Hypercapnic respiratory distress and loss of consciousness: a complication of supraclavicular brachial plexus block
© The Author(s) 2015
Received: 10 June 2015
Accepted: 31 August 2015
Published: 9 September 2015
Supraclavicular brachial plexus block is a common anesthetic technique performed for surgery of the upper extremities. We experienced a case of acute hypercapnic respiratory distress with loss of consciousness during creation of an arteriovenous fistula under ultrasound-guided supraclavicular brachial plexus block using 30 mL of 0.75 % ropivacaine. We detected ipsilateral hemidiaphragmatic paralysis by means of M-mode ultrasonography of the block. We thus speculate that phrenic nerve palsy caused by supraclavicular brachial plexus block was the underlying mechanism of the event. Bedside ultrasonography played a pivotal role in making a differential diagnosis and in managing this patient.
KeywordsSupraclavicular brachial plexus block Ultrasound Hemidiaphragmantic palsy
Phrenic nerve paralysis is known to anesthesiologists as a common complication associated with interscalene brachial plexus block , while it is often ignored after supraclavicular brachial plexus block . We present the case of a patient with ipsilateral hemidiaphragmatic paralysis after supraclavicular brachial plexus block, which manifested as loss of consciousness and hypercapnic respiratory distress. Bedside ultrasonography played an important role in diagnosing hemidiaphragmatic paralysis and managing this patient.
A 78-year-old-man with chronic renal failure had been on hemodialysis via an arteriovenous fistula on his left arm three times a week for 4 years. He was scheduled for revision of an arteriovenous fistula on the right arm because of occlusion of the fistula. He had a prosthetic mitral valve and an intravenous pacemaker that had been set to 65 beats per minute in ventricular back-up mode for 15 years. The pacemaker had been implanted because he had suffered from acute mitral regurgitation due to rupture of the chordae tendinae associated with myoxomatous degeneration of the mitral leaflets and sick sinus syndrome 2 months after the prosthetic mitral valve surgery. The patient’s medical history also included hypothyroidism and chronic hepatitis B with thrombocytopenia and splenomegaly but not chronic obstructive lung diseases (COPD). Preoperative transthoracic echocardiography (TTE) revealed normal left ventricular (LV) ejection fraction (EF = 53 %) with a restrictive pattern of LV inflow, as indicated by a 2.3 ratio of early transmitral inflow peak velocity to atrial transmitral inflow peak velocity, suggesting elevated left atrial pressure. Moderate pulmonary hypertension was diagnosed, with a 48-mmHg tricuspid valve pressure gradient calculated from the tricuspid regurgitant jet velocity. There were no abnormalities in the native aortic valve or the prosthetic mitral valve.
We presented a case of hypercapnic respiratory distress and loss of consciousness resulting from transient phrenic nerve palsy associated with supraclavicular brachial plexus block. Interscalene brachial plexus block almost invariably causes ipsilateral phrenic nerve palsy . However, it is thought to occur less frequently with brachial plexus block via the supraclavicular approach, depending on the amount of local anesthetic used and the techniques employed (e.g., nerve stimulator or ultrasound guidance). Respiratory symptoms are uncommon during the brachial plexus block irrespective of the approaches .
We detected hemidiaphragmatic paralysis in this patient with hypercapnic respiratory distress by means of bedside ultrasonography. There have been few ultrasonographically documented cases of hemidiaphragmatic palsy after supraclavicular brachial plexus block.
Hemidiaphragmatic paralysis is usually asymptomatic at rest, because it is compensated for by other respiratory muscles; at most, it may lead to limitations in exercise . Urmey et al.  investigated the effects of hemidiaphragmatic paralysis on pulmonary function during interscalene brachial plexus block and concluded that the block should not be performed in patients who are dependent on intact diaphragmatic function. Hemidiaphragmatic paralysis causes decreased values on pulmonary function tests, such as forced vital capacity, forced expiratory volume, and peak expiratory flow rate . In addition, it causes abdominal expansion during inspiration, leading to regional hypoventilation in the ipsilateral lower lung and a reduction in gas exchange. These changes are usually compensated for by recruitment of the intercostal or accessory muscles . However, they may become symptomatic, causing dyspnea or hypoventilation in the supine position because of enhanced shift of the paralyzed diaphragm toward the head . In addition to the supine position, there are at least two other possible explanation for the development of hypercapnic respiratory distress with loss of consciousness in this patient. First, limited cardiopulmonary reserve may be responsible, as evidenced by the patient’s implanted prosthetic mitral valve and pacemaker and his advanced age of 86 years . Second, chronic renal failure itself may be a high risk. Afonso et al.  reported three consecutive cases of respiratory arrest necessitating tracheal intubation in patients undergoing arteriovenous graft placement with supraclavicular brachial plexus block; however, the exact underlying causes other than chronic renal failure and obesity could not be delineated. The authors suggested that chronic renal failure may represent a high-risk group for respiratory failure after supraclavicular brachial plexus block.
