Veterinary Nursing Anesthesia and Analgesia Case Journal

Veterinary Nursing Anesthesia and Analgesia Case Journal

The objective of this study is to address anesthesia needs in two specific cases with the first being a 12-week-old Jack Russell puppy and the second being a 12-year-old geriatric cat.

12-Week-old Jack Russell Puppy

This 12-week-old Jack Russell Puppy has eaten a babies dummy. This case study will highlight the anesthesia requirements and protocol and highlight the relevance of effect on renal function, speed of recovery, analgesia, emphasis on knowledge and understanding. Even at 12-weeks of age, this puppy is considered a pediatric patient according to the work of Gleed and Seymour (1991). This means that the patient has a higher oxygen requirement that the adult. The tongue of this patient due to his age is large and the airway is small in diameter. As well, there is a lower functional renal capacity in this age patient all of which make the patient at risk of airway closure or collapse and hypoventilation and this is especially true when influenced by respiratory depressants including volatile anesthetic agents." (Myerscough College 2011) The heart of the pediatric patient is reported as having a high percentage of "non-contractile mass, and the ventricles have low compliance" (Myerscough College 2011) Pediatric patients are not as able to tolerate loss of blood as are older patients and the hypotensive and bradycardic effects of drugs such as opioids are heightened in younger patients. The pediatric patient is prone to glycogen storage due to the liver and this results in pre-operative fasting as well as a slow return of the patient's appetite following anesthesia to occur. Due to reduced renal function, pediatric patients do not tolerate a great many liquids. Pediatric patients are also more prone to hyperthermia due to their reduced ability to thermoregulate as compared to the older patient. There should be an attempt to minimize the time the pediatric patient is under anesthesia and to simultaneously reduce loss of heat. When inhalation agents are used as the only anesthesia in pediatric patients there is a re3quirement for high concentrations and it can be assumed that this will result in depression to the cardiovascular and respiratory system of the pediatric patient. Suggested is an approach that is balanced in nature. There is a need of such as tranquilizers, injectable anesthetic agents and sedatives in lower doses and pre-anesthetic medications include a combination of opioids and benzodiazepines. Another consideration is that of anticholineragics to maintain adequate heart rate resulting in adequate cardiac output. Glycopyrrolate would be chosen over atropine and it is necessary to avoid Acepromizine and alpha-2-agonists because of their cardiac and respiratory depressive effects. It is reported that isoflurane or sevoflurane with a non-rebreathing system can be used in maintenance of anesthesia. Hypoxia can be avoided by pre-oxygenation of patients. Fluids that contain dextrose are appropriate for use in young patients and can be administered through IV. Basic fluid administrating is at the rate of 5-10m./kg/hour and a syringe driver or burette can be used to administer intra-operative fluids. The work of Bennett, et al. (2008) reports that reports a study involving 108 dogs that were admitted to the Queen's Veterinary School Hospital, University of Cambridge for various surgical and diagnostic procedures over a period of nine-months. The study investigated "sevoflurane's role as a maintenance anesthetic for clinical practice." (p.395) The study findings state as follows: "In conclusion, we found that the characteristics of sevoflurane anesthesia under clinical conditions were similar to those of isoflurane. The higher ETCO2 with sevoflurane reflected greater reduction in alveolar ventilation, but the actual differences were of limited biological significance. The higher ETsev reflected sevoflurane's lower potency. Sevoflurane appears as suitable as isoflurane for maintenance of anesthesia in canine patients undergoing a range of elective surgical and diagnostic procedures. Anticipated attributes such as a faster and smoother recovery after sevoflurane require a more appropriate protocol for specific investigation." (Bennett, et al., 2008, p.396)

Case 2- to 12-year-old geriatric cat going for Thyriodectomy Due to Hyperthyroidism

The second case is a 12-year-old geriatric cat going that has been diagnosed with hyperthyroidism and undergoing a thyriodectomy. Hyperthyroidism is generally caused by a benign hyperplasia of the thyroid gland, resulting in excess thyroid hormone production and according to Cagney 2004 causing an increased rate of metabolism, gastrointestinal motility, cardiac output, central nervous system activity and heart rate as well as a decrease in the bodyweight and reduced sleep. It is critically important that a hyperthyroid patient be stabilized before anesthesia due to the increased risk of cardiac and metabolic complications. (Mooney and Peterson, 2004) due to hyperthyroidism. There is likely to be concurrent disease in geriatric patients and a decline in organ function should be anticipated resulting in a decrease in reserve capacity in brain, heart, liver, kidneys, and other organ function. In addition, older and thinner animals are more likely to experience hyperthermia. Decreased cardiac function is reported to worsen the risks associated with "decreased perfusion and oxygenation of organs including the kidneys and liver while under anesthesia. Lower doses of inhalation or injectable agents are required in older patients although this is little understood. The risks that are increased when a geriatric patient is under anesthesia include:

1. Hypoxemia and hypercapnia

2. Dehydration, hypovolaemia, hypotension and poor tissue perfusion

3. Cardiac arrhythmias

4. Hypothermia

5. Prolonged drug action and delayed recovery from anesthesia

6. Adverse drug reactions

7. Stress (Myerscough College 2011)