An online survey of small animal veterinarians regarding current fluid therapy practices in dogs and cats

2024 AAHA Fluid Therapy Guidelines for Dogs and Cats

Fluids are drugs used in veterinary patients capable of producing beneficial therapeutic or inadvertent harmful effects within the body's intravascular, interstitial, and intracellular fluid spaces. The individualized design of a fluid therapy plan requires careful patient assessment and targeted selection of proper fluid types, administration routes, and rates, along with adjustments during therapy tailored specifically as per the individual patient's fluid requirement and therapeutic response. Personalized fluid prescriptions and vigilant patient monitoring help avoid patient morbidity from body fluid deficiencies, fluid excess, and electrolyte derangements and support better patient outcomes. These guidelines provide an overview of fluid dynamics within the fluid spaces of the body, describe various types of fluids and their uses, and outline recommendations for fluid administration for resuscitation, rehydration, and maintenance purposes. The guidelines also outline approaches to fluid therapy for anesthetized patients and reiterate the recommendations of reduced fluid rates in this population of patients. Additionally, the guidelines include practical fluid therapy strategies for patients with various common disorders. The goal of these guidelines is to help veterinary professionals safely and effectively prescribe and administer fluid therapy for canine and feline patients.

Preliminary research on tailored fluid therapy in pigs: comparing customized ionic solutions with Hartmann's solution

BACKGROUND

Fluid therapy in veterinary medicine is pivotal for treating various conditions in pigs; however, standard solutions, such as Hartmann's solution, may not optimally align with pig physiology. This study explored the development and efficacy of a customized fluid therapy tailored to the ionic concentrations of pig blood, aiming to enhance treatment outcomes and safety in both healthy and diseased pigs.

RESULTS

The study involved two experiments: the first to assess the safety and stability of customized fluids in healthy pigs, and the second to evaluate the efficacy in pigs with clinical symptoms of dehydration. In healthy pigs, the administration of customized fluids showed no adverse effects, with slight alterations observed in pO2, hematocrit, and glucose levels in some groups. In symptomatic pigs, the customized fluid group did not show any improvement in clinical symptoms, with no significant changes in blood chemistry or metabolite levels compared to controls. The customized fluid group showed a mild increase in some values after administration, yet within normal physiological ranges. The study reported no significant improvements in clinical or dehydration status, attributing the observed variations in blood test results to the limited sample size and anaesthesia effects rather than fluid characteristics.

CONCLUSIONS

Customized fluid therapy, tailored to mimic the ionic concentrations of pig blood, appears to be a safe and potentially more effective alternative to conventional solutions such as Hartmann's solution for treating pigs under various health conditions. Further research with larger sample sizes and controlled conditions is recommended to validate these findings and to explore the full potential of customized fluid therapy in veterinary practice.

Biomarkers of Coagulation and Inflammation in Dogs after Randomized Administration of 6% Hydroxyethyl Starch 130/0.4 or Hartmann's Solution

Synthetic colloid fluids containing hydroxyethyl starch (HES) have been associated with impairment of coagulation in dogs. It is unknown if HES causes coagulation impairment in dogs with naturally occurring critical illness. This study used banked plasma samples from a blinded, randomized clinical trial comparing HES and balanced isotonic crystalloid for bolus fluid therapy in 39 critically ill dogs. Blood was collected prior to fluid administration and 6, 12, and 24 h thereafter. Coagulation biomarkers measured at each time point included prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen concentration, and the activities of coagulation factors V, VII, VIII, IX, and X, von Willebrand factor antigen, antithrombin, and protein C. Given the links between coagulation and inflammation, cytokine concentrations were also measured, including interleukins 6, 8, 10, and 18, keratinocyte-derived chemokine, and monocyte chemoattractant protein-1. Data were analyzed with linear mixed effects models. No significant treatment-by-time interactions were found for any biomarker, indicating that the pattern of change over time was not modified by treatment. Examining the main effect of time showed significant changes in several coagulation biomarkers and keratinocyte-derived chemokines. This study could not detect evidence of coagulation impairment with HES.

A survey of emergency and critical care veterinarians regarding IV fluid bolus therapy and monitoring practices in small animals

OBJECTIVE

To determine how veterinary emergency and critical care clinicians define IV fluid bolus therapy (FBT) and what constitutes a positive response to a fluid bolus.

DESIGN

Online survey of 222 emergency and critical care veterinarians between December 17, 2018, and March 1, 2019.

