Fentanyl-Induced Chest Wall Rigidity as a Cause of Acute Respiratory Failure in the Intensive Care Unit

We aim to report a case of chest wall rigidity induced by high-dose fentanyl infusion sedation and analgesia in the intensive care unit (ICU) for management of pneumonia and asthma. The patient is an 80-year-old woman, who presented to the hospital with complaints of fever and productive cough with yellowish expectoration of 2 days duration. She also had lethargy over the same time period and had sick contacts in the form of two daughters who both had recently recovered from a "flu-like" illness. She was known to have bronchial asthma treated with seretide 25/250 two puffs ON + PO monteleukast 10 mg ON, hypertension treated with PO losartan 50 mg BD, type 2 diabetes mellitus controlled with PO linagliptin 5 mg OM and a previous right thalamic ischemic stroke 5 years ago for which she was on PO clopidogrel 75 mg OM and PO simvastatin. She developed severe ventilator desynchrony characterized by dramatic sudden onset of severe hypercarbia, severely decreased pulmonary compliance and episodic breath holding. She was empirically treated for asthma exacerbation and treated with steroids, bronchodilators and manual ventilation but despite doing so during this episode the patient failed to respond. The patient was clinically evaluated and dynamic hyperinflation was excluded as a cause of the respiratory failure. There was no evidence of pneumothorax and worsening pneumonia. Considerations of insufficient sedation and analgesia led to deepening sedation and analgesia without good response. Ventilation was dramatically improved after small doses of neuromuscular relaxation. This cycle was repeated many times. The patient was kept on high-dose propofol and fentanyl, but there were repeated cycles of sudden persistent severe hypercarbia, severely decreased pulmonary compliance and episodic breath holding. Eventually a suspicion of fentanyl-induced chest wall rigidity was made after excluding causes of airway resistance and reduction in pulmonary compliance. Gradual reduction in fentanyl infusion was associated with a reduction of episodes of reduced lung compliance and improvement in ventilation. Fentanyl is often used for analgesia and sedation in the ICU. It has a good side effect profile but it is not without harm. High doses of fentanyl can lead to dramatic worsening of respiratory mechanics that may be life threatening. Fentanyl-induced chest wall rigidity is an important side effect that needs to be considered in the differential diagnosis of respiratory failure in the ICU.