119 Continuous Renal Replacement Therapies 1055

Unit V Renal System

Section Seventeen Renal Replacement

PROCEDURE Continuous Renal Replacement 119 Therapies Sonia M. Astle PURPOSE: Continuous renal replacement therapies are used in the critical care unit setting for volume regulation, acid-base control, electrolyte regulation, drug intoxications, management of azotemia, and immune modulation. These methods are most often used in critically ill patients whose hemodynamic status does not tolerate the rapid ﬂ uid and electrolyte shifts associated with intermittent hemodialysis or who need continuous removal or regulation of solutes and intravascular volume.

high pressure to an area of low pressure with transport PREREQUISITE NURSING of solutes. When water moves across a membrane KNOWLEDGE along a pressure gradient, some solutes are carried along with the water and do not require a solute con- • Continuous renal replacement therapy (CRRT) is an extra- centration gradient (also called solute drag). Convec- corporeal blood-purifi cation therapy intended to substitute tive transport is most effective for the removal of for impaired renal function over an extended period of middle-molecular-weight and large-molecular-weight time for, or attempted for, 24 hours per day.1 solutes. • CRRT can be accomplished through a variety of methods, ❖ UF: The bulk movement of solute and solvent through with either arteriovenous (AV) access or venovenous a semipermeable membrane in response to a pressure (VV) access. The VV access is used almost exclusively difference across the membrane. This movement is because of its less invasive nature. In the past, AV access usually achieved with positive pressure in the blood was used, requiring both arterial and venous cannulation. compartment in the hemofi lter and negative pressure in With AV access, the patient’ s systemic blood pressure is the dialysate compartment. Blood and dialysate run required for blood to fl ow into the extracorporeal circuit, countercurrent. The size of the solute molecules com- making it unreliable for hypotensive patients. The newer- pared with the size of molecules that can move through generation CRRT machines have an added extracorporeal the semipermeable membrane determines the degree blood pump that pulls the patient’ s blood into the circuit, of UF. so it is better suited to treat hemodynamically unstable ❖ Osmosis: The passive movement of solvent through a patients.10,18 semipermeable membrane from an area of higher to • The following methods of CRRT are included as listed lower concentration. (details are outlined in Table 119-1 ): ❖ Oncotic pressure: The pressure exerted by plasma ❖ Slow, continuous ultrafi ltration (SCUF) proteins that favor intravascular fl uid retention and ❖ Continuous venovenous hemofi ltration (CVVH) movement of fl uid from the extravascular to the intra- ❖ Continuous venovenous hemodialysis (CVVHD) vascular space. ❖ Continuous venovenous hemodiafi ltration (CVVHDF) ❖ Hydrostatic pressure: The force exerted by arterial • Basic knowledge is required to understand the principles blood pressure that favors the movement of fl uid from of diffusion, ultrafi ltration (UF), osmosis, oncotic pres- the intravascular to the extravascular space. sure, and hydrostatic pressure and how they pertain to ❖ Absorption: The process by which drug molecules pass fl uid and solute management during dialysis. through membranes and fl uid barriers and into body ❖ Diffusion: The passive movement of solutes through a fl uids. semipermeable membrane from an area of higher to ❖ Adsorption: The adhesion of molecules (solutes) to the lower concentration until equilibrium is reached. surface of the hemofi lter, charcoal, or resin. ❖ Convective transport: The rapid movement of fl uid • CRRT uses an artifi cial kidney (i.e., hemofi lter, dialyzer) across a semipermeable membrane from an area of with a semipermeable membrane to create two separate

