Intractable Cough After Cervical Plexus Block for Carotid Endarterectomy

A Rare Trigger for General Anesthesia Conversion

Authors: Zhihao Wang, MD; Ammar Siddiqui, MD; Corrie Amos, MD Institution: Westchester Medical Center, Valhalla, NY

1. Introduction

• Background: Cervical plexus blocks (CPB) are frequently utilized for carotid endarterectomy (CEA) due to their low complication profile.
• Conversion to GA: The most common drivers for converting to general anesthesia (GA) are block failure (40%) and patient anxiety (45%).
• Rare Complication: Intractable coughing is an infrequent complication. While previous reports mention paroxysmal coughing leading to increased bleeding, this case focuses on an immediate, primary cough.
• Objective: To present a case where uncontrollable coughing following CPB necessitated urgent GA conversion.
• Patient Consent: Informed consent was obtained from the healthcare proxy; the case is exempt from IRB review per institutional policy.
• The Procedure: An ultrasound-guided combined superficial and intermediate CPB was performed.
• Supplementation: The block was supplemented by submandibular and incision site subcutaneous injections.
• Local Anesthetic (LA): A total volume of 35 mL was administered, consisting of 25 mL 0.5% ropivacaine and 10 mL 2% lidocaine.
• Ethics: No off-label medications or Investigational New Drugs were used.
• Patient History: A 75-year-old male with hypertension and CAD presented for CEA with 90% right ICA stenosis following a recent TIA.
• Preoperative Findings: MRI confirmed an acute infarct in the right parietal operculum.
• Acute Event: Within minutes of the ultrasound-guided CPB, the patient developed an intermittent, uncontrollable cough.
• Intervention: To ensure surgical field stability, the anesthesia team converted the case to general anesthesia.
• Postoperative Course: The patient reported new hoarseness and coughing with all liquid consistencies.
• Evaluation:

2. Material and Methods

3. Case Report

o   Bedside Swallow: Suggested penetration with all consistencies.

o   Nasolaryngoscopy (POD 2): Revealed pooling of secretions in the vallecula and bilateral pyriform sinuses and mild post-cricoid edema.

o   Clinical Status: Vocal cords were intact and symmetric, but a significant supraglottic squeeze was observed during phonation.

• Resolution: Symptoms improved by the third day, and by POD 5, clinical evaluation showed no overt signs of aspiration with clear liquids.
• Pathophysiology: The intractable cough likely resulted from LA spread to the branches of the vagal trunk.
• Mechanism: This spread may cause impaired laryngeal sensation or motor coordination, leading to aspiration and a subsequent protective cough.
• Clinical Significance: Recognition of this rare complication is vital for the timely decision to convert to GA to proceed with surgery safely.
• Conclusion: Unlike delayed paroxysmal coughing reported in other literature, this immediate cough indicates a direct primary effect of the LA on vagal branches rather than a secondary surgical stimulus.

4. Discussion

5. References

1.     Pandit, J.J. et al. British Journal of Anaesthesia. 2007;99(2):159–169.

2.     Harris RJD, Benveniste G. Anaesth Intensive Care. 2000;28(4):431-433.

3.     Van Houtte E, et al. J Voice. 2011;25(2):202-207.