Review of Continuous Infusion Neuromuscular Blocking Agents in the Adult Intensive Care Unit

Comparison of two pharmacokinetic-pharmacodynamic models of rocuronium bromide during profound neuromuscular block: analysis of estimated and measured post-tetanic count effect

BACKGROUND

Profound neuromuscular block (NMB) is important in surgeries where complete immobility is considered essential to improve tracheal intubation and surgical conditions. Rocuronium bromide is a commonly used NMB agent. This work describes a noninvasive approach for estimation of post-tetanic count (PTC) based on two pharmacokinetic (PK) models, the Saldien and the De Haes models. The aim was to investigate the rocuronium bromide PK-pharmacodynamic (PD) relationship in estimating the PTC effect during profound NMB.

METHODS

In this prospective, non-randomised, observational study, an induction bolus of rocuronium bromide was administered followed by continuous infusion for maintenance of a PTC of 1-2. measured every 3 min. Measurements were analysed as discrete categorical data and by applying the nonlinear mixed-effect modelling approach. Performance of the selected models was evaluated through simulation model-based diagnostics, further assessing the precision of the parameter estimates and the performance of the models at the individual level.

RESULTS

Data from 30 adult patients undergoing elective abdominal or neurosurgical procedures were included. Post-tetanic count response profiles during rocuronium bromide infusion were successfully characterised using the population PD analysis. The models showed a good performance for all PTC categories, albeit with a moderate over-prediction of PTC >6.

CONCLUSIONS

Our findings indicate that using plasma concentrations of rocuronium bromide estimated with either of the two models, combined with a PD model, provides equal model performance when predicting PTC. These promising results may provide an important advance in guiding rocuronium bromide administration when profound NMB in routine clinical practice is desired.

Diagnosis, prevention, and management of delirium in the intensive cardiac care unit

Delirium is a frequent complication in patients admitted to intensive cardiac care units (ICCU) with potentially severe consequences including increased risks of mortality, cognitive impairment and dependence at discharge, and longer times on mechanical ventilation and hospital stay. Delirium has been widely documented and studied in general intensive care units and in patients after cardiac surgery, but it has barely been studied in acute nonsurgical cardiac patients. Moreover, delirium (especially in its hypoactive form) is commonly misdiagnosed. We propose a protocol for delirium prevention and management in ICCUs. A daily comprehensive assessment to improve detection should be done using validated scales (ie, confusion assessment method). Preventive measures are particularly relevance and constitute the basis of treatment as well, acting on reversible risk factors, including environmental interventions, such as quiet time, sleep promotion, family support, communication, and adequate treatment of pain and dyspnea. Pharmacological prophylaxis is not indicated with the exception of patients at risk of withdrawal syndrome but should only be used in patients with confirmed delirium. Dexmedetomidine is the drug of choice in patients with severe agitation, and those weaning from invasive mechanical ventilation. As the complexity of ICCUs increases, clinical scenarios posing challenges for the management of delirium become more frequent. Efforts should be done to improve the identification of patients at risk during admission in order to establish preventive interventions to avoid this complication. Patient-centered protocols will increase the awareness of the healthcare professionals for better prevention and earlier diagnosis and will positively impact on prognosis.

An Evaluation of Continuous Infusion Rocuronium for Sustained Neuromuscular Blockade in Critically Ill Adults

BACKGROUND

Recent medication shortages of the neuromuscular blocking agent (NMBA) cisatracurium have forced the prescribing of aminosteroidal agents such as rocuronium. There are limited data on the use and dosing of continuous infusion (CI) rocuronium in critically ill patients outside of the operating room.

OBJECTIVE

We sought to describe the use of CI rocuronium for sustained neuromuscular blockade in intensive care unit (ICU) patients by characterizing the dosing, utilization, and safety profile in patients with multiple organ failure (MOF) and non-MOF.

METHODS

This was a retrospective review of patients in mixed ICUs from 2 tertiary medical centers who received CI rocuronium between January 2018 and July 2019.

RESULTS

A total of 46 unique rocuronium infusions were utilized for 40 patients during the evaluation period. Of these, 37% had MOF, and 41% had at least 1 organ fail during the rocuronium infusion. The median starting and maximum dose was 8 µg/kg/min. Overall, 64% of train of 4 (TOF) measurements were a TOF 0 (T0) or TOF 1 (T1), with a higher percentage of T0 or T1 in the MOF group compared with the non-MOF group (75% vs 50%). The median time to recovery was more than twice as long for the MOF compared with the non-MOF group (10 vs 4.6 hours). ICU-acquired weakness was diagnosed in 27% of survivors.

CONCLUSION AND RELEVANCE

In ICU patients with MOF, continuous rocuronium infusions were associated with deep levels of paralysis and prolonged recovery times. If neuromuscular blockade is required for critically ill patients, alternative strategies could be considered.

Current Use of Neuromuscular Blocking Agents in Intensive Care Units

Neuromuscular blocking agents can be used for purposes such as eliminating ventilator-patient dyssynchrony, facilitating gas exchange by reducing intra-abdominal pressure and improving chest wall compliance, reducing risk of lung barotrauma, decreasing contribution of muscles to oxygen consumption by preventing shivering and limiting elevations in intracranial pressure caused by airway stimulation in patients supported with mechanical ventilation in intensive care units. Adult Respiratory Distress Syndrome (ARDS), status asthmaticus, increased intracranial pressure and therapeutic hypothermia following ventricular fibrillation-associated cardiac arrest are some of clinical conditions that can be sustained by neuromuscular blockade. Appropriate indication and clinical practice have gained importance considering side effects such as ICU-acquired weakness, masking seizure activity and longer durations of hospital and ICU stays. We mainly aimed to review the current literature regarding neuromuscular blockade in up-to-date clinical conditions such as improving oxygenation in early ARDS and preventing shivering in the therapeutic hypothermia along with summarising the clinical practice in adult ICU in this report.