Nutritional requirements of the critically ill patient

High carbohydrate is preferable to high lipid parenteral nutrition in healthy dogs undergoing prolonged sedation

Parenteral nutrition (PN) is commonly used in intensive care units (ICUs) and is associated with earlier hospital outcome. However, there is scarcity of information about the metabolic effects of PN caloric distribution for dogs. Considering the high tolerance of dogs to lipids and, also, that hospitalized animals usually present insulin resistance, PN formulation with high fat instead high glucose can provide metabolic benefits in this specie. This study evaluated two PN protocols, based on high lipid or high carbohydrate in 12 healthy dogs under sedation/ventilation during 24 h. For baseline data, blood samples were collected 24 h before the study beginning. After fasting, the dogs were anesthetized and put under mechanical ventilation without energy support for 12 h to obtain: daily energy expenditure (DEE), respiratory quotient (RQ), oxygen consumption (VO2), carbon dioxide production (VCO2), lactate, glucose, cholesterol, and triglycerides concentrations. After, the dogs were allocated into two groups: lipid-based energy group (LEG) and carbohydrate-based energy group (CEG). Both groups received the PN infusions at a rate of 3 mL/kg/h for 12 h. Blood tests were performed 12, 24, and 48 h after infusion's completion. VO2 increased after PN in LEG, increasing energy expenditure compared to CEG. RQ remained close to 1 in CEG, indicating carbohydrate preferential consumption. Triglycerides increased in both groups after propofol infusion, remaining higher in LEG until the end of the evaluation. Glycaemia increased in CEG compared to baseline. In conclusion, both PN protocols can be used in healthy animals undergoing prolonged sedation protocols. However, high lipid PN had higher VO2 and DEE, and resulted in higher triglycerides concentrations and lower glycaemia indexes than carbohydrate, making high carbohydrate PN preferable to high lipid PN. Therefore, for use in critically ill patients, the data obtained in this study should be extrapolated, taking into consideration the specificity of each case.

2022 ISFM Consensus Guidelines on Management of the Inappetent Hospitalised Cat

PRACTICAL RELEVANCE

Inappetence may have many origins and, as a presenting sign or observation in the hospitalised patient, is common in feline practice. Nutritional assessment of every patient is encouraged, to identify the need for, and appropriate type of, intervention indicated. The impact of malnutrition may be significant on the feline patient, perpetuating illness, delaying recovery, slowing wound healing and negatively impacting gut health and immunity. Delayed intervention may result in the cat's deterioration; hence prompt control of contributing factors such as the underlying illness, pain, nausea, ileus and stress is vital to optimise voluntary food intake. Management is multimodal, comprising reduction of stress, medications and assisted nutrition in the form of tube feeding or parenteral nutrition. Use of antiemetic, analgesic, prokinetic and appetite stimulant medications may restore appetite, but placement of feeding tubes should not be delayed. Feeding tubes are generally well tolerated and allow provision of food, water and medication with minimal stress, although clinicians must be aware of complications such as stoma site infections and refeeding syndrome.

CLINICAL CHALLENGES

Cats are vulnerable to malnutrition owing to their unique metabolism and specific nutritional requirements. Moreover, their nature as a species means they are susceptible to stress in the hospital environment, which may result in reduced food intake; previous negative experiences may compound the problem. In particular, an inappropriate clinic environment and/or handling may cause or exacerbate inappetence in hospitalised patients, with negative impacts on recovery. Postponing interventions such as feeding tube placement to await improvement, owing to clinician or caregiver apprehension, may hinder recovery and worsen nutritional deficits.

EVIDENCE BASE

The 2022 ISFM Consensus Guidelines on Management of the Inappetent Hospitalised Cat have been created by a panel of experts brought together by the International Society of Feline Medicine (ISFM). Information is based on the available literature, expert opinion and the panel members' experience.

Nutritional Support of the Critically Ill Small Animal Patient

Over the past couple of decades, a component of veterinary critical care was simply to ensure that nutritional support formed some part of the treatment plan. Great emphasis was made on early placement of feeding tubes in critically ill veterinary patients to facilitate enteral feeding. Progress has been made on techniques for nutritional provision, establishing feasibility of nutritional interventions in various patient populations and establishing that nutritional support does have an important role in veterinary critical care. Some refinement of appropriate caloric targets in critically ill animals has decreased complications relating to overfeeding, but further work is required to establish optimal feeding regimes.

