Comparing the insertion and ventilation of laryngeal mask airway according to the patient's head position and muscle relaxation use. A prospective clinical trial.

OBJECTIVES: To assess the insertion and ventilation of the laryngeal mask airway (LMA) classic while using different head positions with or without muscle relaxant. METHODS: This is a double-blind randomized clinical trial. Patients scheduled for ureteral calculus surgery at Shanghai General Hospital, Shanghai, China were recruited between November 2017 and November 2018. A total of 132 adults were consecutively selected. Patients were randomly divided into 4 groups according to head positioning and muscle relaxant use. An 8-cm-high pillow was used to achieve the sniffing position. The insertion time, initial peak pressure (Ppeak), mean pressure (Pmean) of the airway during intermittent positive pressure ventilation (primary endpoint) and fiberoptic score of the LMA position (secondary endpoint) were evaluated via electronic bronchoscopy through the mask bar. All adverse events were recorded. Results: Data were analyzed by ANOVA, 2-way ANOVA, Chi-squared, Cochran-Mantel-Haenszel, and Kruskal-Wallis tests. The insertion time required for the first attempt, fiberoptic score, Ppeak and Pmean did not differ among the groups. However, the incidence of adverse events in groups not using muscle relaxant was higher than in those using muscle relaxant. Conclusion: Use of a sniffing position and muscle relaxant slightly eased the insertion of the LMA but did not affect the fiberoptic score or ventilation parameters. Using a muscle relaxant, but not the sniffing position, reduced the incidence of adverse effects.

The effect of preoperative consumption of potatoes on succinylcholine-induced block and recovery from anesthesia.

Potatoes contain solanaceous glycoalkaloids (SGAs), which inhibit both butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE). The present study investigated the effect of preoperative consumption of potatoes on succinylcholine-induced block and recovery from anesthesia. ASA I-II, adult patients, scheduled for elective surgery, were included in a randomized, blind and controlled study. Patients were randomly divided into two groups. Patients in Group P (n = 21) ate a standard portion of potatoes in their last meal prior to pre-operative fasting, while patients in Group C (n = 23) ate food not containing SGAs. Patients were premedicated with midazolam. Anesthesia was induced with thiopental and fentanyl, and maintained with sevoflurane in 50 % O2/air and fentanyl, as needed. Succinylcholine 1 mg kg(-1) was administered to facilitate endotracheal intubation. Duration of succinylcholine blockade, awakening and recovery times from anesthesia were measured. Serum BuChE levels were also measured at baseline and 4 time-points within 24 h post-consumption. Duration of succinylcholine-induced neuromuscular block, awakening and recovery time from anesthesia was significantly longer in Group P than in Group C (p < 0.05). Serum BuChE levels decreased at 6 h after consumption start in Group P. In addition, in both groups, BuChE levels markedly decreased after succinylcholine blockade, increased thereafter, but did not return to baseline within 24 h of consumption start. None of these differences observed in BuChE levels was statistically significant. This study suggests that potatoes eaten before anesthesia can prolong the duration of succinylcholine-induced neuromuscular block and delay recovery from anesthesia.

[Piriformis syndrome]. / Syndrome du muscle piriforme.

Sciatic pain is often misleading and establishing the link with a local muscular cause can be difficult and lead to errors, especially when faced with a young sportsman, with typical discogenic pain. Simple, specific and reproducible tests enable a better identification and treatment of a muscular cause or canal syndrome. Physiotherapy, or local infiltrations are generally very efficient, and sufficient. Surgery may be considered only in a very limited number of cases, lack of response to the first line treatment and then only if it is the absolute diagnosis, diagnosis which must remain a diagnosis of exception, more so of exclusion.

[Neuromuscular monitoring: methods and machines]. / Uberwachung der neuromuskulären Blockade - Methoden und Geräte.

