Q.618. What is the effect of catheter type on the incidence of recirculation? C
HEMODIALYSIS
ESRD ptns are particularly vulnerable to severe
COVID-19 (older
age & high frequency of co-morbidity, e.g. DM & HT, in this cohort. The
ASN & ISN
hv issued guidelines and a list of resources to guide nephrologists to provide
life-sustaining DX care. These resources that continue to evolve are frequently
updated, including the following: early
recognition & isolation of individuals with respiratory Sm(s);
ptn separation & cohorting within waiting
areas and within DX unit; use of personal protective equipment in DX unit; with added measures for ptns with
confirmed/suspected COVID-19.
Q.618. What is the effect of catheter type on the incidence of re-circulation? 🗘
A. Recirculation:
i. Dcr. if the length of femoral cath. ³ 19 cm.
ii. Highest é femoral catheter compared to central
catheter.
iii. Incr. é in blood pump(Qb.) (reaches 50% é Qb.
of 300).
- A “split 👍 catheter”
é Qb. of 400
ml/min. mean
recirculation rate = (1.3- 4.9%).
Q.619. How to be careful for this access?
A. Malfunction can occur due to either: i. Thrombosis.
ii. Fibrin sheath, So, 👉
- Line reversal (switch) 🗘is accepted é accepted recirculation rate. 🗘
-
Local
A.B. ointment or dry gauze
é exit site decrease infection rate.
-
Cth. dur.(3 w.) increase liability
for infection, so, 1st line Cth. removal.
-
Q/DOKI recommendations
(Cath. care No.15), see next Q.
Q.620.What are the Q/DOKI recommendations for
catheter care?
A. Q/DOKI recommendations (Cath. care No.15) ✋
1)
Internal jugular Low infection
& recirculation rates, most
preferable.
2)
Internal juguler & Rt. subclavian: 15-20 cm. Lt.: 20-24 cm. Femoral: >19 cm.
3)
Avoid subclavian,
apply femoral for bed-bound, single use é CHF.
4)
Duration: one w. for femoral(2-3w. for Silicon cth.) & 3 w. for
I.J.
5)
Exit care: Dressing, dry gauze, povoidine, I2 oint., sterile
technique : (gown,
gloves, mask….).
Q.621. Explain how could the variation in CRRT
modalities expand its spectrum?
A. CRRT 🠞Continuous fluid
& solute removal:
[SLEDD] 🠞Slow
Low Efficiency Daily Dialysis.
[SCUF] 🠞 Pure
convection, No Dzt, No S.F., only U.F. (used é modest U.F.). A simple
bld system é high flux 🠞U.F.
only, limited to input. So, not suitable for azotemia & Kru
shd be present.
[CVVH]🠞[U.F.+ S.F. + No
Dzt]: High
vol. U.F. &
metabolic control, so requires S.F.
[CVVHD]🠞[U.F.+ Dzt+ No
S.F.]: Low
efficiency, limited Dzt. vol. (1-3) L.(2L./ h.).
[CVVHDF]🠞[U.F.+ Dzt+ S.F.].
Q.622. What is difference between I.H.DX. & CVVHD?
A. CVVHD 🠞[U.F.+ Dzt.+
No S.F.]: Low efficiency, limited Dzt. vol. to 33 ml/ min. (1-3) L. (2L./h.)… While I.H.Dx.
Q.D.🠞500-800 ml/min.(30-48) L/h.
& Q.B.= 200-500 ml/min. If bicarbonate module is added 🠞better outcome.
Q. 623.
What clearance benefits can CVVHDF provide?
A. CVVHDF
provides “combined ✌ clearance”:
{ Diffusive
(Dzt) + Convective
clearance (U.F.) = Augmented Clearance.}
Q.624. What is the effect of choosing “pre-dilution” &
post-dilution in CVVHD modality?
A. Pre-dilution🠞Reduces
clearance by 15%,
but it is beneficial in dcr. Hemoconcentration 🠞less liability for
thrombosis.
Post-dilution🠞increased liability
for thrombosis,
but more clearance is expected.
Q. 625.
How to prescribe SLEDD? What is its advantages?
A. R / SLEDD: Q.B. : (200-300) ml/min.
Q.D.: (100) ml/min.
Duration: (8-12) h.
- SLEDD hs bn developed
to be a hybrid هجين between continuous & intermittent
therapy, it hs the foll. advantages:
i. More hemodynamic stability.
ii. Increased clearance compared to convective thpy.
iii. Time off D.X. for
diagnostic procedures.
iv. Done by I.C.U. staff & by ordinary staff.
Q.626. Compare P.D. to CRRT? Mention
advantages & disadvantages?
A. P.D.
needs: [Intact peritoneum +
P.D. cth. (Tenckhoff)].
- Clearance by: i. Diffusion. ii. Convection.