INTERVENTIONS

An online survey was provided to diplomates of the American College of Veterinary Emergency and Critical Care (ACVECC), residents of ACVECC-approved training programs, as well as house officers and emergency clinicians of a corporate multicenter emergency and specialty care veterinary hospital. The survey investigated the administration of various crystalloid, colloid, and blood products for FBT, as well as expected physiological responses.

MEASUREMENTS AND MAIN RESULTS

The majority of respondents considered balanced isotonic crystalloids appropriate for FBT (220/222 [99.1%]). Respondents showed greater variability in acceptance of 0.9% sodium chloride (105/222 [47.30%]), hypertonic (3-7%) sodium chloride (131/222 [59.01%]), and hydroxyethyl starch solutions (90/222 [40.54%]). Most respondents did not consider physiological plasma (44/222 [19.82%]) an appropriate choice. The most commonly used parameters for monitoring FBT responses were heart rate (220/222 [99.10%]), blood pressure (217/222 [97.75%]), capillary refill time (192/222 [86.49%]), lactate (181/222 [81.53%]), pulse pressure (151/222 [68.02%]), and rectal temperature (145/222 [65.32%]). The majority of respondents perceived that 0-20% (165/222 [74.32%]) of hypotensive patients are nonresponsive to FBT.

CONCLUSIONS

Small animal emergency and critical care clinicians favored balanced isotonic electrolyte solutions and hypertonic sodium chloride solutions for FBT over other options. When monitoring responses to FBT, heart rate, blood pressure, capillary refill time, and plasma lactate were among the most commonly monitored parameters, and there was a lack of familiarity with others. Despite the widespread use of FBT, these findings outline the need for further prospective clinical trials regarding the ideal fluid type and rate, as well as the appropriate responses to FBT.

Effectiveness of intravenous fluid resuscitation in hypotensive cats: 82 cases (2012-2019)

OBJECTIVE

To evaluate the effectiveness of intravenous fluid resuscitation in hypotensive cats in an emergency room setting. Secondary objectives were to investigate changes in heart rate (HR) and body temperature (BT) in response to fluid resuscitation, and the association of these changes with patient survival.

DESIGN

Retrospective study.

SETTING

University teaching hospital.

ANIMALS

Eighty-two cats with confirmed hypotension.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical records from 2012 to 2019 were searched for cats that had documented systemic arterial hypotension (blood pressure measured using a Doppler ultrasonic flow probe [DBP] < 90 mm Hg) on presentation to the emergency room. Data collected included patient characteristics and DBP, HR, and BT before and after fluid resuscitation, type and volume of fluids administered, and outcome. The median DBP before and after resuscitative fluid therapy in all cats was 65 mm Hg (range, 20-85 mm Hg) and 80 mm Hg (range, 20-128 mm Hg), respectively (P < 0.001). However, only 30 cats (37%) were classified as responders to fluid resuscitation (DBP ≥ 90 mm Hg following bolus therapy). The mean HR and median BT before resuscitative fluid therapy was 159/min and 36.7°C. Following fluid resuscitation, where measured, the mean HR and median BT was 154/min (P = 1.00) and 35.9°C (P = 1.00). No significant differences in HR and BT were identified between responders and non-responders. Cats had a low survival rate of 7%. All survivors (n = 5) were initially bradycardic (HR < 160/min), compared to only 45% of non-survivors (P = 0.4).

CONCLUSIONS

Bolus fluid resuscitation effectively increases blood pressure in hypotensive cats; however, it does not result in normalization of blood pressure, HR, or BT in the majority of cases.

Crystalloid and Colloid Compositions and Their Impact

This manuscript will review crystalloid (hypo-, iso-, and hyper-tonic) and colloid (synthetic and natural) fluids that are available for intravenous administration with a focus on their electrolyte, acid-base, colligative, and rheological effects as they relate to each solution's efficacy and safety. The goal is for the reader to better understand the differences between each fluid and the influence on plasma composition, key organ systems, and their implications when used therapeutically in animals with critical illness.

Current fluid and blood product availability in veterinary setting: a survey of UK small animal practices

OBJECTIVES

To investigate and discuss current fluid and blood products stocked in small animal practices in the UK.

METHODS

An online survey was circulated to small animal veterinary practices across the UK. The survey included questions regarding the level of hospital care provided, the type of fluid and blood component products stocked, the most frequently restocked products, and the available options in the event that blood products were required but not stocked.

