L3: Choosing Injectable Agents In SA Practice (Garcia)

Question 1

What can you tx GDV VPCs with if severe?

Answer 1

Lidocaine (if p otherwise ok, don’t nee to tx)

Question 2

Increased intraabdominal pressure in a GDV –>

Answer 2

Decreased:

• portal and caval blood flow
• venous return
• CO
• functional residual capacity (volume of air left in lungs below tidal volume)

Question 3

GDV arrhythmias due to:

Answer 3

• hypokalemia
• myocardial ischemia (caused by reperfusion injury)
• endotoxemia

(See flow chart pic)

Question 4

Actions in PREoperative period for GDV

Answer 4

Restore blood volume and perfusion:

• give shock dose 90 ml/kg of crystalloids +/- colloids
• alkalinizing fluids
• improve CV fx
• tx electrolyte abnormalities (K) by adding K to maintenance bag

Question 5

Drugs to AVOID in GDV

Answer 5

Anything long-acting, cardiotoxic, non-reversible

Ketamine (decreases NE and Epi uptake, which can -> arrhythmia/tachy)
Acepromazine (can vasodilate)
Lidocaine in unstable patient

Question 6

Ok drugs to use in GDV (?)

Answer 6

Premed: opioids
Induction: opioids + benzoes or propofol
Maintenance: Iso or sevo
Adjunctives (CRI): fentanyl, lidocaine in CV stable patient to decrease MAC

Question 7

Physiologic changes in patient to consider for a C-section

Answer 7

• dilutional anemia (have more volume w/ same # of cells)
• hypoalbuminemia
• dec. fx residual capacity
• dec. cardiac sphincter tone
• dec. anesthetic requirement
• inc. GFR

Question 8

Effects of dilutional anemia

Answer 8

• inc. plasma volume
• inc. CO, myocardial oxygen consumption
• dec. PCV, Hb, cardiac reserve
• sensitive to hypoxia** (dec. CaO2)

Question 9

Effects of hypoalbuminenia

Answer 9

• dec. protein binding
• dec. drug requirement
• dec. colloid-oncotic pressure

Question 10

Pulmonary function in pregnant patients

Answer 10

Inc. IAP (intra-abd. Pressure) –> dec. FRC, inc. alveolar ventilation

• faster inhalant induction
• careful with apnea
• preoxygenation may be needed

Question 11

Why is there a higher risk of aspiration in pregnant patients?

Answer 11

• dec. cardia sphincter tonus
• slower gastric emptying
• inc. intra-abdominal pressure
• inc. progesterone lvls (which relaxes lower esophageal sphincter)

Question 12

Placental blood flow can decrease under anesthesia due to:

Answer 12

• hypotension
• vasoconstriction
• uterine contraction

Question 13

Renal status of pregnant patients

Answer 13

Inc. GFR, renal blood flow

Dec. BUN/creatinine

Question 14

Anesthetic guidelines for pregnant patients getting C-section

Answer 14

• Induce w/o opioids (can use propofol if stable)
• Don’t sedate unless necessary
• avoid hypotensives and respiratory depressants until delivery
• sedation may be necessary (benzo w/ induction)
• can give epidural pre-op under sedation, or post-op (not under general anesthesia)
• keep it fast and short

Question 15

Preferred anesthetic protocol for C-section

Answer 15

1) place IV catheter
2) give benzo + propofol
3) epidural PF morphine pre or post-op
4) IV opioid right after delivery
5) suction PRN, give doxapram
6) buprenorphine TID, then tramadol TID-QID
* no NSAIDs*

Question 16

Physiologic changes in patient with urethral obstruction

Answer 16

-dec. excretion
-inc. K, BUN, creatinine
+/- arrhythmias if K >6.5 mEq/L

Question 17

ECG change assoc. with hyperkalemia

Answer 17

Serum K ~ 7: High T wave

Serum K ~9: intraventricular block, atrial standstill

Question 18

Hyperkalemia Tx

Answer 18

1) Ca gluconate or chloride
2) Dextrose 0.5 g/kg
3) 0.9% NaCl fluids (in this order)

Insulin 0.2 U/kg
NaHCO3 (bicarb) –> rarely used
+/- Catecholamines (ie. Norepi) –> cause K to go into cells, and causes hyperglycemia

Question 19

Disadvantage of bicarb use for tx of hyperK

Answer 19

Causes alkalinization of blood as K moves intracellular and H moves extracellular

Question 20

Disadvantage of catecholamine use for tx of hyperK

Answer 20

Can be arrhythmogenic

Question 21

Anesthetic protocol for urethral obstruction

Answer 21

• Fluids
• Pre-med: benzo+opioid, or propofol
• close monitoring (before induction if possible)
• AVOID: pain, stress, arrhythmogenic drugs (ketamine)
• propofol decreases sympathetic tone (makes intubation and urethra easier)

Question 22

Pre-anesthetic considerations for trauma cases

Answer 22

• thorough PE
• check CV and resp. Status
• fluid therapy at shock doses (+/- blood)
• thoracic and abd. Rads
• only anesthetize after stable*

Question 23

Anesthetic considerations for pneumothorax

Answer 23

• dyspnea
• CV instability
• thoracocentesis may be required (+/- chest tube if recurrent)

Question 24

Anesthetic protocol for pneumothorax

Answer 24

• fluid therapy (crystalloid + colloids)
• preoxygenate
• induce and intubate quickly
• CAREFULLY ventilate if needed: use low pressure b/c positive pressure can make pneumothorax worse
• tap if needed after induction (8th ICS)
• incline head 10-20 degrees
• pain mgmt: local anesthetic

Question 25

Physiologic considerations with diaphragmatic hernia

Answer 25

• acute
• resp. Distress
• dec. venous return
• V/Q mismatch

Question 26

Preoperative period actions for diaphragmatic hernia

Answer 26

• fluid load
• slant table
• oxygenation
• control ventilation (avoid re-expansion edema)
• monitor SpO2 and PaO2

Question 27

Anesthestic considerations in a GDV (what’s going wrong w/ p)

Answer 27

• dehydration, dec. blood volume
• dec. venous return, CO, BP
• lactic acidosis
• endotoxemia
• V/Q mismatch
• arrhythmias
• dec. tissue perfusion