Collected and revised by: Edda Cava and Barbara Neri
45% of patients in hospital are malnourished or at risk of malnutrition. In COVID-19 patients the length of stay can worsen the nutritional status with increased disability, mortality and worse quality of life at discharge. The risk of malnutrition is high in polymorbid patients, elderly, those with low appetite, loss of skeletal muscle, reduced mobility, mastication problem or dysphagia, mental issue or dementia, social-economic problems. Therefore, all patients with SARS-COV-2 infection should undergo malnutrition screening.
Nutritional Screening for hospitalized patient is NRS-2002 that should be performed weekly. A score higher than 3 is considered risk of malnutrition. Pneumonia is considered already a score of 2 for severity.Indeed, risk of malnutrition is present for age >70, >5% weight-loss in the last 3 months, BMI< 20.5 Kg/m2, reduced food intake in the last week.
Food intake should be monitored with 2-3 days food diary for those patients able to eat.
Requirement for: energy (27-30 Kcal/kg/die), protein (>1g/kg/die SINPE)- (1,5g/kg/die Ansisa), lipids e carbohydrates, the latest with a rate lipids: carbohydrates between 30:70 (in those without respiratory distress) e 50:50 (if mechanical- ventilation).
Vitamin and Oligoelement supplementation, as for viral infection or deficiencies
Essential aminoacid supplementation, if malnourished or sarcopenic patients, or during rehabilitation treatment.
Oral Nutritional Supplements (ONS) if the patient is not able to meet nutritional requirement and covers at least a 50-60% intake for protein-energy requirements.
Artificial Nutrition (AN) should be considered when the food intake is lower than 50-60% of nutritional requirement (even after ONS administration) or in case oral nutrition is impossible for more than 3 days, with Enteral Nutrition (EN) as first choice, for intestinal trophysm and immunity and to sustain microbiota. Moreover, EN has lower risk of infective complications than Parenteral Nutrition (PN). Specific enteral formulae are available for different diseases, such as diabetes or kidney disease to tailor the intervention. In case of diarrhea, semi-elemental formula can be chosen. Nasogastric tube (NGT) is considered a standard approach for EN, connected to an infusion pump to start with incremental infusion rate (Sinpe: 40-60 ml/h then titrate by 10-20 ml/h every 24h) – (Ansisa: day 1-2 at 20-40 ml/h, day 3 at 30-50 ml/h, day 4-5 at 40-60 ml/h, on day 6 maximum tolerated infusion rate, add a fiber-enriched formula).
Supportive or total Parenteral Nutrition (PN), adding a daily mineral and vitamin supplementation, should be considered if EN is not sufficient for the patient, not tolerated, counterindicated or not accepted. Central access is needed if PN is needed >15 days, peripheral access if < 15 days or supportive to enteral nutrition. In patients with mask or canopy for noninvasive ventilation NP can be considered, especially to avoid interruption of assisted ventilation or O2-therapy during the meals, when liquids can be given by straw.
Oral feeding, meals and supplementation
Oral nutrition should be tailored by presence of comorbidity, chewing and swallowing capacity and nutritional status. Meals should be small and frequent. Snack with regular food can be supplemented with powder or liquid nutritional supplements calorie and protein-dense. Patients can have problem with lack of appetite, desaturation during meals, dysphagia, gastroenteric symptoms (nausea, gastric distension, vomit, diarrhea), some of these related to the pharmacological treatment or the enteric localization of the infection.
Post-piloric EN should be considered when there is high risk for aspiration, nausea or gastric residual volume is higher than 300 ml after 4hr.
Periodic blood tests are required on routine basis and based on clinical condition.
ICU and HDU
Assisted ventilation time in COVID-19 patients is about 14 day-long in mean, therefore at high nutritional risk. In ARDS an adequate nutritional support can counteract inflammatory patterns by sustaining immune system and avoiding malnutrition and sarcopenia, helping with breathing weaning and reducing time in ventilation. Moreover, ARDS patient has high risk of sepsis and MOF for kidney and cardiac failure. Also, gastrointestinal function and liver function are affected by high-PEEP during ventilation, and by medications and immobility.
Malnutrition Screening is needed in ARDS patients and >48hr after admission the risk is present. A NUTRIC score ≥5 (without IL-6 dosage) is considered higher nutritional risk.
