Acute Kidney Injury and Kidney Replacement Therapy in the Critically Ill Patient

Answer: A

The drug-induced kidney disease phenotype most likely

associated with these antibiotics is AIN from ceftriax-

one. Acute interstitial nephritis is considered under the

AKI phenotype (Answer A is correct). Azithromycin

would unlikely cause drug-induced kidney disease.

Although AIN is an overall uncommon cause of DIKD,

in 75% of AIN cases, one or more drugs are involved.

Several medications have been associated with this type

of kidney disease, including penicillins, cephalospo-

rins, sulfonamides, ciprofloxacin, vancomycin, NSAIDs

and COX-2 inhibitors, proton pump inhibitors, immune

checkpoint inhibitors, antiepileptic drugs, ranitidine,

diuretics, and cocaine. This patient may have other con-

tributing factors to AKI, including sepsis and shock.

Glomerular disease, nephrolithiasis, and tubular dys-

function have not been associated with cephalosporins

(Answers B-D are incorrect).

Stage 3 AKI is met by both the SCr criteria (3 x baseline)

and the need for KRT (Answer C is correct; Answers

A and B are incorrect). Urinary output is not needed to

stage the kidney dysfunction in this case because the

patient fulfills other criteria (Answer D is incorrect).

Answer: C

Answer C is correct. Drug-dosing recommendations for

IHD can be found in many resources. However, dosing

during continuous KRT and SLED/EDD is less clear.

Primary literature and/or summary tables for continu-

ous KRT and SLED should be referenced because these

recommendations are not usually found in other sources

(Answers A and B are incorrect). Use caution to ensure

that identical modes of continuous KRT are referenced

with similar flow rates. Drug dosing using a sieving

coefficient should only be used when a review of the

literature fails to provide specific drug adjustment rec-

ommendations (Answer D is incorrect).

Answer: A

Solute removal during CVVH is by convection, which

is primarily influenced by membrane pore size, free

fraction of drug, and ultrafiltration rate. Diffusion is the

process of clearance during CVVHD making Answers

B and C incorrect. Membrane binding does occur but

is not the primary route of clearance during CVVH

(Answer D is incorrect).

Answer: A

Answer A is correct. Protein binding is a primary deter-

minant of drug clearance during continuous KRT. Only

unbound drug can be cleared through the circuit; there-

fore, an increase in protein binding while other factors

remain stable would lead to reduced drug elimination

(Answers B and C are incorrect). A high Vd would

reduce drug clearance (Answer D is incorrect). The

impact of high Vd is more significant in IHD, resulting

in less drug removal because there is little time during

the 3- to 4-hour IHD run for a drug to redistribute out of

the peripheral tissues.