In this episode of Hospital Medicine Unplugged, we put hospital dialysis on the clock—HD for speed and control, PD for stability and flexibility—and show you how to choose fast and safely at the bedside.

We open with what hospitals actually do: HD is the default—3x weekly with AVF/AVG/catheter, machines, trained staff, and water systems—because it rapidly clears solute and removes fluid, perfect for hyperK, acidosis, toxins, and crashing volume overload. PD is used less (infrastructure/training barriers) but can be started urgently at the bedside, shines in hemodynamic instability, and needs no anticoagulation or vascular access.

Mechanics in one breath: HD = diffusion + ultrafiltration across a synthetic membrane (precise, fast, intermittent). PD = the peritoneum with osmotic gradients (slower, continuous, gentler).

Complications you need to anticipate:
• HD: intradialytic hypotension, arrhythmias, post-dialysis fatigue; access infections and thrombosis; recovery “hangover.”
• PD: peritonitis and exit/tunnel infections; catheter leaks/malposition; longer LOS when infected; potential glucose load/weight gain.

Hospital scenarios—who gets what:
• Need rapid correction or toxin removal? → HD.
• On pressors/fragile heart/poor access or anticoagulation risk? → PD (gentle, continuous, no heparin).
• Already on PD or peri-op? With precautions, PD can often continue—no automatic switch to HD.
• Frail/elderly? Assisted PD can match in-center HD for hospitalizations, but survival signals are confounded by frailty—individualize.

Access quick hits: HD (temp or tunneled catheter, AVF/AVG preferred long-term). PD (Tenckhoff catheter, ideally double-cuffed, surgically or IR-placed).

Anticoagulation: HD usually needs UFH/LMWH (or citrate/heparin-free protocols in bleeders). PD needs none unless there’s another indication (e.g., AF/VTE)—bleeding risk drops.

Hemodynamics & metabolism: HD = abrupt shifts (watch BP/ischemia). PD = smoother volume control and often better tolerance; slower for severe hyperK/acidosis.

Infections in a line: HD → catheter-related bacteremia early and often when starting with CVCs. PD → peritonitis drives admissions and technique failure. Prevention bundles (asepsis, lock solutions, exit-site care, fast antibiotics) change outcomes.

Nutrition & volume: Both risk protein-energy wasting. PD loses more protein and absorbs glucose (watch weight and glycemia). HD needs tight sodium/UF targets to curb hypotension; PD uses dialysate tonicity (incl. icodextrin) to tune ultrafiltration.

Comparative outcomes (big picture): mortality differences are modality-neutral after adjustment; PD may have higher early hospitalizations (peritonitis) while HD faces vascular and cardiovascular events. Choose the modality, not the myth—patient factors and hospital resources decide.

Bedside playbook you can use today:

1. State the goal (rapid correction vs gentle control).

2. Screen for instability/bleeding/access issues.

3. Pick HD for emergencies/toxins/precise UF; pick PD for instability, poor access, or anticoagulation concerns.

4. Bundle prevention: HD (CVC care + anticoagulation plan) / PD (exit-site care + peritonitis protocol).

5. Monitor smart: HD—telemetry in high-risk, watch UF rate and post-HD labs; PD—daily effluent checks, BP/weight, glucose in diabetics.

6. Plan the exit: access maturation (AVF), assisted PD for frailty, and clear education on infection red flags.

We close with the system moves: invest in urgent-start PD pathways, staff training, and infection bundles; default to AVF/AVG over CVCs; embed anticoag safety and volume targets; and stop reflex peri-op PD→HD switches. The through-line: match physiology to modality, treat today’s risk, and build tomorrow’s resilience.