The effect of defasciculating doses of pancuronium and atracurium on succinylcholine neuromuscular blockade.

Background: A defasciculating dose of non-depolarizing muscle relaxant administered prior succinylcholine decrease its side effects including fasciculations and postoperative myalgias; however it is believed that the dosage of succinylcholine should be increased when such a pre-treatment is used.

Objectives: We hypothesized that a defasciculating dose of pancuronium as a pre-treatment could prolong its duration of effect.

Patients And Methods: Forty patients scheduled for elective orthopaedic surgery were consecutively assigned into 5 groups, a first group without pre-treatment (succinylcholine 1 mg/kg) and 4 subsequent groups of pretreatment with atracurium 0.

Effects of an opioid on respiratory movements and expiratory activity in humans during isoflurane anaesthesia.

Opioids increase abdominal muscle activity during anaesthesia. We proposed that opioid activity during anaesthesia would change chest wall size and movement, and contribute to ventilation. Using an optical system to measure chest wall volume, we studied 10 patients during isoflurane anaesthesia, first under the influence of an opioid and then after reversal with naloxone.

Sugammadex in anesthesia practice.

Importance Of The Field: Neuromuscular blocking agents are currently used during anesthesia but put patients at risk of postoperative paralysis. If the residual neuromuscular blockade is not reversed properly at the end of anesthesia, there is a risk of hypoxemia and pulmonary complication. Sugammadex is able to fully reverse different degrees of neuromuscular blockade induced by steroidal neuromuscular blocking agents.

A randomized, dose-response study of sugammadex given for the reversal of deep rocuronium- or vecuronium-induced neuromuscular blockade under sevoflurane anesthesia.

Background: Sugammadex is the first of a new class of selective muscle relaxant binding drugs developed for the rapid and complete reversal of neuromuscular blockade induced by rocuronium and vecuronium. Many studies have demonstrated a dose-response relationship with sugammadex for reversal of neuromuscular blockade in patients induced and maintained under propofol anesthesia. However, sevoflurane anesthesia, unlike propofol, can prolong the effect of neuromuscular blocking drugs (NMBDs) such as rocuronium and vecuronium.

Resistance to D-tubocurarine of the rat diaphragm as compared to a limb muscle: influence of quantal transmitter release and nicotinic acetylcholine receptors.

Background: The diaphragm is resistant to competitive neuromuscular blocking agents, as compared to peripheral muscles. The basis of this difference may be a higher concentration of acetylcholine released or higher number of postsynaptic nicotinic acetylcholine receptors in diaphragmatic neuromuscular junctions.

Methods: Nerve-evoked twitch-tension was measured in rat hemidiaphragm as was Extensor digitorum longus (EDL) nerve-muscle preparation to determine the effective D-tubocurarine concentration that decreased twitch responses by 50%.

Noninvasive investigation of autonomic activity after carotid stenting or carotid endarterectomy.

Objective: Carotid artery stenting (CAS) has been introduced as an alternative to carotid endarterectomy (CEA) for the treatment of carotid artery stenosis. Both techniques seem to be associated with postoperative hemodynamic lability. Both may induce baroreceptor dysfunction, possibly leading to transient impairment of cardiovascular autonomic activity and resulting in hemodynamic instability.

Pressure-volume curves with and without muscle paralysis in acute respiratory distress syndrome.

Objective: Pressure-volume (PV) curves are recorded after induction of complete muscle paralysis, which may limit their clinical use. The feasibility of recording PV curves without paralysis has not been tested. In 19 patients with acute respiratory distress syndrome (ARDS) and no hemodynamic instability we prospectively evaluated whether PV curves can be safely and reliably recorded under deep sedation without neuromuscular blockade.

Constant flow insufflation of oxygen as the sole mode of ventilation during out-of-hospital cardiac arrest.

Background: Constant flow insufflation of oxygen (CFIO) through a Boussignac multichannel endotracheal tube has been reported to be an efficient ventilatory method during chest massage for cardiac arrest.

Methods: Patients resuscitated for out-of-hospital cardiac arrest were randomly assigned to standard endotracheal intubation and mechanical ventilation (MV; n =457) or use of CFIO at a flow rate of 15 l/min (n=487). Continuous chest compressions were similar in the two groups.

Cholinesterases and the resistance of the mouse diaphragm to the effect of tubocurarine.

Background: The diaphragm is resistant to competitive neuromuscular blocking agents. Because of the competitive mechanism of action of tubocurarine, the rate of hydrolysis of acetylcholine at the neuromuscular junction may modulate its neuromuscular blocking effect. The authors compared the neuromuscular blocking effect of tubocurarine on isolated diaphragm and extensor digitorum longus (EDL) muscles and quantified the acetylcholinesterase activity in hetero-oligomers.

Cardiac troponin I assessment and late cardiac complications after carotid stenting or endarterectomy.

Purpose: When compared with carotid endarterectomy (CEA), percutaneous carotid angioplasty with stent replacement (CAS) is a less invasive technique in the treatment of carotid stenosis. However, periprocedural hemodynamic instability still remains a challenge. This instability might lead to myocardial damage, which is now measured accurately by using cardiac troponin I (CTnI).

The cytosolic phospholipase A2 pathway, a safeguard of beta2-adrenergic cardiac effects in rat.

We have recently demonstrated that in human heart, beta2-adrenergic receptors (beta2-ARs) are biochemically coupled not only to the classical adenylyl cyclase (AC) pathway but also to the cytosolic phospholipase A2 (cPLA2) pathway (Pavoine, C., Behforouz, N., Gauthier, C.

Hemodynamic effects of portal triad clamping with and without pneumoperitoneum: an echocardiographic study.

