1. GENERAL INFORMATION
1.1 General information
Life-threatening metabolic disorders in patients with cancer include hypercalcaemia , hypocalcaemia,hyponatremia, hypernatriaemia, tumour lysis syndrome, hypoglycaemia, hyperammoniemia, lactic acidosis and adrenal failure. Symptoms are non-specific and range from laboratory disturbances to severe clinical symptoms such as coma or death. Metabolic emergencies may occur in all cancers and should be suspected in every patient with cancer.
Patients with metabolic emergencies need to be hospitalized in a medical department or in an Intensive Care Unit (ICU). The department should provide facilities for cardiac monitoring and invasive haemodynamic monitoring, temporary cardiac pacing, ventilatory support and pump-controlled administration of infusions. Facilities for
blood gas analysis, haemoglobin and electrolyte measurements should be readily accessible. Facilities for haemodialysis or haematological rescue must be present.
1.3 Published reviews
- Spinazzé S, Schrijvers D. Metabolic emergencies. Crit Rev Oncol Hematol 2006; 58: 79-89.
- Higdon ML, Higdon JA. Treatment of oncologic emergencies. Am Fam Physician 2006; 74: 1873-80.
2.1 Clinical presentation, diagnosis and physiopathology
The diagnosis of a metabolic oncologic emergency should be suspected in every cancer patient with non-specific symptoms. The clinical presentation depends on the pathophysiologic mechanism of the metabolic emergency and can occur in every organ system with gastro-enterologic (nausea and vomiting, constipation, diarrhoea), pulmonary (dyspnoea, tachypnoea, hypopnoea, hyperventilation), renal (anuria, polyuria, renal failure), cardiovascular (supraventricular and/or ventricular rhythm disturbances, cardiomyopathy) or neurological (confusion, disturbances in consciousness, seizures coma) symptoms. The associated signs such as dyspnoea, cyanosis, icterus, hyperpnoea (e.g. metabolic acidosis), or hypopnoea (e.g. metabolic alkalosis), weakness and decreased reflexes, cardiac arrhythmia (e.g. hypokalaemia and hypercalcaemia) may provide clues as to the nature of the underlying metabolic disorder.
The definitive diagnosis will be established by laboratory examination and radiological work-up.
The main pathophysiologic mechanisms of metabolic oncologic emergencies are:
· Dysfunction of vital organs (kidney, hart, lung, liver) caused by cancer.
· Dysfunction of vital organs related to anticancer treatments
· Paraneoplastic phenomena due to the production of biologically active substances by tumour cells. Paraneoplastic symptoms are unrelated to the stage of the tumour and may precede the diagnosis of the underlying cancer.
3. PREVENTION AND TREATMENT
3.1 General information
The approach of metabolic emergencies consists of:
· Prevention by prophylactic measures
· Early diagnosis
· Treatment of metabolic disturbances with emergency measures to preserve vital functions and to restore biological parameters
· Treatment of the underlying cancer.
Dr. Dirk Schrijvers (Reviewer)
University Hospital Antwerp – Antwerp, Belgium
Dr. Silvia Spinazzé (Associate Editor)