheal temperature is not a reliable index of total respiratory heat loss in mechanically ventilated patients.

BACKGROUND: Minimizing total respiratory heat loss is an important goal during mechanical ventilation. The aim of the present study was to evaluate whether changes in tracheal temperature (a clinical parameter that is easy to measure) are reliable indices of total respiratory heat loss in mechanically ventilated patients. METHOD: Total respiratory heat loss was measured, with three different methods of inspired gas conditioning, in 10 sedated patients. The study was randomized and of a crossover design. Each patient was ventilated for three consecutive 24-h periods with a heated humidifier (HH), a hydrophobic heat-moisture exchanger (HME) and a hygroscopic HME. Total respiratory heat loss and tracheal temperature were simultaneously obtained in each patient. Measurements were obtained during each 24-h study period after 45 min, and 6 and 24 h. RESULTS: Total respiratory heat loss varied from 51 to 52 cal/min with the HH, from 100 to 108 cal/min with the hydrophobic HME, and from 92 to 102 cal/min with the hygroscopic HME (P < 0.01). Simultaneous measurements of maximal tracheal temperatures revealed no significant differences between the HH (35.7-35.9 degrees C) and either HME (hydrophobic 35.3-35.4 degrees C, hygroscopic 36.2-36.3 degrees C). CONCLUSION: In intensive care unit (ICU) mechanically ventilated patients, total respiratory heat loss was twice as much with either hydrophobic or hydroscopic HME than with the HH. This suggests that a much greater amount of heat was extracted from the respiratory tract by the HMEs than by the HH. Tracheal temperature, although simple to measure in ICU patients, does not appear to be a reliable estimate of total respiratory heat loss.

High adenosine plasma concentration as a prognostic index for outcome in patients with septic shock.

OBJECTIVE: Sepsis and septic shock are a common cause of mortality in critically ill patients. Many substances have been implicated in the pathophysiology of these syndromes. We postulated that adenosine may be implicated in the sepsis- or septic shock-induced blood pressure failure. Indeed, this nucleoside is a strong endogenous vasodilating agent released by endothelial cells and myocytes under circumstances of metabolic stress, such as during critical illness. DESIGN: A prospective, comparative observational study. SETTING: The adult intensive care unit of a tertiary care university hospital. PATIENTS: We measured adenosine plasma concentration (APC) in patients with severe sepsis (n = 11), in patients with septic shock (n = 14), in patients with hemorrhagic traumatic shock (n = 14), and in 12 healthy volunteers. APC was evaluated every 12 hrs over 3 days. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: At study entry, we found that APC was higher in patients with septic shock (mean +/- so = 8.4 +/-3.5 micromol/L) than in patients with hemorrhagic traumatic shock (1.1 +/- 0.6 micromol/L) and controls (0.8 +/- 0.3 micromol/L). Intermediate values (3.9 +/- 1.9 micromol/L) were found in patients with severe sepsis. APC in patients with traumatic shock did not differ from controls. In the course of the hospitalization, for both sepsis and septic shock patients, APC decreased significantly but remained higher than controls 72 hrs after entry into the study. In the septic shock group, APC was significantly higher in the nonsurvivor group (n = 6) than in the survivor group (n = 8), whatever the time of sample collection and assay. CONCLUSIONS: High adenosine plasma concentrations are found in patients with septic shock but not during traumatic shock, or in healthy volunteers. Intermediate values of circulating adenosine are found in patients with severe sepsis. APC may be a prognostic index for outcome in septic patients, with much higher values being found in nonsurvivors.

Effect of norepinephrine on the outcome of septic shock.

