Nursing the feline patient
Monitoring the feline trauma patient is a delicate balancing act between collecting information in order to treat and limiting the stress inflicted on the patient while gathering these data. Pain must be managed appropriately for this balance to exist, explained Alison Gottlieb BS, CVT, VTS(ECC), speaking at the Atlantic Provinces Veterinary Conference.
The renal system
The renal system must be watched closely; monitoring urine output is essential for any critically ill animal. With trauma of the bladder or urethra, care must be taken when expressing the bladder to avoid more damage. When measuring urine output, all urine produced must be estimated and noted down, and if this is not feasible, a urinary catheter should be placed. The normal urinary output for a cat is 1-2 ml/kg/hr, so if this amount is not produced the patency of the catheter should be checked. The creatinine, BUN, and electrolytes should be carefully monitored as well; elevations in any of these values are indicators that the renal system is not functioning properly.
Oxygen
Since it is difficult to obtain arterial blood gases for the feline patient, it may be necessary to reply on radiographs and auscultation, and to frequently observe mucous membrane colour, respiratory rate, and respiratory effort. Ms. Gottlieb stressed that the cat must be stable before any radiographs are obtained because using restraint causes additional stress. Cyanosis is not usually observed until the SPO2 is well below 80%; at this point mechanical ventilation needs to be considered.
Cardiovascular monitoring
Cardiovascular monitoring is difficult in the cat because few mean arterial pressure machines are sensitive enough to obtain values from cats that are in shock or that are hypovolemic. The use of a doppler to obtain blood pressure is the best option. It is important to supply heat and closely monitor temperature, as well as pulse, respiration, mucous membrane colour, capillary refill time, and pulse quality. The EKG should be closely monitored, especially if electrolyte abnormalities are present. This can be done either by attaching patches with buttons to connect the alligator clips for continuous monitoring, or by running an EKG strip every few hours. Ms. Gottlieb noted the importance of avoiding alcohol on animals that may receive defibrillation, due to its flammability.
Blood monitoring
Packed cell volume and total solids, blood glucose, and electrolytes should be monitored closely and glucose and potassium (KCl) supplemented if needed. If the patient requires multiple blood samples, a central line should be considered. Blood/plasma transfusions should be administered if values are low; however, every cat must be blood-typed or cross-matched before any blood product is given. Type A blood given to type B cat results in severe, fatal hemolysis, and Type B blood given to type A cat causes hemolysis over two days. This applies to whole blood, packed cells, and plasma. If a feline patient is type B, Oxyglobin® (Biopure Corporation, MA) can potentially be used. Feline packed red blood cells and fresh frozen plasma (either A or B) can be ordered from several national blood banks. Should these not be available, collecting whole blood from a donor may be an option.
A micron filter must always be used; if a patient is receiving multiple transfusions the filter needs to be changed with each unit to prevent the antigens from reacting when combined. Blood products should not be combined with any blood product with Lactated Ringers (LRS) since LRS contains calcium, which will chelate out the anticoagulant. As well, care must be taken to avoid using a hypertonic fluid (hetastarch, 5%Dex, etc.) as this may cause cell lysis.
The rate of transfusion should start slowly for at least the first 15 min. This is done to ensure that if a transfusion reaction is going to occur it can be treated immediately. If any signs of a reaction are witnessed, the clinician should be notified, the transfusion stopped, and diphenhydramine (1-2mg/kg IM) and prednisolone (2-4 mg/kg IM) administered.
Nutrition
Healthy cats can be finicky eaters and are stressed at the slightest change in environment. Feeding sick cats can therefore be a major challenge. Ms. Gottlieb says that the nursing staff can make a huge difference in helping sick cats feel safe, secure, and comfortable. Sometimes something as simple as a box to hide in or covering the cat’s cage with a towel will help them feel relaxed enough to eat. Occasionally heating up canned food helps, as well as using a fishy smelling variety of food. Canned tuna fish, store-bought lunchmeat, or freeze-dried liver treats used for dog training sessions can also be offered. Temporarily removing an e-collar may also entice them to nibble.
Pharmaceutical interventions to increase appetite include cyproheptadine (2-4 mg per cat PO, SID, or BID) given 30 minutes before food can be offered. This is an antihistamine that increases appetite. Diazepam (0.05-0.4 mg/kg IV, IM, or PO) is also effective when used as a feline appetite stimulant. Onset is rapid and the effects are short term. Martazipine is a human antidepressant that is now being used to help increase feline appetite.
A feeding tube can be used if none of the above methods is successful. This procedure is done to administer short-term nutritional support to a patient when it is not eating enough to meet its daily caloric needs. There are two forms of feeding tubes that can be placed that allow the patient to continue to eat and drink: nasoesophageal (NE) and nasogastric (NG). These tubes can be kept in place from several days to weeks; however they are contradicted in patients predisposed to aspiration, esophageal dysfunction, and patients that are actively vomiting. They are also contradicted in patients that have head or neck injuries or surgical procedures of the nasal cavity, pharynx, or esophagus. Surgery is required for all other enteral support routes. These procedures include pharyngostomy tubes, esophagostomy tubes, gastrostomy tubes, and enterostomy tubes.
Esophagostomy tubes are placed when head trauma is present. The tube is inserted directly into the cranial esophagus and advanced to the end of the esophagus and capped. Sutures are then placed and the neck is wrapped with a bandage. Gastrotomy tubes are inserted directly into the stomach and are indicated when esophageal injury or disease is present. These tubes can be placed via laparotomy or percutaneous placement using an endoscope. These too need to be capped, sutured, and wrapped.
Feedings may be administered as a constant rate infusion or as bolus feedings. They are dependent on the patient’s condition and the doctor’s recommendations. For bolus feeding, always offer the patient food or water first, unless instructed otherwise by the doctor. Complete any other treatments the patient may need before giving anything through the feeding tube. The patient should not be stressed or excited after the feeding, because that may cause them to vomit. If the patient vomits after its treatment, skip the next feeding and then resume feedings at a slower rate of administration.
Nursing is an integral part of caring for sick and injured cats. Communication between all members of the team, as well as with the pet’s owner, is paramount to ensuring optimal patient care.
This article is based on a presentation give by Ms. Gottlieb at the Atlantic Provinces Veterinary Conference in Halifax, NS. CVT
