Use of intravenous insulin aspart for treatment of naturally occurring diabetic ketoacidosis in dogs

Comparison of insulin infusion protocols for management of canine and feline diabetic ketoacidosis

OBJECTIVE

Describe the use of fixed-rate intravenous insulin infusions (FRIs) in cats and dogs with diabetic ketoacidosis (DKA) and determine if this is associated with faster resolution of ketosis compared to variable-rate intravenous insulin infusions (VRIs). Secondary objectives were to evaluate complication rates, length of hospitalization (LOH), and survival to discharge (STD).

DESIGN

Randomized clinical trial (January 2019 to July 2020).

SETTING

University veterinary teaching hospital and private referral hospital.

ANIMALS

Dogs and cats with DKA and venous pH <7.3, blood glucose concentration >11 mmol/L (198 mg/dL), and β-hydroxybutyrate (BHB) concentration >3 mmol/L were eligible for inclusion. Patients were randomly assigned to receive either FRI or VRI.

INTERVENTIONS

Neutral (regular) insulin was administered IV as an FRI or VRI. For FRI, the rate was maintained at 0.01 IU/kg/h. For VRI, the dose was adjusted according to blood glucose concentration.

MEASUREMENTS AND RESULTS

Sixteen cats and 20 dogs were enrolled. Population characteristics, mean insulin infusion rate, time to resolution of ketosis (BHB <0.6 mmol/L), complications, LOH, and STD were evaluated. In cats, overall resolution of ketosis was low (9/16 [56.3%]), limiting comparison of protocols. In dogs, resolution of ketosis was high (19/20 dogs [95.0%]) but the time to resolution in the FRI group was not different than that in the VRI group (P = 0.89), despite a 25% higher average insulin infusion rate in the FRI group (P = 0.04). The incidence of complications was low and did not differ between protocols. In cats, LOH and STD did not differ between protocols. All cats that died (5/16) did so within 78 hours and none had resolution of ketosis. Dogs receiving FRI had a shorter LOH (P = 0.01) but STD did not differ between protocols. Six dogs (30.0%) did not survive to hospital discharge but all had resolution of ketosis.

CONCLUSIONS

FRIs can be used in veterinary species but may not hasten resolution of ketosis.

Diabetes Ketoacidosis and Hyperosmolar Hyperglycemic Syndrome in Companion Animals

Diabetes mellitus is a common endocrinopathy in dogs and cats. Diabetes ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) are life-threatening complications of diabetes resulting from an imbalance between insulin and the glucose counter-regulatory hormones. The first part of this review focuses on the pathophysiology of DKA and HHS, and rarer complications such as euglycemic DKA and hyperosmolar DKA. The second part of this review focuses on the diagnosis and treatment of these complications.

Efficacy and Safety of Intramuscular Insulin Lispro vs. Continuous Intravenous Regular Insulin for the Treatment of Dogs With Diabetic Ketoacidosis

The use of rapid-acting insulin analogs as routes of administration other than IV has never been described for the treatment of dogs with diabetic ketoacidosis (DKA). This study aims to compare the efficacy and safety of a new protocol based on IM administration of insulin lispro with that of low-dose IV continuous rate infusion of regular insulin in the treatment of canine DKA. Client-owned dogs with naturally occurring DKA were included. Dogs treated with IM insulin lispro (Group L, n = 11) received 0.25 U/kg. The goal was to achieve a drop of at least 10% in blood glucose between 1 h and the next. If this goal was not achieved, the insulin dose was repeated hourly; otherwise, the insulin dose was not repeated up to a maximum of 3 h, after which the insulin dose was repeated anyway. When blood glucose was ≤250 mg/dL, the insulin dose was reduced to 0.125 U/kg IM every 3 h. Cases receiving IV continuous rate infusion of regular insulin (Group R, n = 13) were treated according to a previously published protocol. The median time to resolution of ketosis was significantly shorter in Group L (12 h; range, 4–27 h) compared to Group R (23 h; 10–46 h; P = 0.04). The median times to resolution of acidemia and ketoacidosis were 13 h (4–35 h) and 17.5 h (4–35 h) in Group L, and 22 h (9–80 h) and 23.5 h (10–80 h) in Group R, respectively. These differences were not significant (P = 0.06 and P = 0.09, respectively). The median length of hospitalization did not differ significantly between groups (P = 0.67). There were no differences in the frequency and severity of adverse events (hypoglycemia, hypokaliemia, and hypophosphatemia) between groups. The new protocol based on IM administration of insulin lispro preliminarily appears effective and safe for treatment of canine DKA.

Use of lispro insulin for treatment of diabetic ketoacidosis in cats

OBJECTIVES

The aim of this study was to evaluate the efficacy and safety of lispro insulin for the treatment of feline diabetic ketoacidosis (DKA). Times to resolution of hyperglycaemia, ketosis and acidosis were compared between cats treated with continuous rate infusion (CRI) of lispro insulin and cats treated with CRI of regular insulin.