1054 119 Continuous Renal Replacement Therapies 1055

TABLE 119-1 Continuous Renal Replacement Therapies Ultrafi ltration Mode of Principles Complications/ Therapies Involved Access Indications Advantages Disadvantages SCUF (slow, Ultrafi ltration Venovenous Patients with diuretic- Continuous, gradual Anticoagulation, bleeding continuous resistant, volume- treatment (fewer Hypotension ultrafi ltration) overloaded, high and low Hypothermia hemodynamically extremes) Access complications (bleeding, unstable conditions Precise fl uid control clotting, infection) who cannot tolerate can be done in Requires strict monitoring of rapid fl uid shifts patient with low fl uid and electrolyte mean arterial replacement to avoid pressure defi cits or overload Air embolism Critical care setting only Poor control of azotemia; dialysis may be needed Minimal solute clearance Not recommended for emergently treating hyperkalemia or acidosis CVVH (continuous Ultrafi ltration Venovenous Patient with volume- Precise fl uid control Anticoagulation, bleeding venovenous Convection overloaded, can be done in Hypotension hemofi ltration) Solute removal hemodynamically patients with low Hypothermia unstable condition with mean arterial Access complications (bleeding, azotemia or uremia pressure clotting, infection) Ease of initiation Requires strict monitoring of fl uid and electrolyte replacement to avoid defi cits or overload Air embolism Critical care setting only Recommended 1 : 1 nurse/ patient ratio Metabolite removal not as effi cient as CVVHDF CVVHD (continuous Ultrafi ltration Venovenous Patients with volume- Precise fl uid control Same as CVVH venovenous Diffusion overloaded, can be done in Hyperglycemia hemodialysis) Solute removal hemodynamically patients with low Hypernatremia unstable conditions mean arterial Hypophosphatemia with azotemia or pressure uremia Ease of initiation CVVHDF (continuous Ultrafi ltration Venovenous Patient with volume- Precise fl uid control Same as CVVH venovenous Convection overloaded, can be done in Hyperglycemia hemodiafi ltration) Diffusion hemodynamically patient with low Hypernatremia Solute removal unstable conditions mean arterial Hypophosphatemia with azotemia or pressure uremia, catabolic Better solute acute renal failure, clearance than electrolyte imbalances/ CVVH/ CVVHD metabolic acidosis Ease of initiation

Adapted from Giuliano K, Pysznik E: Renal replacement therapy in critical care: implementation of a unit-based CVVH program, Crit Care Nurse 18:40–45, 1998.

compartments: the blood compartment and the dialysis solution but is impermeable to larger molecules (e.g., red solution compartment. The semipermeable membrane blood cells, plasma proteins). allows the movement of small molecules (e.g., electro- • Each dialyzer has four ports: two end ports for blood lytes) and middle-size molecules (e.g., creatinine, vasoac- (blood ﬂ ows in one end and out the other) and two side tive substances) from the patient’ s blood into the dialysis ports for dialysis solution ultraﬁ ltrate (dialysate solution 1056 Unit V Renal System

fl ows in one end and out the other). In most cases, the blood and dialysate run through the dialyzer in opposite or countercurrent directions. • Hollow-fi ber dialyzers are used almost exclusively for CRRT. The blood fl ows through the center of hollow fi bers, and the dialysis solution (dialysate) fl ows around the outside of the hollow fi bers. The advantages of hollow- fi ber fi lters include a low priming volume, a low resistance to fl ow, and a high amount of surface area. The major disadvantage is the potential for clotting as a result of the small fi ber size. • All dialyzers have a UF coeffi cient; thus, the dialyzer 2–6,8,9 selected varies in different clinical situations. The UF drain bag higher the UF coeffi cient, the more rapid the fl uid removal.12,16,19 UF coeffi cients are determined with in vivo measurements done by each dialyzer manufacturer. • Clearance refers to the ability of the dialyzer to remove Figure 119-1 Slow continuous ultrafi ltration (SCUF). Fluid metabolic waste products or drugs from the patient ’ s removal, no fl uid replacement. (Copyright Rhonda K. Martin. All blood. The blood fl ow rate, the dialysate fl ow rate, and the rights reserved. Used with permission.) solute concentration affect clearance. Clearance occurs by the processes of diffusion, convection, and UF. • The dialysate (when used during CRRT) is composed of Replacement fluid water, a buffer (i.e., lactate or bicarbonate), and various electrolytes. Most solutions also contain glucose. The buffer helps neutralize acids that are generated as a result of normal cellular metabolism. The concentration of electrolytes is usually the normal plasma concentration, which helps to create a concentration gradient for removal of excess electrolytes. The glucose aids in increasing the Blood pump oncotic pressure in the dialysate (thus aiding in fl uid removal) and in caloric replacement. Although glucose comes in various concentrations, it is usually used in normal plasma concentrations to prevent hyperglycemia. • Heparin or citrate are often used during CRRT to prevent clotting of the extracorporeal circuit during treatment. Saline solution fl ushes can be used alone or with other 31,33 anticoagulants to maintain circuit patency. UF drain bag • An anticoagulant may be used to maintain vascular access patency when CRRT is not in use.4,18,33 • If the patient is taking angiotensin-converting enzyme (ACE) inhibitors, contact with certain fi lters or mem- Figure 119-2 Continuous venovenous hemofi ltration (CVVH). branes in the CRRT system can cause an anaphylactic Fluid removal and fl uid replacement. (Copyright Rhonda K. Martin. reaction and severe hypotension as a result of increased All rights reserved. Used with permission.) levels of bradykinin, a potent vasodilator.15 ACE inhibitors are recommended to be withheld for 48 to 72 hours used in the past for CRRT; however, because of increased before treatment, if possible. incidence rates of vascular injury, bleeding, and infection, • Continuous venovenous renal replacement therapy is they are not recommended for CRRT access. 1,18 Common achieved with a pumped system. sites for the VAC are the internal jugular, subclavian, and • The patient ’ s volume status and serum electrolyte levels femoral veins. The internal jugular approach is the pre- are changed gradually so that patients have fewer prob- ferred access. Cannulation of the subclavian vein may lems maintaining hemodynamic stability than with hemo- cause stenosis and prevent placement of upper extremity dialysis. Specifi cs of these therapies are outlined in Table grafts or fi stulas if long-term dialysis is necessary.4,25,28 119-1 . 1,3,6,10,22–24,28,29 Femoral cannulation is associated with increased • SCUF ( Fig. 119-1 ) is a nonpumped system; CVVH ( Fig. infection.4,16,32 119-2 ), CVVHD ( Fig. 119-3 ), and CVVHDF ( Fig. 119-4 ) • A blood pump provides the pressure that drives the extra- use pump-driven systems. These therapies are used to corporeal system; the blood circuit consists of blood lines, remove both plasma water and solutes and require venous a blood pump, and various monitoring devices. The blood access, most commonly provided with a double-lumen lines are connected to the vascular access and carry the vascular access catheter (VAC). Hemodialysis shunts or blood to and from the patient. The blood pump controls surgically created hemodialysis anastomoses have been the speed of the blood through the circuit. The monitoring 119 Continuous Renal Replacement Therapies 1057

