When Chemotherapy is a Critical Care Drug
Beth Davidow, DVM DACVECC of ACCES and
Karri Meleo, DVM DACVIM (oncology) ACVR (radiation oncology)
Sadie, a 7yr FS DSH, presented to ACCES for hiding more than normal for about a week, urinating more than normal and she had vomited twice in the last day. She [was] indoors only and lived with another indoor cat who was acting normally. Sadie had no previous health problems and was FELV negative when tested as a kitten.
On initial physical exam, she had a temperature of 98.6 F, a heart rate of 170 bpm, and was mildly tachypneic at 64 bpm. She was thought to be 5% dehydrated. She was pink, had normal lung sounds but had very large irregular uncomfortable kidneys on palpation. Her bladder was small.
Based on kidney palpation, renal lymphoma was high on the differential list. Bloodwork indicated a BUN >130, creatinine of 5.8, a WBC of 13,800 with neutrophilia and toxic change. She had normal platelets but was mildly anemic at 28%. Sadie was severely acidotic with a pH of 7.1. On urinalysis, specific gravity was 1.014, and there were numerous WBC and chains of rods. A urine culture was set up which did have growth after 12 hours. These findings were most suggestive of pyelonephritis but normally the kidneys are not quite as big as Sadie’s with infection alone, so lymphoma was still suspected.
Sadie was admitted to the ICU, started on IV fluids at 20ml/hr and on ampicillin, cerenia, and famotidine. Within 8 hours of starting fluids, she became very dyspneic and was moved to oxygen. Thoracic radiographs were taken and showed patchy edema but without heart enlargement.
Dr. Meleo was consulted on the case first thing in the morning. She considered it possible that the suspected cancer could be very fast moving and possibly be in the lungs or causing a secondary vasculitis. Ultrasound was performed. Not only were the kidneys noted to be enlarged and irregular but an intestinal mass was also identified that had not been palpable the day before. Brief ultrasound of the heart showed no left atrial enlargement so lymphoma infiltrating the pulmonary parenchyma was a higher possibility.
When renal values were rechecked, the creatinine had skyrocketed to 13. The owner was given a guarded prognosis but wanted to continue. Cytology was compatible with lymphoma, so Dr. Meleo recommended starting prednisone right away, and upon confirmation, a chemotherapeutic plan was made by Dr. Meleo. Vincristine was administered.
Sadie stabilized slowly over the next 48 hours, was able to be moved out of oxygen and a very low rate of fluids was restarted. Dr. Meleo was able to exam her each day to assess kidney size. She was given L-spar 24 hours after the vincristine. Urine culture returned with an e.coli with resistance to penicillins so marbofloxacin was started.
By the 3rd day of hospitalization, Sadie was starting to improve and tolerate higher rates of IV fluids. Kidneys and the intestinal mass were rechecked with ultrasound and measurements showed that they were decreasing in size. Sadie wasn’t eating much so a nasoesophageal tube was placed and enteralcare liquid diet was started. [On 7/22], kidneys were palpably much smaller and the intestinal mass could no longer be felt. Creatinine had dropped to 5. Cyclophosphamide was started. Sadie was finally sent home after one week with a creatinine of 2.7 and kidneys that palpated normally. The owner was able to coax her to eat and was able to give SQ fluids at home.
Sadie was continued on chemotherapy at Animal Cancer Specialists and did quite well at home, surviving an additional 7 weeks, with good quality of life, eating normally and even starting to gain weight, until she succumbed to her disease.
The close working relationship between ACCES and ACS allowed us to institute chemotherapy quickly while providing the oxygen, IV fluids and nutritional support she needed in the acute phase of the illness. However, it was Sadie’s strong personality and her owner's willingness to support Sadie, that brought her through the initial critical part of the treatment.