Common Anaesthetics: Effects On Pulse Oximetry
| Acepromazine | Potent tranquilizer | Hypotension platelet inhibition; seizures in susceptible animals; animal may be unresponsive to sound/movement if used alone | 3, 5 |
| Butorphanol | Moderate analgesia; mild sedation; minimal cardiovascular effects; less respiratory depression; respiratory depression than oxymophone . | Bradycardia (atropine-responsive); dysphoria; expensive; ±efficacy for severe pain. | 3,5,6 |
| Diazepam | Decreases induction dose; muscle relaxation; ±mild sedation; minimal .cardiovascular effects; treatment of seizures. | Poor tranquilizer; excitement or disorientation; rapid bolus may lead to hypotension | 3,4,5 |
| Ketamine | Dissociative anesthetic agent; good somatic analgesia; stimulates cardiovascular system. | ±Cardiovascu lar depression; ±excessive cardiovascular stimulation; ±respiratory depression; increases intraocular and intracranial pressure; muscle rigidity; no visceral analgesia | 1, 3, 4, 6, 7. |
| Morphine | Excellent analgesia; mild sedation; minimal cardiovascular effects; mild respiratory depression; reversible; lessexlpensive than Oxymorphone. | Bradycardia (anticholinergic-responsive); dysphoria; respiratory depression; histamine release most often seen when given IV; ±hypotension; expensive; vomiting commonlx seen. | 2,3,5,6 |
| Oxymorphone | Excellent analgesia; mild sedation; minimal cardiovascular effects; mild respiratory depression; reversible. | Bradycardia (anticholinergic-responsive); dysphoria expensive; significant respiratory depression at higher doses | 2,3,6 |
| Tiletamine zolazepam | Muscle relaxant/immobilize; some somatic analgesia; stimulates cardiovascular system | Long difficult recoveries; ±cardiovascular,’ depression; ±excessive cardiovascular stimulation;. ±respiratory depression; increases cerebral blood flow; increases intraocular pressure; movement possible with stimulation. | 1, 2, 3, 5, 6, 7 |
Effects to Pulse Oximeter
- Increase in pulse rate reading. 6. Decrease in oxygen saturation (SpO,) reading.
- Decrease in pulse rate reading. 7. Increase in blood pressure.
- Decrease in blood pressure. Low perfusion: indicator may change green to yellow.
- Immediate increase in pulse rate: sedation may be adequate.
- Mot ion artifact: indicator may change green to yellow.
- Decrease in oxygen saturation (SpO,) reading.
- Increase in blood pressure.
Some Distinguishing Attributes of Anesthetic Induction Drugs in Cats and Dogs
| Drug | Distinguishing attributes | Pulse Oximetry |
| Etomidate | Rapid, smooth induction; rapid recovery; least cardiovascular depression of induction drugs; not arrhythmogenic (occasional mild bradycardia); transient hypoventilation; adrenocortical; vomiting and pain on injection; muscle fasciculations; expensive. | 1, 2, 5, 6 |
| Ketamine | Must be combined with tranquilizer (dog); ±increased heart rate and blood pressure; mild respiratory depression; avoid in hypertrophic cardiomyopathy or outflow; tract obstructions; increase intracranial and intraocular pressure. | 1,3,4,6,7 |
| Propofol | Rapid, smooth induction; very rapid recovery; little “hangover” effect; ±hypotension, administer slowly, especially in compromised animals; respiratory depression; ±apnea; contains no preservatives – open ampule supports bacterial and fungal growth; expensive. | 3,6 |
| Thiopental Sodium | Rapid, smooth induction; ±hypotension; ±arrhythmias; respiratory depression, ±apnea. | 3,6 |
Some Distinguishing Attributes of Inhalation Anesthetics in Cats and Dogs
| Drug | Distinguishing attributes | Pulse Oximetry |
| Halothane | Faster induction and recovery than methoxyflurane; dose-dependent cardiovascular depression; increases susceptibility to arrhythmias; dose-dependent respiratory depression; about 25% metabolized by the liver. | 3,6 |
| lsofluarane | Faster induction and recovery that halothane; cardiovascular depression less than halothane or methoxyflurane; arrhythmias less common than with halothane; dose-dependent respiratory depression; less than 1% metabolized by liver; can induce acute renal failure if given with other nephrotoxic drugs. | 3,6 |
| Methoxyflurane | Slow induction and recovery; some residual analgesia during slow recovery; dose-dependent cardiovascular depression; less arrhythmias arrhythmogenic than halothane; dose-dependent respiratory depression (greater than with halothane); up to 50% metabolized by liver; can induce acute renal failure if given with other nephrotoxic drugs. | 3,6 |
a2-adreneric Medication
| Drug | Distinguishing attributes | Pulse Oximetry |
| Medetomidine (Domitor) | BradycardiaA; peripheral vasoconstrictionA; occasional vomiting; moderate hypothermia; diuresis 90 – 120 minutes after treatment; increases systemic blood pressure with corresponding decrease in heart rate; reduction in cardiac output; depressed respiration; rapid sedation; hypertension; quickly reversible; cyanosis, apnea; increase in blood glucose. | 1,2,3,5,6,7 |
| Xylazine | Potent tranquilizer , analgesia, reversible (yophimbine, other a-2 antagonists). Disadvantages include decreased cardiac output, hypotension, bradycardia, first- and second-degree A-V block, ventricular arrhythmias, respiratory depression, animal may move abruptly with stimulation. | 3,6 |
