Case 39 - kidney + pancreas transplantation

Question 1

Should patients with DM 1 and CKD get cardiac studies prior to transplantation surgery?

Answer 1

• DM 1 + CKD patients should get a stress test (exercise vs Dobutamine)
• patients can have significant CAD
• if stress is positive –> undergo angiogram for possible intervention

Question 2

What are your concerns with patients who have DM 1 and are undergoing sx?

Answer 2

DM 1

• insulin defiencey
• at risk for hyperglycemia and DKA
• poor control creates a multisystem disease
• autonomic neuropathy
  
  • slow GI emptying –> inc risk of aspiration
    
    • RSI, metoclopromide, h2 blocker, Na bicitrate
  • labile BP and HR
  • unable to sense angina during MI

Question 3

What are your pre-op concerns for pancreas-kindey transplantation?

Answer 3

1) electrolyte abnormalities
* potassium, phosphate, magnesiu, calcium level
2) glucose

• insulin/oral hypoglycemic agents
• endocrine consult
• insulin pump??

3) Anemia
* due to CKD 2/2 decrease erythropoietin
4) coagulopathy

• obtain lab work
• plt dysfunction 2/2 uremia; corrected with dialysis

5) dialysis

• last dialysis date
  
  • hypovolemic if recent
  • hypervolemic if not recent (pulm edema, CHF)

6) cardiac risk

• CAD??
• potassium levels

Question 4

Why would an a-line be important in this surgery?

Answer 4

• monitoring of ventilation, oxygenation, acid/base status, electrolytes, h/h, glucose
• glucose is labile during sx
  
  • initially steroid is given which casues hyperglycemia
  • once pancreas graft is anastomsed and unclamped, insulin is produced, causing hypoglycemia
  • check glucose q30 min after pancreas graft inserted
• goal with ABG: maintain physiologic pH, Pao2, PaCo2, base deficit, Na and K levels

Question 5

patients presenting with SLK transplant will have altered pharmacokinetics. As such, what happens with opioids and muscle relaxants?

Answer 5

Opioids

• Meperidine and morphine - renal excretion - toxic metabolites

muscle relaxants

• roc and vec slightly prolonged duration of action due to some renal excretion
• consider using cis-at = hoffman elimination
• SUX –> may increase K by 0.5 - 1 meq/L (pts may have pre-existing hyperkalemia)

Question 6

How can you assess if the pancreatic graft is functioning properly?

Answer 6

Measure glucose levels along with C-Peptide

C-Peptide

• generated during insulin biosynthesis
• released into portal circulation along with insulin

1) nonfunctioning graft
* hyperglycemia with decrease C-peptide level
2) functioning graft
* hypoglycema with increase c-peptide level

Question 7

how should you manage glucose levels intraoperatively?

Answer 7

Serial ABGs

• prior to graft placement - Hyperglycemia - q1h check
  
  • pre-existing DM, stress response of surgery, stress dose steroids (anti-rejection)
• Post graft placmeent - Hypoglycemia (insulin synthesis) - q30min check

Insulin Mgmt

native pancreas

• insulin infusion, abg q1h

New Pancreas

• continue insulin infusion (decrease neo-beta islet activity in order to “rest” the beta islet cells)
  
  • possible to get persistent hyperglycemia after sx 2/2 insulin resistent effects of immunosuppressive agents and admin of high dose steroids
• Start dextrose infusion as well
  
  • dextrose solution is warrented to avoid ketosis (energy coming from ketone bodies when glucose is not available)
• ABG q30 min

Question 8

what is the relationship between acidemia and hyperkalemia?

Answer 8

• Acidemia can cause hyperkalemia and vice versa
• extracellular acidosis increase serum K+ by 0.5 meq/L for every decrease in pH of 0.1 unit
  
  • mechanism - body tries to maintain normal pH, therefore cells will take in H+ to decrease plasma concentration. However, to maintain electrical neutrality, K+ is pumped out of the cell into plasma.

Question 9

EKG changes of hyperkalemia and tx of hyperkalemia?

Answer 9

EKG changes

• 6 meq/L - peak T wave
• 7 meq/L - prolong PR interval, sine wave
• 8-9 meq/L - absent p wave, widened QRS, V-fib

Management of hyper K+

• stabilizes cardiac membrane potential
  
  • CaCl
• promote intracellular shift of K+
  
  • hyperventilation
  • sodium bicarb - 1 meq/kg
  • insulin + dextrose (10 U + D 50 10-25g)
• get rid of K+
  
  • kayexalte
  • lasix

Question 10

What are the goals for fluid management for renal transplantation?

Answer 10

Goal: optimize cardiac performance, enable adequate flow to organ

1) balance between wet vs dry

• wet - perfuses kidney well. risk of volume overload, pulm edema, chf
• dry - risk hypotension, end-organ hypoperfusion

2) proper fluid replacement??

• base it on pH, K+, and glucose levels
• LR and plasmalyte -> contains K+
• NaCl -> hyperchloremic metabolic acidosis

Base Deficit

• > 3 meq/L - 0.45% NS + 75 meq/l NaHCO3
• < 3 meq/L - check potassium level

Potassium level

• > 4.5 meq/L - 0.9% NaCl
• < 4.5 meq/L - plasmalyte or LR

Question 11

what is the role of TAP blocks for abdominal surgery

Answer 11

TAP blocks

• cover T10 to L1
• good for kidney incision, may not cover midline incision for pancreas sx as it requires higher dermatomal level
• kidney - unilateral TAP; pancreas (midline incision) requires bilateral TAP
• U/S - area is between iliac crest and subcostal margin, midaxillary line in a transverse plane to lateral abdominal wall.
• inject between internal oblique and transverse abdominus muscle
• Volume block, be mindful of total dose 2/2 to LAST

Question 12

ekg changes associated with hypokalemia?

Answer 12

• First - T wave flattening and inversion
• second - ST depression and T wave inversion
• third - Increased amplitude and width of the P wave and Prolongation of the PR interval
• fourth - Prominent U waves (best seen in the precordial leads)