Bilateral Diaphragmatic Paralysis in a Patient With Critical Illness Polyneuropathy

Bilateral diaphragmatic paralysis (BDP) manifests as respiratory muscle weakness, and its association with critical illness polyneuropathy (CIP) was rarely reported. Here, we present a patient with BDP related to CIP, who successfully avoided tracheostomy after diagnosis and management. A 71-year-old male presented with acute respiratory failure after sepsis adequately treated. Repeated intubation occurred because of carbon dioxide retention after each extubation. After eliminating possible factors, septic shock-induced respiratory muscle weakness was suspected. Physical examination, a nerve conduction study, and chest ultrasound confirmed our impression. Pulmonary rehabilitation and reconditioning exercises were arranged, and the patient was discharged with a diagnosis of BDP. The diagnosis of BDP is usually delayed, and there are only sporadic reports on its association with polyneuropathy, especially in patients with preserved limb muscle function. Therefore, when physicians encounter patients that are difficult to wean from mechanical ventilation, CIP associated with BDP should be considered in the differential diagnosis. (Medicine 94(31):e1288) Abbreviations: BDP = bilateral diaphragmatic paralysis, BiPAP = bilevel positive airway pressure, CIP = critical illness polyneuropathy, CMAP = compound muscle action potential, EPAP = expiratory positive airway pressure, IPAP = inspiratory positive airway pressure, MIP = maximal inspiratory pressure. eng-Chih Lin, MD, and Mei-Yun Liaw, MD management are important. However, in some cases, the diaphragm is the initial or the only muscle involved. It can be myopathic or neuropathic in origin, although some cases are considered idiopathic, occurring in association with the following conditions: spinal cord injury, motor neuron disease, infectious diseases such as herpes zoster, human immunodeficiency virus infection, pneumonia, noninfectious polyneuropathy, cardiac surgery, lung transplantation, postsurgical neuralgic amyotrophy, mediastinal tumors, neurosarcoidosis, chronic inflammatory demyelinating polyradiculoneuropathy, peripheral neuropathy, multiple sclerosis, anterior horn cell disease, Charcot–Marie–Tooth syndrome, POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-protein spike, and skin changes), and critical illness polyneuropathy (CIP). The symptoms of diaphragmatic paralysis depend on whether it is unilateral or bilateral, how rapidly it develops, and the presence of underlying pulmonary disease. Patients with unilateral diaphragmatic paralysis are usually asymptomatic and may spontaneously recover with compensatory mechanisms, especially if there is no underlying pulmonary or neurological disease. In contrast, BDP usually goes unrecognized, especially in patients who are ventilator dependent, until cor pulmonale or cardiorespiratory failure presents with it. Therefore, the early diagnosis of BDP is clinically challenging and requires a thorough understanding of medical history, laboratory data, and clinical experience. Patients with BDP usually present with a restrictive pulmonary disorder, and have marked reduction in functional residual capacity and residual volume because of decreased lung compliance secondary to atelectasis. Vital capacity falls by approximately 50% with abdominal paradoxical breathing patterns. Here, we report a case of BDP resulting from CIP secondary to sepsis. PATIENT INFORMATION The case report was not reviewed by an institutional review board because a case report does not meet the definition of ‘‘research’’ in Chang Gung Medical Foundation Institutional Review Board. Written informed consent was obtained from the patient for publication of this case report. A 71-year-old male who presented with fever and respiratory distress was admitted. The patient had been receiving a 10-day antibiotics for acute calculous cholecystitis. On admission, he was found to have respiratory failure, sepsis, and hypovolemic shock. He was intubated and placed on mechanical ventilatory support (inspiratory positive airway pressure/ expiratory positive airway pressure [IPAP/EPAP]: 20/10 cm H O]. He was a smoker for 20 years, but at the time of t smoked for >10 years. Past medical ension that was controlled by medication renal insufficiency, immunoglobulin A www.md-journal.com | 1 nephropathy, gouty arthritis, osteoarthritis of both knees, and benign prostatic hypertrophy. Five weeks before the present admission, the patient underwent percutaneous transluminal coronary angioplasty and stent placement for triple vessel coronary heart disease. CLINICAL FINDINGS On physical examination, there were diminished breath sounds at both lung bases with contraction of accessory muscles. On neurological examination, the patient was able to freely move all 4 limbs in bed. However, weakness of the right deltoid muscles, bilateral elbow extensors, and hip flexors as well as bilateral atrophy of the hypothenar, adductor pollicis, and first interosseous muscles were noted. Bilateral biceps, brachiradialis, and patellar deep tendon reflexes were reduced. Diagnostic Assessment A chest radiograph revealed no definite lung lesions. Bilateral diaphragmatic elevation was noted during deep inspiration (Figure 1). Initial arterial blood gas values were as follows: pH 7.305, PaCO2 101.2 mm Hg, PaO2 87.6 mm Hg, HCO3 49.2 mm/ L, and O2 saturation 95.1% on room air. Echocardiography showed hypertensive cardiovascular disease with an ejection fraction of 68% and 2:1 atrioventricular block with atrial flutter. Cerebrovascular, immunological, and thyroid disorders were excluded, along with respiratory, cardiac, infectious, and electrolyte imbalance complications. The patient was extubated, but it Chen et al was difficult to wean him from the ventilator, and he was subsequently reintubated. After stabilization of his respiratory pattern and general condition, including hemodynamic status, FIGURE 1. Chest radiograph before discharge showed no active lung lesions and bilateral diaphragmatic elevation during deep inspiration. 