Contents of Today's Veterinary Practice - JAN-FEB 2012

Today's Veterinary Practice provides comprehensive information to keep every small animal practitioner up to date on companion animal medicine and surgery as well as practice building and management.

Page 30 of 83

ANESTHETIC MONITORING: YOUR QUESTIONS ANSWERED |
Table 5. Anesthetic Monitoring Equipment Circulation
Electrocardiography (ECG): UÊMonitors heart rate and rhythm UÊDefinitively diagnoses arrhythmias UÊMonitors progress of cardiac arrhythmia treatment
Ultrasonographic Doppler blood flow detector: UÊMeasures blood flow, pulse rate, and systolic blood pressure (BP) when used with sphygmomanometer
Oscillometric BP measurement: UÊUses a BP cuff on the limb to obtain systolic, diastolic, and mean arterial BP at a set time interval but not continuously
Invasive BP measurement: UÊUses arterial catheter, BP transducer, and monitor to obtain continuous beat-to-beat pulse waves
UÊGold standard for measuring systolic, diastolic, and mean BP
Ventilation
Respirometer: UÊMeasures respiratory rate and tidal volume (minute volume)
Arterial or venous blood gas:
UÊMeasures partial pressure of CO2 (PaCO2 or PvCO2)
Capnography:
UÊNoninvasively measures end-tidal CO2 concentration Oxygenation
Pulse oximetry: UÊNoninvasively measures saturation of oxygen in hemoglobin (SpO2)
Arterial blood gas:
UÊMeasures partial pressure of oxygen (PaO2) in arterial blood samples Body Temperature
Rectal thermometer Esophageal temperature probe Infrared thermometer: UÊMeasures tympanic membrane temperature
Depth of Anesthesia
Gas analyzer: UÊMeasures expiratory inhalant concentration (allows anesthetist to estimate depth of anesthesia together with other vital variables mentioned in this table)
Bispectral index (BIS) monitor: UÊAlgorithmic analysis of a patient's electroencephalogram during general anesthesia
BIS = bispectral index; BP = blood pressure; CO2 = carbon dioxide; ECG = electrocardiography; PaCO2 = partial pressure of carbon dioxide in arterial blood; PaO2 = partial pressure of oxygen in arterial blood; PvCO2 = partial pressure of carbon dioxide in venous blood; SpO2 = saturation level of oxygen in hemoglobin
What Methods & Equipment are Used for Anesthetic Monitoring? *ÀioÀiÌiiÃÊvoÀÊmoniÌoÀin}Ê>nÊ>niÃÌhiÌiâi`Ê«>ÌiinÌÊ include: UÊ Ê «hÞÃiV>lÊ >ÃÃiÃÃminÌÊ Table 4) of the anesthetized patient by qualified person- nel
UÊ ««Ào«Ài>ÌiÊ ÛiÌ>lÊ Ãi}nÊmoniÌoÀin}Ê Table 5).
Adverse side effects of anesthesia are min-
imized when the anesthetist systematically and regularly evaluates circulation, ventilation, oxygenation, and analgesia. ■
In the next article in this series, anesthetic
monitoring equipment and the physiologic components it measures will be discussed in- depth.
References
1. Ko JC. Noninvasive techniques in monitoring anesthetized patients. Vet Tech 1996; 17(5):301-307.
2. Bille C, Auvigne V, Libermann S, et al. Risk of anesthetic mortality in dogs and cats: An observational cohort study of 3546 cases. Vet Anesth Analg 2012; 39:59-68.
3. American College of Veterinary Anesthesiologists. Recommendations for monitoring anesthetized veterinary patients. JAVMA 1995; 206(7):936-937.
4. American Animal Hospital Association. Anesthesia guidelines. JAAHA 2011; 47:378-385.
Jeff Ko, DVM, MS, Diplomate ACVA, is a professor in the Department of Veterinary Clinical Sciences at Purdue University College of Veterinary Medicine. He has
authored numerous articles and book chapters in the field of anesthesia and pain management. Dr. Ko lectures extensively at regional, national, and international conferences. Dr. Ko can be reached at jcko@purdue.edu.
Rebecca
Krimins, DVM, is currently a third- year anesthesia resident in the Department of Veterinary Clinical Sciences at Purdue University College of
Veterinary Medicine. Dr. Krimins is a graduate of Ross University School of Veterinary Medicine.
January/February 2012 Today's Veterinary Practice 29