Muscle relaxing agents are clinically in use for general anaesthesia to optimize the conditions to the endotracheal intubation as well as the surgical conditions. Therefore different musclerelaxants with specific pharmacological characteristics are available. Many factors that depend on the condition of the patient and the used musclerelaxant agent influence the duration of the neuromuscular blockade. Rapid reversal of their effects, particularly in cases of profound blockades, proved to be difficult. In cases of postoperative residual paralysis hypoxic complications because of failure of the ventilation increase the morbidity and mortality of the perioperative period. To avoid these complications in cause of postoperative residual neuromuscular blockade it seems to be necessary to evaluate the status of the muscle function. For the tactile or visual assessment or the objective measurement of stimulation the train-of-four (TOF), double-burst (DBS) or tetanus-stimulation of peripheral nerves like the ulnar nerve may be used. Established methods for the objective monitoring of neuromuscular function is the mechanomyography (MMG), the acceleromyography (AMG), the electromyography (EMG), the kinemyography (KMG) and the phonomyography (PMG). A sufficient recovery of the neuromuscular transmission is reached to a TOF-ratio of 0,9 and should be aimed before the extubation at the end of surgery. No subjective evaluation of the neuromuscular recovery is able to identify residual paralysis above a TOF-ratio of 0,5. Recent studies suggest that objective methods should be used to monitor neuromuscular function to avoid postoperative residual blockades.

Succinylcholine: adverse effects and alternatives in emergency medicine.

Succinylcholine has long been the favored neuromuscular blocking agent for emergent airway management because of its rapid onset, dependable effect, and short duration. However, it has a plethora of undesirable side effects, ranging from the inconsequential to the catastrophic. When patients requiring tracheal intubation present with potential contraindications to succinylcholine use, the emergency physician will need to substitute a rapid-onset nondepolarizing neuromuscular blocking agent, such as rocuronium or mivacurium. An understanding of the pharmacology of these agents is essential.

[Tracheal intubation in prehospital resuscitation: importance of rapid-sequence induction anesthesia]. / Intubation [correction of Induction] trachéale en réanimation préhospitalière: intérêt de l'induction anesthésique à séquence rapide.

OBJECTIVE: To investigate complications of emergency endotracheal intubation (EEI), possibly facilitated by rapid-sequence induction, in the prehospital critical care setting: 1) the difficulty of intubation; 2) the cardiorespiratory consequences of intubation; 3) the relationship between the occurrence of complications and prognosis. STUDY DESIGN: Prospective non randomized, open study. PATIENTS: All patients treated over a 5-month period by a physician-manned ambulance service and requiring EEI. METHODS: Patients were allocated either in with cardiac arrest (CA) group or a group with maintained spontaneous circulation (SC). Difficulty of intubation was assessed by the number of attempts. RESULTS: Two hundred and twenty-four consecutive EEI were carried out by physicians (46%) and residents (38%) not trained in anaesthesia, anaesthetists (8%), or nurse anaesthetists (7%). Trachea was intubated after a maximum of three attempts in all patients. Success rate at the first attempt was 91%. It was 92% in CA patients (n = 76) and 90% in SC patients (P = 0.59). Anaesthetic induction, with (n = 112) or without (n = 12) succinylcholine, was used to facilitate 84% of intubations in SC patients. Complications occurred in 30 patients (20%). There was no relationship between the latter and hospital mortality, duration of ventilatory support, duration of stay in the intensive care unit. CONCLUSION: In this study, EEI in SC patients was frequently facilitated by rapid sequence induction and was associated with a high success rate at the first attempt, as in CA patients. Morbidity was low. All physicians involved in emergency airway management should be skilled in this technique.

Drug therapy for back pain. Which drugs help which patients?

STUDY DESIGN: A brief review of current literature and issues on drug therapy for low back pain. OBJECTIVES: To identify current knowledge and future research needs related to drug therapy. SUMMARY OF BACKGROUND DATA: Drug therapy is one of many possible treatment choices for symptom relief in patients with low back pain. The variety of drugs used suggests that there is no uniquely successful form of drug therapy. One reason for uncertainty and slow progress in this area is the limited quality of many clinical trials for back pain, with inadequate description of patients and outcomes being common deficits. METHODS: A selective review of randomized trials and systematic literature syntheses on drug therapy is given. RESULTS: Despite limitations, there is good evidence to support the efficacy of nonsteroidal anti-inflammatory drugs for acute low back pain and fair evidence for the use of muscle relaxants. There is greater controversy about the use of corticosteroids, which have been administered orally, intramuscularly, and epidurally. There is conflicting evidence regarding epidural injection of corticosteroids, but one meta-analysis suggests they may provide a small symptomatic improvement for patients with radiculopathy. Trials of systemic steroids and antidepressant drugs for managing chronic pain are inconclusive. The only randomized trial of local anesthetic injection into trigger points suggested that this treatment was equivalent to that of saline injection, needling without injection, or vapo-coolant spray alone. CONCLUSION: It seems reasonable to recommend acetaminophen or nonsteroidal anti-inflammatory drugs for patients with acute back pain, with efforts to minimize costs and complications. Muscle relaxants and narcotic analgesics may be appropriate for some patients, but selection criteria are unclear, and these drugs should be prescribed for fixed periods. Drug treatment for chronic low back pain is less clear, and a current controversy centers on the use of chronic narcotic analgesics for such patients. Future research should include evaluating combinations of medications, combinations of medication and physical therapy, systemic corticosteroid therapy, trigger point injections, and narcotic use for patients with chronic pain. Spinal stenosis is common in the older population, and more drug trials are needed for this condition.

Clindamycin-induced neuromuscular blockade.

The purpose of this article is to report the case of a patient who developed prolonged neuromuscular block after a large dose of clindamycin (2400 mg). A 58-yr-old, 65 kg woman with severe rheumatoid arthritis was admitted for wrist arthrodesis. After d-tubocurarine (3 mg) and fentanyl (1.5 micrograms.kg-1), anaesthesia was induced with thiopentone (4 mg.kg-1) followed by succinylcholine (1.5 mg.kg-1) and was maintained with N2O in O2 and isoflurane (0.75-1.0% end tidal) and ventilation was controlled. No further neuromuscular relaxants were given although full return of neuromuscular activity in response to train-of-four and 100 Hz tetanic stimulation was observed after succinylcholine. An overdose of clindamycin (2400 mg, instead of the intended 600 mg) was given i.v. soon after the start of surgery. At the end of surgery, 75 min later, the patient made no attempt at spontaneous ventilation, was unresponsive to painful stimuli and naloxone (0.2 mg i.v.) was ineffective. Controlled ventilation was continued in the Recovery Room where neuromuscular testing showed a train-of-four ratio of 0.27 which improved to only 0.47 five minutes after calcium chloride (1.5 mg.kg-1 i.v.), and to 0.62 after edrophonium (20 mg) and neostigmine (2 mg). Nine hours later the patient began to cough, the TOF had returned to 1.0 and two hours later the trachea was extubated and spontaneous ventilation was resumed. Large doses of clindamycin can induce profound, long-lasting neuromuscular blockade in the absence of non-depolarizing relaxants and after full recovery from succinylcholine has been demonstrated.

Pharmacologic aids to intubation and the rapid sequence induction.

Endotracheal intubation usually can be performed in the emergency setting without the use of pharmacologic adjuncts. However, local airway anesthesia lessens patient discomfort, and the use of sedation and muscle relaxants occasionally may be necessary. Rapid sequence induction of general anesthesia adds benefits as well as risks to airway management; used in the circumstance of a full stomach combined with open eye injury or closed head injury associated with raised intracranial pressure, it should be practiced only by physicians appropriately trained and skilled at the procedure.

Resistance to competitive neuromuscular blocking agents in burn patients: a review.

The quantitative and qualitative aspects of the phenomenon of resistance to competitive (non-depolarizing) neuromuscular blocking agents in burn patients are described. The correlates and temporal features of this resistance are discussed, in addition to therapeutic approaches and the possible mechanisms underlying the resistance.