Blood pressure monitoring during arrhythmia: agreement between automated brachial cuff and intra-arterial measurements.

BACKGROUND: Since arrhythmia induces irregular pulse waves, it is widely considered to cause flawed oscillometric brachial cuff measurements of blood pressure (BP). However, strong data are lacking. We assessed whether the agreement of oscillometric measurements with intra-arterial measurements is worse during arrhythmia than during regular rhythm. METHODS: Among patients of three intensive care units (ICUs), a prospective comparison of three pairs of intra-arterial and oscillometric BP readings was performed among patients with arrhythmia and an arterial line already present. After each inclusion in the arrhythmia group, one patient with regular rhythm was included as a control. International Organization for Standardization (ISO) standard validation required a mean bias <5 (sd 8) mm Hg. RESULTS: In 135 patients with arrhythmia, the agreement between oscillometric and intra-arterial measurements of systolic, diastolic and mean BP was similar to that observed in 136 patients with regular rhythm: for mean BP, similar mean bias [-0.1 (sd 5.2) and 1.9 (sd 5.9) mm Hg]. In both groups, the ISO standard was satisfied for mean and diastolic BP, but not for systolic BP (sd >10 mm Hg) in our ICU population. The ability of oscillometry to detect hypotension (systolic BP <90 mm Hg or mean BP <65 mm Hg), response to therapy (>10% increase in mean BP after cardiovascular intervention) and hypertension (systolic BP >140 mm Hg) was good and similar during arrhythmia and regular rhythm (respective areas under the receiver operating characteristic curves ranging from 0.89 to 0.96, arrhythmia vs regular rhythm between-group comparisons all associated with P>0.3). CONCLUSIONS: Contrary to widespread belief, arrhythmia did not cause flawed automated brachial cuff measurements.

Risk factors and pathogens involved in early ventilator-acquired pneumonia in patients with severe subarachnoid hemorrhage.

Ventilator-acquired pneumonia (VAP) is a common burden in intensive care unit (ICU) patients, but, to date, specific data are not available in patients with severe aneurysmal subarachnoid hemorrhage (SAH). A single neuro-ICU retrospective analysis of 193 patients with SAH requiring mechanical ventilation (MV) ≥48 h admitted from January 2005 to May 2010 was undertaken. The diagnosis of early VAP was prospectively upheld during a multidisciplinary staff meeting, according to the American Thoracic Society (ATS) 2005 guidelines with a threshold of 7 days after the onset of MV. Patients had a median age of 53 (44-62) years and 70 (36 %) were male. The median Glasgow coma scale (GCS) score before MV was 9 (5-14). 142 (74 %) patients had a World Federation of Neurosurgeons (WFNS) score ≥III. Aneurysm was secured with an endovascular coiling procedure in 162 (84 %) patients. 81 (48.7 %) patients declared an early VAP. On multivariate analysis, male sex (odds ratio [OR] 2.26, 95 % confidence interval [CI] [1.14-4.46]), use of mannitol before day 7 (OR 3.03, 95 % CI [1.54-5.95]), and achieving enteral nutrition ≥20 kcal kg(-1) day(-1) after day 7 (OR 2.91, 95 % CI [1.27-6.67]) remained independent risk factors of VAP. The main pathogens involved were methicillin-susceptible Staphylococcus aureus (MSSA) (34.9 %), Haemophilus influenzae (28.1 %), Streptococcus pneumoniae (15.5 %), and Enterobacteriaceae (10.7 %). Early VAP was associated with a longer duration of MV and ICU stay, but not with an excess of mortality. Early VAP bears significant morbidity in patients with severe SAH. Pathogens involved in early VAP are susceptible to antibiotics. Among modifiable risk factors of VAP, early enteral nutrition could be an easy and effective target.

[Is training on basic skills and management of critical events responsible of ethical considerations in anaesthesia and intensive care?]. / L'apprentissage des gestes invasifs et de la gestion d'une situation critique pose-t-il des problèmes éthiques en anesthésie-réanimation?

