Case 55: Next Steps

Case 55 Index

Case continued…

You decide to start this patient on continuous veno-venous hemodialysis (CVVHD). A right internal jugular central venous catheter is placed for dialysis and treatment is initiated.

This patient weighs 70 kilograms. Which of the following is the most appropriate starting rate for the dialysate fluid?
1 liter/hour
Initial dialysate fluid dosing should range somewhere between 25 and 40ml/kg/hour. Try again!
2 liters/hour
Correct! This is an appropriate starting dose for dialysate fluid, somewhere between 25 and 40ml/kg/hour.
3 liters/hour
Initial dialysate fluid dosing should range somewhere between 25 and 40ml/kg/hour. Try again!
Within 15 minutes of starting CVVHD, you receive a call from the ICU nurse that the machine is alarming and the “return pressures are extremely high.” What is the best next step?
Change the central venous catheter to the left internal jugular vein
We should always look for a non-invasive solution first. Additionally, the right internal jugular vein is preferred to the left internal jugular due to the angle of the vein. Try again!
Check for kinks in the catheter or tubing
Correct! This is a non-invasive step that can often provide a solution. Kinks in the catheter or tubing can result in high pressures and machine alarms.
Switch to intermittent hemodialysis
As mentioned earlier, continuous kidney replacement therapy is a better option here, so we should try to figure out how to troubleshoot. Try again!
Start anticoagulation of the dialysis circuit
While anticoagulation may ultimately be needed, there is a lower risk step you can take first. Pick again!

You succeed in troubleshooting the CVVHD, great work!

You sign out for the evening and head home. In the morning, the ICU nurse informs you that the transmembrane pressure has been gradually rising and the effluent pressure has dropped. What is the most likely issue?
Filter membrane clotting
Clotting can cause the transmembrane pressure to increase, however we would not typically see a drop in the effluent pressure. Try again!
Filter membrane clogging
Correct! Clogging occurs when the pores of the membrane become blocked, leading to a rise in transmembrane pressure and a drop in effluent pressure.
Catheter is resting against the vessel wall
This would more often be characterized by changes in the arterial/access pressure or the return pressure. Try again!
Increased intra-thoracic pressure
Increased intra-thoracic pressure or asynchronous breathing on the ventilator can cause issues with dialysis, but this is more often characterized by changes in arterial/access pressure. Pick again!

The patient continues treatment for infection, remains on vasopressors, and continues on CVVHD. Her circuit issues improve. Unfortunately, she is determined not to be a candidate for liver transplantation. Her family decides to focus on comfort care.

Click here close out this tough case!

Case 55 Index
Case 55 Introduction
Case 55 Physical Exam
Case 55 Diagnostic Testing