First Aid For Surgery - Fen

Front 1

Normal plasma osmolality

Back 1

285-295mmol/L; Calculated POSMc = 2[Na] + [glucose]/18 + [BUN]/2.8. Normal osmolar gap is <10mmol/L; osmolar gap >10mmol/L --> THINK lactic acid, ketones, methanol, or ethanol

Front 2

Normal plasma osmolality

Back 2

285-295mmol/L; Calculated POSMc = 2[Na] + [glucose]/18 + [BUN]/2.8. Normal osmolar gap is <10mmol/L; osmolar gap >10mmol/L --> THINK lactic acid, ketones, methanol, or ethanol

Front 3

ICF and ECF

Back 3

2/3 of TBW = ECF; 1/3 of TBW = ICF. Of the 1/3 that is ICF, 1/4 is Plasma and 3/4 is Interstitial (capillary wall separating these compartments)

Front 4

Function of aldosterone at distal tubule

Back 4

Stimulates K+ secretion and Na+ reabsorption

Front 5

Losses that Mimic ECF

Back 5

(1) Hemorrhage; (2) Loss of GI fluid - vomiting, NG suction, diarrhea, fistular drainage; (3) Postop fluid sequestration (third spacing): intestinal obstruction; (4) Intra-abdominal and retroperitoneal inflammation (e.g., pancreatitis, peritonitis); (5) SIRS, burns, sepsis

Front 6

Signs of volume deficit

Back 6

(1) Weight loss and decreased skin turgor; (2) Tachycardia, orthostasis/hypotension, collapsed neck veins; (3) Oliguria/azotemia; (4) Ileus

Front 7

Signs of volume overload

Back 7

(1) Weight gain and peripheral edema; (2) Increased CO, CVP; distended neck veins; heart murmur; (3) Bowel edema; (4) Pulmonary edema

Front 8

Third spacing

Back 8

Shift of ECF from plasma to elsewhere, such as interstitial or transcellular spaces

Front 9

IVF requirements for average 70kg adult patient?

Back 9

About 2.5 L/ day (1,000 + 500 + (20 × 50) = 2,500) or 100 mL/hr (2,500/24 =104) unless other factors warrant a higher rate.

Front 10

Normal UO

Back 10

0.5 cc/kg/hr for adults, 1 cc/kg/hr for kids.

Front 11

Blood urea nitrogen (BUN)/creatinine (Cr) > 20 and FeNa < 1%

Back 11

Indicates hypovolemia!

Front 12

Chronic hyponatremia

Back 12

Chronic hyponatremia may be asymptomatic until < 120 mEq/L. For every 100-mg/dL increment in plasma glucose above normal, the plasma sodium should decrease by 1.6 mEq/L.

Front 13

Normal plasma osmolality

Back 13

285-295mmol/L; Calculated POSMc = 2[Na] + [glucose]/18 + [BUN]/2.8. Normal osmolar gap is <10mmol/L; osmolar gap >10mmol/L --> THINK lactic acid, ketones, methanol, or ethanol

Front 14

ICF and ECF

Back 14

2/3 of TBW = ECF; 1/3 of TBW = ICF. Of the 1/3 that is ICF, 1/4 is Plasma and 3/4 is Interstitial (capillary wall separating these compartments)

Front 15

Function of aldosterone at distal tubule

Back 15

Stimulates K+ secretion and Na+ reabsorption

Front 16

Losses that Mimic ECF

Back 16

(1) Hemorrhage; (2) Loss of GI fluid - vomiting, NG suction, diarrhea, fistular drainage; (3) Postop fluid sequestration (third spacing): intestinal obstruction; (4) Intra-abdominal and retroperitoneal inflammation (e.g., pancreatitis, peritonitis); (5) SIRS, burns, sepsis

Front 17

Signs of volume deficit

Back 17

(1) Weight loss and decreased skin turgor; (2) Tachycardia, orthostasis/hypotension, collapsed neck veins; (3) Oliguria/azotemia; (4) Ileus

Front 18

Signs of volume overload

Back 18

(1) Weight gain and peripheral edema; (2) Increased CO, CVP; distended neck veins; heart murmur; (3) Bowel edema; (4) Pulmonary edema

Front 19

Third spacing

Back 19

Shift of ECF from plasma to elsewhere, such as interstitial or transcellular spaces

Front 20

IVF requirements for average 70kg adult patient?