OBJECTIVE: To provide information on morbidity and ethical questions associated with learning of invasive techniques (tracheal intubation, positioning of central venous or epidural catheters) and management of anaphylactic shock. STUDY DESIGN: Retrospective survey. METHODS: Written questionnaire to 54 anaesthesiologists and 55 residents. RESULTS: Training was primarily performed by residents having a 6 months-experience for general anaesthesia and by more experienced residents for epidural analgesia. Residents observed first two or three procedures performed by seniors, but did not have theoretical lectures in 30 to 50% of cases. Dead bodies or manikins were rarely used. Despite the presence of experienced anaesthesiologists during the first attempts, there was a high morbidity rate which was considered by 22 to 37% of the interviewed anaesthesiologists a loss of benefit for the patients. Despite a high level of coaching, a high morbidity rate was associated with the first attempts. However, only few residents explicitly stated to be concerned by ethical questions. Among anaesthesiologists, who had yet to manage anaphylactic shock, 21 and 35% of them reported that diagnostic and treatment could have been performed faster. Virtual learning was misunderstood but 46% of anaesthesiologist described numerous advantages in using simulator of anaesthesia. CONCLUSION: Despite an apparent morbidity with a loss of benefit, informed consent of the patients were rarely obtained.

[Butyrylcholinesterase deficiency: how to analyse the cholinesterase activity in small children?]. / Déficit génétique de la butyrylcholinestérase: comment interpréter l'activité cholinestérasique chez le jeune enfant ?

We report the case of a prolonged neuromuscular blockade in an 18-month-old age girl following administration of a usual dose of succinylcholine. The diagnosis was highly suggested by the clinical history while cholinesterase activity was included in adult normal values but below values of a personal series of 41 small children. The familial analysis of dibucaine and fluoride number confirmed the hypothesis of an atypical variant (AA phenotype). The cholinesterase activity is higher in small children than in adult and has to be analysed according to the age.

[Body mass index and albuminemia in patients under mechanical circulatory assistance before cardiac transplantation]. / Indice de masse corporelle et albuminémie péri-implantatoires de patients sous assistance circulatoire mécanique (ACM) en attente d'une transplantation cardiaque.

OBJECTIVE: To evaluate the prognostic influence of peri-implantation nutritional status of patients under mechanical circulatory assist (MCA) prior to cardiac transplantation (CT). STUDY DESIGN: Retrospective analysis of patients with cardiogenic shock included from June 1997 to December 2002. PATIENTS AND METHODS: Evaluation at MCA's implantation, at day (D) 30 and at CT or patient's death (D) of body mass index (BMI=body weight (kg)/size (m(2)), albuminemia (Alb g/l), expressed as median values (med) and range (min-max). Odds ratio (OR) and CI 95%) were calculated. A multivariate analysis was performed to determine variables related to D or CT success. RESULTS: Thirty-four patients (30 men), median age 40.5 years (10-63), were included. MCA types were cardiac pumps (N=3); pneumatic (N=18) or electric (N=5) ventricular assist devices and artificial heart (N=8). Global mortality was 56% (19 over 34 patients) and at implantation in the global population (N=34) BMI was 19.4 (9.3-28.1) and Alb 24.6 g/l (15-37.5). At MCA's implantation and D30 respectively, 38 and 42% of the patients had a severe hypoAlb (Alb<30 g/l) and a BMI<19 attesting of a seriously deteriorated nutritional status. No significant statistical difference was observed on median BMI of transplanted patients T (N=15) and expired patients D (N=19). Alb was significantly different (p<10(-4)) between T and D patients: median Alb: 30 g/l (20-37.5) in T patients, 20 g/l (15-31) in D patients. HypoAlb<21 g/l was an independent prognostic factor of death (p=0.004; OR: 0.541; IC95% : 0.36-0.82) and Alb>33 g/l an independent prognostic factor of CT success (p=0.003; OR:1.38; IC95% : 1.12-1.71). CONCLUSION: These results seem to demonstrate that at MCA implantation, a seriously deteriorated albuminemia level (<30 g/l) negatively impacts patients overall survival after CT.

