Q. 612. What is the situation of AKI in ICU?

HEMODIALYSIS 

Q. 612. What is the situation of AKI in ICU?

A. AKI in ICU is a grave 💀 situation  ptn.s are us. septic, overloaded, profoundly acidotic & us. in need for B.P. support & mechanical ventilation. They are twice Catabolic as much as those outside ICU é RRT.

Q. 613. What are the possible indications for CRRT?        

A. “Mehta” et al, dev.: (1) Renal Supportive therapy.   &          (2) R.R.T.

* R.R.T. indications: AEIOU     أيُّيُوُهْ:

 Acidosis é azotemia, decline of s. HCO3 é inadequate i.v. supplements or unacceptable, due to sod. overload.        

‚ Electrolyte abnormality:  [K+, Na+, Ca+ (M), uric a. (tumor lysis)].

ƒ Intoxication: [Lithium, theophylline, eyhylene glycol, Methanol, Asprin, Phentoin].

„ Overload volume: Oliguria/anuria, not responding to diuretics, severe H.T. (.).A.P.O

… Uremia:  There is No clear definition for uremia.

“Mental changes” & “pericarditis” : Late mnf. & should not be used as indicators.

Q. 614. Explain, when R.R.T. is supportive?

A. Supportive R.T.: “MEHTA” said: 

“It represents a change in therapy from ameliorating the conditions directly resulting from lack of intrinsic renal function, to one that supports the patient and the effects of complications from other organ failure”               

- Examples:   i. Significant azotemia.

                   ii. Volume overload. (Without oliguria).

“Mehta” RT et al, Indication for dialysis in ICU: RRT Vs “renal support” therapy.  Blood purification 19 : 227-232, 2001.

Q. 615. Explain, how can “supportive R.T” be beneficial to ICU patient?

A. “Daily fluids” in ICU = {T.P.N.: (1.5-3) L. + blood product:(½- 1½)L. + medications: (1-2) L.= Total 3-7 L./d. }. CRRT  can be used é total body overload + Less thn adequate U.O. despite partial response to diuretics .                     

- R. “Supportive” therapy allow:                               

1)   Free T.P.N.

2)   Fluid removal é CHF.

3)   Total fluid management é MODF syndrome.

- Ptn may need  3 L./d, So, c CRRT allow continuous fluid removal of excess input despite Hpt & fluid support. Also, CRRTc Continuous fluid removal post-operative  Morbidity & M.R., better U.O., better GFR, better nutrition Vs intermittent therapy.

Q. 616. Explain your timing to start CRRT?   

A. Decision to start CRRT is complex, but considering R. Supportive therapy, available requirement and the high M.R. in ICU, EARLIER intervention is appropriate. Earlier CRRT é BUN  60 mg/dl. hs better survival thn CRRT é BUN   60 mg/dl, similarly, decision to withhold CRRT, if no harm if R. function is likely to respond to “furosemide” or “conservative therapy” without extracorporeal therapy is accepted.

Q. 617. What is the role of vascular access in CRRT adequacy?

A. {Poor access [ Recirculation & inadequate flow & low Kt/V.}

   * Recirculation: &

                                                 i.    Kt/V. & Adequacy.

                                               ii.    Inadequate flow.

                                              iii.    Hct à Clotting of the “extra-corporeal system”.    

- Catheter function factors: location, design & ptn. factors.

- “Non-cuffed” catheter ➤ Polyurethane, firm but lax é body temperature, applied é “Seldinger technique” (guidewire) .  

- Siliconecth.: thick wall, more flexible + peel away sheath or stiffening stylet.

- Length: Rt. Jugular † 15 cm., 20 for large ptn., … Lt. jugular † Ÿ 20 cm.

- Silicone cth. duration: 2-3 w.

- Cth. tip † Split tip é blood flow of 300 ml/min.

- Do Not apply subclavian catheter, Use Rt. Int. jug. or femoral Ÿ19 cm in ICU. 

Q.618. What is the effect of catheter type on the incidence of re-circulation? 😎 

 A. Recirculation: †

                         i.    Decrease if the length of femoral cath.  19 cm.

                        ii.    Highest é femoral cath. compared to central cath.

                       iii.    Increase é incr. in bld pump(Qb.) (reach: 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.(Ÿ3 w.) † incr. liability for infection, so, 1^st 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)           Int. jug. & 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.