Anaesthesia for English Bulldog Caesarean Section

Rachel Brown Justine Dooey

Stephanie Harmon

Case Details

6 year old English Bulldog

20 kg bodyweight

Heavily pregnant

2 hours unproductive straining

Caesarian section required

Main Considerations Brachycephalic

Pregnant

Pups

Brachycephalic Breed

Brachycephalic Obstructive Airway Syndrome Stenotic nares Elongated soft palate Hypoplastic trachea Everted laryngeal saccules

Increased Risk of Regurgitation and Aspiration

Effects of Pregnancy on Bitch

Cardiovascular Increased cardiac workload Aortocaval compression → supine hypertension

Respiratory Decreased total lung volume and function Higher O2 demand to CO2 production Rapid desaturation → hypoxaemia

Gastrointestinal Delayed gastric emptying with decreased oesophageal sphincter tone

Neurological ~35% increased sensitivity to anaesthetic agents

Changes in Progesterone and Beta Endorphin levels have Sedative Effects

Haematology Decreased HCT

Anaesthetic Effects on Pups In Utero

Placental transfer of drugs to pups Cross the blood-brain barrier Respiratory Depression Hypotension Bradycardia

Drug transfer from milk• (Little research in dogs)

Anaesthetic Aims

Be cautious of drug overdosesDecrease drug exposure timeIncrease drug elimination rateMaintain hydration and blood pressureMaintain oxygenationProvide analgesia without affecting pupsRapid recovery to decrease respiratory

complicationsMaintain airway

Anticipated Complications

Hypotension Provide I.V. fluids Keep isoflurane concentrations at a minimum

Bradycardia Keep isoflurane at a minimum

Hypoxaemia Provide 100% O2

Hypothermia Bair hugger

Anaesthetic plan

Try to Avoid Pre-Medication but if Necessary Acepromazine I.M.

0.01mg/kg = 0.2mg= 0.1ml Pethidine I.M.

2mg/kg = 40 mg = 0.8mls Pre-oxygenate 3-5 mins before induction Surgical clip and prep whilst awake in lateral recumbency

Induction Propofol I.V.

4mg/kg = 80mg; 10mg/ml; draw up 12ml Fast Intubation with cuffed tube – smaller ET tube than expected

Maintenance Bain breathing system; Isoflurane and O2 4L/min

Isoflurane MAC decreases 40% in pregnant animals IVFT 10ml/kg/hr = 200ml/hr Hartmann’s

Analgesia

Midline Local Anaesthetic Block 50% Lidocaine:Bupivacaine Intradermally

4mg/kg = 80mg = 4ml 1mg/kg = 20 mg = 4ml

When Last Pup Out Methadone 0.2-0.5mg/kg 0.4-1ml I.M. Meloxicam 0.2mg/kg = 0.8ml S.C. – One off dose

Post Operative Care & Analgesia

Bitch Keep ET tube in until fully awake to maintain airway Methadone every 4 hours as needed for pain

1mg/kg = 20mg = 2ml S.C. Send home on Tramadol (not licensed)

2-5mg/kg 2-3 times daily

Pups Assess every 30 seconds Prevent hypothermia Provide 100% O2 Mask or ET intubation if no spontaneous breathing

References

Vullo, Cecilia, et al. "Anesthetic Management during Cesarean Section in English Bulldogs." Journal of Life Sciences 8.1 (2014): 58-64. http://www.davidpublishing.com/davidpublishing/Upfile/5/27/2014/2014052708753330.pdf

D. Flaherty, Anaesthesia for caesarean section BVMS 4 University of Glasgow Lecture.

PREGNANT TIPS | PREGNANCY GUIDE. (n.d.). Retrieved April 30, 2015, from http://pregnancy.pregnantshop.info/8-week-pregnant-english-bulldog

Pricing for our English Bulldogs. (n.d.). Retrieved April 30, 2015, from http://www.bulldozeenglishbulldogs.com/Pricing.html