Thread by @adequator_app

1/20 SLED

#CRRT and #IHD are different treatments, we know now

But, Is there something in between?

✅YES & it´s called...
🤔Wait, whats the name?

#SLED? #PIRRT? #HYBRID? #SHIFT? #AVVH?

💥Lets review this confusing & amazing topic
#tweetorial

2/20

When giving RRT to critical ill patients with AKI #CRRT & #iHD have different advantages

#CRRT
✅Hemodynamic stability
✅Gentle solute removal
✅Steady state similar to kidney

#iHD
✅Lower Cost
✅Machine free time
✅Equipment almost always available

3/20

Therapies mixing the best of both worlds, have being present for a while

💥Smart people delivering what´s NEEDED with the tools AVAILABLE

💥What´s NEEDED?: Replace renal function on unstable critically ill patients without actually killing the patient in the process

4/20

🤔 But why so much confusion with these mixed therapies?

A: The different strategies and nomenclature used in literature make difficult to:

1. Compare it with CRRT
2. Evaluate outcomes and complications as a unique therapy
3. Establish a standard dose

5/20

To overcome the confusion:

💥General FEATURES that DEFINE these therapies💥

1. Use of available tools (#iHD or #CRRT machines)
2. Intentionally "discontinuos" therapy (< 24 hours)
3. Longer⏲than #iHD
4. Higher flows than CRRT & lower than IHD

CRRT 2016, Oxford

6/20

Considering this☝️, 2 interchangeable terms exist:

⚡HYBRID: Word to define MIXED
⚡PIRRT: Prolonged Intermittent Renal Replacement Therapy

We then, can divide them in therapies that:

1. Try to be more like CRRT (SLED, SLED-f)
2. Try to be more like iHD (AVVH, SHIFT)

7/20

⚡️iHD machine trying to be #CRRT⚡️

S-L-E-D
Sustained Low Efficiency Dialysis

🔥From the NAME we know:

1. Sustained (More time but not continuous)
2. Low efficiency (Low Qd and Qb, ⬇ml/min)
3. Dialysis (Diffusion)

8/20

How SLED is performed?

⚡️iHD Machine
⚡️Qb: 200 ml/min
⚡️Qd: 100-200 ml/min
🔥(this is the most challenging parameter to costume on an iHD machine, some machines need software adjustments or home made by-pass systems🔥
⚡️Time 6-12 hours
⚡️Days: 6

Machines adjustments

9/20

How to DOSE a SLED?

❌NO answer to this question
✅Equivalent clearance to other therapies will be logical

Minimal recommended dose in AKI:

⚡️iHD--> 3.9 weekly KtV
⚡️CRRT-> 20-25 ml/kg/hr

How can we translate this to a SLED:

Get your #adequators and calculators

10/20

3.9 Weekly KtV will be achieved with 6 sessions per week that obtain a 60% URR or a 0.9 eKTV (Img1)

The time needed to achieve it, will depend on efficiency parameters, Qd, Qb:

🔥iHD:QB 300/ Qd 500/->T needed 3 hrs (Img 2)
🔥SLED:QB 200/Qd 100/->T needed 7 hrs (Img 3)

11/20

20 ml/kg/hr for 24 hours in a 80 kg male will be equivalent to an eKT/V of 0.9 (Img1)

80 x 20 = 1600
1600 x 24h = 38.4 L
-Urea V = 41 L
38.4/41 = 0.9
eKT/V = 0.9

How much time needed?

🔥CRRT: QB 150/ Qd 26 ->Time 24 h (Img2)
🔥SLED: QB 200/Qd 100 ->Time 7 h (img3)

12/20

⚡️CRRT machine trying to be #iHD⚡️

A-V-V-H
Accelerated V V Hemofiltration

🔥From the NAME we know

1. Accelerated (Not continuos, delivers a dose in less time, needs better efficiency)
2. VV Hemofiltration (Convection)

13/20

🔥How AVVH is performed?

⚡️CRRT machine in CVVH mode
⚡️Qb: 350 ml/min
⚡️Qr:PRE dilution: 50 ml/kg/hr/ 4L/hr /66 ml/min
⚡️Time: 9 hours
⚡️Days: 6

doi.org/10.1053/j.ajkd…

14/20

🔥Lets calculate how will this therapy will perform

80 x 50 = 4L
4x 9h = 36 L
-Urea V = 41 L
36/41 = 0.9
KT/V= 0.9

🤭But wait, remember we are using PRE, that will dilute solutes

🤔How much? 21% (other tweetorial)

36 *(1-0.21)= 28.4
28.4/41= 0.7
KT/V= 0.7

15/20

💥Other PIRRT/HYBRIDS worth mentioning:

#IHD trying to be CRRT
✅SLED-f: Sustained:⬇efficiency hemodiafiltration
✅TRANSITORY HD:4hr iHD + 8hr SCUF (many places consider this a SLED, its not)

#CRRT trying to be iHD
✅SHIFT CVVHD: Similar to AVVH but using diffusion

16/20

🤔 CRRT or PIRRT/HYBRID?

Meta- analysis 2015
7 RCT & 10 observational

-RCT: no difference in mortality, kidney recovery, fluid removal, or UCI days
-Observational: less mortality in PIRRT group (Selection bias)

doi.org/10.1053/j.ajkd…

17/20

The mayor PROBLEM with HYBRID:

DOSE & TIMING OF MEDICATION

-IHD: K during a short time of day, dosing can come after (lots of data)
-CRRT: K is continuos so dosing can be some how predictable
-SLED: K is not continuous but not a short time of the day (Also no data)

18/20

🔥 When to Choose PIRRT/HYBRID ?

1. Need to perform a therapy with the goals of a CRRT or IHD but the respective machine is not available
2. Transition from CRRT to iHD
3. Nocturnal therapy allowing machine independence during the day for procedures or studies

19/20

Conclusions

✅Born to deliver a particular prescription with the available tools
✅Nomenclature & prescription has been motive for confusion
✅PIRRT & HYBRID are the terms that group ALL this therapies
✅We can group them in 2 types: CRRT-->iHD or iHD--> CRRT

20/20
Conclusions 2

✅Dosing should use equivalent clearances of other therapies
✅No evidence of better or worst outcomes than CRRT
✅Dosing & timing of medications is a MAYOR problem
✅Indications such as: night tx & transition to iHD are exlusive indications of PIRRT/HYBRID