[Anthracycline-induced heart failure aggravated by pregnancy. Survival after cardiac assistance with artificial heart device and heart transplantation]. / Myocardiopathie aux anthracyclines décompensée par une grossesse. Guérison par transplantation cardiaque après assistance temporaire par coeur artificiel.

We report a case of a young woman suffering from a steady anthracycline-induced myocardiopathy with a decreased left ventricular function on echocardiography. A pregnancy was initiated, without worsening of the cardiopathy until 34 weeks. Nine days after delivery, an acute heart failure was observed leading to heart transplantation after cardiac assistance with heart cardiac device. As pregnancy is an extended stress test for a chronic failing heart, a multidisciplinary decision of pregnancy initiation and follow up should be preferred in pre and postpartum period, when such a cardiopathy exists.

Increased ß2-adrenergic vasorelaxation at the early phase of endotoxemic shock in rats.

BACKGROUND AND PURPOSE: The early management of the cardiovascular dysfunction of septic shock is critical as it is associated with a poor outcome. Although the use of catecholamines is a common therapy in this syndrome, no data are available on the involvement of ß-adrenoceptor (ß-AR) subtypes and only few studies report an alteration of ß-adrenergic-induced vasodilation in septic shock. The purpose of the study was to evaluate vascular ß1, ß2 and ß3-AR expression and function in an endotoxemic rat model. EXPERIMENTAL APPROACH: Endotoxemia was induced in rats by intravenous injection of lipopolysaccharide (LPS). ß1, ß2 and ß3-AR mRNA expression was evaluated by RT-PCR in aorta and vascular ß1, ß2 and ß3-AR responses were determined on conducting (aorta) and/or resistance (mesenteric and renal) arteries by constructing relaxation curves in response to different ß-AR agonists. RESULTS: The maximal effect of isoproterenol decreased by 31 to 61% in the three vascular beds of LPS-treated rats compared to controls. In aortas from LPS-treated rats, ß1 and ß3-AR mRNA expression was decreased and associated to a reduced ß1 and ß3-induced vasodilation. Conversely, albeit ß2-AR mRNA was unchanged, the maximal ß2-AR-induced vasodilation increased by 49% in aortas from LPS-treated rats compared to controls. This increase was not affected by endothelium removal but was abolished in the presence of a ß2-AR antagonist or an adenylate cyclase inhibitor. CONCLUSIONS: In endotoxemia, ß2-AR vasodilation was increased by a potential recruitment of ß2-AR located on smooth muscle cells. This study suggests that vascular ß2-AR should be a putative new therapeutic target in septic shock.

Right ventricular function during weaning from mechanical ventilation after coronary artery bypass grafting: effect of volume loading.

OBJECTIVE: The study was designed to investigate the right ventricular (RV) reaction to weaning from mechanical ventilation (MV) in patients with and without volume loading after coronary artery bypass grafting (CABG). DESIGN: Controlled study. SETTING: Surgical intensive care unit in a university hospital. PATIENTS: 18 patients were randomized in two groups, Control group (n = 9) and Volume group (n = 9), when the established criteria for weaning from the respirator were satisfied. INTERVENTION: During MV, patients in the Volume group received in rapid (10-min) 6 ml/kg infusion of a 6% hydroxyethyl starch preparation. MEASUREMENTS AND RESULTS: Hemodynamic parameters were measured using a combined right ventricular (RV) ejection fraction-oximetry pulmonary artery catheter at T0 (during MV: baseline), T1 (during MV: 10 min after volume loading or at the same time in the Control group), T2 [after 20 min of spontaneous ventilation (SV)]. In the Control group, RV volumes did not differ throughout the study, while cardiac index (CI) and RV stroke work index (RVSWI) increased from T1 to T2. In the Volume group, RV volumes increased from T0 to T1, further increasing from T1 to T2, whereas CI increased only from T0 to T1. In this group, RVSWI increased from T0 to T1 in 8/9 patients and from T1 to T2 in 6/9 patients. CONCLUSIONS: An increase in RV volumes with a concomitant increase in RVSWI was observed in high preload patients when going from MV to SV, suggesting a preserved RV function during weaning from MV in this group compared with control patients. The depression in RV contractility observed in some patients suggested that rapid volume expansion before weaning from MV in CABG patients must be done carefully.

