Does it make good clinical and financial sense to send a patient home with a continuous peripheral nerve block (CPNB)? Experts at the 2016 International Symposium of Ultrasound for Regional Anesthesia, Pain Medicine, and Peri-operative Application argued yay and nay.
Philippe Macaire, MD, consultant in anesthesiology and pain management at Rashid Hospital Trauma Center, Dubai Health Authority, in the United Arab Emirates, laid out the rationale for sending patients home with a CPNB catheter.
The Benefits of CPNB
Many surgeries are conducted on an ambulatory basis, and pain is a common sequela, he said, pointing to a study of 2,144 ambulatory surgery patients that showed 27% reported mild, moderate or severe pain on the first day after surgery, whereas 6% had moderate to severe pain on postoperative day 3, and 9% and 2% of patients reported mild or moderate to severe pain, respectively, seven days after surgery (Anesth Analg 2005;101:1643-1650).
“More than a third of patients with incision site pain are readmitted for this reason,” Dr. Macaire said (Anesth Analg 1995;80:896-902).
CPNB is more effective in managing postoperative pain than opioid-based analgesia, Dr. Macaire asserted. In one meta-analysis of 19 studies including 603 surgical patients, CPNB was associated with only half the amount of pain than opioid-based analgesia at 24, 48 and 72 hours after surgery (Anesth Analg2006;102:248-257).
“Patients given CPNB also have less nausea and vomiting, fewer sleep disturbances, earlier return to normal social life and give very positive feedback,” Dr. Macaire added.
In his own research, patients required an average of 40.5 hours before being able to walk for 10 minutes if they were administered patient-controlled morphine, while those given basal–bolus CPNB were able to walk 10 minutes after an average of 12.5 hours (Anesthesiology 2006;105:566-573).
CPNB’s Limitations Manageable
“But managing a CPNB can be a challenge,” Dr. Macaire conceded.
Paradoxically, while it accelerates time to mobilization, administering incorrect doses of analgesia can also lead to paresthesia, numbness and delays in rehabilitation, he said (Anesthesiology 2006;105:566-573).
One way of reducing these risks is by making frequent adjustments to the infusion dose or rate, but that requires dispatching a nurse practitioner and having a physician on call—a costly proposition, Dr. Macaire said. Instead, he helped pioneer an approach that uses frequent patient feedback and remote-controlled pumps (Rythmic PCEA pump, Micrel Medical Devices) to make adjustments from afar.
The approach, which he has studied, relies on patient responses to a 10-item questionnaire completed three times daily and submitted through a secure internet portal (Ann Fr Anesth Reanim 2014;33:e1-e7). Through the questionnaire, patients provide information on pain, numbness, mobility and satisfaction, among other things. In the study, an anesthesiologist reviewed the responses an average of 15 minutes after they were submitted online.
“Based on only 10 questions, we were able to determine whether there were any adverse effects or if analgesia was inadequate, and we could decide if the basal rate or the bolus dose needed to be adjusted,” Dr. Macaire said.
The Argument Against Routine CPNB Use
Advanced technologies aside, Amit Pawa, BSc, MBBS, consultant anesthetist at Guy’s & St. Thomas’ NHS Foundation Trust, St. Thomas’ Hospital, in London, asked, “What’s wrong with the status quo?
“Most ambulatory surgery patients receive a single-shot block or surgical wound infiltration and oral multimodal analgesia, and do very well,” Dr. Pawa said. “If a patient actually needs to have a perineural catheter, there is a good chance they also have other health concerns and would benefit from hospital admission.”
Discharging patients with a catheter is associated with a risk for dislocation, Dr. Pawa said, pointing to a study in which 20 volunteers received femoral or interscalene catheters and 15% experienced catheter dislocation (Br J Anaesth2013;111:800-806).
In another study of 509 consecutive patients who received an interscalene CPNB after ambulatory surgery, 6.7% had their catheters dislocate or disconnect, or reported inadequate analgesia, pneumothorax, dyspnea, and nausea and vomiting, among other adverse events, Dr. Pawa said (Anaesthesia 2015;70:41-46).
Although the risk for neurologic damage is small, it is present, as was shown in a study of 300 patients administered a CPNB, Dr. Pawa said. Three individuals in that study developed new-onset neurologic symptoms believed to be catheter related (Reg Anesth Pain Med 2008;33:122-128).
“Knowing these risks, are you still happy sending patients home with a catheter?” Dr. Pawa asked his audience.
Do Patients Actually Need Catheters?
While he admitted that CPNB is associated with very effective pain control, Dr. Pawa said a single-shot nerve block also is associated with good analgesia. According to one publication of 100 shoulder arthroscopy patients, among the 96 patients who received a single shot, analgesia was “excellent” for the first 12 hours postoperatively, and over 80% of individuals required only “simple analgesics” during the five postoperative study days (Arch Orthop Trauma Surg2010;130:417-421).
“A striking 97% of patients reported satisfaction with their analgesia experience,” Dr. Pawa emphasized.
Clinicians also can extend nerve blockade to the outpatient setting without discharging patients with a CPNB, Dr. Pawa said. One approach is to combine single-injection peripheral nerve blocks with IV or perineural dexamethasone (Anaesthesia 2015;70:1180-1185), while a more recent approach is to administer liposomal bupivacaine, which can increase nerve blockade.
Scarce Resources an Issue
One factor that should give providers pause in deciding to equip a homebound patient with a CPNB is the cost of the approach, Dr. Pawa said.
“You need money for training and consumables, and staff needs to be available and on call. It’s complex and expensive!” he said.
That last point resonated with a meeting attendee, who said while there are good arguments both in favor and against using CPNBs, he has refrained from sending patients home with them.
“I think the key problem for many practices in the United States is a shortage of resources,” commented John Strother, MD, an anesthesiologist in private practice in Lexington, Ky. “You need to have a nurse practitioner or a physician who can be immediately available after discharge to troubleshoot any problems, and the patient needs to have close access to a hospital emergency room in the event they have any diaphragmatic paralysis or other complications.
“It also helps to have a very motivated and educated patient who can understand and follow home instructions, and has a good support network at home,” Dr. Strother added.