Reversing Neuromuscular Blockade without Nerve Stimulator Guidance in a Postsurgical ICU-An Observational Study

Abstract

We aimed to determine if not using residual neuromuscular blockade (RNB) analysis to guide neuromuscular blockade reversal administration in the postsurgical ICU resulted in consequences related to residual weakness. This single-center, prospective study evaluated 104 patients arriving in a postcardiac surgical ICU. After demonstrating spontaneous movement and T > 35.5 °C, all patients underwent RNB evaluation, and neostigmine/glycopyrrolate was then administered. When patients later demonstrated an adequate Rapid Shallow Breathing Index, negative inspiratory force generation, and arterial blood gas values with minimal mechanical ventilatory support, RNB evaluation was repeated in 94 of the 104 patients, and all patients were extubated. Though RNB evaluation was performed, patients were extubated without considering these results. Eleven of one hundred four patients had not achieved a Train-of-Four (TOF) count of four prior to receiving neostigmine. Twenty of ninety-four patients demonstrated a TOF ratio ≤ 90% prior to extubation. Three patients received unplanned postextubation adjunct respiratory support-one for obvious respiratory weakness, one for pain-related splinting compounding baseline disordered breathing but without obvious benefit from BiPAP, and one for a new issue requiring surgery. Residual neuromuscular weakness may have been unrecognized before extubation in 1 of 104 patients administered neostigmine without RNB analysis. ICU-level care may mitigate consequences in such cases.

Keywords: Neuromuscular blockade reversals; neostigmine; residual neuromuscular blockade.

Figure 1

(a)—RNB pre-neostigmine administration—histogram indicating number of patients at each Train-of-Four Count (TOFC) or Train-of-Four Ratio (TOFR) as their level of residual neuromuscular blockade (RNB) when analyzed at the preneostigmine administration time point. Total number of patients evaluated = 104. (b)—RNB pre-extubation—histogram indicating number of patients at each Train-of-Four Count (TOFC) or Train-of-Four Ratio (TOFR) as their level of residual neuromuscular blockade (RNB) when analyzed at the pre-extubation time point. Total number of patients evaluated = 94.

Figure 1

(a)—RNB pre-neostigmine administration—histogram indicating number of patients at each Train-of-Four Count (TOFC) or Train-of-Four Ratio (TOFR) as their level of residual neuromuscular blockade (RNB) when analyzed at the preneostigmine administration time point. Total number of patients evaluated = 104. (b)—RNB pre-extubation—histogram indicating number of patients at each Train-of-Four Count (TOFC) or Train-of-Four Ratio (TOFR) as their level of residual neuromuscular blockade (RNB) when analyzed at the pre-extubation time point. Total number of patients evaluated = 94.

Figure 2

Relation of RNB pre-neostigmine vs. pre-extubation—dot plot indicating the pre-extubation accelerometry level achieved as a function of the level of residual neuromuscular blockade (RNB) present at the time of neostigmine administration. X-axis indicates the patients achieving various levels of Train-of-Four Count (TOFC) or Train-of-Four Ratio (TOFR) at the pre-neostigmine administration time point. Y-axis indicates the accelerometry level achieved at the pre-extubation time point for individual patients within each pre-neostigmine level of TOFC or TOFR. Accelerometry level of “0” indicates patients whose pre-extubation RNB was less than TOFC 4 and therefore could not be quantified by acceleromyograhphy. Ninety-three of ninety-four patients had RNB values obtained at both pre-neostigmine and pre-extubation time points. One excluded patient had post-extubation TOFC 4 but no indication of TOFR associated with this.