Experience Brief: Femoral nerve block reduces hospital admissions, opioids in pediatrics

Dr Bhalla

Nationwide Children’s Hospital is one of 13 medical centers nationwide participating in the Pediatric Regional Anesthesia Network, a collaboration designed to support the collection of highly audited data on practice patterns and complications and to facilitate collaborative research in regional anesthetic techniques in infants and children. Participating institutions report the number of regional anesthesia procedures they do each month. Researchers conducted this study at Nationwide Children’s Hospital in Columbus, Ohio, publishing its results in the Journal of Pediatric Orthopaedics in June.¹

Background

Postoperative pain is a key factor that leads to delayed hospital discharge and the need for inpatient admission after surgical procedures. In recent years, there has been an increased use of multimodal techniques in pediatric patients in an attempt to limit pain and speed recovery, while also cutting the need for opioids. 

Femoral nerve block (FNB), an ultrasound-guided regional anesthesia, is one technique that has yielded these results, decreasing the need for postoperative admissions, painkillers, and the incidence of postoperative nausea and vomiting. There are different kinds of regional anesthesia, depending on the part of the body to be numbed. In all cases, however, anesthesiologists use ultrasound to guide a needle to the specific surgical site and deliver local anesthetic to numb only the nerves in that region. The anesthetic blocks pain for up to 24 hours in some cases, significantly reducing postoperative pain. 

This method has been used in adult patients for more than a decade. Although most adult patients remain awake for procedures involving regional anesthesia, pediatric patients, especially young children, are usually under general anesthetic. The type of anesthetic used in regional anesthesia varies, but those used in this study included bupivacaine and ropivacaine, which are among the longest-acting anesthetics available.

Clinicians have conducted few studies examining FNB in children, specifically regarding postoperative results. Research shows, however, that compared to other methods like caudal block there are benefits of peripheral nerve blockade, including a lessened incidence of unwanted effects and need for a lower volume of local anesthetic agent. 

The study reviews our experience with FNB after arthroscopic knee surgery in the pediatric population and evaluates its effects on postoperative pain score, painkiller requirements, and length of hospitalization. The technique used in these patients numbs the femoral nerve, which runs close to the femoral artery and conducts signals running along the front of the thigh, inner leg, and foot. 

Experience

We reviewed the records of 376 patients aged 7 to 18 years who underwent arthroscopic knee surgery at Nationwide Children’s Hospital between July 2008 and July 2011. Of these patients, 131 received an FNB in addition to general anesthesia, while 245 received general anesthesia alone. Results showed that 43 of the FNB patients were admitted to the hospital, compared with 80 who received only general anesthesia. Of the patients admitted, length of hospitalization in patients who received FNB was shorter than that for those who received general anesthesia alone.   

Using a 0 to 10 (0 = no pain) visual analogue scale (VAS), we found there was a significant difference in the high and low pain scores in patients who received FNB and patients who did not. Our results showed that after surgery, the VAS scores were lower in patients who received FNB. For instance, the highest VAS score in the FNB group was 4.0 ± 4.0, compared with 5.3 ± 3.1 in the general anesthesia group. The lowest VAS score of the FNB group was 1.5 ± 1.8, whereas the lowest score in the anesthesia group was 2.1 ± 2.0. 

The need for opioids decreased with the FNB group as well. During the postoperative period, 61% of patients in the FNB group required painkillers, compared to 71% of patients in the general anesthesia group. When looking at anterior cruciate ligament repairs, which we consider among the most painful of all procedures evaluated, there was a significantly lower need for postoperative hospitalization for patients receiving FNB. In the FNB group, 41 of 57 patients required hospital admission, whereas 52 of 55 required admission in the anesthesia group.

Although it’s clear that administering FNB improved the overall postoperative experience, our findings demonstrate that an FNB is most beneficial when used for the most painful procedures. A more recent 2012 review indicates that 95 arthroscopic knee surgeries have been performed in the last year, with only 8 patients needing admission. In fact, we have seen many of these patients at our ambulatory surgery centers. We view this change as a result of improved pain control, as FNB has become the standard of care for arthroscopic procedures at Nationwide Children’s Hospital.  

Since 2010, we have significantly increased the number of blocks we are doing and now perform 150 to 200 a month. This study and results we have experienced firsthand demonstrate the safety and improved outcomes that regional anesthesia offers.  

Read more on postoperative pain.

Reference

1. Schloss B, Bhalla T, Klingele K, et al. A retrospective review of femoral nerve block for postoperative analgesia after knee surgery in the pediatric population. J Pediatr Orthop. 2014;34(4):459-461.

Dr Bhalla is an anesthesiology and pain medicine physician at Nationwide Children’s Hospital, Columbus, OH. He is a fellowship-trained and board-certified pediatric anesthesiologist and is board certified in pain medicine. He has been the Director of Acute Pain and Regional Anesthesia at Nationwide Children’s Hospital since 2011.

Disclosure information: The author report no financial disclosures as related to products discussed in this article.