Week 2 - Investigations Flashcards
What is Perioperative Medicine?
- Bringing internal med into the perioperative setting.
- Encompasses the care of the patient preparing for, having and recuperating from surgery
- Involves surgeons, anaesthetists, intensivists and physicians
Why is perioperative medicine important?
- Historically: surgical condition and the index operation…but nowadays
What are the 5 Basic Principles of The Preoperative Assessment?
- If at all possible, operate when the patient is at their best
- Minimise risks
- Avoid the unnecessary
- Develop a perioperative plan
- Ensure Good Team Work
What Happens in the Preadmission Clinic? (7)
- History and examination – especially of other organ systems, esp CVS and RS
- Determine the need for further tests
- Co-ordination with other services
- Is the patient optimised?
- Consideration of risk vs benefit
- Patient education
- Informed consent
What is Consent? 3 Elements of a Valid Informed Consent?
The voluntary and continuing permission of a competent patient to receive a particular treatment, based on adequate knowledge of the purpose, nature and likely risks of the treatment, including the likelihood of its success and any alternatives to it.
What should you consider when determining if you can consent a patient for a procedure? (6)
- Personal Comfort
- Professional Expectations
- Experience
- Medicolegal
- Local Practice
- Production Pressure
What 6 things are involved in the History Taking for Preadmission for Surgery?
- The presenting complaint/ diagnosis/ operation
- Assessment of Effort Tolerance
- Co-existing diseases: nature and severity, prescribed treatment, current status
- Current medications
- Allergies
- Past surgical & anaesthetic history
What is Effort Tolerance and how is it calculated/categorised?
- What is a high risk surgery? 4 examples?
- Intermediate Risk Surgery? 5 Examples?
- Low Risk Surgeries? 4 Examples
What is involved in the examination of a patient for Preadmission for Surgery?
Which 6 medications are of specific importance to ask about during Medication History for Preadmission for Surgery?
- What are the 4 basic principles to consider regarding a patients medications before surgery?
Drugs – note current trends and recommendations (change all the time)
1. Aspirin, clopidogrel
2. Beta-blockers
3. Statins
4. Warfarin
5. NOACS (rivaroxaban and dabigatran)
6. Anti-diabetics
Perioperative Beta-blockers - Should you cease?
Perioperative Statins - Should you cease?
Perioperative Antihypertensives - Should you cease?
Perioperative Steroids - Should you cease?
Discuss an approach to Medications affecting haemostasis preoperatively? (4)
- Aspirin?
- P2Y12 receptor blockers?
- Warfarin?
- NOACs (dabigatran, rivaroxaban)?
- Estimate thromboembolic risk
- Estimate bleeding risk
- Estimate the timing of anticoagulant interruption
- Determine whether to use bridging anticoagulation.
How long after a coronary stent can a patient have surgery?
Coronary stents - Major Factors
- Can dual anti-plt therapy be continued?
- Duration from PCI to surgery – highest mortality < 30 days post stent
Coronary stents - If High Risk
- Consider continuing dual antiplatelet therapy
- Consider bridging therapy, eg Gp IIb/IIIa inhibitors (tirofiban)
- Monitor!
- Immediate access to cardiac catheterization lab
What should be enquired about during preadmission history taking for this woman?
What preadmission investigations should be performed for this woman and why?
- FBC = For baseline – eg. Haemoglobin to pick up anaemia
- Coagulation profile – can mostly confirm with history but in this instance you want to know if INR is normal in the setting of liver disease/obstructive jaundice
- U&Es = Renal function – difficult to obtain renal disease from history, pt also on ACE inhibitor
- LFTs = For baseline if none done recently
- HbA1c
What is your approach to this patient? What are you worried about? What investigations would you perform?
- Should we just increase the oxygen? = NO - can drop off to hypoxaemia (<60mmHg in arterial blood which equates to ~SpO2 of 90%) – shape of oxygen-haemoglobin curve she’s on the cliff and about to fall off.
- Assessment: ABC
- Airway = Yes, no stridor or snoring
- Breathing = Switch to a Hudson mask and increase oxygen (non-rebreather with 15L/minute)
- Listen to her chest
- Ixs – Chest xray & ABG
- RR = low - opiates = respiratory depression
What preadmission test should be performed for this man and why?
When and why would we perform an echo as part of a preadmission workout? What are we looking for?
When and why would we perform stress testing as part of a preadmission workup? What are we looking for?
What information can you derive from arterial blood gas analysis? (6)
What is an acute abdomen?
What is the initial management for a patient presenting with an acute abdomen?
**What are the Red flags for abdominal pain? **
- 4 Risk factors?
- 2 vitals?
- 3 pain characteristics?
- 4 Accompanying symptoms?
- 4 Findings on examination?
List 9 Immediately life-threatening diagnoses of an acute abdomen?
List 14 Lab studies you may consider in a patient presenting with an acute abdomen?
- Strongly consider a urine pregnancy test in sexually active female patients of reproductive age, irrespective of current contraception use.
