The Erector Spinae Plane Block As A Novel Therapy For Pain Management In Acute Pyelonephritis In The Emergency Department: A Case Report
Sunday, April 7, 2024
2:02pm – 2:09pm
Location: 412
Authors: Christine Prochnow, Vanderbilt University Medical Center Jonathan Brewer, Vanderbilt University Medical Center Jordan Rupp, Vanderbilt University Medical Center Jeremy Boyd, Vanderbilt University Medical Center
The erector spinae plane (ESP) block is a paraspinal fascial plane block commonly used for pain control in thoracic and abdominal surgeries. Additional applications for the ESP block include pain control in rib fractures and neuropathic pain. While the mechanism is not completely understood, it is thought the deposited local anesthetic spreads cranially and caudally through the fascial plane to block the dorsal and ventral rami of the thoracolumbar spinal nerves. A recent literature review revealed case reports and a case series demonstrating the successful use of the ESP block for pain control in renal colic caused by nephrolithiasis. However, there are no documented cases of the ESP block used for managing pain in acute pyelonephritis. In this case report, we describe a novel indication for the ultrasound-guided ESP block where refractory pain from acute pyelonephritis was successfully managed without opioids in the emergency department, facilitating outpatient management and care.
Case Description: A young adult woman with a past medical history of alpha thalassemia, anemia, and chronic palpitations presented to our emergency department for evaluation of severe right-sided flank pain with urinary discomfort and nausea for one day. She also reported a one-time episode of hematuria and improving darkened color of her urine. The patient denied any fever, chills, vomiting, diarrhea, vaginal discharge, or history of nephrolithiasis. Her vital signs upon presentation were within normal limits. Examination demonstrated a well-developed woman in significant pain. Abdominal exam revealed mild suprapubic discomfort and severe right-sided costovertebral angle tenderness to palpation. The patient otherwise had an unremarkable cardiac, respiratory, neurologic, musculoskeletal, and integumentary exam. The CBC and BMP were unremarkable. Urinalysis revealed large leukocyte esterase, positive nitrite, and large blood with microscopic analysis demonstrating a white blood cell count of 587, red blood cell count of 1,016, and 4+ bacteria. A non-contrasted CT abdomen and pelvis did not reveal any acute abnormalities and specifically did not demonstrate urolithiasis, nephrolithiasis, or hydronephrosis. A diagnosis of acute pyelonephritis was made. The patient was provided 1g Tylenol PO, 4mg Zofran PO, 15mg IV Toradol, 1 liter of intravenous fluids (IVF), and 1g of IV ceftriaxone. Unfortunately, her pain was refractory to nonsteroidal anti-inflammatory drugs (NSAIDs). She was offered PO and IV narcotics; however, she was insistent against narcotic utilization despite severe pain. A brief literature search revealed several case reports and a published case series of ten cases demonstrating effective pain management in renal colic with erector spinae plane (ESP) blocks at the eighth thoracic level (T8), but no prior cases were found for treating pain associated with acute pyelonephritis. Given her refractory pain and the literature findings, a right-sided ESP block was offered to the patient, the risks and benefits were discussed, and the patient provided written consent. An ultrasound-guided right-sided ESP block was performed at T8 with the probe oriented parasagittally and with the patient in the prone position. An in-plane approach was used with a 22G 3-1/8 inch Braun Ultraplex needle with the needle tip oriented in a cranial to caudal position. To minimize the risk of local anesthetic intravascular injection, once the needle appeared just above the T8 transverse process, we first aspirated to confirm no blood return, and then 5cc normal saline was deposited to confirm appropriate placement via hydro-dissection. This demonstrated the appropriate lifting of the overlying erector spinae muscle off the right T8 transverse process. Subsequently, 30cc of 0.25% Ropivacaine mixed with 4mg of dexamethasone was deposited in the same space between the erector spinae muscle and the transverse process. The patient was monitored for thirty minutes post-procedure. She did require an additional dose of 4mg Zofran and 1L IVF bolus for nausea and a one-time blood pressure of 98/70. There were no procedural complications. Upon reassessment, she was well-appearing, her nausea was completely resolved, and her blood pressure improved to 118/77. Before the ESP block, her pain score was 10/10. Post ESP block, she reported significant improvement with a pain score of 4/10, satisfaction with her relief, and readiness for discharge home. She was discharged with a 14-day course of 200mg Cefpodoxime twice daily and with a referral to our rapid follow-up clinic for reassessment. Ultimately, her urine culture grew >100,000 colony-forming units of Escherichia coli sensitive to Cefpodoxime. We had our case managers perform a follow-up phone call to update the patient on her urine culture results and to reassess her symptoms. The patient reported satisfaction with the ESP block, and she ultimately did not schedule rapid follow-up in the outpatient clinic due to her improvement.
Conclusions: As flank pain is a common reason patients present to the emergency department, studies currently underway to compare the standard of care with NSAIDs and opioids to ESP blocks in the treatment of renal colic are of important clinical significance in improving quality and safety in patient care. Preliminary data from a prospective, randomized small pilot study of 40 patients with renal colic demonstrated higher patient satisfaction in the ESP block group and that patients in the ESP group had significantly less opioid consumption than the NSAID group (p < 0.001). The data obtained evaluating pain management via the ESP block in renal colic can likely be applied to treating pain with the ESP block in acute pyelonephritis due to the blockade of the same renal sensory pain fibers. Erector spinae plane blocks can be an effective analgesic for treating pain and can serve as another tool in the emergency medicine providers’ armamentarium for treating pain in the emergency department. In this case, we present a patient with severe right-sided flank pain due to acute pyelonephritis with pain refractory to NSAIDs and the desire by the patient to refrain from opioid analgesics successfully managed with an ESP block and reported high satisfaction and significant pain relief post-block. Therefore, the ESP block may provide a safe and effective alternative to pain control in patients with acute pyelonephritis with refractory flank pain and may also be an excellent alternative in patients with underlying renal disease or pregnancy who cannot receive NSAIDs or have limited options for pain control. As ESP blocks are a relatively new technique, further research is needed to better determine the mechanism of action, efficacy, and complications.