Patient energy expenditure (EE) should be determined by using indirect calorimetry with due precautions, otherwise by the predicting formula REE = VCO2 x 8.19 (carbon dioxide production) derived from the ventilator or by VO2 (oxygen consumption) from pulmonary arterial catheter. In emergency situations, the predictive formula for energy needs 20-25 kcal/kg/die can be used with the actual weight in normal range, or BMI 22.5 Kg/m2 for overweight subjects or 25 Kg/m2 in obese subjects, or using 11-14 kcal/kg /die of actual body weight in BMI 30-50 or 22-25 kcal/kg of ideal body weight in BMI >50. In stable patients, EN by NGT can be started at slow infusion rate (SINPE 30-40 ml/h, SINUC 10-20 ml/hr) starting with a 30% of energy needs by calorimetry measurement, and titrating gradually up to 80-100% after the 3rd day. If predictive formulae are used a slightly hypocaloric nutrition (< 70% of estimated) should be provided during the first week, before achieving 80-100%. During the acute phase of disease, overfeeding can cause CO2 values increase, delayed breathing weaning, higher risk of sepsis, and higher blood glucose. A 24hr infusion is suggested in the early phase of disease.
Protein Requirements: during severe phase, 1.3g/Kg/day should be achieved gradually. Protein target should be reached at day 3-5 (Sinpe, ANDID: 1,3 g/kg/die up to a 2-2.5 g/ kg / IBW in obese patients or BMI 25 for BMI 30-40 e >40 kg/m2)- (Ansisa: 1.2- 2 g/kg/day)- (Sinuc 1.5 g/kg/day).
Glutammine supplementation is not recommended except for trauma and burn injuries.
Glucose/carbohydrate should not be given at > 5mg/kg/min or in case of hyperglycemia no more than 3-4 mg/Kg/min.
Intravenous lipid infusion should not be > 1.5 g/Kg/die adapted by single case.
Nutritional formulae at high Omega-3 (3-7 times the recommended dosage for healthy adults of 500mg EPA+DHA).
Severly ill patients with low Vitamin D blood levels (D < 12.5 ng/ml, o 50 nmol/l) can be supplemented.
Recommended fluid hydration is about 1.2-1.5 lt/day, pending variation by clinical condition (e.g. edema, fever, diarrhea, etc).
Pre- intubation period (HFNC, FNC or NIV)
FNC-HFNC patient can be fed orally.
NIV patients who are not able to eat, EN can be limited by NGT that may result 1) air leakage compromising the effectiveness of NIV; 2) stomach dilatation affecting diaphragmatic function and NIV effectiveness. Delayed or insufficient EN provision can cause malnutrition and related consequences, therefore PN should be considered in such cases with vitamin and oligo-elements supplementation.
EN should not be provided in the presence of uncontrolled shock and unmet hemodynamic and tissue perfusion goals; in case of uncontrolled life-threatening hypoxemia, hypercapnia or acidosis. Prone position and ECMO do not limit or contraindicate EN.
Gastric tube is preferred but in case of large gastric residual volume (above 500 mL after 6h or after 48-72h with prokinetic drugs or high risk of aspiration), duodenal tube should be inserted quickly.
In the early phase of disease, overfeeding should be avoided. Energy intake during artificial nutrition should account for calories administered by propofol (1,1/2,2 kcal/ml), dextrose (4 kcal/g), trisodium citrate (3 kcal/g).
EN should be started within 24-48h from the admission in stable hemodynamic patients without uncontrolled hypoxiemia or hypercapnia. PN should be provided only after any effort to ensure EN has been tried. In case NP is chose, a minimal enteral feeding with a polymeric formula should be infused for GI trophism (10 ml/h/24h).
Post-ventilation period and dysphagia
After intubation patients have a high rate of dysphagia that can last for weeks and can limit nutrient intake. Therefore, sometime dietary modifications are needed to adapt texture to the swallowing capability. If the risk of aspiration still persists, a NGT can be needed for EN.
- CO2 production is related to total calories rather than carbohydrates content in the formula.
- Gut microbioma is often impaired and TPN can worsen it. A minimal enteral feeding or oral feeding with probiotics can reduce the risk of bacterial translocation and can help during antibiotic treatment.
- Whey protein up to 40g per day can help during or right after pulmonary rehabilitation or physical therapy/ exercise movement.
- During AN be cautious to prevent refeeding syndrome, expecially in PN.
- Modified texture meals should be provided taking care of low bacterial load to avoid secondary infections.
- SINUC suggests to supplement EN with i.v micronutrients starting from the first day (tiamin 100-300 mg/day, multivitamin, trace elements) for the first 3 days and twice a week afterwards until the EN reaches 1500ml/day.