2 | www.md-journal.com extubation was attempted again. However, extubation and reintubation were performed 4 times because the patient developed marked hypercapnia after each extubation. Respiratory muscle weakness induced by critical illness and septic shock, secondary to the previous history of cholecystitis and sepsis, was then suspected. A nerve conduction study revealed decreased amplitude of compound muscle action potentials (CMAPs) in the bilateral median, peroneal, and tibial nerves as well as in the right ulnar nerve, in addition to decreased conduction velocities in bilateral median, ulnar, peroneal, and tibial nerves. F-latencies were prolonged in bilateral median, ulnar, and tibial nerves as well as in the right peroneal nerve. F-waves were not recorded in the left peroneal nerve. H-latencies were prolonged in bilateral tibial nerves. On sensory nerve conduction studies, decreased conduction velocities were recorded in bilateral median and ulnar nerves across wrists. No CMAPs were detected in the right or left phrenic nerves. These results suggested the presence of a sensorimotor polyneuropathy (Table 1). Therapeutic Intervention On confirmation of the diagnosis of CIP with BDP, the patient was extubated and successfully placed on noninvasive mechanical ventilation using a bilevel positive airway pressure (BiPAP) mask. Bedside pulmonary rehabilitation was initiated, including postural drainage, free breathing exercise, respiratory muscle training such as sitting up in bed to decrease abdominal pressure, limb sensory and motor functional training, and reconditioning exercise. Chest ultrasound revealed no further deterioration, and he continued to receive continuous mask mechanical ventilation (IPAP/EPAP: 18/6 cm H2O). When the patient could tolerate not using the mask for 10 to 20 minutes, he was discharged with a nasal mask BiPAP ventilator with pressure/volume control. Follow-Up and Outcomes Ten months later, the patient was readmitted with hypercapnic respiratory failure. He continued using a nasal mask during the daytime and a full facial mask at night (IPAP/EPAP: 20/5 cm H2O) and was alert but bedridden. Chest ultrasound revealed poor movement and recruitment of bilateral diaphragms, especially on the right side, with a bilateral excursion of approximately 1 cm. A subsequent nerve conduction study revealed deterioration in the sensorimotor polyneuropathy compared with the previous study (Table 2). The patient was discharged with a nasal mask BiPAP ventilator and instructed to perform bedside exercise at home. With regards to the progressive dyspnea and hypercapnia that occurred after each extubation and the repetitive weaning profile in spontaneous breathing, the patient had a low tidal volume and low maximal inspiratory pressure (MIP). Therefore, a diagnosis of critical illness septic shock-induced respiratory dysfunction complicated with CIP was confirmed. The serial changes in MIP and maximal expiratory pressure are shown in Figure 2. Follow-up evaluation, 12 months after the onset of BDP, demonstrated a slow but progressive improvement in the patient’s respiratory function, together with improvement in the neuropathy. Timeline of his clinical course was shown in Figure 3. DISCUSSION For a patient with BDP, chest radiography commonly Medicine Volume 94, Number 31, August 2015 shows elevation of both sides of the diaphragm with volume loss and/or atelectasis at the lung bases. In most cases, severe bilateral diaphragmatic weakness can be diagnosed from Copyright # 2015 Wolters Kluwer Health, Inc. All rights reserved. TABLE 1. Nerve Conduction Study on November 8, 2007 Amplitude, mV Latency, ms Conduction Velocity, m/s F-Wave Latency, ms H-Waves Latency, ms Nerve Stimulation Site Recording Site RT LT RT LT RT LT RT LT RT LT Median, m Wirst APB 1.8 2.9 7.4 6.2 45 45 34.1 31.3 Antecubital fossa APB 1.7 2.5 13.2 11.8 Ulnar nerve, m Wrist ADM 4.1 6.1 4.2 3.3 45 43 31.7 30.8 Below elbow ADM 3.7 5.1 10.7 9.6 Peroneal nerve, m Ankle 1.1 0.9 4.7 38 38 61.2 NR Below fibular head 0.6 0.6 15.5 14.3 Tibial nerve, m Ankle AHB 1.8 3.5 6.2 37 37 61.3 57.9 35.5 34.8 Popliteal fossa AHB 1.4 3.1 18.0 16.4 Median, s Mid palm Index finger 33 2.0 2.0 66 61 Wrist 26 20 4.6 4.5 40 40 Ulnar nerve, s Wrist Little finger 27 24 3.2 3.2 48 48 Sural nerve, s Calf Posterior ankle 17 21 42 47 Phrenic nerve Supraclavicular fossa No pick up, bilateral NR NR re c Medicine Volume 94, Number 31, August 2015 Polyneuropathy With Bilateral Diaphragmatic Paralysis physical examination, orthopnea disproportionate to the severity of underlying cardiopulmonary disease, measurements of vital capacity (<50% of predicted vital capacity in the upright position and a further reduction of 25% in the supine position), and a marked reduction in maximal respiratory pressure. In cases where the diagnosis is uncertain, measurements of transdiaphragmatic pressure, phrenic nerve conduction study, diaphragmatic electromyography (EMG), or chest ultrasound of Sensory latencies are peak latencies, sensory conduction velocities a latency. LT1⁄4 left, NR1⁄4 no response, RT1⁄4 right. the diaphragm may be performed. Chest examination usually reveals limited excursion of the diaphragm, bilateral dullness on percussion over the lower chest, and absent breath sounds. In TABLE 2. Nerve Conduction Study on September 12, 2008