A 64-year-old woman with history of lung cancer comes to the office due to persistent chest pain. The patient has squamous cell carcinoma of the right upper lobe that has invaded the pleura and the 4th and 5th ribs. She has had severe right sided chest pain that is exacerbated by movement or cough. The patient was given an opioid analgesic but could not take them at the prescribed dose due to excessive sedation. Physical examination shows tenderness to palpation of the right chest wall. A nerve block procedure is planned to control the pain by injecting a local anesthetic agent in the vicinity of the involved neural structure. Which of the following is the most appropriate treatment target?

Question

A 64-year-old woman with history of lung cancer comes to the office due to persistent chest pain.  The patient has squamous cell carcinoma of the right upper lobe that has invaded the pleura and the 4th and 5th ribs.  She has had severe right sided chest pain that is exacerbated by movement or cough.  The patient was given an opioid analgesic but could not take them at the prescribed dose due to excessive sedation.  Physical examination shows tenderness to palpation of the right chest wall.  A nerve block procedure is planned to control the pain by injecting a local anesthetic agent in the vicinity of the involved neural structure.  Which of the following is the most appropriate treatment target?

Quizplus · Accepted Answer

11ec160b_35bc_591e_9249_7f89fda62e48_MD0001_00 This patient has severe chest wall pain due to cancer invading the parietal pleura and ribs. She is unable to take opioid medication due to intolerable adverse effects, so she should be offered other interventional pain management strategies. Options include nerve blocks (eg, injection of anesthetic near the nerve), neurolysis (eg, physical or chemical nerve destruction), and neuromodulation (eg, spinal cord stimulation). This patient is undergoing an intercostal nerve block to improve her pain control. Sensation from the parietal pleura, ribs, and overlying skin is mediated by thoracic intercostal nerves that derive from the ventral rami of the thoracic spinal nerves. An intercostal nerve block provides anesthesia over the dermatomal distribution of the nerve that is anesthetized. The intercostal vein, artery, and nerve lie in the subcostal groove along the lower border of the rib and therefore provide a straightforward target for a nerve block. (Choices A and E) The inferior cervical ganglion and the thoracic sympathetic trunk are part of the sympathetic nervous system. They help convey thoracic and upper abdominal visceral pain but do not carry somatic sensory information. Nerve blockade here would decrease sympathetic activity (eg, decrease sweating in hyperhidrosis) but would not significantly improve chest wall pain. (Choice C) The phrenic nerve, which is derived from the C3-C5 nerve roots, delivers motor innervation to the diaphragm and carries pain fibers from the diaphragmatic and mediastinal pleura (not the costal pleura). Pain due to diaphragmatic and mediastinal pleura is often referred to the C3-C5 distribution at the base of the neck and over the shoulder. In addition, a nerve block that could paralyze the diaphragm is not typically recommended. (Choice D) The pulmonary plexus is derived from branches of the vagus nerve and the sympathetic trunk. It innervates the visceral pleura but not the parietal pleura or the chest wall. Unlike the parietal pleura, the visceral pleura can only detect stretch and is not sensitive to pain. Educational objective: Sensation to the parietal pleura, chest wall, and skin of the chest is supplied by the intercostal nerves that derive from the ventral nerve rami. A nerve block can be used to control pain from these areas when opioids are ineffective, contraindicated, or have intolerable adverse effects.

A 64-Year-Old Woman with History of Lung Cancer Comes to the Office