Back 20

About 2.5 L/ day (1,000 + 500 + (20 × 50) = 2,500) or 100 mL/hr (2,500/24 =104) unless other factors warrant a higher rate.

Front 21

Normal UO

Back 21

0.5 cc/kg/hr for adults, 1 cc/kg/hr for kids.

Front 22

Blood urea nitrogen (BUN)/creatinine (Cr) > 20 and FeNa < 1%

Back 22

Indicates hypovolemia!

Front 23

Chronic hyponatremia

Back 23

Chronic hyponatremia may be asymptomatic until < 120 mEq/L. For every 100-mg/dL increment in plasma glucose above normal, the plasma sodium should decrease by 1.6 mEq/L.

Front 24

Hyponatremia with high plasma osmolality (pseudohyponatremia)

Back 24

Causes include (1) HYPERGLYCEMIA (either physiologyic or 2/2 rapid infusion of glucose or mannitol) will cause increased osmotic pressure that shifts fluid from ICF to ECF. The total body sodium in this case is normal but has become diluted due to the fluid shift; (2) Expected Na = 1.6*every 100mg/dL over 100 --> remember 'sweet 16'

Front 25

Hyponatremia with hypotonicity (true hyponatremia)

Back 25

Reflects excess ingestion of water that overwhelms the kidneys (either normal or diseased) or due to increased ADH. Hyponatremia is not due to increased excretion of sodium

Front 26

SIADH

Back 26

Increased vasopressin release from posterior pituitary or ectopic source causes decreased renal free water excretion.

Front 27

Hypovolemic hyponatremia

Back 27

Give e0.9%NaCl. Na repletion with saline isotonic to the patient avoids rapid changes in ICF volume. A major complication of rapid correction fo chronic hyponatremia is CENTRAL PONTINE MYELINOLYSIS

Front 28

How does Ca+ help with hyperkalemia?

Back 28

It stabilizes the membrane potential of cardiac muscle, which would abnormally fire in the presence of high potassium. It does not actually have any effect on the amount of K+ present.

Front 29

Treatment of hyperkalemia

Back 29

(1) 10% calcium gluconate 1 g IV; (2) Albuterol, insulin with glucose, or sodium bicarbonate promote cellular reuptake of K; (3) Kayexalate - cation exchange resin. As opposed to above measures, which immediately protect against dangers of high K+, this actually removes K+ from body; (5) Dialysis

Front 30

S&S of hyperkalemia

Back 30

Cardiac effects are most significant. Confirm hyperkalemia and obtain an ECG. (1) EARLY: peaked T waves, wide QRS, ST depression; (2) LATE: disappearance of T waves, heart block, sine wave - ominous for impending fatal arrhythmia

Front 31

Causes of hyperkalemia

Back 31

(1) MCC is renal failure; (2) K+ spillage from severe injury; (3) In metabolic acidosis, cells take up H+ ions in exchange for intracellular K+, acting as a buffer in states of acidosis and leading to hyperkalemia

Front 32

Causes of hypokalemia

Back 32

(1) MCC is excessive renal secretion; (2) Loss of K+ 2/2 excess mineralocorticoid activity: primary hyperaldosteronism, Cushing's, renal artery stenosis (hyperreninism), congenital adrenal hyperplasia (will cause concomitant hypernatremia); (3) Movement of K into cells 2/2 insulin, catecholamines, alkalemia; (4) Prolonged administration of K-free TPN; (5) Loss of excessive lower GI secretions such as diarrhea, colonic fistulas, VIPoma; (6) Diuretics

Front 33

S&S of hypokalemia

Back 33

(1) Flattened T waves, ST depression, U waves

Front 34

Equation for corrected calcium

Back 34

Corrected Calcium = 0.8 (Normal Albumin – Observed Albumin) + Observed Calcium

Front 35

Ratio of ionized to nonionized Ca is related to pH…how?

