Objective—To determine accuracy and precision of a
point-of-care hemoglobinometer for measuring hemoglobin
concentration and estimating PCV in horses.
Procedure—Blood samples were obtained from 43
horses examined at a veterinary teaching hospital.
Hemoglobin concentration was measured with the
hemoglobinometer and by means of the standard
cyanmethemoglobin method; PCV was measured by
centrifugation. Blood samples were also obtained
from 12 healthy horses, and PCV of aliquots of these
samples was altered to approximately 5 to 80% by
removing or adding plasma. Hemoglobin concentration
and PCV were then measured.
Results—For samples from the clinic patients, hemoglobin
concentrations obtained with the hemoglobinometer
were less than concentrations obtained with
the cyanmethemoglobin method; however, there was
a linear relationship between concentrations obtained
with the 2 methods. Breed, sex, body weight, and
duration of sample storage did not significantly affect
the difference between hemoglobin concentrations
obtained with the 2 methods. There was a significant
linear relationship between PCV and hemoglobinometer
hemoglobin concentration (PCV = [2.83 X
hemoglobin concentration] − 0.62). For samples from
the healthy horses, a substantial negative bias was
evident with the hemoglobinometer when hemoglobin
concentration exceeded 16 g/dL.
Conclusions and Clinical Relevance—Results suggest
that this hemoglobinometer is reasonably accurate
and precise when used to measure hemoglobin
concentration in blood samples from horses with a
hemoglobin concentration < 16 g/dL. (J Am Vet Med
OBJECTIVE To evaluate quality of recovery from general anesthesia in horses after induction with propofol and ketamine versus midazolam and ketamine.
DESIGN Prospective randomized crossover study.
ANIMALS 6 healthy adult horses.
PROCEDURES Horses were premedicated with xylazine (1.0 mg/kg [0.45 mg/lb], IV), and general anesthesia was induced with midazolam (0.1 mg/kg [0.045 mg/lb], IV) or propofol (0.5 mg/kg [0.23 mg/lb], IV), followed by ketamine (3.0 mg/kg [1.36 mg/lb], IV). Horses were endotracheally intubated, and anesthesia was maintained with isoflurane. After 60 minutes, horses were given romifidine (0.02 mg/kg [0.009 mg/lb], IV) and allowed to recover unassisted. Times to first movement, sternal recumbency, and standing and the number of attempts to stand were recorded. Plasma concentrations of propofol or midazolam were measured following induction and immediately before recovery. Recovery quality was scored by 3 graders with a recovery rubric and a visual analog scale.
RESULTS Number of attempts to stand was significantly lower when horses received propofol (median, 2; range, 1 to 3) than when they received midazolam (median, 7.5; range, 3 to 16). For both the recovery rubric and visual analog scale, recovery quality was significantly better when horses received propofol than when they received midazolam. Plasma drug concentration at recovery, as a percentage of the concentration at induction, was significantly lower when horses received propofol than when they received midazolam.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that for horses undergoing short (ie, 60 minutes) periods of general anesthesia, recovery quality may be better following induction with propofol and ketamine, compared with midazolam and ketamine.