Peripheral nerve blocks for postoperative analgesia - Home Study Program

AORN Journal, Jan, 2002 by Jacqueline D. Murauski, Kathleen R. Gonzalez

The article "Peripheral nerve blocks for postoperative analgesia" is the basis for this AORN Journal independent study. The behavioral objectives and examination for this program were prepared by Rebecca Holm, RN, MSN, CNOR, clinical editor, with consultation from Susan Bakewell, RN, MS, education program professional, Center for Perioperative Education.

A minimum score of 70% on the multiple-choice examination is necessary to earn 3 contact hours for this independent study. Participants receive feedback on incorrect answers. Each applicant who successfully completes this study will receive a certificate of completion. The deadline for submitting this study is Jan 31, 2005.

Send the completed application form, multiple-choice examination, learner evaluation, and appropriate fee to

AORN Customer Service
c/o Home Study Program
2170 S Parker Rd, Suite 300
Denver, CO 80231-5711
or fax the information with a credit card number to (303) 750-3212.

BEHAVIORAL OBJECTIVES

After reading and studying the article on peripheral nerve blocks, the nurse will be able to

(1) discuss the advantages and limitations of peripheral nerve blocks,

(2) explain the physiology and pharmacology of a peripheral nerve block,

(3) identify potential complications relevant to adminstration of a peripheral nerve block,

(4) discuss the common types of upper and lower extremity nerve blocks, and

(5) describe the nursing management of the patient undergoing peripheral nerve block.

This program meets criteria for CNOR and CRNFA recertification, as well as other continuing education requirements.

Traditionally, pain has been a major concern for both patients and caregivers, but with the variety of peripheral nerve blocks available, pain can be managed much more effectively now than in the past. Peripheral nerve blocks are used in selected procedures as part of a preemptive and multimodal or balanced analgesia technique to provide safe intraoperative and postoperative analgesia with minimal side effects. The goal of preemptive analgesia is to minimize pain from surgically injured tissue by providing medications (eg, local anesthetics, nonsteroidal anti-inflammatory drugs [NSAIDs], opioids) before the surgical injury occurs and before pain is perceived. Studies have shown that pain may be eliminated or minimized if the afferent nociceptive stimulus from the injured tissue is prevented from reaching the central nervous system by preinjury neural blockade. (1) A peripheral nerve block administered before a surgical procedure may provide this neural blockade. Multimodal or balanced analgesia is the use of more than one method of controlling pain. This method may enhance analgesia due to additive or synergistic effects between different medications and techniques, which results in a decrease in medication requirements overall. Side effects associated with analgesic medications, therefore, also are decreased. (2) Analgesic techniques to control postoperative pain can be targeted at three levels:

* the site of tissue injury,

* the impulses transmitted through the peripheral nerves at the spinal cord level, and

* the perception at the cortical level.

Peripheral nerve blocks target the nociceptive impulses transmitted along peripheral nerves. Blocks also can be combined with additional medications to target pain at other levels. For example, NSAIDs reduce the activation of nociceptors at the site of injury and modify the cortical response, whereas, opioids relieve pain by binding to opioid receptors in the brain and spinal cord to modify the perception of pain and, therefore, the response to pain. (3)

ADVANTAGES AND LIMITATIONS OF PERIPHERAL NERVE BLOCKS

The advantages of using peripheral nerve blocks as part of a multimodal technique have been illustrated in a number of studies. (4) These studies show that patients who receive peripheral nerve blocks experience reduced postoperative pain and analgesia requirements and report more satisfaction with their pain management. In a study of patients undergoing total knee arthroplasty, the use of continuous femoral nerve block was found to expedite rehabilitation efforts after surgery without increasing pain or opioid requirements. (5) In the outpatient setting, peripheral nerve blocks have facilitated early ambulation and discharge by decreasing side effects, such as drowsiness, nausea, and vomiting. (6) In addition, peripheral nerve blocks may allow patients to remain conscious and preserve their protective reflexes (eg, gag reflex) while avoiding the need for airway manipulation and intubation. This reduces the potential side effects and complications of general anesthesia.

There are, however, limitations to peripheral nerve blocks. They

* require technical expertise from a variety of clinicians,

* require additional time for induction and onset, and

* may not be suitable for some patients.

Clinicians with specific technical expertise are required for the administration of the nerve block, and other, equally skilled, clinicians are required to monitor patients intraoperatively and postoperatively. Nurses must be experienced in the preoperative screening and assessment of this patient population and must participate in educating patients and their family members. During the intraoperative and postoperative phases, nurses must observe patients for potential side effects and complications and be prepared to provide preventive measures and assistance with any treatment interventions. Postoperatively, nurses must assess the level of the block and quality of analgesia. Nurses are responsible for postoperative reinforcement of patient and family member education regarding preemptive pain relief, recovery from the peripheral nerve block, and protection of the extremity.