Oxygen consumption after cardiac surgery--a comparison between calculation by Fick's principle and measurement by indirect calorimetry.

Oxygen consumption calculated by Fick's principle (cVO2) was compared to oxygen consumption measured (mVO2) by indirect calorimetry (Deltatrac Metabolic Computer) in 10 patients in the post-operative period after cardiac surgery. For 50 pairs of measurements the mean difference (mVO2-cVO2) was 34 +/- 27 ml/min.m2. The limits of agreement were -20 ml/min.m2 to 88 ml/min.m2. These results showed that cVO2 and mVO2 were not interchangeable in this study.

Rapid gas-chromatographic assay of bupivacaine in plasma.

A method for estimating bupivacaine concentration in human plasma by capillary gas-chromatography using solid injection and nitrogen-specific detection is described. Etidocaine, another anilidetype local anesthetic was used as internal standard and added to the sample before single-step extraction with diethylether. This method demonstrates high sensitivity (6 ng/ml plasma) and combines selectivity, rapidity, and simplicity. Results of this procedure correlate well with those obtained by an HPLC method.

Anaphylactic shock induced by gadoterate meglumine (DOTAREM).

The use of contrast agent for magnetic resonance imaging improves the effectiveness of this diagnostic examination. Complexes of godolinium, which appear to be well tolerated, are used for this purpose. A few cases of anaphylactic shock have been attributed to these agents. We report a case of anaphylactic shock due to gadoterate meglumine (DOTAREM). While undergoing a magnetic resonance imaging examination, a 33-year-old nonatopic female patient became severely hypotensive, lost consciousness, and had generalized erythema immediately after the intravenous injection of this product. She recovered rapidly after she was given injection of epinephrine and her blood volume was restored with intravenous fluids. That DOTAREM had caused this immediate hypersensitivity reaction was proven by the positivity of prick-test and intradermal test at 10-3 (0.37 mg/ml) and in vitro leukocyte histamine release test. The results of these tests indicated that it was the gadoteric acid rather than the meglumine component of DOTAREM that was responsible: positivity of IDR at 10 mg/ml. Skin tests and leukocyte histamine release test to gadopentetate dimeglumine (MAGNEVIST) were negative. In addition of the exceptional character, this observation provides evidence for an immediate hypersensitivity without cross reactivity with gadopentetate dimeglumine.

[Acute hepatic porphyria and Diprivan]. / Porphyries hépatiques aiguës et Diprivan.

Propofol may be used without any restriction in all cases of asymptomatic hepatic porphyria, as a bolus injection for induction and maintenance of anaesthesia and as a continuous infusion to produce anaesthesia of short and medium duration. If in doubt as to the absolute safety of propofol in case of symptomatic hepatic porphyria, preference has to be given to neuroleptanalgesia, benzodiazepines and muscle relaxants. If propofol is to be used, treatment with haematin should be readily available. In all cases, it is essential to determine porphyrins and their precursors prior to and after surgery. Urine collection should strictly adhere to the recommended procedure: sterile conditions, protected from light and high temperature. Any abnormal reaction after the administration of a drug, especially propofol, should be notified to and discussed with the National Porphyria Centre (Centre Français des Porphyries). In case of symptomatic hepatic porphyria the use of propofol should always be notified to the National and to the European Porphyria Centres (Orphan Europe).

[In which patients and for which procedures has the efficacy of postoperative artificial nutrition be proven?]. / Chez quels patients et pour quels types de chirurgie a-t-on démontré l'efficacité de la nutrition artificielle postopératoire?

