College Answer

CREST syndrome refers to the predominantly cutaneous rheumatological condition with Calcinosis, Raynaud’s phenomenon, Esophageal dysmotility, Sclerodactyly and Telangiectasia. Associated conditions include scleroderma (with additional arthralgias, myalgias, contractures, pulmonary fibrosis and pulmonary hypertension, renal impairment etc.).   Patients with CREST syndrome therefore may have many manifestation that may complicate ICU management.  Some of the many resultant potential problems include difficult intubation (limited mouth opening), risk of aspiration (and oesophageal perforation with TOE), malabsorption and nutritional deficiencies, limited respiratory reserve, risk of digital ischaemia with radial arterial lines and vasoconstrictors, skin breakdown/pressure area, and propensity to renal failure.

Discussion

CREST stands for:

• Calcinosis
• Raynauds
• oEsophagitis
• Sclerodactily
• Telangiectasia

It is a member of the scleroderma family of disorders. In fact, its "scleroderma light" - the limited form of systemic sclerosis.

The factors which influence the ICU management of scleroderma therefore also apply to CREST. These are discussed in greater detail in the answer to Question 28 from the first paper of 2012. That answer is reproduced below:

1.  Difficult intubation:
   1. Limited neck extension
   2. Limited mouth opening
2.   Respiratory involvement:
   1. Pulmonary fibrosis
   2. Restrictive lung disease
   3. Pulmonary hypertension
   4. SpO₂ monitoring may be frustrated by poor end-digital perfusion
   5. The rapidly fatal "scleroderma-pulmonary-renal syndrome (SPRS)" may develop, which manifests as a fulminant course of acute normotensive renal failure associated with diffuse alveolar hemorrhage.
3. Cardiovascular involvement of the disease process:
   1. Cardiac problems:
      1. Arrhythmias,
      2. Myocardial fibrosis (thus, restrictive diastolic failure)
      3. Pericardial stricture (also restricts diastolic filling)
   2. Vascular problems
      1. Difficult vascular access: the skin, being very thick, makes it difficult to palpate vessels (veins and arteries both)
      2. Poor distal perfusion of the extremities, leading to gangrene- as one might expect this is not improved by arterial cannulation.
      3. Poor skin perfusion promotes pressure areas
4. Neurological sequelae: 
   1. Corticosteroid-associated psychosis
   2. Cerebral vasculitis
5. Electrolyte disturbances
   1. Hyponatremia and fluid retention due to corticosteroid therapy
   2. Hyperkalemia due to renal failure
6. Renal involvement
   1. Renal failure, renal artery stenosis
   2. Scleroderma "renal crisis"
7. Gastrointestinal and nutritional issues
   1. Oesophagitis
   2. Poor gut motility
   3. Decreased feed tolerance
   4. Risk of aspiration.
   5. Risk of oesophageal perforation
   6. Telangiectasia is present also on mucosal surfaces; there is an increased risk of bleeding from upper GI sites
8. Haematological problems:
   1. Anaemia of chronic disease is coupled with the poor EPO synthesis from damaged kidneys.
   2. Bone marrow function may be suppressed in other ways, particularly if serious immunosuppresants are in use (eg. cyclophosphamide)
9.     Immunosuppressive therapy
   1. Increased infection risk