Retrospective study of complications associated with surgically-placed gastrostomy tubes in 43 dogs with septic peritonitis

OBJECTIVES

To determine the safety of surgically-placed gastrostomy feeding tubes in dogs with septic peritonitis.

MATERIALS AND METHODS

Retrospective analysis of 43 dogs with septic peritonitis that had undergone surgical exploration and gastrostomy tube (de Pezzer or Foley) placement as part of the surgical procedure. Postoperative recovery times, hospitalisation times, complication rates and overall survival times were documented.

RESULTS

The most common cause of septic peritonitis was dehiscence of an enterotomy or enterectomy site. Fifteen dogs had a Foley gastrostomy tube placed and 28 had a de Pezzer gastrostomy tube placed. The median time from surgery to the start of enteral nutrition was 16 hours (range 3 to 28 hours). There were no major complications relating to the gastrostomy tube; minor complications occurred in 11 (26%) patients. The overall median time spent in hospital was 5 days (range 3 to 29 days) for patients surviving to discharge and 22 (51%) dogs survived overall.

CLINICAL SIGNIFICANCE

Gastrostomy feeding tubes provide a safe way to provide enteral nutrition to dogs with septic peritonitis; they are associated with a low complication rate in these patients.

Evaluation of the Prevalence and Risk Factors for Undernutrition in Hospitalized Dogs

Hospitalized dogs are predisposed to undernutrition, which can potentially affect outcome. This study evaluated the prevalence of undernutrition in hospitalized dogs (measured as loss of body condition score, BCS and body weight, BW) and studied the risk factors that affect nutritional status, and outcome (discharge or death). Data was collected prospectively during 9 months from 500 hospitalized dogs with a hospitalization length longer than 24 h in a veterinary teaching hospital in Spain. The BCS and BW changes were modeled using multiple linear regression and outcome was modeled using logistic regression. The risk factors studied were energy intake, hospitalization length, initial BW and BCS, age, sex, severity of clinical signs, department of admission, fasting or nutritional interventions, and the presence of anorexia, vomiting or diarrhea at admission. Most of the dogs (84.0%) consumed less than 25% of their energy requirements and only 3.4% of the dogs met these requirements. The majority of hospitalized dogs maintained their BCS (78.2%) and BW (77%) during hospitalization. Older patients (P = 0.040), higher initial BCS (P < 0.001), and vomiting at admission (P = 0.030) were associated with a decrease of BCS status during hospitalization. BCS was also decreased in patients with low energy intake, particularly in patients with hospitalization length longer than 3 days (P < 0.001). Both longer hospitalization length (P < 0.001) and vomiting at admission (P = 0.004) were also associated with a decrease in BW. Dogs that consumed their theoretical energy requirements [P < 0.001; Odds Ratio (OR) 0.95, 95% CI: 0.92 to 0.98], and had a higher initial BCS (P < 0.001; OR 0.39, 95% CI: 0.22 to 0.63) had a lower odds of dying. Anorexia at admission (P < 0.001; OR 5.67, 95% CI: 2.23 to 15.47) was associated with a higher risk of death. The results from this study support the finding that undernutrition is relatively common during hospitalization, with age, hospitalization length, decreased energy intake, and vomiting at admission as risk factors for undernutrition. Furthermore, an association was found between inadequate energy intake and death.

Capromorelin: a ghrelin receptor agonist and novel therapy for stimulation of appetite in dogs

Ghrelin is a hormone, secreted from cells in the stomach, which is important in the regulation of appetite and food intake in mammals. It exerts its action by binding to a specific G-protein-coupled receptor, the growth hormone secretagogue receptor 1a (GHS-R1a) which is found in areas of the brain associated with the regulation of food intake. Ghrelin causes a release of growth hormone (GH) through binding to GHS-R1a in the hypothalamus and pituitary gland. A class of compounds known as growth hormone secretagogues, or ghrelin receptor agonists, were developed for therapeutic use in humans for the stimulation of GH in the frail elderly, and have subsequently been studied for their effects on increasing appetite and food intake, increasing body weight, building lean muscle mass, and treating cachexia. Subsequent research has shown that ghrelin has anti-inflammatory and immunomodulatory effects. This article reviews the basic physiology of ghrelin and the ghrelin receptor agonists, including the available evidence of these effects in vitro and in vivo in rodent models, humans, dogs and cats. One of these compounds, capromorelin, has been FDA-approved for the stimulation of appetite in dogs (ENTYCE ®). The data available on the safety and effectiveness of capromorelin is reviewed, along with a discussion of the potential clinical applications for ghrelin receptor agonists in both human and veterinary medicine.

