Investigation of the Surgical patient M K ALAM MS;FRCS

Objectives At the end of this presentation students will be able to:  Identify the need for establishing diagnosis.  Describe the whole spectrum of available investigations.  Choose relevant investigations and justify their use.  Understand the side effects and complications of some investigation.  Identify need for assessing physiological status.  Understand the need for screening common asymptomatic disorders.

Diagnosis History Clinical examination Investigations: -Support clinical suspicion -Refute clinical suspicion -Risk to patient -Cost

Other aims of investigation Assess physiological impairment for risk to surgical treatment. Example: Cardiac, renal respiratory diseases Screen for common asymptomatic disorders. Example : Diabetes, coronary artery disorders, hypertension

Hematological investigations FBC or CBC: Anemia (low Hb.), MCV, MCHC (normocytic, microcytic), leukocytosis (infection) Platelet count: Thrombocytopenia ( drug- heparin, ITP, autoimmune), Thrombocytosis ( post-splenectomy) Coagulation profile: PT, INR, APTT (disordered in patients of jaundice, bleeding, anticoagulant, antiplatelet medications)

Biochemical tests Na: mmol/L ( water overload, NG asp., sepsis, vomiting) K: mmol/L (changes- vulnerable to arrhythmias) Urea: mmol/L ( dehydration, renal insufficiency) Creatinine: mmol/L (marker of renal disease) Glucose: mmol/L ( diabetes) Total protein: G/L Albumin: 35-50G/L (nutritional assessment) Bilirubin <17 mmol/L (jaundice) ALP: U/L AST: U/L ALT: 5-30U/L LDH: U/L Creatinine phosphokinase: U/L Amylase <100 u/L

Microbiological investigations Urine (UTI), sputum, stool Hepatitis screening (B, C) Antibiotic sensitivity

Tumour markers PSA- Prostate CEA- Colorectal α- fetoprotein (AFP)- Hepatocellular β-hCG- Testicular, gestational CA Colorectal, pancreas CA Ovarian

Imaging studies Plain x-ray- CXR, AXR, tomograms Side effects: Induction of malignancy, genetic mutation.

AXR (gallstone)

Imaging studies Contrast studies- gastrografin swallow, barium meal, barium enema. Visualize GI tract Single contrast, double contrast Inferior to endoscopy Contraindicated if bowel perforation suspected

Gastrografin & Barium enema

Imaging studies CT scan (oral, iv contrast): Widely used for abdomen, chest, brain, vascular and urinary tract. (anaphylactic reaction, renal injury, radiation) Ultrasound: Safe, low cost. Operator dependent. Investigation of first choice for biliary disease and gynaecology. MRI: Good images of soft tissue (better than CT), blood vessel (MRI angiogram). No radiation, no known deleterious effect. Slow and expensive. Isotope scan: More information about function than structure. I131,Tc99, I123, Ga67, Th201- incorporated into other molecule to localize target organ. Detected by gamma camera. Bone metastasis, renal function, foci of infection, GI bleeding, infarction of myocardium, sentinel node detection PET scan: Expensive. Brain physiology, tumour detection, cardiac physiology.

Intestinal ischemia

Intussusception

Lower GI bleeding Scan

Meckel's scan

Endoscopy Precise diagnosis of GI, pancreatico-biliary, bronchus, urinary tract pathology. Perform cytology/ biopsy. Minimally invasive therapy- laparoscopy, arthroscopy, ERCP. Disadvantages: Unpleasant, uncomfortable (sedation/ anesthesia) Complications: Infection, perforation, aspiration, bleeding, cardiac arrhythmias, respiratory arrest

Upper GI endoscopy & Colonoscopy

CBD stone extraction

ERCP (Stone CBD, Periampullary carcinoma)

Tissue sampling Body fluids- pleura, peritoneum, sputum, urine. Smears, brush cytology FNAC ( insitu vs invasive, follicular adenoma vs carcinoma) Core biopsy Open biopsy Frozen section biopsy: (biopsy frozen in liquid nitrogen, sliced, stained and reported in minutes)

Function tests Cardiac evaluation: ECG, Thallium scan, echocardiography Respiratory function: ABG ( risk pCO2 > 45 mmHg) FVC & FEV1 ( risk- < 70% of predicted) Renal function Endocrine function

Screening Screening for malignant disease.(FOB, mammography, PSA) Screening for surgical disease ( abdominal aortic aneurysm)

Thank you!