Q.556. What are the antidiabetics that should be avoided in dialysis patients?

 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.556. What are the antidiabetics that should be avoided in dialysis patients?

A. For type II. D.M. & according to K/DOKI guidelines:     💢

(1) 1^st gen. S. urea: [Acetohexamide, tolbutamide, chlorpropamide, tolazamide].

(2) 2nd G.S.urea: [Glyburide.].

(3) Biguanides: [Metformin].

(4) a glucosidase inhibitors:  [Acarbose, miglitol].

(5) Meglitinide: [Nateglinide, with caution.].

(6) Incretin mimetic: [Exenatide (Byetta)].

Q.557. What are antidiabetics that are safe to be used in dialysis patients?

A. For type II. DM & according to K/DOKI guidelines (Disc Ref. of Nephrology):

(1) 2nd generation S. urea: [Glimepiride: Start é1 mg.], Glipizide .

(2) Meglitinides: [Repaglinide (Prandin, Novonorm)]. Not studied in HDX. , SAFE in G. III/IV. CKD.

(3) Thiazolidinediones : [Pioglitazone, Rosiglitazone (Avandia)].[Also, SAFE in CKD. III/IV].

(4) Dpp-4 inhibitor: [Sitagliptin:🠋 by:75%].    {🠋50/75% é GFR:<50/30 ml/min. resp., in III/IV.} .

N.B.: {Metabolic implications & Safety of oral anti diabetics: Sulfonylureas (S.U.): Strongly protein(albumin) -bound. So, 🠉 pl. levels cannot be rev-ersed by HD. & displacement fr. albumin by [B.B., Salicylates & warfarin] 🠞 HG  due to 🠉 pl. conc. of free drug. Older S.U.(acetohexamide, chlorpropamide,tolazamide & tolbutamide)  hv bn replaced by newer ag.:[glyburide, glipizide & glimepiride]. Chlorpropamide is almost eliminated by the kidney. Active metb. of acetohexamide (no longer in U.S.), chlorpropamide & tolazamide are excreted largely by the kidney & accumulate in R.I. 🠞 HG. Glyburide hs weak active metabolites wch. excreted in urine & incr. in R.I. Glimepiride is Iry metabolized by the liver, é R. excr. of active metabolites. Glipizide & tolbutamide are metab. by liver & mainly excr. in urine as inactive metabolites. However, each hs one metabolite é weak HG activity, So; Glipizide:2.5-10 mg/d. is the oral hypoglycemic drug of choice in CRF. Glyburide:adj. if GFR<50 mL/min, but shd be avoided é sev. R.I.

Summery: Drugs of relative Safety in ESRD:   

 I.Sulfonylureas: Glipizide:2.5-10 mg/d.: oral hypoglycemic of choice in CRF.                   

II. Meglitinides (Insulin scretagogues): Nateglinide or repaglinide (Novonorm): 🠉 insulin secr.. Nateglinide is hepatically metabolized, é R. excretion of active metabolites. In R.I. accumulation of active metabolites & HG hs occ.. So, use it cautiously, if at all. Repaglinide is mainly metabolized by liver,  < 10 % R. excreted. Hypoglycemia is more common é severe R.I. Start é 0.5, titrated

III. Thiazolidinediones:🠉 Insulin sensitivity & 🠋hepatic gluc. production via PPAR g. binding. Rosi- & pioglitazone are highly protein(alb.)bound & solely metb. by the liver.

Q.558.Discuss the general considerations in short daily hemodialysis? 

A. A (1.5-2.5) h./session, short daily or "quotidian" HDX consists of daily(5-7 d./w .) HDX. Rationale is based upon improved ptn. outcomes, compared é convention-al 3 times/w. HDX, due to improved DX. efficiency & hemodynamic stability. Resources us. limit its use, so, daily HDX shd be prescribed on basis of need, such as : [Control of refractory uremic complications, fluid overload, or intractable H.T]. Selection of nocturnal vs short daily HDX should largely be dictated by availability & ptn. preference. Training: us. requires a full-time six w. commit-ment, alth. two w. cn be sufficient for a ptn. é self-care experience. Newer DX machines require shorter training times. Native A/V fistulae, synthetic grafts & long-term central venous cath. are all acceptabl. Choice of HDX equipment is wide, but still based upon designs of HDX machines that’re used in-center. Appropriate water ttt must be provided to home. A weekly std Kt/V target of 3.0 shd be sought, wch‘s us. ass. é improving in  physiological parameters. Modeling indicates: this target is only achievable é 2.5 h./6 d./w. reg ., using high flux, large surface area Dzer é QB.= 400-500 mL/min & Dzt flow rate of 800 mL/min. Dzt composition is generally not different fr. tht used é conventional HDX. Daily HDX. doesn’t require remote monitoring & security devices like enuresis alarms & connector clamps are also generally not needed. Compared é conventional HDX, short daily HDX is associated é 🠝 clearances of urea (based upon std Kt/V), middle molecules & protein bound molecules. It may also ⮞ [better quality of life, B.P. control, improved appetite & 🠋 rate of hospitalizations]. Effect of daily HDX on Epo is uncertain, with🠝 in H.B. levels being inconsistent. Overall simulated annual direct health care costs are likely to be lower for daily HDX compared é conventional HDX. 

Q.559. What are the technical aspects considered in nocturnal hemodialysis (NHDX)?

A. NHDX  is a form of home HDX performed either by the ptn or partner (partner not absolutely required). It’s performed 5-7 nights/w. during sleep for a variable amount of time based upon the length of sleep desired (usually 6-12 h.). Dzt consists of variable amounts of Na, K+, HCo3, Ca+ & Po4. Typical flow rates: Q.B.: 200-300 mL/min & Q.D.: 300 mL/min. Typical vol. of U.F./d. = 1-2 L.    Systemic anticoagulation: standard heparin regimen: 1000 u./h.. C.V. cth., A/V. fistulas & A/V. grafts have been successfully used for NHDX. Remote monitoring of ptn. by either phone lines ☏ or  Internet, while others don’t practice remote monitoring. Two inexpensive moisture sensors  placed on the floor to detect Dzt & blood leaks. They shd be an obligatory safety measure. Ptn capable of home HDX are eligible for NHDX. Other thn inability of systemic anticoagulation, there’re no exclusion criteria.

 

Q.560. What are the possible outcomes associated with nocturnal HDX?

A. NHDX is associated é marked benefits compared to conventional HDX. Some benefits  hv bn clearly shown, while others require further analysis. Clearance of urea, Po4 & beta 2-microglobulin are markedly enhanced é NHDX. Limited data sugg.:“quality of life” may be improved. Excellent B.P. control is achieved, with almost all ptn.s no longer requiring anti-H.T. drugs. Incr. evid. also sugg.: NHDX 🠞 regression of LVH. Sleep disturbance is minimal during NHDX & sleep archit-ecture appears to improve. NHDX also signif. liberates dietary intake of DX. ptn. Ptn.s are kept on a free diet incl.: unrestricted intake of salt, water, K, PO4 & protein.

No signif. conclusions appear concerning effect of NHDX on survival. Depending upon consumable/personnel cost ratio in different centers, NHDX cn be less or more expensive thn in-center conventional HDX. Enthusiastic acceptance by ptn. & favorable financial profile, NHDX shd be cons-idered for ptn. who’re willing & capable of performing home DX. Current obsta-cles to adoption of NHDX are unfamiliarity é home HDX & financial impact of high frequency of DX.

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 hv at least two weeks of DX supplies with proper medications in case they hv 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).