OBJECTIVE: Despite increasingly sophisticated critical care, the mortality of septic shock remains elevated. Accordingly, care remains supportive. Volume resuscitation combined with vasopressor support remains the standard of care as adjuvant therapy, and many consider dopamine to be the pressor of choice. Because of fear of excessive vasoconstriction, norepinephrine is considered to be deleterious. The present study was designed to identify factors associated with outcome in a cohort of septic shock patients. Special attention was paid to hemodynamic management and to the choice of vasopressor used, to determine whether the use of norepinephrine was associated with increased mortality. DESIGN: Prospective, observational, cohort study. SETTING: Intensive care unit of a university hospital. PATIENTS: Ninety-seven adult patients with septic shock. MEASUREMENTS AND MAIN RESULTS: Data from these patients were examined to select variables independently and significantly associated with outcome during the hospital stay. Nineteen clinical, biological, and hemodynamic variables were collected at study entry or during the first 48-72 hrs and analyzed for each patient. A stepwise logistic regression analysis and a model building strategy were used to identify variables independently and significantly associated with outcome. The overall hospital mortality was 73% (71 patients). Five variables were significantly associated with outcome. One factor was strongly associated with a favorable outcome: the use of norepinephrine as part of the hemodynamic support of the patients. The 57 patients who were treated with norepinephrine had significantly lower hospital mortality (62% vs. 82%, p < .001; relative risk = 0.68; 95% confidence interval = 0.54-0.87) than the 40 patients treated with vasopressors other than norepinephrine (high-dose dopamine and/or epinephrine). Four variables were associated with a poor outcome and significantly higher hospital mortality: pneumonia as a cause of septic shock (82% vs. 61%, p < .03; relative risk = 1.47; 95% confidence interval = 1.07-1.77), organ system failure index < or = 3 (92% vs. 60%, p < .001; relative risk = 1.47; 95% confidence interval = 1.17-1.82), low urine output at entry to the study (88% vs. 60%, p < .01; relative risk = 1.44; 95% confidence interval = 1.06-1.87), and admission blood lactate concentration > 4 mmol/L (91% vs. 63%, p < .01; relative risk = 1.60; 95% confidence interval = 1.27-1.84). CONCLUSIONS: Our results indicate that the use of norepinephrine as part of hemodynamic management may influence outcome favorably in septic shock patients. The data contradict the notion that norepinephrine potentiates end-organ hypoperfusion, thereby contributing to increased mortality. However, the present study suffers from some limitation because of its nonrandomized, open-label, observational design. Hence, a randomized clinical trial is needed to clearly establish that norepinephrine improves mortality of patients with septic shock, as compared with high-dose dopamine or epinephrine. Pneumonia as the cause of septic shock, high blood lactate concentration, and low urine output on admission are strong indicators of a poor prognosis. Multiple organ failure is confirmed as a reliable predictor of mortality in septic patients.

Effects of norepinephrine plus dobutamine or norepinephrine alone on left ventricular performance of septic shock patients.

OBJECTIVE: To determine the hemodynamic effects of the combination of norepinephrine-dobutamine in adult patients with septic shock. Specifically, we tested the hypothesis that norepinephrine in addition to dobutamine would improve cardiac index (CI) and stroke volume index (SVI) and increase left-ventricular afterload. DESIGN: Prospective, descriptive, interventional study with no control group. SETTING: Intensive care unit of a university hospital. PATIENTS: Fourteen patients (group 1) were transferred to the intensive care unit from other wards with septic shock not responsive to dobutamine infusion, low blood pressure (systolic blood pressure of <90 mm Hg), clinical and laboratory signs of infection, clinical signs of poor organ perfusion, and blood lactate of >2.0 mmol/L. They were enrolled and treated by the addition of norepinephrine, while the dose of dobutamine remained constant. Three of these patients required additional fluid loading to achieve adequate ventricular filling (pulmonary capillary wedge pressure [PCWP], 12-15 mm Hg). These patients were compared with 12 patients with septic shock with high CI (CI > 5/min/m2, and other signs as outlined previously) who were treated with norepinephrine alone (group 2). INTERVENTIONS: Patients in group 1 were maintained with the same dobutamine dose, and norepinephrine was added (initial dose, 0.5 microg/kg/min, and increments of 0.3 microg/kg/min) until the correction of mean arterial blood pressure (MAP > or =75 mm Hg). Patients in group 2 received norepinephrine following the same protocol. MEASUREMENTS AND MAIN RESULTS: At study entry, group 1 patients receiving dobutamine had similar MAPs but were significantly older and had significantly lower CIs and SVIs and higher systemic vascular resistance than group 2 patients. In group 1 norepinephrine, in addition to dobutamine, significantly increased MAP, CI, SVI, left ventricular stroke work index (LVSWI), and systemic vascular resistance (SVR). No change in heart rate or PCWP was observed. In group 2, norepinephrine used alone did not modify CI or SVI and it significantly improved MAP, LVSWI, and SVR. No changes in heart rate or PCWP were observed. Blood lactate was significantly decreased in both groups. Comparing the two groups, in response to norepinephrine titrated to increase MAP to a similar concentration, patients with dobutamine-resistant septic shock had a statistically significantly greater increase in CI and SVI than patients treated with norepinephrine alone. There were no other significant differences in hemodynamic and metabolic responses to norepinephrine between groups 1 and 2. CONCLUSION: The addition of norepinephrine to treatment of patients with septic shock unresponsive to dobutamine significantly improves MAP, CI, SVI, and LVSWI. A different pattern of evolution was observed if norepinephrine was used alone in younger patients with higher CI at study entry, increases in MAP and LVSWI, and no concomitant change in CI or SVI. The use of norepinephrine in dobutamine-resistant septic shock may have some beneficial implications for the treatment of patients with inadequate myocardial performance associated with low SVR.

