Welcome to the new Outpatient Surgery website! Check out our login FAQs.
Practical Pain Control
Jeffrey D. Swenson, MD
OSD Staff
Publish Date: October 10, 2007   |  Tags:   Anesthesia

January, 2007

If you would like to extend the excellent pain control of peripheral nerve blocks for up to 72 hours post-operatively but are worried about the risks and hassles of sending patients home with continuous infusion, here's great news. We conducted a study involving 620 healthy orthopedic outpatients who received interscalene, fascia iliaca or popliteal fossa infusions for 48 hours postoperatively??"and only 26 patients needed intervention.

Happily, we were able to handle three-fourths of the interventions during normal business hours. The most common intervention was repeat injection for additional pain control, often due to catheter dislodgement. The next most common intervention was accumulation of fluid under the dressing, because the anesthetic can track along the catheter back up to the skin. Just one patient, who later admitted to being a chronic opioid user, required hospital re-admission for pain control. One more had symptoms of nerve compression, which fully resolved in six weeks.

In this retrospective study, the patients were of all adult ages and educational levels, and had varying degrees of at-home support. Yet, all but one patient easily managed their own catheter care and removed their own catheters at home. In only one case, the patient needed assistance because the catheter had inadvertently been knotted at the tip. We removed it in the office.

The cost-savings this approach enables is also remarkable. Without the continuous infusions, at least 11 percent of our patients??"those who underwent shoulder arthroplasties, knee arthroplasties, below-knee amputations and those who had undergone osteotomies or sustained calcaneus fractures??"would have required hospitalization for post-op pain management. But thanks to the continuous-infusion PNBs, these patients went home the same day as their surgeries and required little intervention after PACU discharge. Incidentally, another 161 patients (26 percent of the study population) were ACL outpatients. Many hospitals still require overnight stays for these patients, which may cost thousands of dollars.

To succeed with a continuous PNB program, you need practitioners with a high level of expertise, a thorough patient education program, and consistent follow-up. We insert all catheters with ultrasound guidance, and we believe this improves our accuracy. We call all patients on the first post-op day and ensure that they have 24/7 phone access to an experienced anesthesiologist. With this foundation in place, a continuous PNB program is not only highly effective, but practical and economical, as well.

Continuous-Infusion PNBs in 620 Patients: Effective, Safe & Manageable



26 (4.2%)

Patient education issues^


Equipment malfunction???


Inadequate pain control*




2 (0.3%)





Post-osteotomy regional pain syndrome (resolved)


Peroneal nerve compression (resolved)


Hospital Readmissions

1 (0.1%)**

Patients Requiring Assistance to Remove Catheter After Infusion

1 (0.1%)**

^ Inadvertent or premature catheter removal; fluid under dressing.
??? Pump disconnected from catheter; catheter tip occlusion.
* Additional injections of bupivicaine required above and beyond the fixed bupivicaine 0.25% infusion rate of 5 mL/h in all patients.
** For additional pain control in chronic opioid user.

Dr. Swenson is a tenured Professor with the Department of Anesthesiology, University of Utah Health Science Center. He is also Director of Anesthesiology with the University of Utah Orthopaedics Hospital in Salt Lake City. For more information about the continuous-infusion PNB program, see: Swenson JD, Bay N, Loose E, et al. Outpatient Management of Continuous Peripheral Nerve Catheters Placed Using Ultrasound Guidance: An Experience in 620 Patients. Anesth Analg. 2006;103:1436-43.