Dialysate

Blood pump

UF drain bag

Dialysate Figure 119-5 Gambro Prismaﬂ ex Continuous renal replacement Replacement fluid therapy machine. (Courtesy Gambro USA, Lakewood, Colo.)

The module calculates and adjusts pump speeds to achieve the selected fl uid goal. The module also records and displays treatment data. Blood pump • SCUF (see Fig. 119-1) is used primarily to remove plasma water. A hemofi lter with a large surface area, high sieving coeffi cient, and low resistance is used to facilitate slow continuous fl uid removal. • CVVH (see Fig. 119-2 ) removes fl uids and solutes via convective clearance. Replacement solution is part of the setup; the replacement solution creates a solute drag UF drain bag effect. • CVVHD (see Fig. 119-3) is used to remove solutes primarily via diffusion. Dialysate solution is part of the setup; fl ow of the dialysate is countercurrent to the blood Figure 119-4 Continuous venovenous hemodiafi ltration fl ow. (CVVHDF). Fluid replacement with dialysate. (Copyright Rhonda K. Martin. All rights reserved. Used with permission.) • CVVHDF (see Fig. 119-4 ) removes fl uids and solutes via diffusion and convection. Dialysate runs countercurrent to the blood fl ow and clears toxins by diffusion. Replace- devices include arterial and venous pressure monitors and ment fl uid is infused at a prescribed rate and clears by an air detection monitor to prevent air that may have convection. entered the circuit from being infused to the patient. Anti- • Other extended renal replacement therapy techniques or coagulant, dialysate, and replacement fl uids can also be “hybrid” techniques (sustained low-effi ciency dialysis, added to the system. extended daily dialysis) generally use standard hemodi- ❖ Integrated pump systems have separate pumps for alysis equipment with reduced blood fl ow and dialysate blood, dialysate, ultrafi ltrate/effl uent, and replacement rates to gradually remove plasma water and solutes. They fl uids (Fig. 119-5). The pumps are controlled by a are used from 4 to 12 hours a day. 26 computerized control module. Blood fl ow rate, dialysate fl ow rate, anticoagulation rate, and fl uid-removal EQUIPMENT rates are entered by the nurse as prescribed. Dialysate, ultrafi ltrate/effl uent, and replacement fl uids are mea- • Dedicated vascular access sured by weight or volumetric scales on the machine. • Hemofi lter/pump system with blood lines 1058 Unit V Renal System

