BONENT CHN cheat sheet

Adequacy: single-pool Kt/V of at least 1.2 per session, or urea reduction ratio of at least 65%, for a three-times-weekly schedule.

Typical prescriptions: blood flow 300-450 mL/min; dialysate flow commonly 500-800 mL/min (often 1.5-2 times blood flow).

Heparin anticoagulation: loading dose about 1000 units, maintenance 500-1500 units/hour, targeting an ACT 1.5-1.8 times baseline.

Intradialytic hypotension sequence: stop ultrafiltration, Trendelenburg position, 100-200 mL 0.9% saline bolus, then reassess blood pressure and UF goal.

Rising venous pressure with increasingly negative pre-pump arterial pressure indicates clotting or combined inflow restriction and outflow obstruction.

Muscle cramps: reduce ultrafiltration rate, give saline or hypertonic saline, and consider sodium modeling; rapid fluid removal is the usual trigger.

Anemia targets in CKD: hemoglobin 10-11 g/dL, transferrin saturation above 20%, ferritin roughly 200-500 ng/mL.

Disequilibrium syndrome presents with headache, restlessness, nausea, and seizures; risk is lowered with slower blood flow and shorter initial sessions.

Post-treatment: hold each needle site 10-15 minutes without obliterating the thrill, recheck weight and vital signs, and inspect for bleeding before discharge.

Each kidney contains about 1 million nephrons; normal GFR is about 125 mL/min, producing roughly 180 L of filtrate per day.

CKD staging by GFR (mL/min/1.73 m²): G1 at least 90, G2 60-89, G3a 45-59, G3b 30-44, G4 15-29, G5 below 15.

Endocrine renal functions: erythropoietin production, 1-alpha hydroxylation of vitamin D to calcitriol, and renin release.

ADH from the posterior pituitary inserts aquaporins in collecting duct cells, increasing water reabsorption; aldosterone increases sodium reabsorption and potassium secretion.

Renal blood flow is about 20-25% of cardiac output, roughly 1.1-1.2 L/min in a resting adult.

CKD-mineral bone disorder sequence: falling GFR leads to phosphate retention and low calcitriol, causing hypocalcemia, secondary hyperparathyroidism, and renal osteodystrophy.

Uremic findings include pruritus, asterixis, pericarditis, encephalopathy, and platelet dysfunction with prolonged bleeding time.

Nephrotoxins include NSAIDs, aminoglycosides, iodinated contrast, and ACE inhibitors or ARBs, which can also cause hyperkalemia and a creatinine rise.

Clearance increases with larger membrane surface area, higher blood flow, higher dialysate flow, and greater membrane permeability; low-flux membranes clear small solutes only.

KoA reflects membrane efficiency (permeability times surface area); Kuf reflects ultrafiltration capacity in mL/hr per mmHg of transmembrane pressure.

Transmembrane pressure equals mean blood compartment pressure minus dialysate compartment pressure; volumetric machines control UF by flow rather than by TMP alone.

Countercurrent blood and dialysate flow maintains the concentration gradient along the whole membrane; concurrent flow lowers clearance.

Air embolism response: stop the blood pump, clamp the venous line, place the patient in left lateral Trendelenburg position, and administer 100% oxygen.

Pre-pump arterial pressure more negative than about -250 mmHg indicates inflow restriction from kinking, a small or infiltrated needle, access stenosis, or hypotension.

Dialysate conductivity is normally about 13-14 mS/cm with pH 7.0-7.4 and sodium 135-145 mEq/L; abnormal values require stopping treatment and verifying mixing.

Reuse acceptance criterion: total cell volume at least 80% of the baseline value; a falling TCV or rising TMP signals fiber clotting and lost surface area.

A blood leak detector alarm means dialysate may be pink or turbid; stop the pump and verify membrane integrity before continuing.

AAMI/ANSI limits for product water: conductivity below 10 µS/cm, total chlorine and chloramine below 0.1 mg/L, and essentially zero hardness.

Carbon tanks remove chlorine and chloramine by adsorption; total chlorine must be tested before each shift and after carbon bed replacement or regeneration.

Reverse osmosis rejects 90-99% of dissolved ions, bacteria, and endotoxin; performance depends on feed pressure, water temperature, and adequate reject flow.

A softener exchanges calcium and magnesium for sodium to prevent scaling; hardness is tested daily and the resin regenerated with brine.

Deionizer resin exhaustion can release previously captured ions; deionization is not a microbiological barrier and supports bacterial growth.

Ultraviolet light at 254 nm and ultrafilters reduce bacteria and endotoxin but do not remove dissolved ions or chlorine.

Microbiological standards: standard dialysate below 200 CFU/mL and endotoxin below 2 EU/mL; ultrapure dialysate is far lower (about 0.1 CFU/mL and 0.03 EU/mL).

Bicarbonate and acid concentrates are kept separate because calcium and magnesium in the acid concentrate precipitate as carbonate when mixed with bicarbonate.

Chloramine exposure causes hemolysis and methemoglobinemia; suspect it with sudden anemia, cyanosis, or a chlorine test above 0.1 mg/L.

Hepatitis B surface antigen-positive patients require a separate room or area and dedicated equipment where mandated; HBV survives on environmental surfaces and is highly transmissible in dialysis units.

Hepatitis C and HIV infection do not require a dedicated dialysis machine; standard precautions with consistent hand hygiene and glove use are sufficient.

Hand hygiene before and after every patient contact is the single most effective measure for preventing dialysis-associated infection.

Catheter care: patient and nurse wear masks, the hub is scrubbed with chlorhexidine and allowed to dry, and a sterile dressing covers the exit site.

Visible blood spills are disinfected with a 1:10 dilution of 5.25% household bleach (about 0.5% sodium hypochlorite) with adequate contact time; low-level surface disinfection uses 1:100.

Needlestick injury: wash the site with soap and water, report immediately, arrange source testing, and start HIV postexposure prophylaxis as soon as possible, ideally within 2 hours.

Sharps safety: never recap or bend needles; activate the safety device and deposit the needle directly into a puncture-resistant container filled no more than three-quarters full.

Machine internal disinfection is performed between patients per manufacturer instructions, and residual disinfectant must be verified absent before the next treatment.

Hepatitis B vaccination response is defined as anti-HBs of at least 10 mIU/mL; nonresponders require revaccination or alternate strategies.