The severe acute respiratory syndrome coronavirus disease-2 (SARS-CoV-2) pandemic of 2020-2021 created unprecedented challenges for clinicians in critical care transport (CCT). These CCT services had to rapidly adjust their clinical approaches to evolving patient demographics, a preponderance of respiratory failure, and transport utilization stratagem. Organizations had to develop and implement new protocols and guidelines in rapid succession, often without the education and training that would have been involved pre-coronavirus disease 2019 (COVID-19). These changes were complicated by the need to protect crew members as well as to optimize patient care. Clinical initiatives included developing an awake proning transport protocol and a protocol to transport intubated proned patients. One service developed a protocol for helmet ventilation to minimize aerosolization risks for patients on noninvasive positive pressure ventilation (NIPPV). While these clinical protocols were developed specifically for COVID-19, the growth in practice will enhance the care of patients with other causes of respiratory failure. Additionally, these processes will apply to future respiratory epidemics and pandemics.

Hypoxemic patients often desaturate further with movement and transport. While inhaled epoprostenol does not improve mortality, improving oxygenation allows for transport of severely hypoxemic patients to tertiary care centers with a related improvement in mortality rates. Extracorporeal membrane oxygenation (ECMO) use is increasing in frequency for patients with refractory hypoxemia, and with increasing regionalization of care, safe transport of hypoxemic patients only becomes more important. In this series, four cases are presented of young patients with severe hypoxemic respiratory failure from Legionnaires’ disease transported on inhaled epoprostenol to ECMO centers for consideration of cannulation. With continued climate changes, Legionella and other pathogens are likely to be a continued threat. As such, optimizing oxygenation to allow for transport should continue to be a priority for critical care transport (CCT) services.

There is some confusion about the contribution of reversal of residual paralysis to the occurrence of postoperative nausea and vomiting. The aim of this review is to discuss whether antagonism of residual paralysis is a cause of postoperative nausea and vomiting, and to assess the risk of residual paralysis if the reversal is omitted. Data from a meta-analysis published before 1998 were considered, along with trials published after that date to assess the influence of reversal of residual paralysis on postoperative nausea and vomiting, and the likelihood of harm when antagonism was omitted. Moreover, an overview of pathophysiological consequences, incidence and clinical consequences of residual paralysis is given and the actual criteria of the adequacy of neuromuscular recovery presented.

When emetic outcomes are combined across all trials and all different neostigmine doses, there is no beneficial effect from omitting neostigmine on postoperative nausea and vomiting, but there is some evidence of a dose-responsiveness with neostigmine; higher doses may have emetic properties. However, omitting reversal introduces a non-negligent risk of residual paralysis. An improved understanding of the pathological consequences of residual paralysis (i.e. impaired laryngeal and pharyngeal muscle function, alterations in hypoxic ventilatory control, reduced margin of safety) led to establishment of more rigorous criteria for defining adequacy of neuromuscular recovery. A train-of-four ratio of ≥0.9 is now accepted as the index of adequate recovery of neuromuscular function. Applying this new definition, residual paralysis becomes a frequent adverse side-effect. Neuromuscular recovery should therefore be routinely monitored in ambulatory patients and residual paralysis prevented by reversing neuromuscular block.

Background and objective Inflammatory liver dysfunction in rats leads to a prolonged vecuronium-induced neuromuscular blockade due to insufficient metabolism. A coexisting resistance against the drug partly counteracts this prolongation. The present study investigates the pharmacodynamics of atracurium whose metabolism does not depend on liver function.

Methods Male Sprague–Dawley rats (n = 14; 290 ± 30 g) were randomly allocated to either a group in which liver inflammation was induced by intravenous injection of 60 mg kg−1 heat-killed Corynebacterium parvum or to a control group. On day 5 after injection, liver function was assessed using the aminopyrine breath test. Under propofol anaesthesia, duration of action of atracurium (4.8 mg kg−1) was measured by evoked mechanomyography (stimulation of the sciatic nerve; contraction of the gastrocnemius muscle). Nitric oxide concentrations, as variables for the severity of the inflammation, were assessed by measurement of nitrite/nitrate plasma concentrations.

Results In C. parvum-injected rats, nitrite/nitrate plasma concentrations were increased (972 ± 597 vs. 25 ± 7 μmol L−1), the aminopyrine turnover was depressed (1.7 ± 0.4% vs. 3.5 ± 0.5%), and the atracurium-induced neuromuscular blockade was shortened (372 ± 128 s vs. 1081 ± 234 s).