• Replacement fl uid as prescribed PATIENT ASSESSMENT AND • Dialysate fl uid as prescribed PREPARATION • Fluid shield, face masks, or goggles • Sterile and nonsterile gloves Patient Assessment • Fluid warmer • Assess baseline vital signs, including hemodynamic • Two 10-mL prefi lled syringes with normal saline (NS) parameters, weight, current medications, laboratory values solution (blood urea nitrogen, creatinine, electrolytes, hemoglobin, • Sterile NS solution, 1 to 2 L and hematocrit), neurological status, and nutritional • Dressing supplies (alcohol wipes, sterile barrier, gauze needs. 7,11,17,27 Rationale: Patients in renal failure often pads, transparent dressing, tape) have altered baseline assessment results, both in physical • Antiseptic solution (e.g., 2% chlorhexidine–based assessment and in laboratory values. Knowledge of this preparation) information before treatments are started is helpful so that • Heparin, 1000 units/mL, or citrate (for priming, as interventions, including net fl uid balance and dialysate prescribed) fl uid, can be individualized. Alterations during treatment • Drainage bag are common because of the rapid removal of fl uid and • Intravenous (IV) accessory spike to connect NS bag to solutes. arterial tubing • Assess the VAC insertion site for signs and symptoms of • Two dialysis luer caps for the VAC infection. Rationale: Insertion sites provide a portal of Additional equipment, to have available as needed, includes entry for organisms, which may result in septicemia if the following: unrecognized or untreated. If the insertion site appears to • Two 5-mL syringes and blunt-tip needles (if needed to be infected, further interventions (e.g., site change, culture, draw up NS for injection) antibiotic treatment) may be necessary. • NS for injection (if prefi lled NS syringes are not used) • Assess the patency of the VAC and the ability to easily • Plastic hemodialysis clamps aspirate blood from both ports. Rationale: Adequate blood fl ow is necessary during treatment to facilitate PATIENT AND FAMILY EDUCATION optimal fl uid and solute removal. Patent catheter ports are necessary for adequate blood fl ow. • Explain the purpose of CRRT—specifi cally why the treat- • Assess adequate circulation to the distal parts of the access ment is performed and the expected clinical outcomes. limb. Rationale: The placement of vascular access may Rationale: The patient and family should understand compromise circulation. that CRRT is necessary to perform the physiological func- tions of the kidneys if the patient is hemodynamically Patient Preparation unstable. • Verify that the patient is the correct patient using two • Explain the procedure, including risks, anticipated length identifi ers. Rationale: Before performing a procedure, the of treatment, and patient positioning, and review any nurse should ensure the correct identifi cation of the patient questions the patient may have. Rationale: Explanation for the intended intervention. provides information and may decrease patient anxiety. • When CRRT is initiated, ensure that informed consent has • Explain the need for careful sterile technique for the dura- been obtained. Rationale: Informed consent protects the tion of treatment. Rationale: The patient and family must rights of the patient. know the importance of sterile technique to decrease the • Ensure the patient understands preprocedural teachings. likelihood of systemic infection. Answer questions as they arise, and reinforce information • Explain the need for careful monitoring of the patient as needed. Rationale: Understanding of previously taught during the treatment, particularly for fl uid and electrolyte information is evaluated and reinforced. imbalance. Rationale: The patient and family should • Position the patient in a comfortable position (that also understand that careful monitoring is a routine part of facilitates optimal blood fl ow through the vascular access). CRRT. Rationale: The patient and family must understand that • Explain the signs and symptoms of possible complications movement may affect blood fl ow through the system and during CRRT. Rationale: Patients and family should be that a comfortable position is important. fully prepared if complications occur (e.g., hypotension, • Following initiation of treatment, continue to reposition hemorrhage, manifestations of fl uid/electrolyte/acid-base the patient at regular intervals. Rationale: Critically ill imbalance). patients are at a high risk for pressure points and skin • Explain the CRRT circuit setup to the patient and family. breakdown. Rationale: It is important that the patient and family know that blood will be removed from the patient ’ s body and will be visible during the CRRT treatment. 119 Continuous Renal Replacement Therapies 1059

Procedure for Initiation and Termination of Continuous Renal Replacement Therapy Steps Rationale Special Considerations Systems (SCUF, CVVH, CVVHD, CVVHDF) 1 . HH 2 . PE 3. Verify orders, which should Familiarizes the nurse with the Ensure patient weight and laboratory include the following: individualized patient treatment and values are assessed and recorded A. Modality reduces the possibility of error.4,6 before initiation of therapy. B. Vascular access Communicate with the C. Type of hemofi lter/dialyzer nephrologist/intensivist ordering D. Anticoagulant type, therapy if questions arise.14,30 concentration, infusion rate, monitoring parameters E. Replacement fl uid and rate (if used) F. Hourly ultrafi ltration UF rate G. Hourly net fl uid goal H. Dialysate solution and rate (if used) I. Blood pressure/vital sign parameters J. Laboratory testing 4. Prepare the system: Correct system setup is imperative for The pump must be plugged into a A. Turn the machine on. safety and optimal functioning. The generator outlet because some B. Load the circuit according to use of anticoagulants prolongs the pumps do not have battery power. the manufacturer ’ s function of the hemofi lter. 4,6 Heparin, if ordered, is usually instructions. administered on a prefi lter port; C. Attach solutions as prescribed. citrate is usually administered at D. Prepare anticoagulant infusion the arterial port of the VAC or as prescribed. infused via the preblood pump. E. Prepare replacement fl uid, Replacement solutions are dialysate, and fl ush infusion administered through the arterial as prescribed. (access) or venous (return) infusion F. For integrated pump units port as ordered (usually arterial) follow the manufacturer ’ s with blood tubing. Connect 1 L NS instructions and prompts from to arterial infusion port (for fl ushing the control screen. system). Dialysate solution (if G. Automated setup instructions CVVHD/CVVHDF are used) is include: connected to the outlet port of the 1. Select therapy/modality. hemofi lter near the venous end with 2. Calibration (if indicated). blood tubing. Each integrated pump 3. Load set. is loaded and primed according 4. Priming. to the manufacturer ’ s 5. Anticoagulant. recommendations, ranging from 6. Dialysate and replacement assembly and priming of all fl uid rates. components to “one-touch” circuit 7. Blood fl ow. rate loading and priming. Some unit’ s 8. Fluid removal rate. air detectors are activated after the H. After priming per machine is primed. manufacturer instructions, go to Step 5. 5. Leave the priming bag, collection Preserves the sterility of the system. Some systems have a collection bag bag, and protective caps in place for the priming solution, which until the blood lines are attached stays attached to the venous blood to the VAC. line until it is attached to the VAC. 6. Remove gloves and discard in the Reduces transmission of appropriate receptacles. microorganisms; Standard Precautions. Procedure continues on following page 1060 Unit V Renal System