METHODS

Client-owned cats with naturally occurring DKA, newly diagnosed with diabetes mellitus (DM) or already receiving treatment for DM, were included. Diagnosis of DKA involved the presence of at least two clinical signs consistent with DKA (eg, polyuria/polydipsia, anorexia, severe lethargy, vomiting and dehydration), blood glucose (BG) concentration >13.9 mmol/l (>250 mg/dl), blood beta hydroxybutyrate (BHB) concentration >2.5 mmol/l and venous pH <7.3 or bicarbonate <15 mEq/l. Cats were treated with a standard protocol of an intravenous (IV) CRI of regular insulin (group R) or lispro insulin (group L). The time to resolution of DKA was defined as the time interval from when the IV CRI of insulin began until marked hyperglycaemia (BG >13.9 mmol/l [>250 mg/dl]), ketosis (BHB concentration >1 mmol/l) and acidosis (venous pH <7.3 and/or bicarbonate <15 mEq/l) resolved.

RESULTS

Eighteen DKA cases (nine per group) were enrolled into the study. There were no significant differences in the median time to resolution of three variables (hyperglycaemia, ketosis and acidosis) between the two groups. Two cats in group R developed hypoglycaemia during the CRI of insulin. One cat in group L and three cats in group R developed hypophosphataemia, which required phosphate supplementation.

CONCLUSIONS AND RELEVANCE

IV CRI of lispro insulin has few side effects and appears to be as effective as IV CRI of regular insulin in the treatment of cats with DKA.

Comparative Pathogenesis of Autoimmune Diabetes in Humans, NOD Mice, and Canines: Has a Valuable Animal Model of Type 1 Diabetes Been Overlooked?

Despite decades of research in humans and mouse models of disease, substantial gaps remain in our understanding of pathogenic mechanisms underlying the development of type 1 diabetes. Furthermore, translation of therapies from preclinical efforts capable of delaying or halting β-cell destruction has been limited. Hence, a pressing need exists to identify alternative animal models that reflect human disease. Canine insulin deficiency diabetes is, in some cases, considered to follow autoimmune pathogenesis, similar to NOD mice and humans, characterized by hyperglycemia requiring lifelong exogenous insulin therapy. Also similar to human type 1 diabetes, the canonical canine disorder appears to be increasing in prevalence. Whereas islet architecture in rodents is distinctly different from humans, canine pancreatic endocrine cell distribution is more similar. Differences in breed susceptibility alongside associations with MHC and other canine immune response genes parallel that of different ethnic groups within the human population, a potential benefit over NOD mice. The impact of environment on disease development also favors canine over rodent models. Herein, we consider the potential for canine diabetes to provide valuable insights for human type 1 diabetes in terms of pancreatic histopathology, impairment of β-cell function and mass, islet inflammation (i.e., insulitis), and autoantibodies specific for β-cell antigens.

Beta-hydroxybutyrate Concentrations in Dogs with Acute Pancreatitis and Without Diabetes Mellitus

BACKGROUND

β-hydroxybutyrate (BOHB) concentrations have not been quantified in dogs with acute pancreatitis (AP).

OBJECTIVE

The aim of this study was to investigate BOHB concentrations in dogs with AP.

ANIMALS

A total of 154 client-owned dogs without DM.

METHODS

Prospective clinical study. Dogs were enrolled into 1 of 3 groups: AP, sick without an AP diagnosis, or fasted. Dogs were diagnosed with AP (44) if they had vomiting or anorexia, and either ultrasonographic findings consistent with AP or increased pancreatic lipase. Sick dogs without AP (68) had vomiting or anorexia but a diagnosis of AP was either not suspected or was excluded based on ultrasonographic findings or a normal pancreatic lipase. Dogs without anorexia or vomiting that were fasted for over 10 hours for a procedure were also enrolled (42). BOHB was measured on whole blood with a portable ketone meter. The Kruskal-Wallis test was performed to compare BOHB in the 3 groups. Pair-wise comparisons were performed using the Mann-Whitney test and Bonferroni corrected P-values are reported.

RESULTS

Median BOHB concentration was significantly higher in dogs with AP (0.3 mmol/L, range 0-2.9 mmol/L) compared to sick dogs without AP (0.20 mmol/L, range 0-0.9 mmol/L, P = .007) and fasted dogs (0.1 mmol/L, range 0-0.4 mmol/L, P = .0001). Median BOHB concentration was significantly higher in sick dogs without AP compared to fasted dogs (P = .0002).

CONCLUSIONS AND CLINICAL IMPORTANCE

In dogs without DM, BOHB is significantly higher in dogs with AP compared to other dogs. The diagnostic utility of this finding remains to be investigated.