The Elective Rotation: A Critical Care Hospital Pharmacy Podcast

Show notes at http://www.pharmacyjoe.com/episode40

In this episode, I’ll discuss the recognition and treatment of serotonin syndrome (SS), malignant hyperthermia (MH), and neuroleptic malignant syndrome (NMS).

Muscular rigidity, significant hyperthermia, and autonomic instability are all common features of serotonin syndrome, malignant hyperthermia, and neuroleptic malignant syndrome. A thorough review of the patient’s current and recent medications is the best way to tell the difference between these 3 conditions.

Serotonin syndrome

Seretonin syndrome can result from an overdose or drug interaction involving one or more of the many drugs that increase serotonergic activity.

The Hunter Criteria is often used for the diagnosis of serotonin syndrome. To fulfill the Hunter Criteria, a patient must have taken a serotonergic agent and meet ONE of the following conditions:

1. Spontaneous clonus

2. Inducible clonus PLUS agitation or diaphoresis

3. Ocular clonus PLUS agitation or diaphoresis

4. Tremor PLUS hyperreflexia

5. Hypertonia PLUS temperature above 38ºC PLUS ocular clonus or inducible clonus

Serotonin syndrome is very similar to neuroleptic malignant syndrome. A thorough review of the patient’s current and recent medications and history of present illness is essential for differentiating between the two syndromes. SS develops over 24 hours, whereas NMS develops over a period of days. Serotonin syndrome is accompanied by neuromuscular hyperreactivity (tremor, hyperreflexia, and myoclonus); NMS is accompanied by sluggish neuromuscular responses (rigidity and bradyreflexia).

Cases of serotonin syndrome that I’ve seen have included an opioid plus two serotonergic medications. I once encountered a young adult female in my emergency department with confusion, hyperthermia, tachycardia, tremor, hyperreflexia, and diaphoresis. She was on therapeutic doses of citalopram and hydrocodone, but had taken three cyclobenzaprine 10 mg tablets for her severe back pain. The team initially thought she was having an anticholinergic reaction from the extra cyclobenzaprine. I was able to point out that the patient was diaphoretic so anticholinergic toxicity was unlikely, and that cyclobenzaprine is also a serotonergic agent (in fact it is structurally nearly identical to amitriptyline). We gave the patient cyprohpetadine and lorazepam and she recovered quickly.

Treatment of serotonin syndrome

In addition to supportive care, benzodiazepines are given to eliminate agitation, tremor, clonus, and elevations in heart rate and blood pressure. Start with 1 or 2 mg of IV lorazepam or midazolam and titrate the dose to effect. Cyproheptadine, an anti-serotonergic antihistamine can be given as well. Give 12 mg orally or by orogastric tube as the initial adult dose.

Show notes at pharmacyjoe.com/episode39. In this episode I’ll: 1. Discuss an article about evidence based medicine 2. Answer a drug information question about IV compatibility 3. Share a resource for calculating a patient’s Candida Score

Show notes at pharmacyjoe.com/episode39

In this episode I'll:

1. Discuss an article about evidence based medicine

2. Answer a drug information question about IV compatibility

3. Share a resource for calculating a patient's Candida Score

Article

Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials

Lead author: Gordon CS Smith

Published in British Medical Journal December 2003

Background

Using high quality evidence to guide patient care decisions is of vital importance. However, for most patient care decisions, there is not a randomized controlled trial that you can look to for guidance. Patients with multiple co-mordbidities, at extremes of age, or who are pregnant are often excluded from trials. But patients like these exist, and you’ll need to make individualized decisions about their care.

This article is one of my favorites to have students and residents read to put evidence-based medicine in perspective.

Purpose

To determine whether parachutes are effective in preventing death or major trauma related to gravitational challenge.

Methods

The study was a systematic review of randomized controlled trials. Medline, Web of Science, Embase, the Cochrane Library databases, appropriate internet sites and citation lists were examined for studies showing the effects of using a parachute during free fall. The primary outcome measure was death or major trauma, defined as an injury severity score > 15.

Results

The authors were unable to identify any randomized controlled trials of parachute intervention.

Conclusions

The authors concluded that:

No randomized controlled trials of parachute use have been undertaken.

The basis for parachute use is purely observational, and its apparent efficacy could potentially be explained by a “healthy cohort” effect since individuals who jump out of airplanes without a parachute are likely to have psychiatric co-morbidities.

Individuals who insist that all interventions need to be validated by a randomized controlled trial need to come down to earth with a bump.

Show notes at pharmacyjoe.com/episode38. In this episode, I’ll cover treatment strategies for hypertensive emergencies.

Show notes at pharmacyjoe.com/episode38

Today’s episode topic is being presented at the request of another "Pharmacy Joe” who left this message on pharmacyjoe.com about using clonidine for hypertensive emergencies. If you’d like to call in a topic request use the Speakpipe widget at the end of the show notes or at pharmacyjoe.com/contact.

