Introduction

• Measurement of arterial blood pressure can be performed in bovine anesthesia in conjunction with other monitoring.
• Arterial blood pressure should be maintained above 60-70 mmHg to reduce the risk of developing peri- and post-operative morbidities and mortalities.
• Arterial blood pressure does not equate to cardiac output, but can give a good indication of cardiovascular performance. 
• Arterial blood pressure = cardiac output x systemic vascular resistance.
• In general, increased blood pressure is associated with increased cardiac output, increased peripheral resistance or a lighter plane of anesthesia. Under anesthesia an increase in mean arterial pressure may precede movement.
• In most cases, decreased mean arterial pressure is associated with decreased cardiac output as a result of myocardial depression, eg due to anesthesia being too deep, systemic inflammatory response syndrome (SIRS) or severe acidosis (pH<7.1).
• All inhalational anesthetic agents cause a dose dependent hypotension.
• Hypotension may also be associated with bradycardia, Dysrhythmias Dysrhythmias or reduced venous return (due to positioning, hypovolaemia or severe abdominal distension).
• Some premedicant drugs can cause Hypotension Hypotension, eg alpha-2 agonists.
  • Depends on which drug, the chosen dose and the route of administration.
  • IV administration can cause initial hypertension; but usually in cattle, the main eventual effects are hypotension and bradycardia.
• Measurement of arterial blood pressure can be done either directly or indirectly.

Arterial blood pressure measurement

Further Reading

Publications

Refereed Papers

• Recent references from PubMed and VetMedResource.
• R Seddighi & T J Doherty (2016) Field Sedation and Anesthesia of Ruminants. Vet Clin North Am Food Anim Pract 32 (3) pp 553-570 PubMed.

• E J Abrahamsen (2013) Chemical restraint and injectable anesthesia of ruminants. Vet Clin North Am Food Anim Pract 29 (1) pp 209-27 PubMed.

• G Smith (2013) Extralabel use of anesthetic and analgesic compounds in cattle. Vet Clin North Am Food Anim Pract 29 (1) pp 29-45 PubMed.

Other sources of information

• A Valverde & M Sinclair (2015) Ruminant Anesthesia. In: Veterinary Anesthesia and Analgesia. Blackwell Publishing.
• K Clarke & C Trim (2014) Patient Monitoring and Clinical Measurement and Anaesthesia of Cattle. In: Veterinary Anaesthesia. 11th edn. Elsevier.