Pain, Agitation/Sedation, Delirium, Immobility, Sleep Disruption, and Neuromuscular Blockade

Answer: D

Propofol infusion syndrome is a well-documented and

complex set of adverse events, potentially resulting in

multiorgan failure. An elevation in lactate, creatine

kinase, transaminases, SCr, and triglycerides and the

presence of a metabolic acidosis are some of the abnor-

malities that should concern the critical care provider

for the presence of PRIS (Answer D is correct). Both

DVT and critical illness polyneuropathy are serious

concerns in the ICU patient; however, the abnormalities

in the case are not representative of these complications

(Answers A and B are incorrect). There are currently

no known abnormal laboratory values to help determine

whether delirium is present in an ICU patient (Answer

C is incorrect).

This patient is at risk of propylene glycol toxicity after

receiving a lorazepam drip for more than 48 hours.

Lorazepam is dissolved in propylene glycol, an alcohol

that can induce an osmolar gap and metabolic lactic aci-

dosis, particularly in patients with significant hepatic or

renal failure. Quantitative propylene glycol levels may

be unavailable; therefore, surrogate markers such as an

abnormal osmolar gap (greater than 10 mmol) and met-

abolic acidosis may indicate propylene glycol toxicity

and a need to discontinue lorazepam. Although loraz-

epam drips are not routinely used for general sedation

in adult ICUs, they may be used for other indications

(e.g., severe EtOH [ethyl alcohol] or benzodiazepine

withdrawal), and clinicians should remain aware of this

serious complication (Answer B is correct). With an

oxygen saturation of 98% on 2 L of oxygen, this patient

does not meet the predefined criteria of ARDS (Answer

A is incorrect). Encephalopathy will not cause a meta-

bolic acidosis; therefore, an ammonia concentration

would not be helpful at this stage (Answer C is incor-

rect). With a low fractional excretion of sodium and a

high BUN/SCr ratio, the patient’s laboratory values are

indicative of a pre-renal concern versus acute tubular

necrosis (Answer D is incorrect).

Answer: D

It is inappropriate to initiate an NMBA in a patient who

has a sedation score indicating “agitation.” This implies

that the patient may potentially detect pain or discomfort

while paralyzed (Answers B and C are incorrect). The

goal should be to achieve a deeply sedated and/or non-

agitated state before initiating an NMBA in an effort

to avoid any patient discomfort that may be undetected

during paralysis (Answer D is correct). The SAT would

be inappropriate in someone who is rated “agitated” on

the sedation scale or in a patient requiring escalating

doses of sedation (Answer A is incorrect).

Answer: B

The pharmacokinetics/dynamics of prolonged fentanyl

infusions have not been well described in the adult ICU

population. Most data for fentanyl are derived from

short-term infusions or boluses in healthy volunteers

and in animal models. Fentanyl is hepatically metabo-

lized primarily by the CYP3A4 enzyme, and decreased

clearance of fentanyl has been described in patients with

significant liver disease. Other properties of fentanyl

(e.g., high volume of distribution, high protein binding,

and high lipophilicity) may contribute to unpredictable

clearance and a prolonged context-sensitive half-time

for patients in acute renal failure or in patients who have

inadequate nutritional status (Answer B is correct).

Propofol is a CYP3A4 inhibitor; therefore, it should not

induce the metabolism of fentanyl (Answer C is incor-

rect). Propofol is known to chelate trace elements and

increase urinary loss of zinc when used for more than

5 days; propofol has not been shown to cause hypocal-

cemia (Answer D is incorrect). Disease states identified

as risk factors for PRIS may include sepsis, acute liver

failure, and history of pancreatitis; ARDS is not cur-

rently a documented risk factor (Answer A is incorrect).

Answer: B

Withdrawal from certain home medications may occur

if these medications are not reinitiated within a few

days of admission. The onset of withdrawal symptoms

will vary depending on the half-life of each medication.

Symptoms may include agitation, anxiety, psycho-

sis, insomnia, hypertension, and tachycardia and can

occur with medications such as opiates, GABA receptor

agonists, antiepileptics, antidepressants, and antipsy-

chotics. A pharmacist can assist the medical team by

obtaining a thorough medication history and assessment

of home medication compliance to help identify drug

withdrawal symptoms. Reinitiating these medications