Plasma Concentrations of Brain-derived Neurotrophic Factor in Patients Undergoing Minor Surgery: A Randomized Controlled Trial

We measured perioperative plasma concentrations of brain-derived neurotrophic factor (BDNF), a major mediator of synaptic plasticity in the central nervous system, in males, 30-65 years old, undergoing lumbar or cervical discotomy. Patients were randomly allocated to a general anesthetic with propofol induction and maintenance or with thiopental induction and isoflurane maintenance. BDNF plasma concentrations were measured before induction (baseline), 15min after induction but before start of surgery, at skin closure, in the post-anesthetic care unit, and 24h postoperatively. Data from 26 patients (13 in each group) were analyzed. At each time point, BDNF plasma concentrations showed large variability. At baseline, concentrations were 631±337 (mean±SD)pgml−1 in the propofol group and were 549±512pgml−1 in the thiopental-isoflurane group (P=0.31). At 15min, concentrations significantly decreased in the propofol group (247±219pgml−1, P=0.0012 compared with baseline) but remained unchanged in the thiopental-isoflurane group (597±471pgml−1, P=0.798 compared with baseline). At skin closure and in the post-anesthetic care unit, concentrations were not different from baseline in both groups. At 24h, concentrations significantly decreased below baseline in both groups (propofol: 232±129pgml−1, P=0.0015; thiopental-isoflurane: 253±250pgml−1, P=0.016). In the propofol group, there was a weak but statistically significant positive correlation (R 2=0.38, P=0.026) between the duration of surgery and BDNF plasma concentrations at skin closure. These data suggest that in males undergoing elective minor surgery, BDNF plasma concentrations show a specific pattern that is influenced by the anesthetic technique and, possibly, by the duration of surger

Drug interactions in the context of neuromuscular blockade: clinical implications and safety issues

Les Curares (myorelaxant) ont été découverts par les Indiens de l'Amérique du Sud et sont une partie irremplaçable de l'anesthésie moderne. La relaxation musculaire est très important pour l'intubation, la chirurgie et aux soins intensifs. Les curares peuvent être dangereux pour les patients si un bloc neuromusculaire résiduel n’est pas détecté et correctement traité. Aujourd'hui les myorelaxants sont d'une action plus courte avec un profil d'effets secondaires plus favorable et nous avons enfin un antagoniste à portée de la main, le Sugammadex, qui peut terminer l'action d'un certain myorelaxant, le rocuronium à tout moment de l'anesthésie. La surveillance neuromusculaire est devenue un standard de pratique clinique. Cependant les interactions médicamenteuses peuvent mener à une prolongation ou la récurrence de leur effet. Ceci reste toujours un problème en anesthésie

How to make tonsillectomy a safer procedure: the anaesthetist's view

Anaesthetists use specific drugs peri-operatively to try to decrease the incidence and severity of postoperative pain and of postoperative nausea and vomiting. These drugs are usually administered pre-operatively with the premedication, or intra-operatively when the patient is still anaesthetised. The aim of this approach is to prevent the occurrence of intolerable pain or to avoid any nausea or vomiting symptoms which may be clearly unpleasant for the patient and which interfere with the patient's well-being, recovery and satisfaction. However, since most of these drugs are given prophylactically, and since not all patients will actually be suffering from intolerable pain or severe nausea and vomiting symptoms postoperatively, many patients will receive these drugs unnecessarily. Thus, for the individual patient, the risk of suffering from drug-related adverse reactions without profiting from any benefit may be relevant. Perhaps a 'wait-and-see' approach should be considered; especially non-steroidal anti-inflammatory drugs or dexamethasone should not be given pre-operatively to all patients but should be provided exclusively to those in whom alternative analgesics (for instance, paracetamol combined with a weak opioid) or alternative anti-emetics (for instance, a setron or droperidol) have failed or are associated with unacceptable adverse effects. There is no evidence that prophylactic administration of an analgesic or an anti-emetic is more efficacious than the therapeutic administration. An interesting alternative to achieve satisfactory posttonsillectomy analgesia may be with local anaesthesia swabs that are applied onto the wound