Back 35

(1) Acidosis causes an increase in ionized fraction; (2) Alkalosis causes decreased in ionized fraction

Front 36

Causes of hypocalcemia

Back 36

(1) Acute pancreatitis; (2) Massive soft-tissue infections (nec fasc); (3) Acute/chronic renal failure; (4) Pancreatic/small bowel fistulas; (5) HypoPTH; (6) Hypoproteinemia; (6) Severe Mg depletion (preventing PTH secretion)

Front 37

S&S of hypocalcemia

Back 37

(1) Numbness and tingling of fingers, toes, and around mouth; (2) Increased reflexes; (3) Chvostek's sign: tapping ovre facial nerve in front of tragus of ear causes ipsilateral twitching; (4) Trousseau's sign: Carpopedal spasm following inflation of sphygmomanometer cuff to above systolic BP for several minutes; (5) Muscle and abdominal cramps

Front 38

Causes of hypercalcemia

Back 38

(1) Hyperparathyroidism; (2) Cancer [esp. breast, multiple myeloma]; (3) Drugs [thiazides]

Front 39

Treatment of hypercalcemia

Back 39

(1) Vigourous repletion with salt solution - dilates Ca and increases urinary calcium excretion; (2) May be augmented with furosemide; (3) Definitive treatment of acute hypercalcemic crisis in patients with hyperPTH is surgery

Front 40

Harris-Benedict equation and Fick equation (in patients with Swan-Ganz catheters) used to estimate basal energy expenditure (BEE).

Back 40

General estimate of BEE: (1) Males: 25kcal/kg/day; (2) Females: 22kcal/kg/day. Multiply this by the desired goal (postsurgery gets 1.3-1.5xBEE); Fever gets 12% increase per degree celsius

Front 41

Respiratory quotient

Back 41

RQ is defined as the ratio of carbon dioxide released to oxygen consumed per unit metabolism of a substrate (i.e., VCO2/VO2).

Front 42

Causes of elevated anion gap metabolic acidosis

Back 42

MUDPILES: (1) Methanol/Metabolism [inborn errors]; (2) Uremia; (3) DKA; (4) Paraldehyde; (5) Iron/INH; (6) Lactic acidosis; (7) Ethylene glycol; (8) Salicylates/Stychnine. NARROW DOWN TO FOUR: Ketoacidosis, lactic acidosis, renal failure, intoxication!

Front 43

Causes of normal gap metabolic acidosis

Back 43

HARD-UP: (1) Hyperparathyroidism; (2) Adrenal insufficiency/Anhydrase [carbonic anhydrase] inhibitors; (3) RTA; (4) Diarrhea; (5) Ureteroenteric fistula; (6) Pancreatic fistulas

Front 44

Assess the acid-base disorder step by step

Back 44

(1) Acidosis [pH < 7.40] or Aklalosis [pH > 7.40]? (2) Respiratory [pH and PCO2 move in opposite directions] or Metabolic [pH and PCO2 move in same direction]? (3) Simple or mixed?

Front 45

Metabolic acidosis: two kinds

Back 45

(1) Anion gap acidosis: due to addition of unmeasured acid; (2) Nonanion gap acidosis: due to HCO3 loss; REMEMBER: AG = Na - [Cl + HCO3]. Normal AG = 10

Front 46

Metabolic alkalosis: two kinds

Back 46

(1) Loss of H+ from kidneys or GI tract --> renal: mineralocorticoid excess, diuretics, K+-losing nephropathy; GI: vomiting, gastric drainage, villous adenoma of colon; (2) Gain of HCO3: milk-alkali syndrome, exogenous NaHCO3, lactated ringers, packed RBC, TPN all contain substrates that metabolize to bicarbonate!

Front 47

Respiratory acidosis

Back 47

HYPERCAPNIA 2/2 one of two mechanisms: (1) Hypoventilation (brain stem injury, neuromuscular disease, ventilator malfunction); (2) Ventilation-perfusion (V/Q) mismatch (COPD, pneumonia, PE, foreign body, pulmonary edema)

Front 48

Respiratory alkalosis

Back 48

Hyperventilation 2/2 anemia, anxiety, increased ICP, salicylates, fever, hypoxemia, sepsis, pregnancy, CHF, pneumonia, asthma, liver disease; Alkalosis causes a decreased in serum K+ and ionized Ca, resulting in paresthesias, carpopedal spasm, and tetany