This study reviewed 19 prospective studies for the incidence of postoperative nutritional support on outcome in elective surgery. It compared enteral and parenteral nutrition initiated no more than three days preoperatively or postoperatively and prolonged maximally for one month, to a simple infusion of glucose or saline. As all studies had methodological weaknesses, concerning mainly the sample size, it is impossible to propose relevant recommendations. Nevertheless, among the 11 studies on total parenteral nutritional support (nitrogen and caloric supply with carbohydrates and/or lipids), three of them produced valuable results. As the available data do not show any beneficial effect, a routine postoperative nutritional support cannot be recommended, even in patients at high risk of postoperative complications. However for the latter a possible benefit cannot be totally excluded in some of them. When an alimentation per mouth cannot be started during the 8 to 10 days after surgery, an artificial nutritional support becomes mandatory.

[Bronchopleural fistula after transbronchial passage of a feeding tube]. / Fistule bronchopleurale après passage transbronchique d'une sonde d'alimentation.

Inadvertent transbronchial insertion of a narrow-bore feeding tube using a metallic wire resulted, twice in less than 24 hours, in a right pneumothorax complicated by a bronchopleural fistula. This accident occurred in a conscious patient but with central neurologic chronic disorders recently aggravated by a postoperative Gayet-Wernicke syndrome. The incidence of transbronchial insertion is relatively important [2 to 4%]. Risk factors include a previous endotracheal intubation and an altered mental status. The insertion may be especially hazardous when the patient is uncooperative or unconscious or has lost the cough reflex. The presence of a cuffed endotracheal tube should not be considered as a safeguard for tracheobronchial penetration. Recommendations for prevention are presented. The usual procedure of testing for proper location of the tube following its insertion consisting in the injection of air through the tube with auscultation for gastric borborygmi, is inadequate and should no longer be used.

[Decrease in plasmatic cholinesterase activity in severe bacterial infections: comparison with the decrease observed in severe liver cirrhosis]. / Diminution de l'activité de la cholinestérase plasmatique au cours des infections bactériennes sévères: comparaison avec celle observée en cas de cirrhose grave.

As the influence of sepsis on plasma cholinesterase activity is not clearly established, plasma cholinesterase activity was measured in 30 healthy surgical orthopaedic patients, 11 patients with severe postoperative infections and 18 patients with patent cirrhosis (Child-Pugh C). Plasma cholinesterase activities were significantly decreased (P < 0.001) in patients with postoperative infections (1,706 +/- 535 Ul.L-1) and in those with patent cirrhosis (1,318 +/- 538 Ul.L-1) in comparaison to healthy surgical patients (4,716 +/- 1,232 Ul.L-1). The decrease in patients with postoperative infections and in those with patent cirrhosis was similar. It remains to be assessed whether the activity of anaesthetic agents biotransformed by plasma cholinesterase is modified during severe infections.

[Comparison of cardiac output measured continuously by thermodilution and calculated according to Fick's principle]. / Comparaison du débit cardiaque mesuré en continu par thermodilution et celui calculé selon le principe de Fick.

Recently, a thermodilution technique for continuous measurement of cardiac output was introduced. The aim of this study was to evaluate the accuracy of continuous cardiac output measurement using the thermodilution technique (CCO) and to assess the correspondence between CCO and cardiac output obtained with the Fick's principle (Fick-CO). Nine patients were studied in the postoperative period after cardiac surgery. A new pulmonary artery catheter modified by attachment of a thermal filament (Intellicath, Model PA3-H-8Fr) was inserted and connected to a continuous cardiac output computer (Vigilance Monitor). Oxygen consumption was continuously measured using the gas exchange method (Deltatrac Metabolic Monitor). Fick-CO was calculated according to the Fick's principle. The study in each patient consisted of 6 serial determinations of both CCO and Fick-CO at 10 min intervals. For 54 pairs of measurements, the mean difference (Fick-CO-CCO) was 0,6 L.min-1. The limits of agreement were--0,6 to 1,8 L.min-1 respectively. The relative error was 6% for CCO and 10% for Fick-CO. It is concluded that CCO and Fick-CO cannot be considered as being interchangeable. However, the accuracy of CCO is acceptable. The technique does not require any user calibration and eliminates the need of bolus injections. Further studies are necessary to determine the benefits of this new technique in the various clinical situations.