- Patients with obvious signs of diffuse peritonitis or sepsis may require immediate surgical management without further diagnostic imaging.
Describe an approach to Imaging in a patient with an acute abdomen?
Approach
1. The initial imaging modality should be guided by the working diagnosis, as based on the patient history, vital signs, and examination.
2. The following recommendations apply to nonpregnant adults.
3. In pregnant women with acute abdominal pain, ultrasound and/or MRI of the abdomen and/or pelvis without contrast are the preferred initial imaging modalities.
4. Maintain a low threshold for obtaining diagnostic imaging in older patients, for whom abdominal pain is associated with higher morbidity and mortality as well as lower initial diagnostic accuracy.
List 4 Cardiovascular causes of acute abdominal pain?
- Clinical features and diagnostic findings for each?
List 8 Gastrointestinal causes of acute abdominal pain?
- GI tract perforation
- Mechanical bowel obstruction
- Acute appendicitis (including perforated appendicitis
- Peptic ulcer disease
- Diverticulitis
- Gastroenteritis
- Neutropenic enterocolitis (typhlitis)
- Epiploic appendagitis
List 5 Biliary and pancreatic causes of acute abdomen?
- Acute pancreatitis
- Symptomatic cholelithiasis
- Choledocholithiasis
- Acute cholecystitis
- Acute cholangitis
List 7 Genitourinary causes of acute abdominal pain?
- Ruptured ectopic pregnancy
- Ovarian torsion
- Testicular torsion
- Acute pyelonephritis
- Nephrolithiasis
- Pelvic inflammatory disease
- Acute urinary retention
What is Lipase? What does an elevated lipase tell us?
What is included in full blood count? (8)
- Red blood cell (RBC) count
- Hemoglobin (Hb)
- Hematocrit (Hct)
- Mean corpuscular volume (MCV)
- Mean corpuscular hemoglobin (MCH)
- Mean corpuscular hemoglobin concentration (MCHC)
- White blood cell (WBC) count
- Platelet count
What WBC parameters are measured on an FBC?
- WBC count
- Segmented neutrophil count
- Band neutrophil count
- Eosinophil count
- Basophil count
- Lymphocyte count
- Monocyte count
CHINAA acronym for causes of eosinophilia?
For causes of eosinophilia, think CHINAA: Collagen vascular disease (e.g., eosinophilic granulomatosis), Helminths, Hyper-IgE syndrome, Neoplasms, Allergies, Addison disease.
Thrombocytosis
- Definition?
- 10 causes?
Definition: absolute platelet count of > 400,000/mm3
What LFT ratio should you look at to determine the etiology of hepatocellular injury?
Outline bilirubin metabolism.
List 4 Parameters of hepatic synthesis?
3 Pancreatic Parameters?
Lactic Acid (Lactate)
- Reference range?
- Physiology?
- 10 Common causes of Hyperlactatemia?
- 5 Clinical features of Hyperlactatemia?
Reference range: < 2.0 mmol/L
Physiology: Lactic acid is the end product of anaerobic glycolysis, which is accomplished in the Cori cycle.
The majority of lactic acid is produced by muscle cells and RBCs, especially in hypoxic states.
What is CRP? 5 Clinical Applications?
C-reactive protein (CRP)
- Promotes the opsonization of pathogens, which leads to increased phagocytosis by macrophages
- Activates the complement system
- High sensitivity for detecting inflammation but not specific to any disease or organ
- Increases 6–12 hours after the inflammatory process begins
- Half-life is 24 hours.
6 Parameters of fat metabolism?
- Total cholesterol
- Triglycerides
- LDL = Bad - A lipoprotein that transports cholesterol from the liver to extrahepatic tissue.
- HDL = Good - A lipoprotein that transports cholesterol from extrahepatic tissue to the liver.
- LDL/HDL ratio
- Total cholesterol/HDL ratio
Explain the different types of medical imaging commonly used in the diagnosis of surgical disease, including the appropriate use of the techniques and interpretation, for:
- MAMMOGRAM?
- Mammography is a medical imaging technique that uses low-dose X-rays to visualize the breast tissue. It is primarily used for breast cancer screening and diagnosis.
- Two low-dose x-rays of the breast are obtained (mediolateral oblique and craniocaudal) to screen for breast abnormalities.
- Used for early detection of breast abnormalities: Mammography detects the majority of cancers and can detect lesions ∼ 2 years before they are clinically evident.
- In postmenopausal women and women ≥ 30 years of age with a suspicious breast mass, mammography is preferred over ultrasound. In premenopausal women < 30 years of age, ultrasound is preferred, because the higher density of breast tissue decreases the diagnostic power of mammography.
- Mammography has greatly improved the rate of early detection of noninvasive carcinomas.
What are 7 indications for the use upper gastrointestinal (UGI) scope?
An inspection of the upper gastrointestinal tract (up to the duodenal papilla) with an endoscope.
What are 2 limitations for the use upper gastrointestinal (UGI) scope?