RESULTS

There were 423 responses including 27 duplicates. The remaining 396 respondents represented a spectrum of practices including 19 referral practices. Crystalloids were stocked in all practices. Lactated Ringer's solution was the most frequently re-stocked product in 355 of 396 (90%) of practices. Where synthetic colloids were stocked, gelatin-based colloids (155/178 [87%]) were stocked in preference to hydroxyethyl starches (23/178 [13%]). Blood products were stocked by 81 of 396 (20%) of practices. If a blood product was required but not stocked, 31% of practices would use a pet blood banking service, 28% would use their own blood donors, and 21% would refer.

CLINICAL SIGNIFICANCE

This study provides an insight into the fluid and blood products stocked and used by a selection of veterinary practices within the UK and serves as a baseline for ongoing research and decision-making in both veterinary practice and industry.

Recognition, Treatment, and Monitoring of Canine Hypovolemic Shock in First Opinion Practice in the United Kingdom

The aim of this study was to gain a greater understanding of the detection, treatment, and monitoring of hypovolemic shock (HVS) in dogs by general practitioners in the United Kingdom (UK). An online survey was devised and distributed by email to first opinion practices in the UK. All veterinarians working in first opinion practice treating small animals were eligible to complete the survey. Most respondents (n = 164, 93%) were confident with HVS diagnosis. Isotonic crystalloid fluids were the most common fluid type for first-line treatment and administered as a 10-30 mL/kg bolus over 10-30 minutes by 57% respondents. Initial intravenous isotonic crystalloid fluid rates for HVS management ranged from maintenance fluid requirements to 90 mL/kg/hr for an undefined time period. A synthetic colloid was the most popular second-line fluid choice, typically considered after a total administered volume of 60-90 mL/kg of isotonic crystalloid fluids. Only 72 respondents (40.7%) were able to measure blood lactate in-house, which was used routinely by 36 respondents (20.3%) for initial treatment decision making. Respondents treating HVS most frequently were more likely to use lactate for initial decision making (P = .008). This study highlighted variabilities in the initial approach, fluid management strategies and monitoring instituted by UK general practitioners when faced with canine patients in HVS. This suggests that there is a discrepancy in what is determined to be the most optimal diagnostic and treatment plan for canine HVS patients.

Why measuring outcomes is important in health care

A new strategy has been introduced in human health care, namely, achieving the best outcomes for the lowest cost and thus maximizing value for patients. In value-based care, the only true measures of quality are the outcomes that matter to patients. When outcomes are measured and reported, it fosters improvement and adoption of best practices, thus further improving outcomes. Understanding outcomes is central in providing value and represents an opportunity for redefining veterinary patient care. Value is created by improving the outcomes of patients with a particular clinical condition over the full cycle of care, which normally involves multiple specialties and care sites. To be successful, a key aspect of value based care is working as teams (integrated practice units) centered around the patient's clinical condition. As veterinary medicine has become more specialized and more complex, multidisciplinary communication and trust among the care team are paramount in providing value to patients (and clients). Use of patient-reported outcomes is an essential aspect for improving clinical care, because it enhances the connections among doctors and with patients. Designing and implementing owner-reported outcomes in veterinary clinical practice will lead to an understanding of the effects of treatments on outcomes and quality of life (QOL) of our patients from the owner's perspective, a key way to assess a veterinary patient's QOL.

Starch Wars-New Episodes of the Saga. Changes in Regulations on Hydroxyethyl Starch in the European Union

After a safety review of hydroxyethyl starch (HES) solutions in 2013, restrictions on the use of HES were introduced in the European Union (EU) to reduce the risk of kidney injury and death in certain patient populations. Similar restrictions were introduced by the Food and Drug Administration in the United States and other countries. In October 2017, a second safety review of HES solutions was triggered by the European pharmacovigilance authorities based on a request by the Swedish Medical Products Agency to completely suspend HES. After several meetings and repeated evaluations, the recommendation to ban HES was ultimately not endorsed by the responsible committee; however, there was a vote for more restricted access to the drug and rigorous monitoring of policy adherence. This review delineates developments in the European pharmacovigilance risk assessment of HES solutions between 2013 and 2018. In addition, the divergent experts' opinions and the controversy surrounding this official assessment are described. As the new decisions might influence the availability of HES products for veterinary patients, potential alternatives to HES solutions, such as albumin solutions and gelatin, are briefly discussed.