Intravenous lidocaine has no impact on rocuronium-induced neuromuscular block. Randomised study

Intravenous lidocaine is increasingly used in surgical patients. As it has neuromuscular blocking effects, we tested the impact of an intravenous lidocaine infusion on the time course of a rocuronium-induced neuromuscular block

Time course of rocuronium-induced neuromuscular block after pre-treatment with magnesium sulphate: a randomised study

BACKGROUND: A previously published study suggested that pre-treatment with magnesium sulphate (MgSO(4)) had no impact on the speed of onset of rocuronium-induced neuromuscular block. We set out to verify this assumption. METHODS: Eighty patients (18-60 years) were randomly allocated to MgSO(4) 60 mg/kg or placebo (saline). Study drugs were given intravenously for 15 min before induction of anaesthesia with propofol, sufentanil and rocuronium 0.6 mg/kg. Anaesthesia was maintained with a target-controlled propofol infusion. Neuromuscular transmission was measured using train-of-four (TOF)-Watch SX acceleromyography. RESULTS: Onset was analysed in 37 MgSO(4) and 38 saline patients, and recovery in 35 MgSO(4) and 37 saline patients. Onset time (to 95% depression of T1) was on average 77 [SD=18] s with MgSO(4) and 120 [48] s with saline (P<0.001). The total recovery time (DurTOF0.9) was on average 73.2 [22] min with MgSO(4) and 57.8 [14.2] min with saline (P<0.003). The clinical duration (Dur25%) was on average 44.7 [14] min with MgSO(4) and 33.2 [8.1] min with saline (P<0.0002). The recovery index (Dur25-75%) was on average 14.0 [6] min with MgSO(4) and 11.2 [5.2] min with saline (P<0.02). The recovery time (Dur25%TOF0.9) was on average 28.5 [11.7] min with MgSO(4) and 24.7 [8.4] min with saline (P=0.28). CONCLUSION: Magnesium sulphate given 15 min before propofol anaesthesia reduces the onset time of rocuronium by about 35% and prolongs the total recovery time by about 25%

Reclassifying Anaphylaxis to Neuromuscular Blocking Agents Based on the Presumed Patho-Mechanism: IgE-Mediated, Pharmacological Adverse Reaction or "Innate Hypersensitivity"?

Approximately 60% of perioperative anaphylactic reactions are thought to be immunoglobulin IgE mediated, whereas 40% are thought to be non-IgE mediated hypersensitivity reactions (both considered non-dose-related type B adverse drug reactions). In both cases, symptoms are elicited by mast cell degranulation. Also, pharmacological reactions to drugs (type A, dose-related) may sometimes mimic symptoms triggered by mast cell degranulation. In case of hypotension, bronchospasm, or urticarial rash due to mast cell degranulation, identification of the responsible mechanism is complicated. However, determination of the type of the underlying adverse drug reaction is of paramount interest for the decision of whether the culprit drug may be re-administered. Neuromuscular blocking agents (NMBA) are among the most frequent cause of perioperative anaphylaxis. Recently, it has been shown that NMBA may activate mast cells independently from IgE antibodies via the human Mas-related G-protein-coupled receptor member X2 (MRGPRX2). In light of this new insight into the patho-mechanism of pseudo-allergic adverse drug reactions, in which as drug-receptor interaction results in anaphylaxis like symptoms, we critically reviewed the literature on NMBA-induced perioperative anaphylaxis. We challenge the dogma that NMBA mainly cause IgE-mediated anaphylaxis via an IgE-mediated mechanism, which is based on studies that consider positive skin test to be specific for IgE-mediated hypersensitivity. Finally, we discuss the question whether MRGPRX2 mediated pseudo-allergic reactions should be re-classified as type A adverse reactions