Health Care in PWS

Features of PWS requiring special attention:

High pain threshold
Individuals with PWS frequently have decreased sensitivity to pain. Therefore, known injuries must be assessed for more serious problems, and signs of unreported injuries should be sought. In the absence of a verbal complaint of pain, other symptoms of specific injuries should be evaluated.

Bone fractures
Due to the high pain threshold, it is not unusual for a person with PWS to have an undetected broken bone. Following a fall or other injury, a person with PWS should be closely monitored for a change in walking or arm movement. Observe for deformities, swelling or bruising.

Bruising
Many individuals with PWS bruise easily but, because of the high pain threshold, are often unable to say how they came by the bruise.

Vomiting/abdominal pain
Individuals with PWS do not commonly exhibit a vomiting reflex. If a person with PWS suddenly reports pain or bloating, is vomiting and has abdominal distention, there may be life-threatening bowel inflammation or necrosis, and emergency surgery may be needed. It also may be a warning that the person has ingested a large amount of food. In either case, death can occur in hours. These abdominal conditions are more prevalent in a teenager or adult with PWS. Recent reports have highlighted deaths due to "binge-eating", especially when the person with PWS usually has their food intake well-controlled and does not have a significant weight problem (see below).

Food foraging
If left unsupervised, an individual with PWS may consume life-threatening amounts of food. A dramatic weight increase within a day - especially if coupled with reports of stomach distress or vomiting - may be a sign that the person is severely ill. Stomach rupture is possible. Diarrhoea or significant fluid retention are also reasons for concern. People with PWS can be quite indiscriminate in what they eat, eg poisonous berries, out-of-date food, frozen food, food from waste bins or off the ground. There are reports of people with PWS eating large quantities of items like salt or shampoo, though this is not thought to be very common. The lack of vomiting reflex (see above) may not alert the observer to the fact that the person has ingested items such as these.

Excessive fluid intake
There have been a few reports of people with PWS drinking excessive amounts of fluid, leading to potentially fatal low sodium and potassium levels.

Temperature
An individual with PWS may not be pyrexial even when seriously ill and may run dramatically below-normal temperatures at times. Even slight temperature elevations should be considered a warning sign.

Obesity-related problems
High blood pressure, diabetes, congestive heart failure and respiratory failure are the most common problems for the child/adult who is significantly overweight.

Respiratory problems/Obstructive sleep apnoea
Excessive weight in addition to the hypotonia of PWS can lead to serious respiratory problems. Sleep apnoea is common and but may also occur in those who are not seriously overweight.

Skin lesions/cellulitis
A common feature of PWS is skin-picking. A person with PWS should be carefully monitored for open, raw sores and infection. If there are open sores, staff should be alert for signs of acute infection. A propensity to cellulitis in those who are overweight may be exacerbated by these skin-picking behaviours.

Anaesthesia
There is nothing inherent in PWS which gives cause for concern with the administration of anaesthesia. However, individual health problems related to PWS should be taken into account. These include:

  • obesity (complications caused by obstructive apnoea, pulmonary hypertension, altered blood oxygen or blood carbon dioxide levels, significant oedema).
  • high pain threshold (see above)
  • temperature instability - parent or carer should be asked for information about patient's usual temperature
  • thick saliva - may complicate airway management
  • food seeking behaviours - the person may have eaten food even if they say they have not. Unless carer or parent can verify this, the person should be assumed to have food in their stomach.
  • hypotonia (especial in infants) may cause difficulties in ability to cough and clear airways
  • excessive post-operative drowsiness in some individuals.

Infant-specific issues
Hyptonia makes sucking difficult and failure to thrive is the major problem of the infant with PWS. Most infants also have a very weak cry and are very sleepy. Respiratory problems are common in infants and assistance with clearing secretions may be needed. Insufficient fluid intake, due to feeding difficulties, can occur. An infant being fed by NG tube may need close monitoring, due to risk of reflux and aspiration.

Mental health problems
Some teenagers and adults with PWS may also experience mental health problems. These can include: depression, lethargy, hallucinations and hearing voices, and acute psychotic episodes. Professional psychiatric help should be sought in these cases.

Adrenal Insufficiency during Acute Illness in People with PWS: New Research suggests treatment to Minimise the Risks of Sudden Death.
by Dr Nicholas Finer, Clinical Director, Wellcome Clinical Research Facility, Addenbrook's Hospital, Cambrdge.

When people with PWS become ill, they may show few signs of illness and in particular often do not develop a fever, don’t vomit and may not report pain or discomfort, and this may explain why they are at risk of sudden death. Important findings from Dutch researchers1 have shed light on a possible explanation for this, and suggest treatment that could reduce these risks.

Normally during illness the adrenal glands (small glands that sit on top of the kidneys) increase the amount of steroid hormones they secrete into the blood stream. These hormones (the main one is cortisol) help the body combat infection and stress. The adrenal glands are controlled by the pituitary gland that lies at the bottom of the skull, and which produces a hormone called ACTH that signals the adrenal glands to produce cortisol; the pituitary gland itself is regulated by a part of the brain called the hypothalamus. It is known that a shortage of cortisol is very dangerous and so people who do not have functioning adrenal glands (a condition known as Addison’s Disease) or who take large doses of steroid medications for asthma or other conditions that results in adrenal suppression must take extra cortisol if they fall ill.  The same is true for people who are on replacement cortisol for pituitary disease.

The Dutch investigators studied 25 children with PWS and looked at the ability of their hypothalamus to stimulate the pituitary to stimulate the adrenals to produce cortisol. The children had normal cortisol levels during the day, but nearly two thirds of them failed to increase their cortisol levels in response to a drug called metyrapone. Metyrapone blocks cortisol synthesis, and so should cause an acute increased demand for ACTH production, a situation mimicking stress. Patients with an insufficient ACTH response during the metyrapone test are therefore considered as having adrenal insufficiency during stressful conditions. A particularly vulnerable time for children with PWS could be during the early morning when cortisol levels are normally at their lowest and any failure to increase levels could be critical

The authors of this research suggest that in illnesses that cause ‘moderate stress’ (e.g. influenza, upper respiratory tract infection, ear infection) children (and probably adults too) with PWS should take extra cortisol (given in the form of hydrocortisone tablets 50mg four times daily) until they are over the acute illness.  For more serious illnesses hydrocortisone should probably be given by injection and in higher doses; this would mean hospital admission in practice.  This advice accords with the ‘Sick Day Rules’ given to patients known to have adrenal insufficiency for other reasons and would seem a sensible and safe precaution, although the benefits of this are not proven and are based on these early findings from this study.  Parents or people with PWS may wish to carry this information with them as it is unlikely to be known by non-specialist doctors.

1Roderick F. A. de Lind van Wijngaarden and colleagues. J Clin Endocrinol Metab, May 2008, 93(5):1649–1654