Nerve stimulation‐guided femoral and sciatic blocks in an alpaca (Vicugna pacos) for the removal of a sequestrum from the distal femur

Abstract

A 2‐year‐old female intact huacaya alpaca weighing 66.6 kg presented for the removal of a bone sequestrum from the distal femur. Nerve stimulator‐guided femoral and sciatic nerve blocks were applied to provide analgesia for distal femoral surgery. The blocks were simple to perform using existing equipment and current techniques translated from small animals. The techniques reported here for both femoral and sciatic nerve blocks in an alpaca can be used as an alternative to an ultrasound‐guided approach, especially in field situations where additional expensive equipment may not be available or desirable.

Ultrasound‐guided sciatic nerve block in two alpacas (Vicugna pacos) as part of an anaesthesia plan for hindlimb fractures

“…Therefore, interest in locoregional anaesthesia in other species is growing 25–27 . Locoregional anaesthesia for the hindlimb has been reported in alpacas, where two electrostimulation‐guided sciatic and femoral nerve blocks were performed for distal femur or stifle surgery 11,12 . In both cases, boluses of morphine 0.1 mg/kg were necessary during the surgery due to cardiovascular increments during maintenance.…”

“…A previous study found that ketamine and lidocaine infusions decreased sevoflurane minimum alveolar concentration in alpacas without adverse effects during the recovery period 36 . In addition, if extra analgesia is required, intraoperative morphine administration can be used 11,12 …”

“…[25][26][27] Locoregional anaesthesia for the hindlimb has been reported in alpacas, where two electrostimulation-guided sciatic and femoral nerve blocks were performed for distal femur or stifle surgery. 11,12 In both cases, boluses of morphine 0.1 mg/kg were necessary during the surgery due to cardiovascular increments during maintenance. The authors could not exclude an incomplete antinociception provided by the PNB.…”

“…Different techniques have been described to perform PNBs, including, blind techniques that use anatomical landmarks, as well as electrostimulation‐ and ultrasound‐guided techniques 10 . Electrostimulation‐guided sciatic and femoral nerve blocks have been reported previously for a stifle surgery in an alpaca 11 and also for removal of a sequestrum of the distal femur in an alpaca 12 …”

“…10 Electrostimulation-guided sciatic and femoral nerve blocks have been reported previously for a stifle surgery in an alpaca 11 and also for removal of a sequestrum of the distal femur in an alpaca. 12 Ultrasound-guided nerve blocks allow visualisation of the structures, reduction of local anaesthetic dose requirements, improvement of anaesthetic block quality and prevention of complications like arterial puncture. 13 While numerous techniques have been described in dogs and cats, 8,14 only a few reports of these techniques can be found in camelids.…”