[Indications and role of albumin for vascular loading during postoperative intensive care]. / Indications et place de l'albumine dans le cadre du remplissage vasculaire en réanimation postopératoire.

Prospective clinical trials comparing human albumin to other plasma volume expanders during the three first postoperative days in adult patients were analysed. Fifteen studies were selected. Nine of them concerned the evaluation during the immediate postoperative period, after cardiac surgery with cardiopulmonary bypass (CPB). Only one trial referred to hyperoncotic albumin and therefore did not allow to produce recommendations. However, a priori hyperoncotic albumin should not be used for plasma volume expansion. All other studies compared isooncotic albumin to crystalloid or hydroxyethylstarches (HES). It is concluded that albumin can be recommended neither after vascular (aortic abdominal surgery), nor abdominal surgery and can be replaced by Ringer lactate solution in a volume 1.5 to 2 times higher than with albumin. After cardiac surgery, mainly uncomplicated coronary artery bypass graft or valve replacement, albumin can be substituted by HES. These conclusions are only valid for blood losses below 50% of blood volume. The place of isooncotic albumin for fluid resuscitation in case of blood loss exceeding 50% of blood volume cannot be specified.

[Value of epidural blood-patches for the treatment of spontaneous intracranial hypotension]. / Intérêt du blood-patch pour le traitement de l'hypotension intracrânienne spontanée.

OBJECTIVE: Spontaneous intracranial hypotension (SIH) is a rare syndrome. It is due most often to a spinal meningeal leak. Symptoms due to SIH are often difficult to treat and epidural blood-patch (BP) has been proposed. The aim was to evaluate the effects and the problems associated with lumbar blood-patch to treat SIH. STUDY DESIGN: Case series. PATIENTS AND METHODS: The diagnosis of SIH was made in six consecutive patients on clinical signs and radiological findings (CT-scan and MRI). A lumbar BP (L1-L2 level) was performed as soon as possible after diagnosis. A maximum of three procedures was allowed in case of failure of the initial BP. RESULTS: BP was effective and well tolerated for five patients (3 immediately after BP, 2 others patients needed 2 and 3 BP). In one patient, an incomplete response was observed and was related to a large CFS leak diagnosed by CT-myelogram. CONCLUSION: When the diagnosis of spontaneous intracranial hypotension is confirmed, a repeated blood patch lumbar procedure can be efficient to treat these patients.

[Cholinesterases]. / Les cholinestérases.

OBJECTIVE: To review current data on butyrylcholinesterase. DATA SOURCES: Search through Medline data bases of articles in French or English. STUDY SELECTION: Original articles and case reports were selected. Letters to editor were excluded. DATA EXTRACTION: The articles were analyzed in order to obtain current data on biochemical structure, action, major pathological variations, especially with regard to the recent informations obtained by molecular biology concerning the identification of genetic variants. DATA SYNTHESIS: Butyrylcholinesterase must be differentiated from acetylcholinesterase, which cannot hydrolyse succinylcholine. The physiological action of butyrylcholinesterase remains unknown, although it can hydrolyse many drugs. Excluding genetical mutations, several physiopathological situations alter butyryl-cholinesterase activity. Butyrylcholinesterase activity assessment does not allow the diagnosis of genetic variants. Whatever the origin, only deficits of more than 50% modify significantly the metabolism of succinylcholine or mivacurium. The diagnosis of a prolonged neuromuscular blockade is obtained with systematic monitoring of the neuromuscular function in case of administration of mivacurium or succinylcholine. Mivacurium should only be re-injected when one response at train of four is obtained. In case of prolonged neuromuscular blockade, the anticholinesterasic agent should not be administered when no response at train of four is obtained. The biochemical methods using inhibitors (dibucaine, fluoride) of the butyrylcholinesterase and a familial study lead to the diagnosis in most cases because the atypical and fluoride variants are the most frequent. When results are doubtful, genetic molecular methods with the use of PCR and restriction enzymes allow a rapid diagnosis.