- P.D. is inferior to CRRT in: i. Sepsis. &
ii. Malnutrition, but:
- P.D. hs the foll.
advantages:
1) Simple system.
2) Inexpensive.
3) Lack of anticoagulation.
4) Hemodynamic stability.
5) No vascular access troubles.
- By increased
frequency of exchange & conc. of dextrose 8 Adjust quality
& quantity of U.F. However, P.D. has many disadvantage, see
next Q.
Q.627. Then what is the disadvantages of P.D.?
A. P.D. hs many disadvantage:
1) Hyperglycemia & Wt. gain.
2) Risk of peritonitis.
3) Need for intact peritoneum.
4) Less clearance compared to SLEDD
& CRRT.
5) Respiratory embracement ( increased intra-abdominal pressure).
Q.628. What is the Equal Renal Clearance (EKR)?
What is its significance?
A. EKR: In a 70 kg ♂ é 10 kg overload, BUN: 90 mg/dl., ERK c [Urea, Inulin,
Amylase & B2 microglobulin] clearance
(6
d/w.) c
CVVH
: (3 L/h., pre-fluid Dzt-dilution) c = 33.
SLEDD
(12 h./7d./w., Q.b.:
300, Q.d.: 100 ml/min.)c 31.
I.H.D.
(4 h., Q.b.: 350 ml/min., Q.d.: 600 ml/min.) c 21.
Q. 629.
What is the effect of dose of therapy in CRRT modalities on
patient survival?
A. Ronco et
al, used (Lactate-based) post-filter CVVH
é different replacement fluid rates (S.F.):
20, 35, 45 ml/kg/h. é delivered U.F. rate of 31, 56, 68
L/d. The highest survival in 35 (57%) &
45 (58%) ml/kg./h. (S.F.). [Ronco
C., e al, Effects of different doses of CVVH on outcome of acute renal failure.
A prospective randomized trial, Lancet, 365:26-30,2000].
Generally, during COVID-19 pandemic, ptns receiving home DX should hv their
regular follow-up visits performed via telemedicine rather than in-clinic visits. Moreover, home visits
by health care professionals shd be minimized or hold. Pnts should have at least
two weeks of DX supplies with proper medications in case they have to self-isolation.
If in-person visit is clinically indicated,
proper infection control measures for the outpatient unit should be applied with
limitation of the number of ptns seen per day. Non-urgent procedures should be postponed.
The ASN has provided guidelines for nephrologists caring for hospitalized
patients requiring DX for ESRD and AKI, adherence to the suggested guidelines is advised:
Ptns e COVID-19
should be co-localized on a floor or ICU,
if possible. Co-localization within adjacent
rooms can enable one DX nurse to
simultaneously deliver DX for > one ptn. If ptn is in a negative-pressure isolation
room, then one HDX nurse will need to be dedicated for the care of that ptn in
a 1:1 nurse-to-ptn
ratio. If possible, ptns with suspected/confirmed COVID-19 who’re not critically ill shd be dialyzed in
their own isolation room rather than being transported to the in-ptn DX
unit.
Video & audio streams should be used to troubleshoot alarms from outside the room to minimize the need for DX nurse or the nephrologist to enter an isolation room. CRRT is preferred among critically ill ptns in ICU who hv ESRD/AKI. Even among ptns who’re hemodynamically stable and who cd tolerate intermittent HDX (IHD), CRRT or prolonged intermittent renal replacement therapy (PIRRT), also called sustained low-efficiency DX (SLED), should be performed instead, depending upon machine & staffing availability. As CRRT or PIRRT can be managed without 1:1 HDX support. This would potentially help decrease wastage of personal protective equipment and limit exposure among HDX nurses. With CRRT capacity overwhelming, CRRT machines can be used to deliver prolonged intermittent ttt (eg, 10 hs rather than continuous) with higher flow rates (eg, 40-50 mL/kg/h). This will enable CRRT machine to be more available for care of another ptn after terminal dysinfection. If available, HDX or CRRT machines are scarce, clinicians may need to consider ttt of AKI with PD. Ptns with suspected/confirmed COVID-19 who develop AKI, and an emphasis should be placed on optimizing volume status to exclude and ttt pre-renal (functional) AKI while avoiding hypervolemia, wch may worsen ptn’s respiratory status. Ptns with AKI with no need for DX should be managed on a limited contact bases. Physical evaluation and U/S studies should be coordinated e primary/consulting teams to minimize contact, as much as possible. Ptns receiving ACEi/ARBs) should continue their therapy (unless there’s a contra-indication e.g. hyperkalemia or hypotension). There’s no evidence that stopping ACEi/ARBs limit the severity of COVID-19. Pts e stage 4/5 CKD who’re referred for DX access placement should undergo their procedures as planned (not hv their planned procedure deferred).
COMMENTS