Presently, no drug has been officially and specifically approved for COVID-19 treatment, and symptomatic treatment remains the only viable option: it is hoped that with a good state-of-health, patients will gradually develop immunity and recover. Health officials such as the National Health Commission of the PRC, as well as health professionals, marked nutrition support as a key element for COVID-19 illness management, especially for severe and critical cases. In the following article, MXNS experts in China reviewed existing literatures on the importance of nutritional support for pneumonia, hoping to provide a general insight for the COVID-19 illness management. 

Why is nutritional support needed for patients with pneumonia?

Due to impaired lung function, malnutrition can become a serious challenge for patients with pneumonia.

1. Severe respiratory disorders may lead to hypoxia (a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level) or hypoxemia (an abnormally low level of oxygen in the blood), resulting in a high number of compensatory respirations, characterized by increased breathing frequency and shortness of breath. As the overworking breathing muscles undergo intense stress, the energy expenditure for breathing may reach ten times as high as that of a healthy person, drastically increasing the body’s energy requirement [1]. 

2. Meanwhile, in the case of a viral infection, inflammatory responses such as hypercatabolism and hypermetabolism significantly increase the body’s energy requirements. 

3. At the same time, pneumonia’s symptoms such as weakened immune system, aerophagia from long-term open mouth breathing, decreased mobility, or even depression, compromise patients’ nutritional status [2]. 

All three factors contribute to the risk of malnutrition in patients with pneumonia. Moreover, pneumonia weakens cell metabolism and recovery capacity, immunity, and muscle strength and volume. As muscle strength and volume reduces, so does respiratory efficiency, triggering a vicious downward spiral in the body system. Hence, maintaining a good nutritional status is not only the key to pneumonia treatment efficiency, but also a prerequisite to preventing the disease condition from worsening.

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Risk of malnutrition is higher in older adults with pneumonia

As of early February, the epidemiological data indicated that the patients over 60 years old represent the highest proportion of coronavirus cases in China: 44.1% in Wuhan, 35.1% in Hubei, and 31.2% in China [3]. 

The risk of malnutrition in elderly patients with pneumonia, notably due to organ degenerative changes, decreased protein synthesis, inflammatory response, and reduced hormone level (reduced thyroid and adrenal function), is higher compared to that of young and/or healthy elderly [4]. 

A study on elderly nutrition status has pointed out that the malnutrition incidence in elderly patients with pneumonia is 35.7%, the nutritional risk incidence is 58.3%, and the total incidence of malnutrition and/or nutritional risk is as high as 94.0% [5]. 

Another study showed that among elderly patients with community-acquired pneumonia, the malnutrition rate reached 34.4%, with the malnutrition incidence rate in the severe pneumonia group (48.2%) significantly higher than that of the non-severe pneumonia group (24.7%) [6]. 

A retrospective analysis of 105 elderly pneumonia cases issued similar conclusions by dividing subjects into the death group (n = 41) or the cured group (n = 64) and observing two malnutrition indicators: hypoproteinemia and anemia.

The results indicated that both hypoproteinemia and anemia incidence were significantly higher in the death group than in the cured group (hypoproteinemia: 56.09% (death) vs. 23.44% (cured), p<0.05; anemia: 58.54% (death) vs. 29.68% (cured), p <0.05) [7]. 

Therefore, poor nutritional status appears to be one of the potential influencing factors for severe pneumonia, calling for early assessment and intervention in the pneumonia treatment [6] [8] [9].

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Nutritional support has notable benefits for the elderly and critically ill patients

During the COVID-19 epidemic in China, patients over 60 years old not only accounted for a higher proportion among critically ill patients, but also manifested a higher mortality rate than all other age groups [3]. Looking at the current evidence, we believe that malnutrition makes an important risk factor in severe illness development for older adults, for malnutrition not only hinders the treatment, but also dims the prognosis for elderly patient population. 

Previous research literatures suggest that, if patients with pneumonia get nutritional support in time, treatment effect could be enhanced. 

A study compared elderly patients with severe pneumonia who did not receive nutritional support at an early stage (control group) against those who received enteral nutritional support within 24-48 hours upon illness onset (experimental group). The group receiving enteral nutritional support demonstrated a significantly higher cure rate than the control group (90.0% vs. 71.4%, respectively, p<0.05) [10].

Another study observed the combined effect of respiratory and nutritional support on elderly patients with severe pneumonia. The control group (n = 45) received only respiratory support, while the experimental group (n = 45) also received nutritional support (enteral intake via the nasogastric tube). The experimental group required a shorter time to cure respiratory failure than the control group did (4.61 ± 0.72 days vs. 5.93 ± 1.04 days, respectively). In fact, the partial pressure of carbon dioxide (PaC02) was significantly lower, and the partial pressure of oxygen (PaO2), as well as the level of albumin, hemoglobin, and body weight, were significantly higher (p <0.05) in the experimental group [11].

