Case report: Unusual complication during outpatient continuous regional popliteal analgesia
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Continuous regional anesthesia applied as pain therapy at home is clinically established standard practice after upper and lower limb surgery. Persistent motor block at discharge or after continuous infusion of local anesthetics, however, might lead to complications related to the insensate extremity. We report a rare case of a foot fracture due to stumbling after continuous sciatic nerve block at home and discuss the related clinical implications.
After uncomplicated ambulatory foot surgery under regional anesthesia, a patient was discharged with a continuous sciatic popliteal nerve block for pain therapy at home. After stumbling, the patient remained symptom-free even until catheter removal three days after surgery. Radiography done one week after surgery revealed a styloid fracture of the fifth metatarsal bone. Her subsequent recovery was uneventful.
The true incidence of complications related to falls at home associated with lower extremity blockade remains unknown, as symptoms of possible complications may be masked by the effects of the local anesthetic. However, with increasing use of postoperative regional anesthesia, it is mandatory to develop and adhere to clinical care maps, and to elaborate and teach strategies to further enhance patient safety.
KeywordsNerve Block Ropivacaine Regional Anesthesia Catheter Removal Hallux Valgus
Étude de cas: Complication inhabituelle pendant un bloc régional poplité continu chez un patient ambulatoire
L’anesthésie régionale continue utilisée comme traitement de la douleur à domicile est une pratique standard reposant sur des bases cliniques après chirurgie du membre supérieur ou inférieur. Un bloc moteur persistant au moment du congé de l’hôpital ou après instillation d’anesthésiques locaux peut, toutefois, conduire à des complications liées à l’extrémité insensibilisée. Nous décrivons un cas rare de fracture du pied secondaire à un faux-pas après un bloc continu du nerf sciatique à domicile et discutons de ses implications cliniques.
Après une chirurgie ambulatoire non compliquée du pied sous anesthésie régionale, une patiente a obtenu son congé avec un bloc nerveux continu du sciatique poplité pour le contrôle de la douleur au domicile. Après avoir trébuché, la patiente est restée asymptomatique jusqu’au retrait du cathéter trois jours après l’intervention chirurgicale. La radiographie pratiquée une semaine après la chirurgie a révélé une fracture de la styloïde du cinquième métatarsien. Sa guérison s’est déroulée sans incidents.
La véritable incidence des complications liées aux chutes à domicile, associées à des blocs nerveux des membres inférieurs, reste inconnue; de même, les symptômes des complications possibles peuvent être masquées par l’action de l’anesthésique local. Cependant, avec l’utilisation croissante de l’anesthésie régionale postopératoire, il devient impératif d’élaborer des plans de soins cliniques et de s’y tenir, et d’élaborer et enseigner des stratégies pour améliorer encore la sécurité des patients.
Perioperative fast-track management has been shown to be a safe, effective way to improve efficiency, patient satisfaction, and outcome. The ambulatory setting allows bypassing the postanesthesia care unit after surgery, thereby optimizing costs and the workload.1 Early discharge, with lower hospital cost, is possible if regional anesthesia with subsequent tailored continuous perineural block (cPNB) can be provided at the patient’s home.2,3 Considering that pain and postoperative nausea and vomiting are the main reasons for prolonged hospitalisation4 or re-hospitalisation5 after ambulatory surgery, the introduction of continuous regional techniques for outpatients might reduce the incidence of these complications.6 Reduction of opioids and their related side effects,7 better joint function after painful joint surgery,8 possible reduction of chronic pain, and optimisation of the patient’s daily activities are some of the additional advantages of regional anesthesia techniques. These advantages can explain the increasing interest in these techniques for ambulatory procedures.9-11
Several potential inherent risks have been described, including infection, nerve injury, catheter migration, local anesthetic toxicity, catheter retention, and pressure ulcers due to insensate extremities.12 The most feared complications of continuous regional analgesia of the lower extremities at home, however, are the effects of stumbling.
We did not find any reports of falls by patients who had undergone single sciatic (continuous) nerve block based on an OVID and PubMed search (1992 to April 2012) using the keywords “nerve block,” “sciatic,” “sciatic nerve block,” “accidental fall,” “fall,” and “fell.” Case reports in the literature have dealt with continuous femoral nerve block and combinations with sciatic nerve block as potential risk factors for falls at home.13-20
We present a rare case of stumbling causing a complication of a continuous popliteal sciatic nerve block during home therapy with a subsequently undetected styloid fracture of the fifth metatarsal bone. The patient gave written informed consent for publication of this article.
The patient was premedicated with midazolam 3.75 mg po and paracetamol 1 g po. In the operating room and after application of routine monitors, she underwent an uneventful, ultrasonography-guided right popliteal block with an initial bolus of 20 mL mepivacaine 1.5%. A perineural catheter (Stimulplex; B. Braun, Freiburg, Germany) was introduced 4 cm beyond the tip of the needle, subsequently checked by ultrasonography, and finally secured to the skin with a transparent dressing. The surgical procedure was uneventful, and the patient was discharged to the outpatient clinic immediately after the procedure.
