Intravenous lipid emulsion to reverse phrenic nerve palsy for patients with respiratory distress following brachial plexus block.

Abstract

Phrenic nerve palsy after brachial plexus block (BPB) is common, and can cause significant respiratory distress due to hemidiaphragmatic paralysis. We describe two cases of using 1ml/kg bolus of 20% intravenous lipid emulsion to effectively reverse phrenic nerve palsy after BPB for shoulder surgery, avoiding the need for intubation and preserving BPB analgesia. This rescue technique may offer an alternative to invasive or non-invasive ventilation for patients in respiratory distress following BPB. In settings where avoidance of ventilation is preferable, such as ambulatory care or hospitals without an intensive care unit, this rescue technique may be particularly of interest. We received informed consent for publication from our cases. Description: Case One. A 75-year-old man was transferred from a rural community hospital for emergent arthroscopic washout of his right gleno-humeral joint for suspected septic arthritis. He had a history of ischaemic heart disease and moderate chronic obstructive pulmonary disease. Preoperatively an ultrasound-guided right supraclavicular block was performed with 20 ml of 0.75% Ropivacaine. On emergence, he had significant respiratory distress. High flow 30 L/min humidified nasal oxygen 42% was administered and a portable chest x-ray was performed, demonstrating right hemi-diaphragmatic palsy. He remained distressed and no ICU beds were available. A 1 ml/kg (60 ml) dose of 20% ILE (Intralipid, Fresenius Kabi, Australia) was administered. Within 5 minutes the patient’s respiratory distress improved. His oxygen saturation returned to above 95% on humidified high flow 42% oxygen and he was able to speak in full sentences. Case Two. A 69-year-old man presented for an elective right total shoulder replacement. He had a past medical history of ischaemic heart disease with extensive coronary artery stents and obesity. The patient had an ultrasoundguided right interscalene block with 20 ml of 1% ropivacaine preoperatively. Post-extubation he developed respiratory distress with oxygen saturations falling to 84% despite 15 L/min of oxygen via Hudson mask. A portable chest x-ray and motion mode ultrasound scan were consistent with right phrenic nerve palsy. Given his significant past cardiac history a rapid reversal of the phrenic nerve palsy was sought. A 1ml/kg (100ml) bolus of 20% ILE (Intralipid) was administered. Within 5 minutes, the patient was able to coordinate his breathing more coherently and the respiratory distress improved. His oxygen saturation improved to 95% on 2 L/min nasal oxygen. Discussion: Case reports have described the use of ILE to reverse total spinal anaesthesia after attempted interscalene block, and to reverse supraclavicular BPB.1,2 To our knowledge, reversal of phrenic nerve palsy with ILE has not been previously reported. The context of practicing in a rural referral hospital is important to consider for our cases. The treating anaesthetist considered the benefits of treatment with ILE to outweigh the risks of invasive or non-invasive ventilation and transfer. Clinicians working in metropolitan day surgery settings may concur, whilst those practicing in a tertiary centre with available ICU beds may consider intubation and ventilation preferential. We report two cases of ILE used to reverse phrenic nerve palsy after BPB, with subsequent resolution of hemidiaphragmatic paralysis and respiratory distress. Our observations support the potential use of a 1ml/kg dose of ILE as a rescue technique to manage respiratory distress after BPB, and provide an alternative to invasive or noninvasive ventilation.