A four-week intervention compared two groups of older adults with severe pneumonia: one received enteral nutritional support (experimental group) and the other one a normal diet (control group). Both anthropometric measurements (Body Mass Index, upper arm muscle circumference, triceps skinfold thickness) and immune system indicators (T-lymphocytes count, immune cell subsets count) were significantly better for the experimental group. Moreover, the complication incidences of experimental group (gastric retention, diarrhea, bloating, hyperglycemia, upper gastrointestinal bleeding) was significantly lower than that of the control group (5% vs. 21.42 %, respectively) [12]. 

Dong et al. concluded that, after receiving nutrition support for 28 days, patients with severe or non-severe pneumonia may expect to see significant improvements in nutritional indicators such as prealbumin, albumin, and chronic health status (as assessed by Acute Physiology and Chronic Health Evaluation (APACHE) II score) [5].

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Pneumonia patients with malnutrition may find themselves trapped in a vicious circle: pneumonia symptoms increase the risk of malnutrition, and malnutrition negatively impacts patients’ treatment and prognosis, which further worsens the disease condition.

To combat such challenge, nutritional support is the key. Preferably initiated at the early stage of the disease, nutrition support has demonstrated its superiority in improving the nutritional status of patients, shortening the length of treatment, improving disease prognosis, strengthening the immune system and reducing complications.

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– About the authors – 

Lin Wan, MSc, RD

Lin is a nutrition specialist in Biofortis China. She manages operational aspects of clinical trials, coordinates communication among all stakeholders, and offers her professional insight from a nutritional perspective. Prior to joining Biofortis China, she worked as registered dietitian in hospitals and specializes in disease-specific nutrition intervention.

Dingqiang Li, Ph.D., DVM

Dr. Li leads the team responsible for implementation of clinical trials in China and he possesses rich experience in various aspects of conducting clinical trials. He closely works with Biofortis research centers in Europe and North America, clients and local key health professionals.


– References –

[1]Jin, F.N., & Fan, M. (2015). Progress review on nutrition therapy for severe pneumonia. Modern Medicine & Health, (16), 2443-2445. DOI: 10.3969/j.issn.1009-5519.2015.16.013

[2]Mahan, L.K., Escott-Stump, S., & Raymond, J.L. (2012). Krause’s Food & the Nutrition Care Process.

[3]Epidemiology Working Group for NCIP Epidemic Response. The epidemiological characteristics of an outbreak of 2019 novel coronavirus diseases (COVID-19) in China. (2020), Chinese Journal of Epidemiology. 41(2): 145-151.

[4]Yao, K.W., Li, J.S., Ma, L.J. & Wu, J.Z. (2003). Investigation of Nutritional State of the Senile Patients with Pneumonia. Journal of Beijing University of Traditional Chinese Medicine, 26(4), 72-74. DOI: 10.3321/j.issn:1006-2157.2003.04.025

[5]Dong, H.Y., Ceng, Y., Xie, J., Zhou, Z.Y., Huang, Y., & Hao Dong-Hui, et al. (2015). Nutritional assessment and nutritional interventions in the elderly inpatients aged over 80 with pneumonia. Practical Geriatrics, 29(5): 415-418.

[6]Kang, Y., Fang, X.Y., Hou, Y.P., Zhang, Y., Chen, X.L., & Wang, X.J. (2018). Relationship between Nutritional Status and Severity of Pneumonia in Elderly Patients with Community-acquired Pneumonia. Chinses Gerenal Practice, 21(28), 86-90. 

[7]Zhou, X.M., Sun, H.P., Liu, B.X. & Liu, S.S. (2010). Impact of malnutrition on treatment for elderly patients with pneumonia. Hebei Medical Journal, 32(4), 429-430. DOI: 10.3969/j.issn.1002-7386.2010.04.024

[8]Rice, T. W., Wheeler, A. P., Thompson, B. T., Steingrub, J., Hite, R. D., & Moss, M., et al. Initial trophic vs full enteral feeding in patients with acute lung injury: the eden randomized trial. (2012). Journal of the American Medical Association, 307(8), 795-803.

[9]Riquelme, R.,Torres, A. , El-Ebiary, M. , De, l. B. J. P. , Estruch, R. , & Mensa, J. , et al. (1996). Community-acquired pneumonia in the elderly: a multivariate analysis of risk and prognostic factors. American Journal of Respiratory and Critical Care Medicine, 154(5), 1450-1455.

[10]Wu, N., Qi, Y.Q., Chen, X.S., & Wan, W.H. (2013). Clinical application of respiratory support combined with nutrition support in elderly patients with severe pneumonia. Chinese Journal of Multiple Organ Diseases in The Elderly, 12(1), 29-33.

[11]Feng, Y.G. (2015). Exploration on application value of respiratory support combined with nutritional support in the treatment of elderly patients with severe pneumonia. International Journal of Geriatrics, (36), 212. 

[12]Xin, H.Y., Niu, L., Ning, J., Hou, Y.Y., & Hu, D.H. (2019). Effect of Enteral Nutrition Support on Nutritional Level and T Lymphocyte Subsets in Elderly Patients with Severe Pneumonia. Journal of Henan University of Science & Technology (Medical Science) (2), 108-110.