Procedure for Initiation and Termination of Continuous Renal Replacement Therapy—Continued Steps Rationale Special Considerations 7. Wash hands. Reduces transmission of microorganisms on the hands after removal of gloves and before performing a sterile procedure. 8. Prepare a sterile fi eld with sterile Prepares material and maintains barrier under the VAC. aseptic technique. 9. Place 4 × 4 gauze pads onto the Prepares material and maintains sterile fi eld. Open sterile aseptic technique. container, syringes, blunt-tip needles, and NS (or prefi lled NS syringes) and place on the sterile fi eld. 10. Add antiseptic solution (e.g., 2% Prepares solution used to cleanse chlorhexidine–based preparation) VAC ports. Povidone-iodine, to sterile container or use hypochlorite, and chlorhexidine prepackaged bactericidal agents. solutions are acceptable bactericidal (Level D * ) agents.4,18,31 11. Wash hands and apply sterile Maintains aseptic technique. gloves. 12. Attach blunt-tip needles to two Prepares syringe for VAC fl ushing. With Quinton catheters, a 20–30 mL 10-mL syringes; with help of per lumen fl ush for hemocaths and assistant, fi ll with NS or use permacaths is recommended.1 prefi lled syringes per institutional standards. 13. Saturate four of the 4 × 4 pads in Prevents introduction of pathogens. Be sure to remove any crust or the antiseptic solution. Using two drainage at the catheter insertion of the soaked pads, perform a site. 1-minute scrub of the arterial and venous ports of the VAC. Alternatively, perform a 30-second scrub of the ports with antiseptic swabs. 14. Ensure clamps are closed on the Provides access to the arterial side of Be sure the VAC clamp is closed arterial and venous ports of the the VAC. The VAC is not opened to before removing arterial and venous VAC; then remove the cap from air unless caps require changing, port caps. the arterial port of the VAC and reducing the chance of discard. Alternatively, many contamination and infection. facilities are using dialysis- specifi c luer caps that lock into the VAC. 15. Attach an empty 5-mL syringe to Verifi es the patency of the arterial Do not forward-fl ush an indwelling the arterial port, open the clamp, port. Note any resistance, which port before aspirating. This prevents and gently aspirate 5 mL of blood may indicate a clotted or kinked dislodgment/embolism of clots and and anticoagulant. Close the port. Prevents bolus of prevents a bolus of anticoagulant to clamp, remove the syringe, and anticoagulant to the patient (if used) the patient. Observe for clots. A discard it in an appropriate and decreases transmission of clotted or kinked port decreases receptacle. microorganisms. 4,18 blood fl ow and reduces effi cacy of the treatment. 16. Attach a 10-mL syringe with NS Prevents clotting of blood until Note any resistance on fl ushing. fl ush solution to the arterial port. dialysis is initiated. Open the clamp and fl ush; then close the clamp.

