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Preoperative factors associated with hypotension in young anaesthetised dogs undergoing elective desexing
Author(s) -
Costa RS,
Raisis AL,
Hosgood G,
Musk GC
Publication year - 2015
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/avj.12306
Subject(s) - medicine , cohort , perioperative , mean arterial pressure , confidence interval , body mass index , anesthesia , blood pressure , cohort study , heart rate
Objectives Document the proportion of dogs with perioperative hypotension and explore the association of sex, age and body mass and indices of hydration with mean arterial blood pressure ( MAP ) in two cohorts of young, healthy anaesthetised dogs. Methods Dogs were anaesthetised with a standardised protocol. The proportion of dogs with invasively measured MAP <60 mmHg for ≥10 min was recorded. The area under the MAP *time curve ( MAP ‐ AUC ) was calculated for a standard perioperative period. The association of explanatory variables, including sex, age, body mass and indices of hydration (urine specific gravity ( USG ), packed cell volume and total solids) measured prior to surgery, with the MAP ‐ AUC was explored using regression analysis in the first cohort (n = 71) and externally validated in the second cohort (n = 24). Results In cohort 1, 35 of 71 dogs (0.49, 95% confidence interval ( CI ) 0.37–0.61) dogs and 17/24 dogs in cohort 2 (0.71, 95% CI 0.53–0.89) developed hypotension. Regression analysis showed that age and USG were significantly associated with MAP ‐ AUC for cohort 1 ( P = 0.0138). There was a positive association of MAP ‐ AUC with age and a negative association with USG . The association of MAP ‐ AUC with USG was supported in cohort 2, with a significant negative association ( P = 0.014, r = −0.54) Conclusion The high frequency of hypotension in both cohorts supports blood pressure monitoring during anaesthesia of young, healthy dogs. USG , an index of hydration, appears negatively associated with MAP during anaesthesia, suggesting that subclinical dehydration may contribute to lower MAP during surgical anaesthesia.