What are 5 Therapeutic Uses of Upper GI Scope?
What are 6 Indications for Use of Capsule Endoscopy?
What are 3 Limitations of Capsule Endoscopy?
What are 3 Therapeutic Uses of Capsule Endoscopy?
Capsule endoscopy is a valuable tool for the evaluation of small intestinal pathologies, especially in cases where conventional endoscopic methods are limited.
What are 6 Indications for Use of Enteroscopy?
Enteroscopy is a procedure used to examine the small intestine (small bowel).
What are 3 Limitations of Enteroscopy?
What are 5 Therapeutic Uses of Enteroscopy?
What are 6 Indications for Use of Proctoscopy?
Proctoscopy is a common medical procedure in which an instrument called a proctoscope is used to examine the anal cavity, rectum, or sigmoid colon. A proctoscope is a short, straight, rigid, hollow metal tube, and usually has a small light bulb mounted at the end.
What are 2 Limitations of Proctoscopy?
What are 4 Therapeutic Uses of Proctoscopy?
What are 6 Indications for Use of Sigmoidoscopy?
Sigmoidoscopy is the minimally invasive medical examination of the large intestine from the rectum through to the nearest part of the colon, the sigmoid colon. There are two types of sigmoidoscopy: flexible sigmoidoscopy, which uses a flexible endoscope, and rigid sigmoidoscopy, which uses a rigid device.
What are 3 Limitations of Sigmoidoscopy?
What are 4 Therapeutic Uses of Sigmoidoscopy?
Sigmoidoscopy is a valuable diagnostic tool for evaluating lower gastrointestinal conditions, including rectal bleeding, colorectal cancer screening, anorectal disorders, and inflammatory bowel disease. However, its limitations in terms of reach and inability to perform interventions beyond the sigmoid colon should be considered, and further evaluation with a complete colonoscopy may be required in certain cases.
Endoscopic retrograde cholangiopancreatography (ERCP)
- What is it?
- Indications?
- Contraindication?
- Characteristic findings in Choledocholithiasis?
- 4 Complications?
A diagnostic and/or therapeutic procedure in which a side-viewing endoscope is inserted into the duodenum and contrast is injected via the ampulla of Vater into the bile ducts. Different instruments can then be introduced via the endoscope to cannulate the common bile duct. If necessary, a sphincterotomy of the ampulla of Vater or removal of gallstones from the common bile duct can also be performed.
6 Indications for Endoscopic Retrograde Cholangiopancreatography (ERCP)?
3 Limitations of Endoscopic Retrograde Cholangiopancreatography (ERCP)?
4 Therapeutic Uses of ERCP?
Cystoscopy
- What is it?
- 7 Indications?
- Procedure?
- 3 Complications?
Cystoscopy is endoscopy of the urinary bladder via the urethra. It is carried out with a cystoscope. The urethra is the tube that carries urine from the bladder to the outside of the body. The cystoscope has lenses like a telescope or microscope.
What are 6 Indications for Cystoscopy?
3 Limitations of Cystoscopy?
4 Therapeutic Uses of Cystoscopy?
Cystoscopy is a valuable diagnostic and therapeutic tool for evaluating various urinary tract conditions. While it has limitations in terms of reach and potential discomfort, it offers the ability to directly visualize the bladder and urethra, perform biopsies, remove tumors or polyps, and manage urinary stone-related issues.
6 Indications for Colonoscopy?
2 Limitations of Colonoscopy?
4 Therapeutic Uses of Colonoscopy?
Causes of Acute pancreatitis?
Most common causes
1. Biliary pancreatitis (∼ 40% of cases; mostly caused by gallstones)
2. Alcohol-induced (∼ 20% of cases)
3. Idiopathic (∼ 25% of cases)
Describe the pathophysiology and sequelae of acute pancreatitis.
- Capillary leakage?
- Pancreatic necrosis?
- Hypocalcaemia?
Sequence of events
1. Intrapancreatic activation of pancreatic enzymes: secondary to pancreatic ductal outflow obstruction (e.g., gallstones, cystic fibrosis) or direct injury to pancreatic acinar cells (e.g., alcohol, drugs)
2. Increased proteolytic and lipolytic enzyme activity → destruction of pancreatic parenchyma
3. Attraction of inflammatory cells (neutrophils, macrophages) → release of inflammatory cytokines → pancreatic inflammation (pancreatitis)
Acute Pancreatitis
- 7 Symptoms?
- Examination findings?
Symptoms of Acute Pancreatitis
- Constant, severe epigastric pain.
- Classically radiating towards the back
- Worse after meals and when supine
- Improves on leaning forwards
- Nausea, vomiting
- Fever
- If pulmonary complications are present: chest pain, dyspnea
What sign is this?
= Cullen Sign
Periumbilical ecchymosis as a result of retroperitoneal hemorrhage, commonly seen in acute pancreatitis.
What sign is this?
Grey Turner sign = Right-sided flank ecchymosis suggestive of retroperitoneal hemorrhage, commonly seen in acute pancreatitis.