Retrospective evaluation of ProcalAmine administration in a population of hospitalized ICU dogs: 36 cases (2010-2013)

OBJECTIVE

To describe the use of ProcalAmine as a source of parenteral nutrition in hospitalized dogs and to report complications possibly referable to its use.

DESIGN

Retrospective study.

SETTINGS

Private veterinary teaching hospital.

ANIMALS

Thirty-six dogs hospitalized in ICU receiving ProcalAmine between October 2010 and March 2013.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The most common underlying disease process in this population of dogs was trauma (n = 8). Median duration of administration was 4 days and median resting energy requirement provided via ProcalAmine was 33%. ProcalAmine was administered via central catheters in 86% of cases and via peripheral catheters in 14% of cases. The overall mechanical complication rate was 19%. Metabolic complications possibly associated with ProcalAmine administration were documented in 12/36 dogs. Hyponatremia was most commonly identified (n = 6) followed by hyperglycemia (n = 4), hypochloremia (n = 2), azotemia (n = 2), metabolic alkalosis (n = 2), hyperchloremia (n = 1), and metabolic acidosis (n = 1).

CONCLUSION

ProcalAmine appears to be relatively safe and a viable option for parenteral nutrition in ill and injured dogs. Due to the potential for electrolyte derangements and other metabolic complications, daily monitoring of these parameters is advisable.

Postoperative management of dogs with gastric dilatation and volvulus

The objective of the study was to review the veterinary literature for evidence-based and common clinical practice supporting the postoperative management of dogs with gastric dilatation and volvulus (GDV). GDV involves rapid accumulation of gas in the stomach, gastric volvulus, increased intragastric pressure, and decreased venous return. GDV is characterized by relative hypovolemic-distributive and cardiogenic shock, during which the whole body may be subjected to inadequate tissue perfusion and ischemia. Intensive postoperative management of the patients with GDV is essential for survival. Therapy in the postoperative period is focused on maintaining tissue perfusion along with intensive monitoring for prevention and early identification of ischemia-reperfusion injury (IRI) and consequent potential complications such as hypotension, cardiac arrhythmias, acute kidney injury (AKI), gastric ulceration, electrolyte imbalances, and pain. In addition, early identification of patients in need for re-exploration owing to gastric necrosis, abdominal sepsis, or splenic thrombosis is crucial. Therapy with intravenous lidocaine may play a central role in combating IRI and cardiac arrhythmias. The most serious complications of GDV are associated with IRI and consequent systemic inflammatory response syndrome and multiple organ dysfunction syndrome. Other reported complications include hypotension, AKI, disseminated intravascular coagulation, gastric ulceration, and cardiac arrhythmias. Despite appropriate medical and surgical treatment, the reported mortality rate in dogs with GDV is high (10%-28%). Dogs with GDV that are affected with gastric necrosis or develop AKI have higher mortality rates.

Plasma transferrin concentration as a nutritional marker in malnourished dogs with nutritional treatment

Rapid turnover proteins, such as transferrin (Tf), are used as dynamic nutritional assessment proteins in human medicine. However, nutritional status in veterinary medicine is mostly assessed on the basis of classical static factors, such as body weight, body condition score and plasma albumin level. This study evaluated the clinical usefulness of Tf as a nutritional assessment marker by measuring plasma Tf concentrations in malnourished dogs before and after nutritional treatment. Posttreatment plasma Tf concentrations were significantly higher than the pretreatment concentrations, although the albumin concentration did not change significantly. The numbers of dogs that exhibited increases in plasma Tf concentrations were significantly related to weight gain. Furthermore, the survival rates at day 60 after treatment initiation were significantly higher in dogs with plasma Tf concentrations above the reference value (180 mg/dl) after the nutritional treatment than in those with a plasma Tf concentration<180 mg/dl. In conclusion, the plasma Tf concentration is related to nutritional condition and would be a candidate for a novel nutritional assessment marker in dogs.

