Failure to thrive

Background

Non-specific term indicating inappropriate weight loss or insufficient weight gain, due to insufficient caloric intake, insufficient caloric absorption, or excessive caloric demand.
Separated into pediatric and adult (often seen in geriatric populations or in those with chronic illnesses).

Defined as weighing <5th percentile for age and sex, or weight deceleration crossing two major growth lines on a growth chart.
Does not imply a defect in social, intellectual, or emotional development, but if untreated may lead to any combination of those.
Classically divided into endogenous (medical) and exogenous (psychosocial or environmental) causes

A detailed history and physical examination (including accurate height and weight) are usually sufficient to establish a cause. Over 80% of cases are due to insufficient caloric intake from exogenous causes.
- History should focus on breastfeeding technique, frequency, and duration, or amount of formula and method of preparation.
- Observed feeds can often be useful to identify problems.
If an endogenous cause is suspected, specific lab tests or imaging studies may be helpful to evaluate for metabolic abnormalities, the presence of infections, malignancy, or anatomic malformations. Additional testing should be ordered on a case by case basis and is only recommended if a specific etiology is suspected.

Most cases can be discharged with PCP follow up. PCPs can make appropriate referrals for nutritional counseling, lactation coaching, or formula supplementation.
Indications for hospitalization include failure of outpatient management, suspicion of endogenous cause requiring urgent management, suspicion of abuse or neglect, signs of traumatic injury, severe psychosocial impairment of the caregiver, or evidence of serious malnutrition (<70th percent of predicted weight for length).

Usually multifactorial and seen in patients with chronic illnesses.
Patients often have a combination of physical impairment, malnutrition, depression, and cognitive impairments.
Defined as unintended weight loss >5% from baseline, decreased appetite, poor nutrition, inactivity, and often accompanied by dehydration, depressive symptoms, and impaired immune function.

History and physical examination are often sufficient to make the diagnosis. Many elderly patients with failure to thrive will be unable to provide an accurate history, so family members or caregivers must be involved.
- A thorough review of medications is necessary, as polypharmacy may contribute to failure to thrive.
- A Mini Mental Status Exam (MMSE) should be performed to screen for cognitive decline.
Limited laboratory and imaging studies are recommended to screen for treatable medical conditions that may contribute to failure to thrive.
- CBC with cultures, CMP, ESR, CRP, TSH, UA, HIV, RPR, PPD, and CXR are usually indicated.

Chronic or recurrent infections
Immunodeficiency
Endocrine disorder
Cancer
Chronic lung disease
Chronic renal insufficiency
Heart failure
Hepatic failure
Hip or other large bone fracture
Inflammatory bowel disease
Malabsorption or malnutrition
Rheumatologic diseases
Stroke
Depression
Dementia
Psychosis
Medication side effects or interactions
- Anticholinergics, antiepileptics, benzodiazepines, beta blockers, central alpha antagonists, diuretics, steroids, neuroleptics, opioids, SSRIs, and TCAs are common culprits

If a specific medical cause can be identified, treatment should be tailored to the etiology, taking into account the potential risks for already frail patients.
Oftentimes, treatment will involve nutritional supplementation, physical/occupational/speech therapy, modifications of living environment, and treatment of depression and/or dementia.

Authors: