Phrenic nerve block combined with stellate ganglion block for postoperative intractable hiccups: a case report

Abstract

Postoperative intractable hiccups slow patient recovery and generate multiple adverse effects, highlighting the importance of investigating the pathogenesis and terminating the hiccups in a timely manner. At present, medical and physical therapies account for the main treatments. We encountered a case in which postoperative intractable hiccups after biliary T-tube drainage removal ceased with the application of an ultrasound-guided block of the unilateral phrenic nerve and stellate ganglion. No complications developed, and the therapeutic effect was remarkable. To our knowledge, this approach has not been reported to date. Simultaneously blocking the phrenic nerve and stellate ganglion may be a treatment option for intractable hiccups.

Introduction

Hiccups refer to a paroxysmal spasms of the unilateral or bilateral diaphragm with sudden glottis closure during inspiration and a characteristic short, loud sound. This condition results from stimulation of relevant muscles and nerves, including the diaphragm, phrenic nerve, vagus nerve, and central nerve. The term “intractable hiccups” means the spasms last for more than 48 hours. Long-term hiccups give rise to severe complications, including dehydration, weight loss, fatigue, insomnia, and depression. ¹ This case report describes a man with persistent postoperative hiccups that interfered with wound healing after biliary T-tube drainage removal, inducing constant vomiting, disordered eating, and sleeplessness. The patient subsequently developed dehydration and electrolyte disturbance, which worsened his postoperative complications and detrimentally impacted rehabilitation. Thus, it became necessary to terminate the hiccups as soon as possible. When conventional therapy failed, we performed an ultrasound-guided block of the unilateral phrenic nerve and stellate ganglion, which effectively resolved the hiccups without complications. This case is reported in accordance with the CARE guidelines. ²

Case report

A man in his early 60 s was hospitalized because he had experienced dull epigastric pain for more than 1 month. He was subsequently diagnosed with gastric body and fundus malignancy, choledocholithiasis with cholangitis, and intrahepatic and extrahepatic bile duct dilation. Preoperative physical examination, laboratory testing, electrocardiography, pulmonary functional testing, and echocardiography were negative. With the patient under tracheal intubation and general anesthesia, we performed a combined operation including open total gastrectomy with esophagojejunostomy, choledochotomy and drainage, choledochoscopic exploratory basket stone extraction, and T-tube drainage. No adverse postoperative complications occurred, and the patient was uneventfully discharged. The T-tube was removed 3 months later, after which the patient developed persistent hiccups at a frequency of 60 times/minute with vomiting and disordered eating. Enhanced computed tomography of the chest and abdomen showed thickening of the lower thoracic esophageal wall secondary to the total gastrectomy with no abnormality in the remaining anastomosis. In the lower abdomen, some small intestinal segments were dilated with effusion and sightly swollen walls. Painless electronic gastroscopy revealed a total gastrectomy status (absence of the whole stomach), anastomotic inflammation, reflux esophagitis (Los Angeles grade C4), and output loop edema. After admission, the patient was given anti-inflammatory therapy and enteral nutrition support through an indwelling nasogastric tube. One week of treatment with gabapentin, chlorpromazine, metoclopramide, acupuncture, and physical therapy failed to mitigate the hiccups. Ultrasonic examination demonstrated spasmodic contraction of the diaphragm. Ultrasound-guided block of the right phrenic nerve and stellate ganglion was planned with the patient’s consent. During the operation, the patient was in the supine with his head turned toward the left. A high-frequency ultrasound probe was placed on the right side of the neck. An axial scan along the surface of the anterior scalene muscle showed that the phrenic nerve ran from outside to inside around the anterior scalene (Figure 1). Using the in-plane technique, the needle was gradually advanced toward the phrenic nerve, and 3 mL of 0.2% ropivacaine with 10 µg dexmedetomidine was injected. At the C6 level, an axial scan was used to first identify the longus colli muscle (Figure 2). Next, using the in-plane technique, the needle penetrated the prevertebral fascia and approached the stellate ganglion, after which 3 mL of 0.2% ropivacaine with 10 µg dexmedetomidine was injected. Approximately 5 minutes later, the hiccups gradually decreased; they finally stopped 8 minutes after the operation. At that time, the patient’s blood pressure, oxygen saturation, and heart rate were 132/70 mmHg, 99%, and 70 beats/minute, respectively. The patient behaved normally and developed no complications. The next day, the patient reported the development of hiccups at 30 times/minute with slightly reduced amplitude. Thus, another ultrasound-guided block of the right phrenic nerve and stellate ganglion was performed, 5 minutes after which the hiccups ceased. On the third day, the frequency of hiccups decreased to 20 times/minute, and the amplitude declined further. Two similar nerve block operations were carried out at 8-hour intervals. By the fourth day, the patient reported total disappearance of hiccups and vomiting, and he began ingesting a liquid diet. No further discomfort or complications developed, and the hiccups did not relapse during 4 months of follow-up.

Figure 1.

Phrenic nerve block. The white arrows indicate the needle.

Figure 2.

Stellate ganglion block. The white arrows indicate the needle.

Discussion

Intractable hiccups lasting days or months are rare and may be excruciating and uncorrectable. Hiccups occur by a reflex action involving the vagus nerve, phrenic nerve, sympathetic nerve, diaphragm, and respiratory auxiliary muscles. Possible causes include gastrectasis induced by excessive eating, spicy food, fluid intake, or mental stress such as anxiety. ³ The complicated pathogenesis of intractable hiccups includes central nervous system disorders, tumors, esophagitis, gastric dilatation, intestinal obstruction, infection, and peripheral nervous system stimulation after surgery or other stimuli. ⁴ The hiccup is considered a specific reflex arc containing afferent and central components. Vagus, phrenic, and sympathetic nerve chains in the lower chest (T6–T12) constitute the afferent path. The brain stem, midbrain, reticular structure, and hypothalamus surround the central nerves. The efferent nerve consists of the phrenic nerve (C3–C5), anterior scalene innervation (C5–C7), recurrent laryngeal nerve (vagus nerve branch at glottis), and accessory nerve toward the intercostal muscles (T1–T11). ⁵ Medications such as baclofen, gabapentin, metoclopramide, chlorpromazine, and haloperidol have been proven effective for hiccup therapy. ⁶ The intractable hiccups in this case may have developed secondary to removal of the biliary duct drainage T-tube; removal may have caused stretching of organs and tissues in the abdomen, stimulated the parasympathetic nerve, and induced diaphragmatic spasm. Because gabapentin, chlorpromazine, metoclopramide, acupuncture, and physical therapy were ineffective, we considered nerve blocks and surgery according to a general consensus. ⁷ Lopez and Kumar ⁸ reported that when nonpharmacologic and pharmacologic therapies fail to improve hiccups, a stellate ganglion block may be a viable treatment option. Lee et al. ⁹ reported three cases of stellate ganglion block in the treatment of persistent postoperative burping, indicating that stellate ganglion block is an effective method and may be considered in combination with other methods to treat persistent burping. The phrenic nerve and stellate ganglion serve as the main afferent pathway, while the phrenic nerve is the efferent route and may be the target for resolving hiccups. We thus conducted an ultrasound-guided block of the unilateral phrenic nerve and stellate ganglion and obtained satisfactory results. The stellate ganglion is a sympathetic ganglion associated with the C6, C7, and T1 ganglia. ¹⁰ Although the mechanism underlying the efficacy of stellate ganglion block in the treatment of hiccups is unknown, the cerebral cortex, hypothalamus, amygdala, and hippocampus may play a role because all of these structures have extensive connections with the stellate ganglion. ¹¹ Stellate ganglion block modulates the autonomic nervous, cardiovascular, endocrine, and immune systems through the hypothalamus. Lee et al. ⁹ considered that the stellate ganglion block interrupts the sympathetic sector of the afferent nerve in the hiccup reflex arc to relieve the patient’s symptoms. In another study, an ultrasound-guided unilateral phrenic nerve block substantially reversed intractable hiccups in five patients with cancer. ¹² We speculate that the combination of stellate ganglion block and phrenic nerve block may achieve better results in the treatment of intractable hiccups. Given the ganglion and nerve’s small size, complex anatomy, possible locational variation, and proximity to multiple vital organs and major blood vessels and nerves, blocking the stellate ganglion and phrenic nerve without imaging guidance tends to be unsuccessful and injure blood vessels and nerves. Conversely, an ultrasound scan accurately depicts the stellate ganglion, phrenic nerve, and surrounding tissues with a low dose of local anesthetics. ¹³ Thus, ultrasound guidance increases the chance of a successful block with minimal complications. When using a phrenic nerve block, the alleviation of hiccups may be accompanied by restricted respiration. ¹⁴ However, evidence has shown that in patients without respiratory insufficiency, unilateral diaphragm paralysis does not reduce low oxygen saturation-induced dyspnea, and the compensation by the other side of the diaphragm and intercostal muscles might not reduce undesirable consequences.^15,16 In the present case, the normal pulmonary function test results and absence of chest tightness, shortness of breath, coughing, and expectoration increased the patient’s safety during the nerve block procedure, throughout which the oxygen saturation, heart rate, and blood pressure were monitored. Considering the severity of the hiccups, which had undermined the patient’s health, we performed a simultaneous block of the unilateral stellate ganglion and phrenic nerve to ameliorate the symptoms as early as possible. To extend the effective operating time, we used ropivacaine, a long-acting local anesthetic with minimal cardiotoxicity, and its adjuvant dexmedetomidine. Kang et al. ¹⁷ utilized ropivacaine to stop hiccups. Dexmedetomidine, a highly selective novel α2 receptor agonist used for sedation, facilitates local anesthesia in stellate block by its favorable therapeutic effect, prolonged operating time, and high patient satisfaction. ¹⁸ In the present case, the hiccups ceased immediately after the local anesthetic injection without low oxygen saturation, dyspnea, or hoarseness. However, patients with respiratory insufficiency should be monitored for dyspnea because phrenic nerve block may adversely affect respiratory function.

The favorable outcome of this case proves the efficacy of simultaneous block of the phrenic nerve and stellate ganglion in terminating intractable hiccups. This is the third-choice treatment after addressing the etiology and administering conventional therapy, and it may quickly reverse the symptoms. Respiratory function should be fully assessed before the operation. Constant monitoring and availability of first aid items are also required. For respiratory insufficiency, blocking only the stellate ganglion is recommended. This invasive operation is guided by ultrasound for precise treatment, low risk, and a curative effect.