Page 136 - Basic Monitoring in Canine and Feline Emergency Patients

2. Decreased cardiac output: this patient has under- which improved with increased ventilation. An
lying heart disease and is recovering from anesthesia. echocardiogram was also performed at this time and
VetBooks.ir Medications he received intraoperatively and post- moderate pulmonary hypertension was present with-
out further worsening of his cardiac function making
operatively could have decreased his cardiac output
and lung perfusion.
thromboembolism could still not be ruled out.
3. Pulmonary thromboembolic event: it is possible decreased cardiac output less likely. A pulmonary
that this patient had a pulmonary thromboembo- This case demonstrates one of the limitations
lism postoperatively that decreased perfusion to the of ETCO monitoring in anesthetized patients:
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lungs and therefore impeded carbon dioxide deliv- the value of the displayed ETCO informs the
2
ery to the lungs. Postoperative patients, especially clinician that the PaCO is at least the value of
2
those with underlying diseases such as neoplasia or the recorded ETCO but it is not uncommon for
2
cardiac disease are hypercoagulable and more likely the blood PaCO to be higher in critically ill
2
to produce blood clots. patients. Therefore, it is very important to check
the PaCO not only when the patient’s ETCO
2
2
In response to his condition, the dog’s respiratory reading is climbing but also periodically (at least
rate was increased from 20 to 28 and the PaCO every 8 to 12 hours) to ensure that the ETCO is
2
2
decreased to normal limits. This response to treat- properly representative of the PaCO reading
2
ment made us believe the patient had poorly venti- even when the ETCO remains constantly within
2
lated areas of his lungs such as occur with atelectasis, normal limits.

128 L.A.M. Ilie