* Level D: Peer-reviewed professional and organizational standards with the support of clinical study recommen dations. 119 Continuous Renal Replacement Therapies 1061

Procedure for Initiation and Termination of Continuous Renal Replacement Therapy—Continued Steps Rationale Special Considerations 17. Repeat Steps 15–16 on the Provides access to the venous side of venous port. the catheter. 18. Disconnect the access line from Loose connections introduce air into the primed circuit and attach it to the circuit. the arterial port of the VAC; secure the connection. 19. Disconnect the return line from Loose connections introduce air into the primed circuit and attach it to the circuit. the venous port of the VAC; secure the connection. 20. Open the clamps on the VAC Opens the circuit in preparation for Perform a fi nal check for air in the ports and the access and return starting the blood pump. circuit. blood lines. 21. Check that all alarms are on and Ensures safe delivery of therapy. parameters are set. 22. Turn the blood pump on and Prevents hypotension from rapid Observe for blood leaks, air in the gradually increase the blood fl ow blood and fl uid shifts. system, and pressure alarms. Assess to the prescribed rate. the patient ’ s vital signs, which should remain within 20% of baseline parameters. 23. Note blood pump fl ow rate, Ensures safe delivery of therapy. Increased arterial pressure indicates arterial and venous monitor problems with the vascular access pressures, transmembrane (TMP) or blood infl ow. Increased venous fi lter pressure, the amount and pressure indicates clotting of the color of UF, and vital signs on system. Decreased venous pressure initiation and hourly or per indicates clotting of the hemofi lter. institutional standards. 24. Remove PE and discard supplies Safely discards used supplies. in the appropriate receptacles. 25. HH 26. Prepare a fl uid balance fl ow sheet Accurate calculations of hourly fl uid Hourly fl uid balance is usually and calculate the net fl uid gain/ balance prevent hypervolemia and calculated by subtracting the total loss prescribed each hour or hypovolemia and ensure that output (including UF removed) document in the electronic health clinical goals are being met. from the total intake. record. Flushing 1 . HH 2 . PE 3. Connect the NS with primed Prepares port for fl ushing. tubing to the arterial port of the VAC and the access line of the circuit via a three-way stopcock. 4. Clamp the arterial port of the Prevents any more blood from Note: Be sure that the NS fl ush is VAC by turning the stopcock off entering the circuit via the arterial running freely to prevent rupture or to the VAC port. port during fl ushing. back fi ltration. Hemostasis and clot formation in the arterial limb of the tubing are possibilities if the fl ushing procedure is prolonged. 5. Open the NS fl ush while the Flushing allows the nurse to assess Flushing contributes to the patient ’ s pump continues to run. Note the the patency of the system. 3 IV intake; the volume of fl uid amount of NS that has infused. should be documented. When the circuit is fl ushed of blood, clots may be observed. Flushing does not dissolve existing clots. Procedure continues on following page 1062 Unit V Renal System

Procedure for Initiation and Termination of Continuous Renal Replacement Therapy—Continued Steps Rationale Special Considerations 6. If clots are not observed, turn off Continues therapy. If numerous clots are observed, the the NS by moving the stopcock hemofi lter may need to be replaced. “off” to the NS fl ush and open to Heparin will not dissolve existing the arterial port of the VAC. clots. 7. Remove PE and discard used Safely discards used supplies. equipment in appropriate receptacles. 8 . HH Termination 1 . HH 2 . PE 3. Turn off all infusions into the Prepares for termination of therapy. circuit. 4. With the IV accessory spike, Prepares for fl ushing blood from the attach the NS fl ush solution to tubing. the arterial infusion line of the circuit. If using NS fl ushes, this line can be used to fl ush the circuit when terminating the treatment. 5. Return the blood in the circuit Follow instructions on the pump for If clots are identifi ed beyond the to the patient. When the entire termination. The blood should be venous bubble trap, stop the pump; circuit is clear of blood, turn off fl ushed from the circuit back to the do not return blood to the patient. the pump and clamp off both the patient to prevent unnecessary arterial and venous lines. blood loss. 6. Continue terminating the procedure according to the manufacturer ’ s guidelines. 7. If the VAC is to be discontinued, CRRT therapy may no longer be remove it per institutional needed. guidelines. 8. Record the amount of NS Ensures accurate fl uid balance. The fl ush solution infused to the infused. patient must be recorded as intake. 9. If the VAC is not to be removed, Maintains aseptic technique. prepare the sterile fi eld. Open and place the sterile barrier under the VAC. 10. Place 4 × 4 gauze pads onto the Maintains aseptic technique. sterile fi eld. Open the sterile container, syringes, blunt-tip needles, and NS (or prefi lled NS syringes) and place them on the sterile fi eld. 11. Add antiseptic solution (e.g., 2% Prepares solution used to cleanse chlorhexidine–based preparation) VAC ports. Povidone-iodine, to the sterile container (or use hypochlorite and chlorhexidine prepackaged bacterial solution). solutions are acceptable bactericidal (Level D * ) agents. 3,10,19 12. Remove gloves and discard in Safely discards used supplies. appropriate receptacles. 13. Wash hands. 14. Don sterile gloves.