Excretion of lidocaine and bupivacaine in breast milk following epidural anesthesia for cesarean delivery.

BACKGROUND: There is a lack of information and knowledge about the practical importance of even low concentrations of the excretion of local anesthetics into breast milk, particularly concerning bupivacaine. The present work aims to confirm, under practical clinical conditions of admission of parturients, the passage of local anesthetics (lidocaine and bupivacaine) into breast milk after an epidural anesthesia. METHODS: Twenty-seven pregnant women admitted for cesarean delivery received epidural anesthesia with 0.5% bupivacaine and 2% lidocaine. Blood and milk samples were simultaneously collected at 2, 6 and 12 h after the beginning of the epidural infusion. Lidocaine, bupivacaine and its main metabolite, pipecolylxylidide (PPX), were determined in serum and milk by a gas-liquid chromatographic technique. APGAR scores were systematically performed at delivery and a clinical examination was done 24 h after delivery. RESULTS: Our data indicate that lidocaine and bupivacaine as well as PPX are excreted into breast milk. The milk/serum ratio based upon area under the curve values were 1.07 +/- 0.82, 0.34 +/- 0.24 and 1.37 +/- 0.61 mean +/- SD for lidocaine, bupivacaine and PPX, respectively. Most of the newborns had a maximal APGAR score. Our study does not reveal any adverse reactions related to the excretion of local anesthetics into breast milk. CONCLUSION: This study documents the magnitude of excreted lidocaine, bupivacaine and PPX in breast milk, and indicates that the use of both lidocaine and bupivacaine for epidural anaesthesia is safe with regard to breast-feeding.

Sufentanil, fentanyl, and alfentanil in head trauma patients: a study on cerebral hemodynamics.

OBJECTIVES: To determine the effects of bolus injection and infusion of sufentanil, alfentanil, and fentanyl on cerebral hemodynamics and electroencephalogram activity in patients with increased intracranial pressure (ICP) after severe head trauma. DESIGN: Randomized, unblended, crossover study. SETTING: Intensive care unit and trauma center in a university hospital. PATIENTS: Six patients with head trauma and ICP monitoring, sedated at the time of the study with propofol infusion and full neuromuscular blockade. INTERVENTIONS: Following a randomized order, in an unblended and crossover fashion, the level of sedation was deepened with a 6-min injection of either sufentanil (1 microg/kg), alfentanil (100 microg/kg), or fentanyl (10 microg/kg) followed by an infusion of 0.005, 0.7, and 0.075 microg/kg/min, respectively, for 1 hr. The three opioids were given to each patient at 24-hr intervals. MEASUREMENTS AND MAIN RESULTS: Mean arterial pressure (MAP), ICP, cerebral perfusion pressure (CPP), and jugular vein bulb oxygen saturation (Svjo2) were continuously measured and recorded at 1-min intervals throughout the 60-min study period. Sufentanil, fentanyl, and alfentanil infusions were associated with a significant but transient increase in ICP (9+/-2 mm Hg [SD], 8+/-2 mm Hg, and 5.5+/-1 mm Hg, respectively; p<.05). The increase in ICP peaked at 5, 6, and 3 mins, respectively, then gradually decreased and returned to baseline values after 15 mins. This result was accompanied by a significant decrease in MAP (21+/-2 mm Hg, 24+/-2 mm Hg, and 26+/-2 mm Hg, respectively; p<.05) and, thus, in CPP (30+/-3 mm Hg, 31+/-3 mm Hg, and 34+/-3 mm Hg, respectively; p<.05). After 5 mins, MAP and CPP gradually increased, although they remained significantly decreased throughout the study period. No changes in lactate-oxygen index, used as an ischemia index, were observed. Changes in electroencephalogram tracings were characterized by a switch from a fast to a decreased activity, together with an improvement in the background activity. CONCLUSION: The results of the present study show that alfentanil, sufentanil, and fentanyl produce similar transient increases in ICP when administered by bolus injection in patients with increased ICP. No evidence of cerebral ischemia was observed in the study patients.

Upper-extremity deep vein thrombosis after central venous catheterization via the axillary vein.