The decrease of cardiac index observed during portal triad clamping (PTC) with and without pneumoperitoneum has been studied only with right heart catheterization. To better understand this decrease of cardiac index, we investigated the balance between the adequacy of preload and the ability of the heart to pump against an increased afterload, by using transesophageal echocardiography. Ten patients with PTC performed during laparoscopy and 10 with PTC performed during laparotomy were studied.

Comparative effect of intraoperative propacetamol versus placebo on morphine consumption after elective reduction mammoplasty under remifentanil-based anesthesia: a randomized control trial [ISRCTN71723173].

BACKGROUND: Postoperative administration of paracetamol or its prodrug propacetamol has been shown to decrease pain with a morphine sparing effect. However, the effect of propacetamol administered intra-operatively on post-operative pain and early postoperative morphine consumption has not been clearly evaluated. In order to evaluate the effectiveness of analgesic protocols in the management of post-operative pain, a standardized anesthesia protocol without long-acting opioids is crucial.

Cardiac autonomic control during balloon carotid angioplasty and stenting.

Hemodynamic alterations during balloon carotid angioplasty (BCA) and stenting have been ascribed to the consequences of direct carotid baroreceptor stimulation during balloon inflation. BCA with stenting in patients with carotid atheromatous stenoses offers a unique opportunity for elucidating the cardiovascular autonomic response to direct transient intravascular stimulation of the baroreceptors. We analysed the consequences of BCA on the autonomic control of heart rate and on breathing components in nine patients with atheromatous stenoses involving the bifurcation and the internal carotid.

beta2-Adrenergic signaling in human heart: shift from the cyclic AMP to the arachidonic acid pathway.

We have recently established that enhancement of intracellular calcium cycling and contraction in response to beta2-adrenergic receptor (beta2-AR) stimulation exclusively relies on the activation of the cytosolic phospholipase A2 (cPLA2) and arachidonic acid production, via a pertussis toxin-sensitive G protein (possibly Gi), in embryonic chick cardiomyocytes. We aimed to investigate the relevance of the beta2-AR/Gi/cPLA2 pathway in the human myocardium. In left ventricular biopsies obtained from explanted hearts, beta2-AR stimulation exerted either an inhibition of cPLA2 that was insensitive to pertussis toxin (PTX) treatment, or an activation of cPLA2, sensitive to PTX treatment.

Effect of partial liquid ventilation on bacterial clearance during Pseudomonas aeruginosa-induced lung injury in rats.

Objective: Partial liquid ventilation (PLV) has been shown to exhibit anti-inflammatory properties during non-infectious models of acute lung injury. The aim of this experimental study was to assess the effects of PLV on bacterial clearance during Pseudomonas aeruginosa-induced pneumonia in rats.

Design: The rats were assigned to four groups 4 h after bacterial challenge according to the kind of mechanical ventilation [gas ventilation (GV) or PLV, 6 ml/kg perflubron plus 2 ml/kg per h] and to the level of PEEP used (3 or 8 cm of water).

Discrepancies between perceptions by physicians and nursing staff of intensive care unit end-of-life decisions.

Several studies have pointed out ethical shortcomings in the decision-making process for withholding or withdrawing life-supporting treatments. We conducted a study to evaluate the perceptions of all caregivers involved in this process in the intensive care unit. A closed-ended questionnaire was completed by 3,156 nursing staff members and 521 physicians from 133 French intensive care units (participation rate, 42%).

Potentiation of mivacurium blockade by low dose of pancuronium: a pharmacokinetic study.

Background: Mivacurium is potentiated by pancuronium to a much greater extent than other relaxants. In a previous investigation we suggested that this potentiation could be due to the ability of pancuronium to inhibit plasma cholinesterase activity, but we did not measure plasma concentrations of mivacurium. In the current study we performed a pharmacokinetic analysis by measuring the plasma concentration of mivacurium when preceded by administration of a low dose of pancuronium.

Effect of severe thrombocytopenia on patient outcome after liver transplantation.

Objective: The objective was to identify factors associated with thrombocytopenia and to assess to what extent thrombocytopenia increases bleeding complications in liver transplant patients.

Design: Retrospective study.

Setting: Surgical intensive care unit in a university hospital.

Bactericidal activity response of blood neutrophils from critically ill patients to in vitro granulocyte colony-stimulating factor stimulation.

Objective: Neutrophil function impairment is common in nonneutropenic critically ill patients. Whether granulocyte colony-stimulating factor (G-CSF) may be useful for preventing nosocomial infection in these patients is debated. The response of blood neutrophils from critically ill patients to G-CSF was investigated in vitro.

Molecular diversity and routes of colonization of Candida albicans in a surgical intensive care unit, as studied using microsatellite markers.

To evaluate the colonization of Candida species and the importance of cross-contamination with Candida albicans, we prospectively screened clinical specimens obtained from surgical patients in the intensive care unit (ICU) who had a high risk of yeast colonization. Genotyping of C. albicans was performed using microsatellite markers.

A comparison of two depths of prolonged neuromuscular blockade induced by cisatracurium in mechanically ventilated critically ill patients.

Objectives: To compare two levels of continuous cisatracurium-induced curarization in hypoxemic, ventilated patients.

Design And Setting: An open-labeled, multicenter, prospective, randomized study.

Patients: Hundred two patients with a ratio between arterial oxygen tension and inspired oxygen tension (PaO(2)/FIO(2)) less than 200 despite optimization of sedation and ventilation were randomized into group 1 (n=52) with an end point of no response at orbicularis oculi to train-of-four (TOF) stimulation or group 2 (n=50) with an end point of two responses.