Surgical sieve

The surgical sieve is a thought process in medicine. It is a typical example of how to organise a structured examination answer for medical students and physicians when they are challenged with a question.^[1] It is also a way of constructing answers to questions from patients and their relatives in a logical manner, and structuring articles and reference texts in medicine. Some textbooks put emphasis on using the surgical sieve as a basic structure of diagnosis and management of illnesses.^{[2][3][4][5][6]}

The Sieve

Although there are several versions around the world with slight variations, the surgical sieve usually consist of the following types of process in the human body in any particular order:

• Congenital
• Acquired
  • Vascular
  • Infective
  • Traumatic
  • Autoimmune
  • Metabolic
  • Inflammatory
  • Neurological
  • Neoplastic
  • Degenerative
  • Environmental
  • Idiopathic

A more extensive, and perhaps more concise mechanism of employing the surgical sieve is using the mnemonic MEDIC HAT PINE:

• Metabolic (conditions relating to metabolism, biochemistry, and the like)
• Endocrinological (conditions relating to the various secretory systems within the body)
• Degenerative (conditions relating to age-related destruction of tissue, or stress-related destruction of tissue)
• Inflammatory/Infective (conditions that primarily present in a way that involves the profane activation of the immune system)
• Congenital (conditions present at birth)
• Haematological (conditions relating to the blood system, in one way or another)
• Autoimmune (conditions relating to the inappropriate activation of the immune system, in one of many ways)
• Traumatic (conditions relating to a physical response between two or more objects)
• Psychological/Neurological (conditions relating to the nervous system, in one way or another – whether that be the CNS or the PNS)
• Idiopathic/Iatrogenic (conditions without a known cause, or without a known cause outside of medical intervention)
• Neoplastic (conditions relating to cancers)
• Environmental (conditions relating to exposures, and dose-response relationships thereof)

Examples

What are the causes of an acute confusional state in a patient?

1. Idiopathic/Iatrogenic: polypharmacy, sedatives, analgesics, steroids, drug withdrawal
2. Vascular: stroke, TIA, vascular dementia
3. Inflammatory: infection, systemic inflammatory response syndrome
4. Traumatic: head injury, Intracranial hemorrhage, shock
5. Autoimmune: thyroid disease
6. Metabolic: electrolyte imbalance, DKA, hypoglycaemia, SIADH
7. Infective: sepsis, local infection
8. Neoplastic: brain tumour, carcinomatosis
9. Degenerative: Alzheimer's Disease, dementia

What are the causes of splenomegaly?

1. Idiopathic: Idiopathic thrombocytopenic purpura
2. Vascular: portal vein obstruction, Budd-Chiari syndrome, haemoglobinopathies (Sickle-cell disease, thalassemia)
3. Infective: AIDS, mononucleosis, septicaemia, tuberculosis, brucellosis, malaria, infective endocarditis
4. Traumatic: haematoma, rupture
5. Autoimmune: rheumatoid arthritis, SLE
6. Metabolic: Gaucher's disease, mucopolysaccharidoses, amyloidosis, Tangier disease
7. Inflammatory: sarcoidosis
8. Neoplastic: CML, metastases, myeloproliferative disorders

Pathologic Basis Of Disease

Robbins Pathologic Basis Of Disease^[7] is an internationally used reference textbook in pathology. Its chapters under the heading 'General Pathology' can be considered to be a version of the surgical sieve:

3. Acute and chronic inflammation
4. Tissue Repair
5. Hemodynamic Disorders
6. Genetic Disorders
7. Diseases of Immunity
8. Neoplasia
9. Infectious Diseases
10. Environmental and Nutritional Pathology

In popular culture

The surgical sieve is frequently used by Gregory House, who is a physician in the TV series House^[8] in order to diagnose the diseases that his patients are suffering from. In some episodes various forms of the surgical sieve are scribbled on to House's whiteboard while his team struggle to diagnose difficult cases. In the episode 'Paternity' the mnemonic 'MIDNIT' is used to run through the sieve (metabolic, inflammation, degenerative, neoplastic, infection, trauma).

References