In this episode I’ll:
1. Discuss an article about dexmedetomidine-associated hypotension in critically ill patients.
2. Answer the drug information question “What side effects occur with long-term use of metronidazole?”
3. Share a resource for patient safety in critical care.
Article
Predictors of dexmedetomidine-associated hypotension in critically ill patients
Lead author: Anthony T Gerlach
Published in International Journal of Critical Illness & Injury Science September 2016
Background
Dexmedetomidine is a popular sedative for use in critically ill patients. Hypotension is a common side effect that may limit the dose or even use of dexmedetomidine in critically ill patients. The authors of this study sought to determine predictors of dexmedetomidine-associated hypotension.
Methods
The study was a retrospective study covering 4 ICUs within a single center. Patients who were hypotensive at baseline were excluded. 283 patients met the inclusion criteria. The primary endpoint was the finding of hypotension (MAP < 60 mmHg).
Results
Hypotension was experienced by 42.8% of patients in the study. The median MAP nadir was 54 mmHg. After multi-variate analysis, the risk factors associated with dexmedetomidine-related hypotension were:
1. Baseline MAP
2. APACHE II score
3. History of coronary artery disease
The hypotensive group had an average baseline MAP of 82 mmHg, and more patients in the hypotensive group had a baseline MAP of < 70 mmHg.
Conclusion
The authors concluded:
Dexmedetomidine-associated hypotension was common and occurred in over 40% of patients. The current analysis identified a baseline MAP < 70 mmHg, history of coronary artery disease, and increasing APACHE II score as factors independently associated with the development of hypotension. High-dose dexmedetomidine was not significantly associated with increased risk of hypotension. Clinicians should use dexmedetomidine cautiously in patients with low baseline blood pressure and increasing the severity of illness. Further trials are needed to determine factors associated with the development of hypotension and potential impact of protocols on minimizing the risk of this adverse effect.
Discussion
Despite being a single center study, several elements suggest the results may apply to other ICUs.
- No patient received a bolus of dexmedetomidine. The one mcg/kg over 10-minute bolus of dexmedetomidine is still listed in prescribing information as a potential treatment option . However, it is not commonly used in clinical practice due to excessive side effects.
- The dose range for dexmedetomidine was up to 1.4 mcg/kg/hour which is a commonly used maximum dose range. However, only one-third of the patients in the study received a dose >1 mcg/kg/hour.
- Excessive titration (dose adjustment more frequent than every 30 minutes) was similar in both the hypotensive and non-hypotensive group (15.4% vs. 19.8%).
Drug information question
Q: What side effects occur with long-term use of metronidazole?
A: Peripheral or optic neuropathy, and rarely encephalopathy may occur with prolonged metronidazole use.
Long-term use of metronidazole usually occurs when treating a liver abscess. Most case reports I have seen indicate side effects such as peripheral or optic neuropathy and encephalopathy are reversible upon stopping the metronidazole. There may be a cumulative neurotoxic dose of metronidazole, but case reports range from 228 grams down to just 3.8 grams before toxicity.
Resource
The Patient Safety Network at the Agency for Healthcare Research and Quality hosts a series of web-based ‘morbidity & mortality’ cases. You can find these cases here. Some of the most recent cases are:
Cognitive Overload in the ICU
Lost in Sign Out and Documentation
Benefits vs. Risks of Intraosseous Vascular Access
If you like this post, check out my book – A Pharmacist’s Guide to Inpatient Medical Emergencies: How to respond to code blue, rapid response calls, and other medical emergencies.
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