Clinical signs for screening acute undernutrition

Famine oedema
Clinical models
Activities of daily living
Summary - the use of clinical models

For many years, it has been recognised that undernutrition increases both susceptibility to, and the severity of, infection. Vitamin, mineral and other dietary deficiencies, depressed cell mediated and humeral immunity, gastric acidity, mucosal integrity and altered flora are all known to increase susceptibility to infection and the ability of an individual to utilise their energy and protein reserves ^{83, 84}. The situation in an emergency is usually made worse by the breakdown in public health infrastructure and the congregation of displaced people in crowded and unhygienic conditions ⁸⁵. This combination of poor public health environment and immunosuppression means that in famine it is usually infection combined with metabolic dysfunction rather than absolute loss of fat or fat-free mass that kills people. This is different from the situation in industrialised countries where exhaustion of fat or fat-free mass is more often the terminal event ^{86, 73}.

Therefore, the clinical signs of infection or metabolic dysfunction are likely to be useful prognostic indicators. This possibility has been investigated in children but rarely in adults ^{87, 88}. Although reported as effective in identifying children at a high risk of mortality ⁸⁸, these models have been criticised because the interactions between the features used, such as oedema and hypoprotinaemia, were not taken into account ⁴.

Famine oedema

In both children and adults, famine oedema has long been recognised as an important sign relating to the severity of undernutrition (see above). In adults, famine oedema is common (see Table 2) and usually (but not always) related to a poor prognosis (see Figure 2) ^{89, 42, 39, 92}. For this reason the presence of famine oedema is usually used as an indicator of severe undernutrition. It is important to note, however, that the prognostic significance of adult famine oedema varies according to the context and in some occasions, the sign is of less use as an indicator of severity.

Famine oedema in adults should be diagnosed in a similar way to that in children, using firm pressure applied over a bony prominence for approximately 3 seconds and assessing whether an indentation remains after the pressure is removed. The severity of oedema should be graded using the system devised by Beattie during the Second World War (see Table 4) ⁸⁹. In our experience pitting oedema of grade 3 and above are often associated with a markedly worse prognosis particularly if they occur in male patients ³⁹. Lesser grades of oedema rarely appear to be clinically relevant.

It is important to note that oedema in adults may be induced by reasons other than undernutrition including cardiac, vascular, renal and hepatic disease. Differentiating between nutritional oedema and oedema secondary to other causes can be difficult and usually requires clinical expertise.

Table 4 Classification of famine oedema based on the Beattie classification ⁸⁹

Grade	Extent of oedema
0	absent
1	minimal oedema on the foot or ankle that was demonstrable but not obvious
2	obvious oedema on foot or ankle
3	oedema demonstrable up to knee
4	oedema demonstrable up to inguinal ligament
5	total body oedema (anasarca)

Features of famine oedema not included in the Beattie classification
Ascites	in isolation probably not a useful indicator of the severity of primary undernutrition. Prognosis relates to extent of accompanying oedema. Often occurs in secondary to disease (especially TB)
Peri-orbital	in isolation does not appear to reflect a poor prognosis
Scrotal	probably the result of ascitic fluid tracking downwards under the influence of gravity, in isolation does not appear to reflect a poor prognosis
hydroarthrosis	significance unknown

Clinical models

In adults, until recently the use of clinical models to assess nutritional status appears to have been restricted to the nutritional assessment of surgical patients ⁹¹.Since 1992, similar assessments have been made amongst severely undernourished adult inpatients in several therapeutic feeding centre during different famines. A model using three clinical signs: apparent dehydration, oedema and inability to stand has proved useful in predicting prognosis among adult patients ⁹². These three clinical signs were far better at predicting mortality than BMI, were easy to elicit and the model only involves counting.

To be useful in screening admissions to therapeutic feeding centres during famine rather than predicting prognosis in those already admitted, an indicator of nutritional status must be added to this basic clinical model. This allows the model to differentiate between those with clinical illness but no undernutrition, better treated in medical units, from those with both illness and undernutrition, best treated in specialised feeding centres. A combination model, "The Concern Health and Nutrition Evaluation Score" (CHANCES) has been used in Ajiep in South Sudan during 1998 (see Table 5). In addition to the basic signs demonstrated in Table 5, additional relevant criteria, in particularly social criteria such as presence of a carer or distance away from feeding centres can also be added to the model.

Preliminary indications are that this model performed well ⁹³.

Table 5 The CHANCES screening model for acute adult undernutrition during famine

Category	Action	MUAC (mm)	Relevant clinical signs
Normal	Do not admit	> 185	+/-
Moderate undernutrition	Supplementary feeding	160 - 185	-
Severe undernutrition	Therapeutic feeding	160 - 185	+
Severe undernutrition	Therapeutic feeding	< 160	+/-

* An adult presenting with bilateral oedema (Beattie grade 3 or more), but not low MUAC, should be referred to a clinician in order to assess whether s/he has nutritional oedema. If the oedema is nutritional s/he should be admitted to the Therapeutic Feeding Centre.

Activities of daily living

Some workers have suggested that measuring functional ability rather than anthropometry may provide a useful screening tool. Functional ability is usually measured using scores derived from the answers to a set of several related questions. Such an instrument should be able to differentiate between those who can and cannot care for themselves. Valid and reliable sets of questions can, however, be time consuming to develop and test. Currently available instruments (e.g. those used for needs assessment in the elderly) may be appropriate in emergency situations but still require field testing during famine and identification of valid and reliable cut-off points. The CHANCES model creates a composite function/clinical score, with function being assessed solely by ability of an individual to stand. As in the CHANCES model, an indicator of nutritional status would need to be included to allow the instrument to differentiate between those with clinical illness but no undernutrition, best treated in medical units, and those with undernutrition, best treated in specialist feeding centres.

Summary - the use of clinical models

In our opinion, the combination of MUAC and clinical signs, based upon the CHANCES clinical model, is the method of choice for screening acutely undernourished adult admissions into feeding centres.

Admission criteria into adult therapeutic feeding centres should be based upon the following cutoffs:

MUAC < 160 mm irrespective of clinical signs

MUAC < 161-185 mm plus one of the following:

- Bilateral pitting oedema (Beattie grade 3 or worse)
- Inability to stand
- Apparent dehydration

Famine oedema (Beattie grade 3 or worse) alone as assessed by a clinician to exclude other causes.

Access to food (quantity and quality)
Distance from centres
Presence /absence of carers
Shelter
Dependants
Cooking utensils

MUAC < 161-185 mm and no relevant signs or few relevant social criteria.

In any particular situation, workers should take these suggested standards as the starting point and adapt them according to situation-specific factors.

It is important to note that the CHANCES model presented here screens adults in urgent need of nutritional support. If in a particular situation, the needs are such that workers have to make the CHANCES model more stringent in order to avoid being overwhelmed by admissions it is essential that they call for assistance and additional resources. In such situations vigorous advocacy is essential to publicise the extent of the crisis and call for help.