Use of neuromuscular blocking agents in acute respiratory distress syndrome

Drug class effects on respiratory mechanics in animal models: access and applications

Assessment of respiratory mechanics extends from basic research and animal modeling to clinical applications in humans. However, to employ the applications in human models, it is desirable and sometimes mandatory to study non-human animals first. To acquire further precise and controlled signals and parameters, the animals studied must be further distant from their spontaneous ventilation. The majority of respiratory mechanics studies use positive pressure ventilation to model the respiratory system. In this scenario, a few drug categories become relevant: anesthetics, muscle blockers, bronchoconstrictors, and bronchodilators. Hence, the main objective of this study is to briefly review and discuss each drug category, and the impact of a drug on the assessment of respiratory mechanics. Before and during the positive pressure ventilation, the experimental animal must be appropriately sedated and anesthetized. The sedation will lower the pain and distress of the studied animal and the plane of anesthesia will prevent the pain. With those drugs, a more controlled procedure is carried out; further, because many anesthetics depress the respiratory system activity, a minimum interference of the animal's respiration efforts are achieved. The latter phenomenon is related to muscle blockers, which aim to minimize respiratory artifacts that may interfere with forced oscillation techniques. Generally, the respiratory mechanics are studied under appropriate anesthesia and muscle blockage. The application of bronchoconstrictors is prevalent in respiratory mechanics studies. To verify the differences among studied groups, it is often necessary to challenge the respiratory system, for example, by pharmacologically inducing bronchoconstriction. However, the selected bronchoconstrictor, doses, and administration can affect the evaluation of respiratory mechanics. Although not prevalent, studies have applied bronchodilators to return (airway resistance) to the basal state after bronchoconstriction. The drug categories can influence the mathematical modeling of the respiratory system, systemic conditions, and respiratory mechanics outcomes.

Seizure activity following atracurium continuous rate infusion in three mechanically ventilated juvenile dogs

OBJECTIVE

To describe patient recovery in dogs that had undergone mechanical ventilation (MV) and received atracurium as a continuous rate infusion (CRI).

CASE SERIES SUMMARY

Three dogs were treated with atracurium CRI while mechanically ventilated and were successfully weaned. All were pediatric patients (2-3 months old) ventilated due to respiratory fatigue and hypoxemia. All dogs experienced seizure activity in the initial 24 h following extubation and were treated with various anticonvulsant protocols; no patients experienced documented seizures after 48 h of discontinuation from MV.

NEW OR UNIQUE INFORMATION PROVIDED

All three successfully weaned dogs that had received an atracurium CRI experienced new onset seizures in their recovery from MV. Atracurium use in long-term MV has not been described previously, and seizures in dogs following atracurium administration has not been described in the clinical setting. Although causation cannot be proven in this case series, atracurium use should be carefully considered and be monitored appropriately when used for a prolonged duration.