The Inappetent Hospitalised Cat: clinical approach to maximising nutritional support

PRACTICAL RELEVANCE

Inappetence is one of the most common presenting complaints in clinically ill cats requiring hospitalisation. When prolonged, poor food intake can lead to malnutrition and may be associated with impaired metabolic function, immunosuppression, compromised wound healing, and increased morbidity and mortality. It is important to recognise that inappetence or anorexia is always secondary to another condition, and that treatment goals should be targeted at the primary condition. The current emphasis in the nutritional support of hospitalised inappetent cats is to provide more effective means of increasing nutritional intake--for example, by initiating enteral nutrition via feeding tubes-- rather than rely solely on traditional approaches such as increasing palatability of foods or using appetite-stimulating drugs.

CLINICAL CHALLENGES

Cats that are ill enough to require hospitalisation are at increased risk of becoming malnourished because of the combined catabolic effects of their disease and poor nutritional intake. This article highlights some of the problems encountered in treating inappetent cats and discusses a clinical approach to providing better nutritional support.

PATIENT GROUP

Inappetence and anorexia are associated with a myriad of clinical conditions in cats and can be seen in individuals of any age or breed.

EQUIPMENT

Provision of nutritional support to cats may involve the use of feeding tubes such as naso-oesophageal or oesophagostomy tubes. In cases where enteral nutrition is not feasible (eg, cats with gastrointestinal failure), parenteral nutrition should be considered.

EVIDENCE BASE

Various studies have documented the high prevalence of inappetence or anorexia in clinically ill cats. Additional studies have linked poor food intake in cats with serious sequelae such as immunosuppression and hepatic lipidosis. More recently, techniques for providing more effective nutritional support, such as oesophagostomy tubes, have been clinically evaluated and shown to be associated with minimal complications.

Normograde, minimally invasive technique for oesophagostomy in cats

A percutaneous technique to place oesophageal feeding tubes in cats is described. Nineteen traumatised cats underwent different surgical procedures for facial and/or oral trauma and subsequent oesophagostomy. The tube placement was easy to perform, requiring a 14G over-the-needle vascular catheter, a curved forceps and a 1.2mm feeding tube. During insertion, the tube was directed aborally (normograde direction) to its definitive position in a one-step procedure. The tube was removed when the patient started to eat voluntarily. A major limit of this technique was represented by the small diameter of the feeding tube, requiring the use of a liquid diet. However, considering the absence of complications, the rapidity of the procedure and its cost efficacy, it was considered as an effective alternative to more complicated and invasive techniques, in particular if a short period of starvation is predictable.

Critical care nutrition for feline patients

Nutritional treatment in critical care patients is an important component of the complete treatment plan. Assessment of nutritional status and careful consideration of the disease course will help guide the selection of the most appropriate assisted-feeding method. Enteral nutrition is favored over parenteral nutrition when the gastrointestinal tract is functional. Common routes of enteral feeding include nasoesophageal, esophagostomy, gastrostomy, and jejunostomy feeding tubes. Parenteral nutrition is indicated for patients who cannot tolerate enteral feedings, or are poor anesthetic candidates for proper feeding tube placement. Appropriate diet selection and implementation of proper feeding guidelines and monitoring will aide in limiting complications associated with enteral and/or parenteral feeding.

Complications and outcomes of one-step low-profile gastrostomy devices for long-term enteral feeding in dogs and cats

Sixteen dogs and cats with a variety of primary diseases were retrospectively evaluated following endoscopic placement of a one-step low-profile gastrostomy device. Overall, the devices were well tolerated, with most complications being minor in nature. Complications included bloody or purulent peristomal discharge, peristomal swelling, peristomal inflammation, discomfort associated with the device, leaking through the device, chewing at the device, premature removal of the device, peritonitis, and aspiration pneumonia. Dogs survived for up to 2241 days, and cats survived for up to 593 days after initial device placement. The median survival time after device insertion for dogs was 89 days, and for cats it was 87 days.

Nutrition in critical illness

Malnutrition associated with critical illness has been unequivocally associated with increased morbidity and mortality in humans. Because malnutrition may similarly affect veterinary patients, the nutritional requirements of hospitalized critically ill animals must be properly addressed. Proper nutritional support is increasingly being recognized as an important therapeutic intervention in the care of critically ill patients. The current focus of veterinary critical care nutrition, and the major focus of this article, is on carefully selecting the patients most likely to benefit from nutritional support, deciding when to intervene, and optimizing nutritional support to individual patients.