Endocrine - Metabolic Flashcards
Islet of Langerhans
1-2% pancreas weight
Hormone produced & secreted into capillary blood vessel
Venous blood from islet drains into hepatic portal vein & then into general circulation
4 types α β Δ & pancreatic polypetide
Pancreas
α 25% islet cells & secrete glucagon
β 60-70% islet mass & secrete insulin
Δ cells secrete hormone somatostatin
Peptides or Proteins
Insulin - facilitates glucose transport
Glucagon
Amino Acids
Dopamine
Epinephrine
Norepinephrine
Steroids
Lipid soluble derived from cholesterol
Estrogen or progesterone
Insulin Half-Life
5-8 minutes
Insulin Degradation
Liver & kidney
What does not require insulin or glucose?
Brain
Glucose Storage
Liver insulin promotes
Excess glucose → glycogen (via glycogenesis)
Pancreatitis
Pancreas inflammation
Pancreatitis Causes
Gallstone & alcohol
Trauma - ERCP, obstruction, & medications
Pancreatitis S/S
Abdominal pain
N/V
Febrile
Pancreatitis
Anesthetic Considerations
Hydration
Pain management
Monitor electrolytes
NPO until pain & inflammation resolved
Pancreatitis Preop
↑WBC
Liver dysfunction
Electrolyte abnormalities
Pancreatitis Complications
Pancreatitis necrosis - cell death 2° inflammation
Pancreatic pseudocyst
Pancreatic Pseudocyst
Contains only fluid
Most common complication d/t chronic pancreatitis
Pancreatic Cancer
4th most common cancer in US
Correlation b/w obesity, smoking, & chronic pancreatitis
Pancreatic Cancer S/S
Abdominal pain
Weight loss
Pain suggests retroperitoneal invasion
Jaundice indicates biliary obstruction
Pancreatic Cancer
Treatment
Surgical resection Painless jaundice → pancreas head tumor Pancreatectomy or Whipple Surgical 5 year survival 10% Non-surgical 5mos
Cystic Fibrosis
Autosomal recessive disorder
Chromosome 7 mutation
Results in defective chloride ion transport in lungs, pancreas, liver, GI, & reproductive organs epithelial cells
↓Cl¯ ↓Na+/H2O → viscous secretions → luminal obstruction & exocrine gland scarring
1° morbidity & mortality cause = chronic pulmonary infection
CF Anesthetic Considerations
Delay elective surgical procedures until obtain optimal pulmonary function
Volatile agents ↓airway pressure via ↓bronchial smooth muscle & hyperactive airways
Avoid anticholinergic drugs to maintain secretions in less viscous state (thin)
Type 1 Diabetes
T-cell mediated autoimmune pancreas β cell destruction
80-90% β cell function lost before hyperglycemia occurs
T1D S/S
Hyperglycemia, fatigue, weight loss, polyuria, blurred vision, & IV volume depletion
Polyuria/polydipsia/polyphagia
T1D
Diagnosis
Blood glucose >200mg/dL
HbA1C >7
Diabetic Ketoacidosis
Blood glucose >250mg/dL
Most commonly associated w/ T1D
Type 2 Diabetes
β cell insufficiency & insulin resistance
Insulin resistance → circulating free fatty acids, cytokines, insulin antagonist, & target tissue defects at insulin receptors
Impaired glucose associated w/ ↑body weight, ↓insulin secretion, & reduction in peripheral insulin action
↑insulin level desensitizes target tissues ↓insulin response
Polyuria/polydipsia/polyphagia
T2D S/S
Polyuria, polydipsia, weight loss
Fasting glucose >126mg/dL
2 hour plasma glucose level >200 during oral glucose test
What factors contribute to insulin resistance?
Abdominal obesity
Excess calorie consumption
Lack exercise
Genetic susceptibility
Metabolic Syndrome
Insulin resistance Visceral obesity Low HDL cholesterol HTN ↑triglycerides
Metabolic Syndrome S/S
Fasting glucose >110mg/dL Abdominal waist >40in (M) or >35in (F) Triglyceride >150 HDL <40mg/dL (M) or <50mg/dL (F) Blood pressure > 130/85
Diabetes Complications
DKA Hyperosmolar hyperglycemic state Hypoglycemia - diaphoresis, tachycardia, & nervous (general anesthesia masks S/S) Monitor electrolytes Impaired mental status Anxiety Lightheaded Coma
DKA
Most commonly caused by an infection
↓insulin → free fatty acids catabolism → ketones
ABSOLUTE ↓insulin → hyperglycemia
Polyuria, dyspnea, N/V
HHS
RELATIVE ↓insulin → hyperglycemia
Glycogenolysis & gluconeogenesis → osmotic diuresis
Polyuria, polydipsia, confusion, lethargy
Oral Antidiabetics
Sulfonylureas
Biguanides (Metformin)
Glitazones
Glucosidase inhibitors
Insulin Secretion
50 units/day (adults)
Insulin Functions
Facilitates glucose & K+ into adipose & muscle cells
↑glycogen, protein, & fatty acid synthesis
↓glycogenolysis & gluconeogenesis, lipolysis, & catabolism
Short Acting Insulin
Regular
ONLY IV
Rapid Acting Insulin
Lispro & apart
Intermediate Acting Insulin
NPH
Lispro protamine
Lente
Long Acting Insulin
Glargine
Ultralente
Diabetes Preop
+ prayer sign indicates cervical spine immobility (unable to align palms flat)
Potential difficult intubation
T1D 30%
Diabetes Anesthetic Considerations
Glycemia control to prevent infection, improve wound healing, & ↓morbidity/mortality
Assess cervical spine mobility
Insulinoma
Benign pancreatic tumors
Women 2x
Insulinoma Diagnosis
Whipple’s triad
- Hypoglycemia w/ fasting
- Symptomatic glucose <50mg/dL
- Symptom relief w/ glucose admin
Insulinoma Anesthetic Considerations
Preop management w/ Diazoxide (inhibits insulin release from β cells)
Treatment = surgical intervention
Monitor blood glucose intraop
Hyperglycemia after tumor removed
Continue to monitor blood glucose under general anesthesia hypoglycemia S/S masked under GA
Diabetic Neuropathy S/S
Hypertension
Painless myocardial ischemia
Reduced HR response to Atropine & Propranolol
Resting tachycardia
Lack diaphoresis
↑risk ST segment & T wave abnormalities
Limited ability to compensate → cardiovascular instability (post-induction hypotension or sudden cardiac death)
Intraop Blood Glucose Management
Avoid hypoglycemia
Maintain blood glucose <180mg/dL
Dependent on patient baseline
Hyperglycemia associated w/ ______
Infection
Poor wound healing
↑mortality
Worse neuro outcomes
Surgical Stress Response
↑counter regulatory hormones
↑inflammatory mediators → stress hyperglycemia
Hs
Hypoglycemia Hypovolemia Hydrogen ions Hypoxia Hypothermia Hyper/hypokalemia
Ts
Thrombosis Toxins Tamponade (cardiac) Trauma Tension pneumothorax
Hyperkalemia Treatment
Insulin 10 units
50% dextrose
Bicarbonate
Calcium gluconate - stabilizes the myocardium via lowering threshold potential
Kayexalate
Albuterol β agonist shifts K+ intracellular
