Plus-Hex CLINICAL
Figure 1 . It is possible to reduce the preoperative starvation time to 4 hours in cats fed wet food [ 21 ] . [ Image : www . istockphoto . com ]
Where possible , preoperative blood tests are encouraged and are deemed the gold standard , due to the systemic risks of organ dysfunction . They are also important when considering nutrition , as patients with protein levels below 2.3 g / l are at higher risk of wound breakdown and delayed healing . Preoperative or enteral nutrition is also recommended for patients experiencing hypoalbuminaemia suggestive of proteinlosing enteropathy , anaemia or lymphopenia [ 25 , 26 ] . In these cases , unless the surgery is urgently needed , it should be delayed until hypoproteinaemia is corrected , either through dietary means or supplementation with DL-methionine and cysteine , or through the provision of fresh frozen plasma [ 17 ] .
In human medicine , postoperative nausea and vomiting is reported in 26 – 31 % of patients . While this has not been documented in small animals , prophylactic antiemetics could be considered where signs of nausea are evident , including salivation , excess swallowing , yawning , shivering or depressed mentation [ 2 ] .
Gut microbiome science has advanced recently to encompass an appreciation of the microbiome ' s effects on genetic diversity , as a modifier of disease , a vital component of immunity , an influencer of metabolism rates and a modulator of drug interactions . This delicate balance is affected by factors including diet , antibiotics , probiotics and variations in macronutrients , all of which can change a patient ' s unique intestinal microbiome , including differentiation along the length of the gastrointestinal tract [ 27 ] .
The role of nutrition in healing
Fuel sources for a sick patient are often the same as those for the healthy patient – protein and fats for carnivores and carbohydrates for herbivores [ 28 ] .
Poor nutritional status can be caused by inadequate nutrient intake or absorption , serious underlying disease and protein losses [ 29 ] . In the case of surgical or hospitalised patients , this may be related to deliberately withholding food prior to anaesthetic or sedative agents or to anorexia or inappetence .
Reduced nutritional intake results in a protein and / or calorie deficiency , which leads to stress starvation , a process in which the body catabolises lean body mass , and leads to cachexia , or loss of lean body mass [ 29 ] . The degree of infection risk , wound healing , immunity , mobility , mortality and tolerance of invasive procedures are compromised by reduced nutritional status [ 2 , 30 ] .
Any patient that has been inappetent or anorexic for 3 days or more ( including prior to admission ), has not been consuming 80 % of its calculated resting energy requirement ( RER ), or has experienced an unintentional weight loss of 10 % or more , should be considered for assisted feeding . This is especially important where hospitalisation may be a contributing factor in the inappetence , for example , if it is causing stress but is deemed necessary by the veterinary surgeon ( VS ) [ 29 , 31 ] , or where pain is an implicating factor in the inappetence , so concurrent analgesia should be provided [ 17 ] .
Volume 39 ( 1 ) • February 2024
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