A 17-year-old female patient is admitted to the ICU with acute-onset right-sided hemiparesis and hemianopia. Brain imaging demonstrated parietal cortical and subcortical lesions that do not follow vascular distribution. Her laboratory workup was significant for lactic acidosis. Patient has had similar episodes in the past, occasionally associated with seizures. She has residual motor deficit at baseline and impaired cognitive function. Patient’s mother states that her other daughter is suffering from a similar condition.
Which of the following is MOST likely to be found during further workup?
Correct Answer: A
This patient is most likely suffering from the syndrome of mitochondrial encephalopathy, lactic acidosis, and strokelike episodes (MELAS). MELAS is caused by mutations of mitochondrial DNA and is characterized by maternal pattern of inheritance and multisystem manifestations. Muscle biopsies demonstrate presence of ragged-red fibers (RRF) in areas of mitochondrial proliferation. The proposed diagnostic criteria for this relatively rare condition were based on an analysis of 69 cases and include: “Invariant” criteria:
Two of the following factors “secure” the diagnosis, per authors of the proposed diagnostic criteria:
Patients with MELAS typically develop symptoms in childhood. The neurologic component of the presentation includes strokelike episodes with hemiparesis, hemianopia, or cortical blindness. Brain imaging in MELAS patients commonly demonstrates parieto-occipital lesions in the cortex and subcortical areas that may not follow vascular pattern of distribution. The symptoms may partially resolve, but often the neurologic disability progresses with age. Seizures (generalized or focal), dementia, recurrent headaches, vomiting, and hearing loss are also common. Short stature and muscle weakness are frequently observed on physical examination.
High-grade bilateral stenosis of internal carotid arteries (Answer B) would be an unlikely explanation of the neurologic syndrome in this 17- year-old patient without known risk factors for vascular disease. Moderately elevated CSF protein with moderate pleocytosis (Answer C) and normal glucose are typical CSF findings in patients with acute viral encephalitis. This patient, however, does not have other evidence of an ongoing infectious process and has a history of chronic neurologic problems, making the diagnosis of acute encephalitis less likely. Adrenal hemorrhage (Answer D) with acute adrenal gland failure is known as Waterhouse–Friderichsen syndrome. It is typically caused by Neisseria meningitidis infection and is associated with prominent hemorrhagic rash. The patient described above does not have a rash and has no evidence of adrenal gland failure. Antimitochondrial antibodies (Answer E) are a diagnostic finding in primary biliary cirrhosis.
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Drug and alcohol withdrawal: A 72-year-old man was admitted to the ICU after surgical control of abdominal sepsis. The patient’s shock has resolved, but he remains mechanically ventilated and could not be extubated because of agitation. After morning rounds a medical student approaches you and expresses concern that this patient is at high risk for ICU delirium which, in turn, increases mortality. She asks if there are any pharmacological options to address ICU delirium.
Which of the following is currently recommended for prevention or treatment of ICU delirium in this patient?
Correct Answer: D
The only current recommendation for pharmacological treatment in delirium is for the use of dexmedetomidine in mechanically ventilated patients who cannot be extubated due to agitation. The recommendation, however, is based on a single small (n = 71) trial that demonstrated an increase in ventilator-free hours in the dexmedetomidine group compared to placebo group.
The 2018 Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU (PADIS) address pharmacologic interventions in patients with ICU delirium. All of the recommendations regarding pharmacological therapy are deemed conditional by the authors and are based on low-quality evidence.
Haloperidol (Answer A), Haloperidol (Answer A), risperidone (Answer C), and dexmedetomidine have demonstrated effectiveness in preventing delirium in low-quality clinical trials. However, PADIS guideline authors recommended against using these agents in all critically ill patients due to the lack of robust evidence of improved outcomes and potential for side effects. A study of rosuvastatin (Answer E) showed that it did not reduce delirium or cognitive impairment at 12 months. There are some studies to suggest dexmedetomidine helps in the treatment of delirium by decreasing the use of drugs that might be causing delirium, including sedatives and analgesics. Neither haloperidol (Answer B) nor atypical antipsychotic agents are recommended as treatment for ICU delirium. Currently available evidence suggests that these agents do not reduce mortality, duration of delirium, mechanical ventilation, or ICU length of stay.
The PADIS guidelines recommend using a multicomponent nonpharmacologic intervention aimed at reducing modifiable risk factors for delirium. Existing evidence suggests that improved compliance with the ABCDEF bundle may reduce mortality.
The ABCDEF bundle includes:
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