Page 91 - Basic Monitoring in Canine and Feline Emergency Patients

The elevated lactate (see Chapter 1) implies that the intravenous fluids during the procedure rather than
tissues are not receiving adequate oxygen/not able to 10 mL/kg/h. This led to fluid overload and pulmo-
VetBooks.ir utilize oxygen appropriately, consistent with nary edema. The patient was treated with oxygen
support and intravenous furosemide and made a
decreased perfusion, COHb, or cyanide toxicosis.
At this point, you could perform co-oximetry (if
available) to quantify the amount of COHb pre- complete recovery.
sent, which would be useful in differentiating
COHb from cyanide toxicosis. However, since
short-term provision of oxygen is unlikely to harm Bibliography
this patient and is the mainstay of treatment for Auckburally, A. (2016) Pulse oximetry and oxygenation
COHb toxicosis, high levels of O should be pro- assessment in small animal practice. In Practice 38,
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toxicosis even if co-oximetry is not available. Boron, W. (2012) Transport of oxygen and carbon diox-
Oxygen therapy helps to out-compete the CO for ide in the blood. In: Boron, W., Boulpaep, E. (eds)
the Hb binding sites and also helps to provide more Medical Physiology, 2nd edn. Elsevier, St Louis,
oxygen to the plasma portion of the bloodstream. Missouri, USA, pp. 672–684.
Brunelle, J., Degtiarov, A., Moran, R., et al. (1996)
Simultaneous measurement of total hemoglobin and
Case study 3: Post-operative SpO drop its derivatives in blood using co-oximeters: Analytical
2 principles; their application in selecting analytical
A 6-month-old 3-kg miniature poodle undergoes a wavelengths and reference methods; a comparision
routine ovariohysterectomy at your clinic. During of the results of the choices made. Scandinavian
recovery/extubation, the patient appears to be in Journal of Clinical and Laboratory Investigation 56,
respiratory distress and diffuse crackles are aus- 47-69.
culted in all lung lobes. The pulse oximeter Chan, E., Chan, M., Chan, M. (2017) Pulse oximetry:
throughout the procedure read 98%, but now understanding its basic principles facilitates appreci-
reads 90% with a strong waveform that matches ation of its limitations. Respiratory Medicine 107,
789–799.
her heart rate. Duke-Novakovski, T. (2017) Basics of monitoring equip-
What does the precipitous drop in the pulse-ox ment. Canadian Veterinary Journal 58, 1200–1208.
reading from anesthesia to recovery indicate? Gewib, H., Timm, U., Kraitl, J., et al. (2017) Non-invasive
While under general anesthesia this patient was multi wavelengths sensor system for measuring car-
breathing 100% oxygen, which should cause her boxy- and methemoglobin. Current Directions in
PaO to be between 400–500 mmHg. Her pulse-ox Biomedical Engineering 3, 441–444.
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will read 98–100% as long as the PaO is >100 mmHg Gracia, R., Shepherd, G. (2004) Cyanide poisoning and
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(on the flat portion of the disassociation curve). its treatment. Pharmacotherapy 24, 1358–1365.
Therefore, it is possible that her lung function was Hackett, T. (2002) Pulse oximetry and end tidal carbon
decreasing throughout the procedure, but this was dioxide monitoring. Veterinary Clinics of North
not detected until she was removed from oxygen and America: Small Animal Practice 32, 1021–1029.
placed back on room air since the pulse-ox reading Herrmann, K., Haskins, S. (2005) Determination of P for
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feline hemoglobin. Journal of Veterinary Emergency
would remain 100% even with significant alterations and Critical Care 15, 26–31.
in lung function while she was receiving 100% oxy- Jubran, A. (2004) Pulse oximetry. Intensive Care
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O until her PaO was <80 mmHg (i.e. >75% of lung gauze swab placement on pulse oximeter readings
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function lost) All possible causes of iatrogenic res- in anesthetized dogs and cats. Veterinary Record
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should be considered in this patient including but not Marino, P.L. (2014) Systemic oxygenation. In: Marino, P.L.
limited to aspiration pneumonia, a pulmonary (ed.) The ICU Book, 4th edn. Wolters Kluwer,
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Further investigation revealed a math error Proulx, J. (1999) Respiratory Monitoring: Arterial blood
resulting in the patient receiving 100 mL/kg/h of gas analysis, pulse oximetry, and end tidal carbon

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