Page 618 - Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice

606 SPECIAL THERAPY

developed vomiting, oral ulcerations, and hyperglyce- thrombophlebitis was the most common cause of cathe-
mia. 41 However, all cats developed anemia, thrombocy- ter failure. 20 In a retrospective study of three-in-one PPN
topenia, hypertriglyceridemia, villous atrophy, and in 80 dogs and 47 cats, the median duration of PPN
hepatocellular changes. 41 administration was 3.0 days. 14 As in the previous studies,
In 1993, Lippert et al 43 published the first retrospec- hyperglycemia was the main metabolic complication
tive study on the use of TPN in clinical patients. This (15% of animals overall). 14 Twenty-four other metabolic
study reported the results of the use of TPN in 72 dogs complications also occurred, and four septic cases were
and 12 cats. 43 The median duration of TPN was 3.8 days, documented (3%). 14 The complication rate was 0.18
with a range of 1 to 14 days. 43 Thirty-nine mechanical and 0.15 complications per day of PPN for dogs and
complications occurred, and metabolic complications cats, respectively. 14 One notable feature of this study is
were common, including hyperglycemia (37%), electro- that animals that received some enteral nutrition in
lyte abnormalities (30%), and hyperlipidemia (23%). 43 combination with PPN administration were more likely
Seven percent of animals developed sepsis (i.e., clinical to survive compared with animals not receiving any
signs of sepsis in combination with either a positive cath- enteral nutrition. 14
eter tip culture or positive blood culture). 43 In this study, To date, these are the most comprehensive published
both total calories and protein were administered at a studies on results of parenteral nutrition use in clinical
higher level than is currently done at most institutions. 43 patients (see Table 25-1 for a summary of these studies).
The next major retrospective study was published in However, there are several other studies that have been
1998 and reported the results of the use of TPN in helpful in enhancing the use of parenteral nutrition in
209 dogs. 62 Similar to the Lippert study, the median dogs. The first is a study by Chandler et al 19 in which
duration of administration was 3.5 days (range, 0.5 an amino acid solution, a dextrose solution, and an elec-
to 25 days). 62 One hundred-eighteen mechanical trolyte solution were administered to compare their
complications occurred, and 37% of the dogs had at least effects on nitrogen balance. These solutions were individ-
one mechanical complication. 62 Hyperglycemia was the ually administered to three healthy dogs via a peripheral
most common metabolic complication, with 32% of dogs vein for 10 hr/day for 4 days. 19 Only the amino acid solu-
evaluated developing this abnormality, but 329 individual tion resulted in a positive nitrogen balance, suggesting
metabolic complications occurred in this population of that in healthy dogs it provided adequate amino acids
dogs. 62 Seven percent of the animals developed sepsis. 62 to prevent breakdown of lean body mass. 19 In 2001,
The overall complication rate was 0.52 complications per Mauldin et al 49 reported a study evaluating parenteral
day of TPN. 62 nutrition in healthy dogs. In this study, dogs received
Two retrospective studies on the use of TPN specifi- intravenous infusions of either nonlactated Ringer’s solu-
cally in cats also have been published. 21,58 The median tion or isocaloric solutions containing 0, 1.36, or 2.04 g
duration of TPN administration in these studies was of amino acids per kilogram of body weight per day, with
4.8 and 3.7 days, respectively. 21,58 Although the number the remaining calories (to meet MER) provided by dex-
of mechanical and septic complications was similar trose and lipid solutions for 12 hr/day for 7 days. 49 On
between the two studies, 18% of cats in the Crabb et al Ringer’s and 0 g/kg amino acids, dogs had negative
study became hyperglycemic, compared with 47% in nitrogen balance, and a regression analysis suggested that
the larger Pyle et al study. 21,58 The overall complication intravenous administration of 2.32 g/kg/day of amino
rate was 0.62 per day of TPN in the Pyle study and acids would result in zero nitrogen balance in a healthy
0.29 in the Crabb study. 21,58 There also were two inter- dog of beagle size (i.e., the minimum amount required
esting findings regarding hyperglycemia from these two to prevent catabolism of lean body mass by supplying
studies. 21,58 First, the study from Pyle et al showed that basal amino acid requirements). 49 Zentek et al published
hyperglycemia was significantly associated with an a study of parenteral nutrition in healthy laboratory dogs
58
increased mortality rate 24 hours after starting TPN. using a three-in-one solution with the majority of calories
In this study, cats’ energy requirements were calculated either from glucose or lipid. 73 In this study, PPN
by multiplying the resting energy requirements (RER) was administered cyclically (over 10 hr/day) to meet
by an illness factor. In the Crabb et al study, cats in which MER. 73 Depending on the formula (high glucose or high
the RER was multiplied by an illness factor were more lipid), dogs had significant increases in blood glucose and
likely to develop hyperglycemia than those in which triglycerides, respectively, but there were no significant
energy requirements were provided at or below RER. 21 differences in hormonal concentrations (e.g., insulin-like
Two studies have been published on partial parenteral growth factor-1, insulin, glucagon, T3, T4). 73 An in vitro
nutrition (PPN) in clinical veterinary patients. One used a study also was recently published assessing physical effects
commercial three-in-one solution containing dextrose on the stability of lipid-based parenteral nutrition
amino acids and lipid that provided 1.26 kcal/kg/hr solutions. 66 This is important information as factors such
for between 10 to 24 hr/day (n ¼ 9) for a median of as temperature and handling can affect the nutrition
36 hours. 20 In this study, venous thrombus or and physical stability of parenteral nutrition solutions.