This may be splitting hairs with the definition, but I’d avoid clonidine or any other oral medication in a hypertensive emergency. I’d reserve clonidine for the treatment of acute, asymptomatic hypertension. Clonidine is just a short-term band-aid solution for acute hypertension, as it should not be continued long term. I was unable to find any studies describing a rebound effect from stopping clonidine within the first few days, but there is such an effect seen with dexmedetomidine (another alpha agonist) as early as after 24 hours of treatment, so I suppose it would be possible for your internist to have seen some patients experience a rebound effect after clonidine.

In this episode, I'll cover treatment strategies for hypertensive emergencies. A hypertensive emergency is present when severe hypertension is associated with acute, ongoing end-organ damage. Severe hypertension in the absence of end-organ damage used to be called a hypertensive urgency, but is now referred to as acute asymptomatic hypertension. Whether treating a hypertensive emergency or acute asymptomatic hypertension, an excessive hypotensive response is potentially dangerous, and may lead to ischemic complications such as stroke, myocardial infarction, or blindness.

End organ damage is typically found in the form of neurologic, cardiac, vascular, or renal damage.

The general goal of treatment for most hypertensive emergencies is to achieve a 10-20% reduction in systolic BP in the first hour, and an additional 5-15% reduction in BP in the first 24 hours.

There are two notable exceptions to this general goal:

1. In the acute phase of ischemic stroke, the blood pressure is usually not lowered unless it is ≥185/110 mmHg in patients who are eligible for alteplase therapy or ≥220/120 mmHg in patients who are not eligible for alteplase therapy.

2. In acute aortic dissection, the systolic blood pressure is rapidly lowered to a target of 100 to 120 mmHg within 20 minutes.

Let’s review each type of hypertensive emergency and the ideal agents to use in each case:

Show notes at pharmacyjoe.com/episode37. In this episode I’ll: 1. Discuss an article about prolonged empiric antibiotic therapy in adult ICUs 2. Answer a drug information question about eosinophilic nephritis 3. Share a 4T score calculator

Show notes at pharmacyjoe.com/episode37

In this episode I'll:

1. Discuss an article about prolonged empiric antibiotic therapy in adult ICUs

2. Answer a drug information question about eosinophilic nephritis

3. Share a 4T score calculator

Article

A Multicenter Evaluation of Prolonged Empiric Antibiotic Therapy in Adult ICUs in the United States

Lead Author: Zachariah Thomas

Published in Critical Care Medicine December 2015

Background

Antibiotics decrease morbidity, mortality, and healthcare costs when given to treat infection; but they increase morbidity, mortality, and healthcare costs when given in the absence of infection.

Purpose

The purpose of this study was to determine the rate of prolonged empiric antibiotic therapy in adult ICUs in the United States. The secondary objective was to examine the relationship between the prolonged empiric antibiotic therapy rate and certain ICU characteristics.

Methods

Multicenter, prospective, observational, 72-hour snapshot study in 67 ICUs from 32 hospitals in the United States.

Results

Prolonged empiric antibiotic therapy was defined as empiric antibiotics that continued for at least 72 hours in the absence of adjudicated infection. The prolonged empiric antibiotic therapy rate was determined as the ratio of the total number of empiric antibiotics continued for at least 72 hours divided by the total number of empiric antibiotics.

A total of 660 unique antibiotics were prescribed as empiric therapy to 364 patients. Of the empiric antibiotics, 333 of 660 (50%) were continued for at least 72 hours in instances where Centers for Disease Control infection criteria were not met. Suspected pneumonia accounted for approximately 60% of empiric antibiotic use.

The most frequently prescribed empiric antibiotics were vancomycin and piperacillin-tazobactam. ICUs that utilized invasive techniques for the diagnosis of ventilator-associated pneumonia had lower rates of prolonged empiric antibiotic therapy than those that did not, 45.1% versus 59.5% (p = 0.03). No other institutional factors were significantly associated with prolonged empiric antibiotic therapy rate.

The authors concluded that 50% of all empiric antibiotics ordered in critically ill patients were continued for at least 72 hours in absence of adjudicated infection.

Show notes at pharmacyjoe.com/episode36. In this episode I ll review the definition, recognition, causes & pharmacotherapy treatments of stridor in critically ill adult patients.

Show notes at pharmacyjoe.com/episode36

In this episode I’ll review the definition, recognition, causes & pharmacotherapy treatments of stridor in critically ill adult patients.

Defintion

Stridor is an abnormal inspiratory sound, and a sign of upper airway obstruction that requires immediate attention.

Recognition

Stridor can be heard without a stethoscope. It is usually a high pitch sound that occurs during the inspiratory phase. Observe your patient from the end of the bed and see if the noise is worse when their chest expands (inspiration) or falls (expiration). A noise on inspiration is consistent with stridor, and indicates an upper airway obsctruction. A noise on expiration indicates lower airway obstruction such as bronchospasm. Respiratory Wiki has two sound file examples of stridor.

Causes

Stridor can be caused by a mass or foreign body in the upper airway, or by laryngeal edema. Laryngeal edema post endotracheal extubation is the most likely cause of stridor in an adult patient in the ICU.

Show notes at pharmacyjoe.com/episode35. In this episode I’ll: 1. Review an article on propofol related infusion syndrome 2. Answer a drug information question about surgical antibiotic prophylaxis 3. Share a great resource I use for investigating drug induced thrombocytopenia