Neuromuscular blockade: indications, peripheral nerve stimulation, and other concurrent interventions

Neuromuscular blocking agents (NMBAs) are used in critical illness to reduce metabolic demands and prevent ventilator asynchrony in patients refractory to sedation and anxiolysis. Concurrent interventions for patients receiving neuromuscular blockade include many factors related to prevention, maintenance, and monitoring during immobilization. Prevention interventions include skin care, turning regimes, physical therapy, eye care, and pulmonary toilet to prevent atelectasis, pneumonia, skin breakdown, and corneal ulceration. Maintenance interventions include provision of nutrition, sedation, anxiolysis, and psychosocial support. Monitoring interventions include trending oxygenation parameters and ventilatory care parameters, as well as assessment of the depth of paralysis by assessing clinical evidence of movement, airway pressure waveforms, and peripheral nerve stimulation results. Cost of therapy is influenced by preventing the side-effects of immobility, the choice of NMBA, and concurrent drug therapies, as well as by titration of the NMBA to the lowest drug dose possible to obtain clinical end-points. Clinical end-points are individualized by the prescribing physician and may range from "no movement" to "movement acceptable but no evidence of spontaneous respirations" to "movement acceptable but no ventilator asynchrony." Whenever "no movement"c is identified as the goal, a nerve stimulator is used to identify the depth of paralysis and prevent accidental surplus drug administration, which may result in prolonged paralysis. Methods for using the nerve stimulator and troubleshooting techniques are discussed.