Conclusions A systemic inflammatory response syndrome with liver dysfunction results in decreased sensitivity to atracurium. Further investigations are needed regarding a possible up-regulation of acetylcholine receptors or an increased protein binding of atracurium during sepsis to clarify reasons behind this phenomenon.

Adequate relaxation of the masseter muscle is important during endotracheal intubation and for the patency of a patient’s airway during recovery from anaesthesia. We evaluated onset and recovery from cisatracurium-induced neuromuscular block at the masseter and adductor pollicis muscles. Thirty patients were randomly allocated to receive either 0.1 or 0.15 mg kg−1 cisatracurium. The evoked response was measured at both muscles using acceleromyography. Onset time was significantly shorter at the masseter muscle than at the adductor pollicis (0.1 mg kg−1 cisatracurium: 155±52 vs. 229±44 s; 0.15 mg kg−1 cisatracurium: 105±24 vs. 174±35 s). Following 0.1 mg kg−1 cisatracurium, recovery to a TOF-ratio of 0.7 was faster at the masseter compared to the adductor pollicis (P < 0.05). In the 0.15 mg kg−1 cisatracurium group recovery of T1 to 75% of control and to a TOF-ratio of 0.7 occurred sooner at the masseter (P < 0.05). We conclude that onset and recovery from cisatracurium neuromuscular block occurs more rapidly at the masseter than at the adductor pollicis. It appears unlikely that residual paralysis is present at the masseter once neuromuscular function at the adductor pollicis has completely recovered.

In order to compare the neuromuscular effects following rocuronium 0.6 mg kg−1 and atracurium 0.5 mg kg−1 30 children aged from 18 to 67 months were studied under the same anaesthetic conditions. After induction of anaesthesia with etomidate and fentanyl, neuromuscular blockade was monitored by recording the electromyographic response of the adductor pollicis muscle to a supramaximal train-of-four (TOF) stimulation of the ulnar nerve at 2 Hz for 2 s at 20-s intervals. Intubation was performed when more than 90% muscle relaxation was achieved, thereafter anaesthesia was maintained with 70% nitrous oxide in oxygen and isoflurane 0.5% end-tidal. Mean onset of action was significantly faster following rocuronium (86±44.9 s) (mean±SD) compared with atracurium (126.3±61.0 s). Clinical duration with rocuronium was 22.8±5.31 min and thus significantly shorter than that of atracurium, which was 31.5±6.01 min. A statistically significant difference between rocuronium and atracurium also had been found for recovery of T1 to 50%, 75% and 90% as well as for the time taken to a TOF ratio of 70%. The recovery index for rocuronium and atracurium was not significantly different with 9.2±3.43 min and 10.9±2.65 min, respectively. Thus, rocuronium may be more advantageous than atracurium for short-lasting surgical procedures in young children.

A survey was conducted among British, French and German anaesthetists to evaluate possible national differences in the peri-operative use of muscle relaxants and their reversal agents. The same non-depolarizing relaxants are used in all three countries, with the exception of d-tubocurarine, which is only available in Great Britain, and alcuronium which is mainly used in Germany. The French anaesthetists seem to use significantly less succinylcholine than their peers in Great Britain or Germany for both elective and emergency intubation. Monitoring of neuromuscular blockade still relies mainly on ‘clinical judgement’. Reversal of non-depolarizing muscle relaxants is performed routinely in Great Britain, while a substantial number of French anaesthetists avoid the use of a reversal. Dose regimes for neostigmine vary largely, with German anaesthetists administering the lowest, and British anaesthetists administering the highest doses. Side effects of reversal agents are reported by colleagues from all three countries in too high a percentage to justify uncritical administration of these drugs. In Germany there seems to be a noteworthy lack of recovery facilities.

A general relation between the rate of onset and rate of recovery from non-depolarizing blockade has been demonstrated, with recovery consistently about ten times slower than onset. This observation has led to the suggestion that non-depolarizing agents share a common mechanism of action. Rocuronium, a recently introduced steroidal non-depolarizing agent, is claimed to have a very rapid onset but an intermediate duration and appears to test this hypothesis. To investigate this paradox we have calculated the rates of onset and recovery of rocuronium using the isolated human forearm and compared them with those of pipecuronium. The mean ratio of recovery time/onset time for rocuronium was 31.3, which is significantly greater than that for pipecuronium, 11.6 (P < 0.01). Whilst pipecuronium conforms to the same general relation between onset and offset described previously for other non-depolarizing agents, rocuronium appears to have a disproportionately rapid rate of onset for its rate of recovery. This suggests that onset, recovery, or both onset and recovery, from rocuronium blockade occur in a different manner to that of other non-depolarizing agents.