Complications of Nerve Blocks


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Complications of an Interscalene Nerve Block for the Shoulder

Last Updated:| By Rae Uddin

Interscalene nerve block before shoulder surgery can cause complications.

An interscalene nerve block is a form of local anesthetic used prior to shoulder surgery. This anesthetic is applied to specific nerves within the shoulder by an anesthesiologist using a thin needle. Immediately after interscalene nerve block application, a treated patient’s shoulder and arm begins feeling heavy and numb. A surgeon can then perform shoulder surgery and the treated patient will not feel pain or discomfort during this procedure. Patients should discuss the potential complications of an interscalene nerve block with a doctor before having shoulder surgery.

Breathing Difficulties

Patients who receive an interscalene nerve block before shoulder surgery can develop breathing complications, explains Dr. Stephen Breneman with the American Association of Orthopaedic Surgeons. Affected patients can experience shortness of breath or may have difficulty inhaling deeply. This complication of an interscalene nerve block can occur if this anesthetic numbs a portion of a patient’s diaphragm, the large muscle involved in lung expansion and contraction. Rarely, a lung may be punctured during interscalene nerve block administration. If this occurs, affected patients can experience severe breathing difficulties that require prompt medical attention

Vocal Hoarseness or Difficulty Swallowing

Approximately 15 percent of patients experience vocal hoarseness or difficulty swallowing as complications of an interscalene nerve block for shoulder surgery, ShoulderDoc medical professionals report. Administration of the interscalene nerve block can numb a patient’s vocal box, which can cause her voice to sound unusually quiet, raspy or rough. Numbness within the throat following interscalene nerve block treatment can limit a patient’s ability to voluntarily swallow. These complications of an interscalene nerve block are typically temporary and subside once this anesthetic medication wears off.

Seizure or Heart Rate Abnormalities

Rarely, patients who receive an interscalene nerve block can develop seizure complications. Approximately 0.3 percent of patients treated with interscalene block prior to shoulder surgery developed seizure complications, reports Dr. Hector Herrera and colleagues in a February 2009 article published in “The Internet Journal of Anesthesiology.” Certain patients may also develop heart rate abnormalities following interscalene nerve block administration. These complications most frequently occur if the interscalene nerve block is inadvertently injected into a patient’s bloodstream.

Bleeding, Infection or Bruising

Infrequently, patients can experience unusual bleeding, infection or bruising complications after receiving an interscalene nerve block. Such complications typically arise at the site of injection and may require additional medical treatment to resolve.

Permanent Nerve Damage

Permanent nerve damage complications following interscalene nerve block are extremely rare, affecting approximately one in 10,000 treated patients, Breneman reports. Affected patients can experience chronic sensations of numbness, tingling or weakness within the treated shoulder or arm.

The role of legal nurses in a regional block case:

I have reviewed cases involving nerve blocks and complications and my role often includes teaching because many factors have to be considered when this occurs.  Patient selection, medical history need to be assessed as some patients are more high risk for an adverse event. The skill of the anesthesiologist, the use of digital ultrasound and reducing risk of adverse events by the following: use the least dose required to achieve the desired results, using a “test” dose to identify intravascular injection, careful aspiration prior to each injection while observing for blood, and most importantly vigilant monitoring observing for signs and symptoms of toxicity between injections and after completion.  Signs of toxicity can be delayed up to 30 minutes. Patents must be engaged in reporting anything they are experiencing so frequent communication is important.

Most often, the issues arise around what was or was not done when signs of toxicity are reported. The lack of proper monitoring or management plan for treating complications are often at the core of these bad outcomes as the treatment of local anesthetic system toxicity differs from other cardiac arrest scenarios .

Contact me for more information on this subject or if you’d like an opinion on a case of Local Anesthetic System Toxicity.

Jane Shufro







Discharge Readiness

Locate ExpertsByJane Shufro September, 2014                      

Part 2.

In last month’s Blog I outlined a popular current discharge scoring system, the modified Aldrete, and the use of established safe discharge criteria in the PACU setting.   The scoring system evaluates 5 key parameters to ensure the safe transfer or discharge of the patient post operatively.

The clinical scoring system provides a reliable guide for nursing assessment, has been widely supported by The Joint Commission and proven to be efficient to use over the years. A well documented standardized discharge scoring system can prove to be a valuable asset, if you know what it means and where to find it in the medical record review.  Both paper PACU records and EHR integrate the scoring system into the nurses’ assessments area.  You will also find the information on the discharge nursing note.  In performing a medical record review, it’s prudent to compare the numerical scores with what else is documented in the same time frame.  For example, does the patient have a score of “2” for awake and alert but the nurse’s notes state the patient is sedated?   Validate that the scoring reflects what was really going on.

Not just a number…..

Now that you have a good basic idea of how numerical scores for discharge are used, let’s put it together the way you would when doing a case review.  Say, for example, a PACU nurse documents at 2 pm that the patient is responsive but sleepy on supplemental O2, unlabored resps, moving well with a blood pressure of 98/68. The patient’s baseline BP was 130/70 so he should have an Aldrete score of “7”. (Sleepy=1, activity=2, resps=2, O2 sat=1, and hemodynamic=1) You note a discrepancy because a score of “8” is documented instead.   Does it matter?  The answer is:  that depends.

The use of discharge criteria reinforces the value of having a system to maintain high standards of care, but there are limitations.  First, the criteria are broad and miss certain parameters that need to be assessed before readiness can be determined.   For example, vital sign ranges and expected pain or nausea levels and whether the patient needs to void are not included. Post- operative vital sign parameters may be inaccurate if preoperative values were abnormally high for the patient due to anxiety or other causes. Expecting the postoperative blood pressure to be within 20% of an elevated blood pressure may not be appropriate.

In the example above, it’s clear one needs to look beyond the numerical scoring data when analyzing a medical record review of a surgical patient.  The data alone does not replace the critical thinking or professional judgments of the nurse.  A patient may seem to fit all of the discharge criteria, yet a safe discharge requires an assessment on a case-by-case basis.  There are times when it’s reasonable to err on the side of caution as discharge goals can fail patients when used as a stand -alone measure.

Safe ambulatory surgery includes appropriate patient selection and timely discharge.  Discharge protocols must be established and consistently followed using scoring criteria and individualized assessments.

Hospital and unit based discharge policies should be requested and reviewed. Obtain copies of the scoring systems used as each facility has their own way of documenting these and they vary.  Pain, Sedation and Discharge are common types of scales that can be requested.   Websites such as American Society of Anesthesiologists (ASA) and American Society of Perianesthesia Nurses (ASPAN) are a good source of current practices.

Reviewing postoperative records can be a challenge.   It’s necessary to have an understanding of current discharge practices and protocols because limitations exist that have important implications for nursing.  Guidelines are evolving and are sometimes inconsistent, adding to the burden of finding literature to support the standards of care in this area.

If you need more information or have a question, contact me anytime.