*Level D: Peer-reviewed professional and organizational standards with the support of clinical study recommendations. 119 Continuous Renal Replacement Therapies 1063

Procedure for Initiation and Termination of Continuous Renal Replacement Therapy—Continued Steps Rationale Special Considerations 15. Attach blunt-tip needles to two Prepares the syringe for VAC A 20–30 mL per lumen fl ush is 10-mL syringes; with the help of fl ushing. recommended.1 an assistant, fi ll the syringes with NS or use prefi lled syringes per institutional standards. 16. Saturate two 4 × 4 gauze pads in Prevents introduction of infection. Be sure to remove any crust or antiseptic solution. Perform a drainage. 1-minute scrub of the arterial and venous ports of the VAC. Alternatively, perform a 30-second scrub of the ports with chlorhexidine swabs (if approved by the catheter ’ s manufacturer). 17. Be sure clamps are closed on the Opens the system under sterile Be sure the port clamp is closed arterial and venous ports of the conditions for system termination. before removing the arterial line. VAC before disconnecting the arterial blood line from the arterial vascular access. Alternatively, if dialysis luer caps are used, the circuit lines can be disconnected without opening the VAC ports. 18. Repeat Step 18 on the venous system line. 19. Attach a 10-mL syringe with NS Prevents clotting of blood until to the arterial port. Open the anticoagulant is instilled. clamp and fl ush, then close the clamp. 20. Repeat Step 20 on the venous port. 21. Instill the prescribed Maintains patency of the accesses. Label each port with the date, time, anticoagulant into each access and anticoagulant used, and your port according to institutional initials. standards. Use only the “fi ll” amount listed on the VAC ports to avoid instilling anticoagulant into the patient. (Many facilities are now using NS instead of heparin and dialysis-specifi c locking caps to prevent opening the VAC ports to air.) 22. Clamp and cap the arterial and Maintains sterility of the VAC. venous ports with the sterile needleless luer caps. 23. Change the vascular access Prevents infection. dressings according to institutional guidelines. 24. Remove PE and discard used Safely discards used supplies. equipment in the appropriate receptacle. 25. HH Procedure continues on following page 1064 Unit V Renal System

Expected Outcomes Unexpected Outcomes • VAC accessed without complications • Clotting/decreased patency of the access sites • Blood easily aspirated from the access site • Crack in the VAC or end caps • Accumulated fl uid and waste products removed • Bleeding from the VAC insertion site or access/return • Acid-base balance restored lines • Blood urea nitrogen and creatinine values restored to • Signs and symptoms of infection at the insertion or baseline levels access site • Electrolyte levels within baseline values • Dislodgment of the VAC • Hemodynamic stability and maintenance of optimal • Decreased circulation in the extremity with the intravascular volume vascular access • Nutritional status maintained • Hematoma formation at the VAC insertion site • Physiological complications (dysrhythmias, chest pain, fl uid or electrolyte imbalance, complications related to anticoagulation, air embolism, hypotension, seizures, nausea and vomiting, headaches, muscle cramping, dyspnea, exsanguination, hemorrhage) • Introduction of pathogens or air into the circuit • Technical problems with the blood pump (blood leak, air leak, clotting, disconnection of circuit, hemolysis, hemofi lter rupture) • Hypothermia21 • Malnutrition

Patient Monitoring and Care Steps Rationale Reportable Conditions These conditions should be reported if they persist despite interventions. 1. Obtain and record predialysis and Predialysis weight is an important • Increase or decrease in weight daily weight. factor in deciding how much UF is needed and helps guide ongoing treatment.4 2. Perform ongoing assessments, Provides information in response to • Hypotension including the following: treatment.1,6,10,13 Monitors for • Hypertension A. Vital signs complications. • Tachycardia/bradycardia B. Jugular vein distention • Tachypnea C. Presence of edema • Fever D. Intake and output • Hypothermia21 E. Neurological assessment • Jugular vein distention F. Pulmonary assessment • Crackles G. Cardiac monitoring • Edema • Change in level of consciousness, dizziness • Change in cardiac rhythm 3. Monitor the circulation to the Assesses for any decrease in • Diminished capillary reﬁ ll extremity where the VAC is perfusion distal to the VAC site.4,6 • Diminished or absent peripheral located. pulses, or pain • Pale, mottled, or cyanotic color • Cool to the touch • Diminished or absent movement or sensation. 119 Continuous Renal Replacement Therapies 1065

