Permanent hemidiaphragm paralysis after interscalene block

Given the new oxygen requirement you can infer something happened perioperatively. Given the known risks of interscalene block (ISB) and the hemidiaphragmatic paralysis on the same side, the ISB is likely the cause of the new O2 requirement in someone at risk of hypoxia with diaphragmatic paralysis. Recommended dose for interscalene block is 15 to 30 CC of 0.375 to 0.5% ropivacaine. However, lower doses are equally effective with fewer side effects and risks. Doses as low as 5cc have been shown to be effective. Higher doses lead to increased complications and decreased satisfaction. Some authors advocate 15-20 cc to maximize pain relief while minimizing risks. (See ASRA website and article by Fredrickson et al, Importance of Volume and Concentration for Ropivacaine Interscalene Block in Preventing Recovery Room Pain and Minimizing Motor Block after Shoulder Surgery, Anesthesiology, 2010). So one could argue the dose was of a higher concentration and of a higher volume possibly increasing risk, although arguably still within published limits. Male sex, diabetes, and obesity also increased the patient's risk of perioperative neuropathy, so one could argue a lower concentration and or volume should have been utilized. Further, improper technique could have resulted in intraneural injection or direct trauma to nerve roots by the needle itself. Use of a nerve stimulator could have decreased this risk by ensuring a proper distance, but direct needle trauma is the least likely ISB related cause. An ultrasound image of the pre and post block site could also be useful, and in private practice is often needed for insurance billing purposes. As far as the surgery's possible role it is probably unlikely to have contributed. Per Nickless et al "The surgical procedure itself is unlikely to be associated with persistent diaphragm paralysis because the phrenic nerve courses distant from the glenohumeral joint and is unlikely to be affected by direct manipulation during the surgical procedure or by postoperative swelling.." (Persistent diaphragmatic paralysis associated with interscalene nerve block after total shoulder arthroplasty: a case report)

Permanent hemidiaphragmatic paralysis is a known complication of interscalene block. There is a published case series of 14 cases requiring surgical treatment (see Kaufman et, al. Surgical Treatment of Permanent Diaphragm Paralysis after Interscalene Nerve Block for Shoulder Surgery, Anesthesiology 2013). By using too high of a volume, a compression neuropathy could have developed causing permanent injury which Kaufman et al found as one of the primary causes of permanent injury. Direct toxicity from the high concentration and high dose could also have contributed, especially in a higher risk patient. Intraneural injection and direct trauma by the needle could have also resulted in injury, although less likely as the anatomical course of the phrenic nerve roots is usually a reasonable distance away from the interscalene groove.

It appears that the patient suffered permanent damage to his phrenic nerve. Phrenic nerve injury is known to happen with interscalene block, but permanent damage is a rare occurrence. The Doctor Who did the procedure how to duty to inform the patient of this potential risk and I find in this case the fact that permanent damage to current meeting that a laceration or other neural injury to the phrenic nerve, was suffered by the patient. This is particularly disturbing in light of the fact that ultrasound guidance was used to perform this block. I would be pleased to opine and rendering opinion on this case. I can be reached at 301-704-8684. Please see my website. DRDAVIdsherer.com to learn about me and my extensive experience and writing.

There is a temporal relationship between the procedure and the injury. That is all that needs to be said.

If, indeed, the right hemidiaphragmatic paralysis was on the same side as the injection, then I would need to know more about the performance of the block. For example, was ultrasound used? Also, were paresthesias elicited? And finally was the patient awake or asleep for the block? So whether or not there was medical negligence will depend on more information.

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The inter scalene nerve block is a commonly performed pain procedure to treat postoperative pain for shoulder surgery. From the information provided, the provider appears to have used proper technique to place the block, but it is still considered an invasive procedure that carries the risk of nerve injury, including the potential for injury to the phrenic nerve. The provider did use ultrasound-guidance which reduces the incidence of nerve injury as the one described to this patient because the needle tip is observed in real-time and in relationship to the anatomical structures. If proper techniques were used with the ultrasound-guided nerve block, it is unlikely to result in a permanent nerve injury at the phrenic nerve. The typical situation is temporary paralysis of the same side phrenic nerve. However, the surgery itself carries the risk of injury to the brachial plexus. This is not outside the realm of possibility as the cause of the patient's permanent phrenic nerve injury. From the surgical case, this injury could occur with traction, manipulation of the arm, or improper retractor placement. It is interesting to note that there was postoperative surgical complication which necessitated another surgery. It is possible the dislocation itself could have contributed to brachial plexus nerve injury at C3-5.

The clear increase in oxygen requirements for the patient after many days postoperatively is unusual. This is not a typical occurrence from this surgery nor the anesthesia technique. If there are proper tests (e.g. EMG) demonstrating paralysis of the phrenic nerve on the ipsilateral side of surgery, then it is likely this injury or change in nerve function occurred as a result of this surgery. However, from the information provided, it is impossible to ascertain which specific procedure caused the injury. It is possible for the injury to have occurred from the inter scalene nerve block, but it is rare to have permanent nerve damage. The information provided does not imply that the nerve block was a difficult one or performed with any unusual issues. The use of ultrasound-guidance, performing the block with the patient responsive to painful stimulus, and lack of paresthesias upon injection make it less likely the cause of a permanent phrenic nerve injury. On the contrary, the fact that the patient did have a dislocated prosthesis from the shoulder arthroplasty implies a level of difficulty for the surgery itself. It seems more likely that excessive traction and/or manipulation during surgery would have contributed to a prolonged stretch to the phrenic nerve that could produce a permanent injury. It is also possible the shoulder dislocation itself could have contributed to injury to the brachial plexus. I believe an error in treatment had occurred, but it is unclear at what point the injury could have occurred in terms of causation. In addition, the patient has multiple co-moribidites including COPD and OSA that make him high risk for pulmonary complications without any error. This further confounds the situation because it would not be unusual to have a patient with this history to require supplemental oxygen postoperatively. It would not become obvious that the phrenic nerve was injured until multiple days that the patient could not wean from oxygen requirements.

Transient phrenic nerve palsy is associated with nearly 100% of interscalene blocks. However, with this patient, their palsy persisted long after surgery. This is an exceptionally rare complication, with some reports citing an incidence of 0.048%. The exact etiology of the injury (or if it was pre-existing before surgery) has not been elucidated. There are case reports of prolonged phrenic nerve palsies after shoulder surgery with interscalene blocks; however, no definitive cause has been determined with many of them. I suspect the cause, in this case, was also likely multifactorial, including but not limited to direct nerve trauma during needle placement/injection, neurotoxic effects of anesthetic medications, local ischemic changes, nerve compression from the volume of anesthetic used, nerve compression from paracervical hematoma formation, postsurgical adhesions and fascial thickening, and improper surgical positioning. It should be noted that the dislocation may have necessitated more aggressive manipulation and positioning, which theoretically may have increased the possibility of phrenic nerve injury. https://www.sciencedirect.com/science/article/pii/S010400142100018X https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6334858/

Phrenic nerve palsy can result in a 20-25% reduction in the forced vital capacity of the lung on the affected side. In a patient with COPD, OSA and obesity, this may be enough to reduce the effectiveness of the lung to adequately oxygenate, thus resulting in a reduction of quality of life and cause a dependence on supplemental O2, as in this case.