L3: Choosing Injectable Agents In SA Practice (Garcia) Flashcards
What can you tx GDV VPCs with if severe?
Lidocaine (if p otherwise ok, don’t nee to tx)
Increased intraabdominal pressure in a GDV –>
Decreased:
- portal and caval blood flow
- venous return
- CO
- functional residual capacity (volume of air left in lungs below tidal volume)
GDV arrhythmias due to:
- hypokalemia
- myocardial ischemia (caused by reperfusion injury)
- endotoxemia
(See flow chart pic)
Actions in PREoperative period for GDV
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
Drugs to AVOID in GDV
Anything long-acting, cardiotoxic, non-reversible
Ketamine (decreases NE and Epi uptake, which can -> arrhythmia/tachy)
Acepromazine (can vasodilate)
Lidocaine in unstable patient
Ok drugs to use in GDV (?)
Premed: opioids
Induction: opioids + benzoes or propofol
Maintenance: Iso or sevo
Adjunctives (CRI): fentanyl, lidocaine in CV stable patient to decrease MAC
Physiologic changes in patient to consider for a C-section
- dilutional anemia (have more volume w/ same # of cells)
- hypoalbuminemia
- dec. fx residual capacity
- dec. cardiac sphincter tone
- dec. anesthetic requirement
- inc. GFR
Effects of dilutional anemia
- inc. plasma volume
- inc. CO, myocardial oxygen consumption
- dec. PCV, Hb, cardiac reserve
- sensitive to hypoxia** (dec. CaO2)
Effects of hypoalbuminenia
- dec. protein binding
- dec. drug requirement
- dec. colloid-oncotic pressure
Pulmonary function in pregnant patients
Inc. IAP (intra-abd. Pressure) –> dec. FRC, inc. alveolar ventilation
- faster inhalant induction
- careful with apnea
- preoxygenation may be needed
Why is there a higher risk of aspiration in pregnant patients?
- dec. cardia sphincter tonus
- slower gastric emptying
- inc. intra-abdominal pressure
- inc. progesterone lvls (which relaxes lower esophageal sphincter)
Placental blood flow can decrease under anesthesia due to:
- hypotension
- vasoconstriction
- uterine contraction
Renal status of pregnant patients
Inc. GFR, renal blood flow
Dec. BUN/creatinine
Anesthetic guidelines for pregnant patients getting C-section
- 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
Preferred anesthetic protocol for C-section
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*
Physiologic changes in patient with urethral obstruction
-dec. excretion
-inc. K, BUN, creatinine
+/- arrhythmias if K >6.5 mEq/L
ECG change assoc. with hyperkalemia
Serum K ~ 7: High T wave
Serum K ~9: intraventricular block, atrial standstill
Hyperkalemia Tx
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
Disadvantage of bicarb use for tx of hyperK
Causes alkalinization of blood as K moves intracellular and H moves extracellular
Disadvantage of catecholamine use for tx of hyperK
Can be arrhythmogenic
Anesthetic protocol for urethral obstruction
- 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)
Pre-anesthetic considerations for trauma cases
- thorough PE
- check CV and resp. Status
- fluid therapy at shock doses (+/- blood)
- thoracic and abd. Rads
- only anesthetize after stable*
Anesthetic considerations for pneumothorax
- dyspnea
- CV instability
- thoracocentesis may be required (+/- chest tube if recurrent)
Anesthetic protocol for pneumothorax
- 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