OBJECTIVE: To determine the frequency of central venous catheter-induced thrombosis of the axillary vein. DESIGN: Prospective, controlled study. SETTING: Tertiary care university center. PATIENTS: Sixty patients in a medical-surgical intensive care unit who required central venous catheterization via the axillary vein. INTERVENTIONS: Single-lumen, silicone elastomer or polyurethane catheters were inserted for a mean duration of 14.7+/-7.4 days (range, 4-33 days). On catheter removal, bilateral upper-extremity phlebographic examination was performed in each patient. The incidence of deep vein thrombosis in catheterized arms was compared with that in uncatheterized arms. MEASUREMENTS AND MAIN RESULTS: Of the 60 patients who underwent axillary vein cannulation, one patient had clinical signs of arm vein thrombosis, but no patient had clinical sign of pulmonary embolism. There were 35 patients (58.3%) who developed positive phlebographic examinations homolateral to the catheter. Fibrin sleeves that developed around the catheters were observed in 28 patients (47%). Five patients (8.3%) had phlebographic signs of partial axillary vein thrombosis: nonobstructive clots adherent to the vessel wall and/or the catheter. Two patients (3.3%) had phlebographic signs of complete axillary vein thrombosis. No thrombosis was observed in patients with catheterizations lasting < or =6 days, two cases were observed for duration of 7-14 days, and five cases were observed for duration of > or =15 days (p < .01). In the seven patients with axillary vein thrombosis, the vessel was cannulated with fewer than three puncture attempts, and the mean duration for catheter insertion (10+/-2.5 min) was not different from that of patients with no axillary vein thrombosis (14+/-9 min). CONCLUSIONS: Based on the data from the present study, we conclude that axillary vein catheterization is associated with a 11.6% frequency of upper-extremity deep vein thrombosis. This rate of vein thrombosis is similar to that observed after internal jugular or subclavian vein cannulation. Given the acceptable rate of this clinically important complication, axillary vein cannulation offers an attractive alternative site for catheter insertion to the internal jugular or subclavian vein in the critically ill. Because thrombosis is rare or absent in catheterizations lasting <15 days, it seems wise to withdraw axillary catheters after a maximum of 2 wks.

Changing a hydrophobic heat and moisture exchanger after 48 hours rather than 24 hours: a clinical and microbiological evaluation.

OBJECTIVE: Complications following ventilation with dry and cold gases may be prevented by the use of artificial noses or heat and moisture exchangers, which are a solution to both the problems of humidification and heat preservation. The aim of the present study was to determine whether changing hydrophobic heat and moisture exchangers (HMEs) every 48 h rather than 24 h would affect their efficacy to preserve the heat and moisture of inspiratory gases. The impact of a prolonged use of the HME on its microbial colonization was also assessed. DESIGN: Prospective observational study. SETTING: ICU of a university hospital. PATIENTS: Twelve patients requiring controlled mechanical ventilation for more than 2 days were evaluated. INTERVENTIONS: The patients were ventilated with a heat and moisture exchanger (HME) (Maxipleat Filter, Europe Medical, France). The hydrophobic HME was placed between the Y-piece and the connecting tube and changed after 48 h of continuous use. Temperature (degree C), relative humidity (%) and absolute humidity (mgH2O/l) were obtained using the capacitive sensor principle. Bacterial colonization (tracheal secretions and ventilator side of the HME) were obtained on days 1 and 2. MEASUREMENTS AND RESULTS: After 48 h of ventilation with the same HME, tracheal tube occlusion was never observed. Using the same hydrophobic HME for 48 h rather than 24 h did not affect its technical performance: temperature at 24 h: 32.5 +/- 1.3 degrees C, at 48 h: 32.7 +/- 1.8 degrees C; relative humidity (RH) at 24 h: 99.0 +/- 1.4%, at 48 h: 99.0 +/- 1.4%; absolute humidity (AH) at 24 h: 34.0 +/- 2.4 mgH2O/l, at 48 h: 34.4 +/- 3.5 mgH2O/l. Peak and mean airway pressures did not change over the 48-h study period, with identical tidal and minute volumes in the study patients. Total respiratory heat losses were not modified during the 48-h study period (at 24 h: 152 +/- 47 cal/min, at 48 h: 149 +/- 65 cal/min). Evaporative and convective heat losses were not modified either. On day 1, eight patients had positive cultures of their tracheal secretions at a colony count of 10(3) or higher cfu/ml. After 48 h of use of the same HME, only six patients had a positive culture of their tracheal secretions. Cultures from the ventilator sides of the HMEs were all sterile (12/12) after 48 h of use. CONCLUSIONS: Changing the hydrophobic HME after 48 h rather than 24 h did not affect its technical performance in terms of heat and water preservation of ventilatory gases. There is also some indirect evidence of very little, if any, change in HME resistance. No bacterial colonization of the ventilator sides of the HMEs was observed after 48 h of use. However, other large clinical trials should be undertaken to confirm the safety of extending the time between HME changes.

