Laparoscopic insertion of a diaphragmatic pacing system in patients with non‐spinal injury‐related neurological respiratory failure: the first reported UK cases

Abstract

We report the first UK cases of laparoscopic insertion of a diaphragmatic pacing system in patients with respiratory failure due to motor neurone disease and neuralgic amyotrophy of phrenic nerves, as opposed to spinal cord-injured patients [1]. These are the first two cases of a planned series of five to be completed in July 2009. Case report Coincidental with a national neurological meeting presentation on diaphragmatic pacing, the Neurology Department was approached by one of the patients with a request to be considered for the procedure. Following local Clinical Ethics Committee approval the first two cases were screened for suitability, consultant surgical and anaesthetic teams approached and proctoring with training was arranged with the initial inventing site [2]. Both patients were male. Patient 1 was 51 years old, with a diagnosis of bilateral neuralgic amyotrophy affecting the phrenic nerves. His sitting FVC was 53% of predicted. Patient 2, aged 54 years, had respiratory onset motor neurone disease with a sitting FVC of 61% of predicted. Although both had normal arterial blood gases on air, each required noninvasive ventilation (BiPAP) at night to maintain adequate ventilation. Neither patient had any other significant co-morbidity. With no previous experience of anaesthesia for this surgery, the peri-operative management plan was based on that in the USA with the added precaution of arterial lines and HDU postoperatively. After pre-operative assessment and familiarisation with the patients' BiPAP machines, the patients were pre-oxygenated in the sitting position. Induction of anaesthesia was achieved with remifentanil and propofol. Intubation was achieved with a further bolus of remifentanil, so avoiding the use of neuromuscular blocking drugs. Anaesthesia was maintained with sevoflurane and remifentanil, the latter titrated to reduce any diaphragmatic augmentation of respiration, so facilitating 'mapping' of the motor point of each hemidiaphragm. At the point at which maximal contraction of the diaphragm occurred, electrodes were implanted and tunnelled percutaneously to a pacing device on the abdomen. Analgesia was provided by parecoxib, paracetamol and local infiltration with 0.5% bupivacaine. Small increments of morphine were required postoperatively by Patient 1. Patient 2 was discharged home from HDU the following morning. Patient 1 was discharged later the next day after requiring further analgesia for port site pain. Discussion Our experience in Patient 1 was that he required much greater doses of remifentanil than quoted in the American literature, and his wake up time was, as a consequence, prolonged. Both patients were only able to generate small tidal volumes of around 120-150 ml when awake but intubated, which did not improve over time. Following extubation each received immediate non-invasive BIPAP ventilation with their own system before transfer to the PACU. Although diaphragmatic pacing has been used to stimulate respiration as an aid to extubation, usually diaphragmatic pacing is incremental over a planned period and therefore was not used to facilitate extubation in our cases.