Neuraxial anaesthesia and peripheral nerve blocks during the COVID-19 pandemic: a literature review and practice recommendations

Coronavirus disease 2019 (COVID‐19) has had a significant impact on global healthcare services. In an attempt to limit the spread of infection and to preserve healthcare resources, one commonly used strategy has been to postpone elective surgery, whilst maintaining the provision of anaesthetic care for urgent and emergency surgery. General anaesthesia with airway intervention leads to aerosol generation, which increases the risk of COVID‐19 contamination in operating rooms and significantly exposes the healthcare teams to COVID‐19 infection during both tracheal intubation and extubation. Therefore, the provision of regional anaesthesia may be key during this pandemic, as it may reduce the need for general anaesthesia and the associated risk from aerosol‐generating procedures. However, guidelines on the safe performance of regional anaesthesia in light of the COVID‐19 pandemic are limited. The goal of this review is to provide up‐to‐date, evidence‐based recommendations or expert opinion when evidence is limited, for performing regional anaesthesia procedures in patients with suspected or confirmed COVID‐19 infection. These recommendations focus on seven specific domains including: planning of resources and staffing; modifying the clinical environment; preparing equipment, supplies and drugs; selecting appropriate personal protective equipment; providing adequate oxygen therapy; assessing for and safely performing regional anaesthesia procedures; and monitoring during the conduct of anaesthesia and post‐anaesthetic care. Implicit in these recommendations is preserving patient safety whilst protecting healthcare providers from possible exposure.

Association of obesity with failure of ultrasound-guided axillary brachial plexus block: a two-centre, prospective, observational, cohort study

The objective of this study was to evaluate whether the failure rate of ultrasound-guided axillary brachial plexus block is similar in obese patients compared with non-obese patients when performed as the primary anaesthetic technique. We recruited 105 obese (body mass index ≥ 30 kg.m-2 ) and 144 non-obese patients to this prospective, observational, cohort study conducted at two Canadian centres. A perineural technique of axillary brachial plexus block was performed using 30 ml ropivacaine 0.5% under real-time ultrasound guidance. Sensory and motor block assessment was carried out every 5 min until 30 min after block completion in all four terminal nerve distributions (radial, median, ulnar and musculocutaneous nerve). A composite score consisting of three sensory points and three motor points was used for assessment in each nerve distribution. A failed block was defined as a score of less than 14 points out of a possible 16 points, or a sensory block score less than 7 out of 8 points 30 min after block completion. Thirty minutes after block completion, obese patients had a higher failure rate of 33.7% (34/101) compared with 17.8% (24/135) for non-obese patients, with a failure rate difference (95%CI) of 15.9% (6.4-27.1%) between the groups. The median (IQR [range]) time to achieve a successful block in obese patients was 25 (20-30 [5-30]) min, compared with non-obese patients at 20 (15-30 [5-30]) min (p = 0.003). Despite a higher sensory-motor failure rate as per the composite score, the axillary brachial plexus block provided adequate surgical anaesthesia as indicated by a low need for conversion to general anaesthetic in obese (8.6%) and non-obese patients (7.0%; p = 0.656). This study showed that despite ultrasound guidance, obese patients had a slower onset time and higher axillary brachial plexus block failure rate at 30 min compared with non-obese patients.

Pain management using a novel hybrid technique of perineural stimulation combined with regional anaesthesia through a stimulating perineural catheter for below knee amputation

Pain after amputation can be difficult to manage due to its complex aetiology. A multimodal approach to analgesia, including regional anaesthetic techniques, is advised. However, optimal pain management cannot always be achieved, and high doses of opioid analgesics may contribute to adverse effects. We describe the management of an elderly patient with significant co-morbidities undergoing below knee amputation. Pre-operatively, a popliteal sciatic stimulating perineural catheter and a femoral non-stimulating perineural catheter were placed. When pain control was suboptimal on the first postoperative day, a combination of local anaesthetic and a brief period of peripheral nerve stimulation through the sciatic stimulating perineural catheter was used to augment pain control, thereby avoiding additional opioid use. Although nerve stimulation utilising specialised equipment, such as percutaneous stimulator electrodes, has been previously described in acute pain medicine, we demonstrate the use of a novel hybrid technique which combines nerve stimulation through a perineural catheter and local anaesthetic. Further research is warranted to explore the utility of this neuromodulation technique in clinical practice.

Peripheral nerve stimulation through a 'dry' peripheral nerve catheter for shoulder analgesia: a case report

Revision shoulder surgery can pose significant analgesic challenges as locoregional blocks are often avoided to enable early recognition of iatrogenic nerve injuries. Our case describes the utilisation of pre-operative and intra-operative low-frequency percutaneous peripheral nerve stimulation via a 'dry' interscalene catheter, inserted pre-operatively for a patient presenting for revision total shoulder arthroplasty who was experiencing significant shoulder joint pain despite a prior total shoulder arthroplasty. The clinical considerations and safety aspects are discussed further.