Clinical effects of isoflurane and sevoflurane in lambs

The perioperative care of lambs and ewes when the former undergo major experimental (scoliotic) surgery

“…Mask induction was well-tolerated and effective; tracheal intubation was normally completed in 2-3 min. 14 The anaesthetic produced adequate surgical conditions in all the lambs with a median (minmax) recorded FE No in vitro reactions were observed on mixing blood from 18 ewe-lamb pairs, and no adverse effects were observed in the single lamb requiring transfusion (which received 25 mL/kg of maternal blood at 0.5 mL/kg/h rising to 5 mL/kg/h after 30 min).…”

“…The revised technique produced 18 scoliotic lambs, with a more rapid recovery from anaesthesia 14 (70-90 min to stand), and a briefer interval until successful reunification and with no lamb rejection. Two lambs died however from peri-acute postoperative C. perfringens endotoxaemia.…”

“…After intubation, anaesthesia was maintained with the same agent used for induction: end-tidal isoflurane (FE 0 Iso) and sevoflurane (FE 0 Sevo) concentrations were measured and held at 1.8% and 2.8%, respectively. 14 The endotracheal tube was connected to a circle breathing system in which a Penlon Nuffield 200 Ventilator (Penlon InterMed, Abingdon, Oxon, UK) with paediatric adapter (Newton valve) was connected at the bag mount. Spirometry (Datex AS/3; Datex-Engstrom, Helsinki, Finland) revealed that tidal volumes (VT) of 15-20 mL/kg delivered at a frequency (fr) of 17/min produced peak inspiratory pressures of 16-30 cmH 2 O and eucapnia, i.e.…”

“…P1-8 had a mean age of 4.6 (range 3-6) weeks and weight of 11 (9)(10)(11)(12)(13)(14)(15)(16)(17) kg. Operating conditions were adequate in all cases, but two lambs died.…”

Preanesthesia, Anesthesia, Analgesia, and Euthanasia

“…There is little difference in cardiovascular and respiratory effects between the three agents (Hikasa Halothane 0.76% (Valverde and Doherty, 2008) 0.69% (Valverde and Doherty, 2008) 0.96 ± 0.12% (Hikasa et al, 1998) 1.3 ± 0.1% (Antognini and Eisele, 1993) Isoflurane 1.14 ± 0.01% (Cantalapiedra et al, 2000) 1.19-1.53% (Valverde and Doherty, 2008) 1.31 ± 0.03% (Doherty et al, 2002b) 1.29 ± 0.11% (Hikasa et al, 1998) 1.5 ± 0.3% (Antognini and Eisele, 1993) Desflurane Not reported 9.5% (Lukasik et al, 1998a) Not reported Sevoflurane Not reported 3.3% (Lukasik et al, 1998b) 2.33 ± 0.15% (Hikasa et al, 1998) MAC values for calves are assumed to be similar to adult cattle. More rapid recovery of the animal anesthetized with sevoflurane may be advantageous in specific situations such as anesthesia of pre-weanling lambs (Vettorato et al, 2012;Clutton et al, 2014). Because sevoflurane is approximately seven times the cost of isoflurane and a higher MAC is required for a surgical plane of anesthesia, any advantages of this agent may be outweighed by the cost per volume of inhalant needed (Sellers et al, 2013).…”