Comparing two heat and moisture exchangers, one hydrophobic and one hygroscopic, on humidifying efficacy and the rate of nosocomial pneumonia.

OBJECTIVE: Many heat and moisture exchangers with filter (HMEF) have been developed. In-house data from companies provide some information about their performances; unfortunately, to our knowledge, no comparative evaluation in clinical conditions has been undertaken of these newer products. The aim of this study was to compare the efficiency of two HMEFs, one hydrophobic and one hygroscopic, on humidifying capacity and the rate of bronchial colonization and ventilator-associated pneumonia in ICU patients. DESIGN: Prospective, randomized study. SETTING: ICU of a university hospital. PATIENTS: All patients who required mechanical ventilation for > or = 24 h during the study period. INTERVENTIONS: On admission to the ICU, patients were randomly assigned to one of two groups. In one group, the patients were ventilated with a hygroscopic device (Humid-Vent Filter Light HMEF; Gibeck; Upplands Vaesby, Sweden). The condensation surface was made of paper (Microwell) impregnated with CaCl2. The filter membrane was made of polypropylene. In the other group, the patients were ventilated with a hydrophobic device (Pall BB100 HMEF). The condensation surface was made of a hydrophobic resin with a hydrophylic layer. The filter membrane was made of ceramic fibers. In both groups, HMEFs were changed daily. MEASUREMENTS AND RESULTS: Both groups of patients were similar for the tested characteristics, including parameters of mechanical ventilation. Sixty-six patients were ventilated for 11.7+/-11 days with the Humid-Vent Filter Light HMEF and 70 patients for 12.2+/-12 days with the Pall BB 100. Patients ventilated with the Humid-Vent Filter Light underwent 6.0+/-3.0 tracheal aspirations and 1.7+/-2.0 instillations per day, and those with the Pall BB 100, 6.0+/-3.0 and 1.6+/-2.0 per day, respectively (not significant [NS]). Abundance of tracheal secretions, presence of blood, and viscosity, evaluated by semiquantitative scales, were similar in both groups. No difference in the rate of atelectasis was observed between the two groups (7.5% and 7.1%, NS). One episode of tracheal tube occlusion was observed with the Humid-Vent Filter Light HMEF, and one with the other HMEF (NS). One patient in each group (NS) was switched to an active heated humidifier because of very tenacious bronchial secretions despite repeated instillations. Tracheal colonization was observed at a rate of 67% with the Humid-Vent Filter Light and 58% with the Pall BB 100 (NS). A small, but NS difference was observed in the rate of ventilator-associated pneumonia: Humid-Vent Filter Light, 32% (27.1 per 1000 ventilator days); and Pall BB 100, 37% (30.4 per 1000 ventilator days). Bacteria responsible for tracheal colonization and pneumonia were similar in both groups. Three patients in each group died from their nosocomial pneumonia. CONCLUSION: Despite differences in their components, the two HMEFs tested achieved similar performances in terms of humidification and heating of inspired gases. Only one episode of endotracheal tube occlusion was detected and very few patients (one in each group) had to be switched to an active heated humidifier. No difference was observed either in the rate of tracheal colonization or of ventilator-associated pneumonia. These data show that the hygroscopic HME (Humid-Vent Filter Light) and the hydrophobic HME (Pall BB 100) are suited for use in ICU patients.

[Survey of 39 South East Group hospital centers on the practice of antibiotic prophylaxis in surgery]. / Audit sur 39 centres hospitaliers des pratiques d'antibioprophylaxie en chirurgie et le groupe du sud-est pour l'étude de l'antibioprophylaxie.

A survey was carried out in 39 hospitals regarding the prescribing of perioperative antibiotics. The day of the survey, hospital pharmacists collected information on prescription patterns of antibiotics and, for 3 days, the duration of their administration. A total of 1,131 cases were surveyed, originating from digestive surgery (20%), orthopaedics (31%), gynaecology (15%), ophthalmic surgery (15%), and others (19%). Duration of surgery was 72 +/- 68 min. For all types of surgeries, antibiotics not recommended by the French consensus conference were prescribed. Third generation cephalosporins were used in 17% of patients in gynaecological surgery. In 20% of cases, antibiotics were administered at an inappropriate time: 9.5% after the beginning of surgery, 8% at the time of pre-medication, and 2.5% the day before surgery. Administration exceeded 48 hours in 10% of the cases. In conclusion, special attention should be paid to limit the prescription of third generation cephalosporins, to inject antibiotic at the induction of anaesthesia and to reduce the duration of their administration.