Oxygen administered via a face mask may have transiently relieved the patient’s respiratory symptoms when he had difficulty breathing soon after brachial plexus block. We speculate that this may have resulted in further depression of respiration and thus in hypercapnia and, consequently, loss of consciousness. Recognition of risk factors for developing symptomatic hemidiaphragmatic paralysis in this patient or earlier examination with ultrasound might have led us to avoid brachial plexus block or to initiate ventilatory support earlier instead of administering oxygen via face mask.
Bedside ultrasound plays a pivotal role in the management of acute respiratory distress and in finding its underlying causes . M-mode recording of the diaphragmatic dome through a respiratory cycle is an easy way to document a nonfunctioning diaphragm, while in the present case, the supine chest roentgenogram was not conclusive for the diagnosis of hemidiaphragmatic paralysis. Absence of thickening of the diaphragm at the zone of apposition with the rib base is an alternative ultrasonographic technique for the diagnosis of diaphragmatic paralysis .
Point-of-care ultrasound is becoming an essential diagnostic skill for all physicians . Anesthesiologists routinely use ultrasound machines for procedures such as catheter placement or nerve blocks, as well as transesophageal echocardiography for cardiac surgery. Thus, they are familiar with ultrasound machines and should therefore be able to improve patient care by the addition of diagnostic ultrasonography. Training to ensure competent use of this technology is thus of utmost importance [8, 9].
A decreased cardiopulmonary reserve, advanced age, and, possibly, chronic renal failure may have been risk factors in this patient for developing hypercapnic respiratory distress and loss of consciousness with supraclavicular brachial plexus block. Bedside ultrasonography was very useful in establishing the correct diagnosis; it allowed for ventilator support until the return of diaphragmatic function and precluded unnecessary examinations such as brain computed tomography or magnetic resonance imaging.
Patient’s family reviewed the case report and gave written permission for the authors to publish it.
chronic obstructive lung diseases
laryngeal mask airway
- SpO2 :
oxygen saturation by pulse oximetry
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
- Urmey WF, Talts KH, Sharrock NE. One hundred percent incidence of hemidiaphragmatic paresis associated with interscalene brachial plexus anesthesia as diagnosed by ultrasonography. Anesth Analg. 1991;72:498–503.View ArticlePubMedGoogle Scholar
- Neal JM, Moore JM, Kopacz DJ, Liu SS, Kramer DJ, Plorde JJ. Quantitative analysis of respiratory, motor, and sensory function after supraclavicular block. Anesth Analg. 1998;86:1239–44.PubMedGoogle Scholar
- Renes SH, Spoormans HH, Gielen MJ, Rettig HC, van Geffen GJ. Hemidiaphragmatic paresis can be avoided in ultrasound-guided supraclavicular brachial plexus block. Reg Anesth Pain Med. 2009;34:595–9.View ArticlePubMedGoogle Scholar
- McCool FD, Tzelepis GE. Dysfunction of the diaphragm. N Engl J Med. 2012;366:932–42.View ArticlePubMedGoogle Scholar
- Gottardis M, Luger T, Flörl C, Schön G, Penz T, Resch H, et al. Spirometry, blood gas analysis and ultrasonography of the diaphragm after Winnie’s interscalene brachial plexus block. Eur J Anaesthesiol. 1993;10:367–9.PubMedGoogle Scholar
- Fujimura N, Namba H, Tsunoda K, Kawamata T, Taki K, Igarasi M, et al. Effect of hemidiaphragmatic paresis caused by interscalene brachial plexus block on breathing pattern, chest wall mechanics, and arterial blood gases. Anesth Analg. 1995;81:962–6.PubMedGoogle Scholar
- Afonso A, Beilin Y. Respiratory arrest in patients undergoing arteriovenous graft placement with supraclavicular brachial plexus block: a case series. J Clin Anesth. 2013;25:321–3.View ArticlePubMedGoogle Scholar
- Lichtenstein DA, Mezière GA. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest. 2008;134:117–25.PubMed CentralView ArticlePubMedGoogle Scholar
- Solomon SD, Saldana F. Point-of-care ultrasound in medical education—stop listening and look. N Engl J Med. 2014;370:1083–5.View ArticlePubMedGoogle Scholar