Patient Monitoring and Care —Continued Steps Rationale Reportable Conditions 4. Monitor electrolytes, glucose, and Must be monitored because of • Hyperkalemia or hypokalemia albumin during treatment as continued fl uid and electrolyte • Hypernatremia or hyponatremia prescribed or per institutional shifts during treatment. Amino • Hypercalcemia or hypocalcemia standards. acids are also lost through the • Hyperglycemia or hypoglycemia hemofi lter. • Hypermagnesemia or hypomagnesemia • Hyperphosphatemia or hypophosphatemia • Hypoalbuminemia 5. Administer medications to correct Patients with renal failure are • Hyperkalemia or hypokalemia electrolyte abnormalities as predisposed to many electrolyte • Hypernatremia or hyponatremia needed during treatment. abnormalities. During CRRT, • Hypercalcemia or hypocalcemia (Level D * ) medications or electrolyte • Hyperglycemia or hypoglycemia replacements may be given as • Hypermagnesemia or prescribed for individual patients.6,34 hypomagnesemia Renal diet with adjusted protein, • Hyperphosphatemia or potassium, phosphorous, hypophosphatemia carbohydrate, and fl uid intake that • Hypoalbuminemia takes into account the patient’ s • Unexpected change in weight (loss current catabolic state, renal or gain) function, adequacy of dialysis, and removal of amino acids via dialysis is required.4,6,7,11 6. Monitor the CRRT circuit (e.g., Disconnections or introduction of air • Disconnections, cracks, or leaks occlusions; kinks in UF, blood, or into the circuit are always possible • Excessive clotting vascular access lines; hemofi lter). during treatment. Bleeding or • Blood leaks/hemofi lter rupture exsanguination can also occur.3,4,7,10 • Malfunction of dialyzer or access Clotting of the circuit is a potential complication. If the hemofi lter needs replacing, the extracorporeal blood volume should be returned to the patient if possible. Blood leaks from the dialyzer into the dialysate may occur and necessitate termination of treatment. In the event of a fi lter leak, do not return circuit blood to the patient. Venous or arterial pressures that are out of range may indicate dialyzer or access malfunction. 7. Monitor UF for rate, clarity, and A decrease in UF production can • Decreases in UF production air bubbles. occur from clotting of the • Change in color or characteristics dialyzer. 4,6,10 Pink or blood-tinged of UF UF is indicative of a fi lter leak or • Air in UF rupture. 8. Administer anticoagulant as Heparin or citrate is often used to • Suspicion of clotting in the circuit prescribed. prevent clotting of the circuit. 4,6 The heparin/citrate dose varies according to patient condition and laboratory values. 9. Monitor anticoagulation per Because heparin or citrate is • Abnormal coagulation study results institutional standards. commonly used to prevent system clotting, coagulation studies should be routinely monitored.

* Level D: Peer-reviewed professional and organizational standards with the support of clinical study recommen dations.

Procedure continues on following page 1066 Unit V Renal System

Patient Monitoring and Care —Continued Steps Rationale Reportable Conditions 10. Monitor the vascular access. Bleeding and/or infection can occur • Decrease in access function or from the access site. Clotting of the patency access can occur. 4,6,25,32 • Bleeding • Site redness or edema • Warmth • Purulent drainage • Pain or tenderness • Fever 11. Monitor the patient for Complications are possible with • Muscle cramps complications associated with CRRT. 4,6,9,10,13,20 • Dialysis disequilibrium (headache, CRRT treatment. nausea and vomiting, hypertension, decreased sensorium, seizures, coma) • Air embolism • Dialyzer reaction (hypotension, pruritus, back pain, angioedema, anaphylaxis) • Hypoxemia • Hypothermia21 12. Monitor the blood pump for Alerts the nurse to problems with the • Problems with the blood pump proper functioning. procedure. 13. Follow institutional guidelines for Identiﬁ es need for pain interventions. • Continued pain despite pain assessing pain. Administer interventions analgesia as prescribed.

Documentation Documentation should include the following: • Patient and family education • Completion of informed consent • Date and time of treatment initiation, mode of therapy, • Vital signs/hemodynamic parameters fi lter change • Status of pulse distal to vascular access site • Condition of vascular access regarding patency, quality • Hourly fl uid balance calculation of blood fl ow, ease of access procedure • Patient ’ s response to CRRT and daily progress • Date and time of VAC insertion and dressing change toward treatment goals • Condition of insertion site and any signs or symptoms • Unexpected outcomes of infection • Nursing interventions • Blood fl ow rate and arterial and venous monitoring • Daily weight pressures • Laboratory assessment data • Type and content of dialysis and replacement fl uids • Pain assessment, interventions, and effectiveness • Anticoagulation type and dose

References and Additional Readings For a complete list of references and additional readings for this procedure, scan this QR code with any freely available smartphone code reader app, or visit http://booksite.elsevier.com/9780323376624 .