According to our clinical protocol, after surgery a continuous infusion of ropivacaine 0.15% was initiated at a rate of 5 mL·hr-1 through a disposable elastomeric pump (Easy-pump; B. Braun) after recovering mobility of her toes. The patient was prescribed diclofenac 3× 50 mg po for the first three days after surgery and discharged home accompanied by a relative. She was allowed full use of the lower extremity based on the symptoms. A pain nurse conducted telephone monitoring according to our standard protocol (see below) until catheter removal.
Discussion of the risks and benefits of cPNB and ambulant treatment, with written informed consent;
Detailed verbal instructions to the patient and relatives regarding catheter care, side effects, and management;
Comprehensive written instructions highlighting management and side effects of the catheter given to the patient before discharge;
Written contact information about an anesthesiologist who is available 24 hr a day and for the pain nurse in charge of the follow-up;
Discharge (accompanied by a responsible adult) only after recovery of motor function.
Follow-up telephone contact established by the pain nurse from POD 1 until catheter removal. The patient is questioned specifically about adequate pain control, side effects/complications (e.g., persistent motor block, accidental falls). Patient is reminded about contacting the anesthesiologist/pain nurse and how to remove the catheter correctly at POD 3;
Postoperative visit at the outpatient clinic within one week after surgery, where pain and sensory and motor function are assessed and patient is examined for erythema, discharge, and/or swelling of the operated limb. Catheter entry is assessed for swelling/infection;
Follow-up data sheet of the outpatient with cPNB is kept in the patient’s records;
Prescriptions for oral diclofenac (non-steroidal anti-inflammatory drug) 3× 50 mg po for three days as an adjunct to the catheter-based analgesia;
Catheter removal at POD 3 (according to pump volume used).
Since January 2009, a total of 740 patients have been managed with this regimen at our institution. The duration of the catheter in place was 4.3 ± 1.4 days, with the most frequently reported side effect being persistent motor block of the ankle and foot (5.9% of cases). This side effect was successfully managed over the telephone by advising the patient to stop the infusion temporarily.21 After this long case series, the patient presented here represents the first case (0.14% incidence) of stumbling and subsequent minor fracture due to continuous popliteal nerve block.
The risk of harm due to falls was declared to be the subject of a national patient safety effort by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) in 2005.22 The risks related to the use of cPNB for the lower extremity are somewhat underestimated.19 Muraskin et al.15 and Fiolkowski et al.,23 who performed nerve blocks on volunteers, showed that these blocks impair proprioception and joint stiffness. The inability to control stiffness has been blamed for contributing to falls in the elderly and patients with peripheral neuropathy.24 Despite the large number of cPNBs performed for lower extremity surgery, there are fewer case reports of an increase in the incidence of falls due to lower extremity cPNB.16 Despite initial recovery of motor function following a bolus of local anesthetic, a subsequent motor block can develop, as reported by 5.9% of our patients. Salinas et al., who also conducted a study of volunteers, reported that after an infusion of 0.2% ropivacaine at 10 mL·hr−1 through a femoral catheter, a subsequent quadriceps motor block developed within five hours after an initial recovery.25 The relation between prolonged sitting and increased numbness and pinprick sensation with subsequent motor block remains unclear. The additional nerve compression could have led to an additional effect on nerve conduction or produced a more “toxic” level of local anesthetic, leading to impaired sensory and motor function. Therefore, during patient education, the use of aids that increase stability while walking and turning (e.g., walkers, crutches) should be emphasized. Also, the analgesia provided by ongoing continuous regional anesthesia can mask symptoms of an injury after stumbling or falling. Therefore, the patient’s education and daily follow-up by telephone are the main instruments for early detection of any residual motor block.6,10,11
The true incidence of complications at home related to lower extremity blockade remains unknown, as symptoms of possible complications may be masked by the effects of the local anesthetic. However, with increasing use of ambulatory regional anesthesia postoperatively, it is mandatory to develop and to adhere to clinical care maps and to teach strategies to further enhance patient safety.
Disclosure of funding
Conflicts of interest
- 13.Goodman MJ. American Academy of Orthopaedic Surgeons (AAOS). Risk Management Spotlight. Fall Prevention Following Regional Nerve blocks for Postoperative Analgesia. AAOS Online Bulletin, 2006. Available from URL: http://www2.aaos.org/aaos/archives/bulletin/toc.cfm?IssueMonthName=February&IssueYear=2006 (accessed June 2012).
- 17.Atkinson HD, Hamid I, Gupte CM, Russell RC, Handy JM. Postoperative fall after the use of the 3-in-1 femoral nerve block for knee surgery: a report of four cases. J Orthop Surg (Hong Kong) 2008; 16: 381-4.Google Scholar
- 22.The Joint Commission. Fatal falls: Lessons for the Future - Sentinel Event Alert; Issue 14: 2000; Available from URL: http://www.jointcommission.org/sentinel_event_alert_issue_14_fatal_falls_lessons_for_the_future/ (Accessed June 2012).