Paul F. White

The Use of Prolonged Peripheral Neural Blockade After Lower Extremity Amputation: The Effect on Symptoms Associated with Phantom Limb Syndrome

BACKGROUND: Phantom limb syndrome (PLS) is common after limb amputations, involving up to 90% of amputees. Although many different therapies have been evaluated, none has been found to be highly effective. Therefore, we evaluated the efficacy of a prolonged perineural infusion of a high concentration of local anesthetic solution in preventing PLS. METHODS: A perineural catheter was placed immediately before or during surgery in 71 patients undergoing lower extremity amputation. A continuous infusion of 0.5% ropivacaine was started intraoperatively at 5 mL/h using an elastomeric (nonelectronic) pump, and continued for 4 to 83 days after surgery. PLS was evaluated on the first postoperative day and then 1, 2, 3, and 4 weeks, and 3, 6, 9, and 12 months after surgery. To evaluate the presence and severity of PLS while the patient was receiving the ropivacaine infusion, it was discontinued for 6 to 12 hours before each assessment period (i.e., until the sensation in the extremity returned). The severity of phantom limb and stump pain was assessed using a 5-point verbal rating scale (VRS), with 0 = no pain to 4 = intolerable pain, and “phantom” sensations were recorded as present or absent. If the VRS score was >1 or significant phantom sensations were present, the ropivacaine infusion was immediately restarted at 5 mL/h. If the VRS score remained at 0 to 1 and the patient had not experienced phantom sensations for 48 hours, the infusion was permanently discontinued and the catheter was removed. RESULTS: Median duration of the local anesthetic infusion was 30 days (95% confidence interval, 25–30 days). On postoperative day 1, 73% of the patients complained of severe-to-intolerable pain (visual analog scale >2). However, the incidence of severe-to-intolerable phantom limb pain was only 3% at the end of the 12-month evaluation period. At the end of the 12-month period, the percentage of patients with VRS pain scores were 0 = 84%, 1 = 10%, 2 = 3%, 3 = 3%, and 4 = none. However, phantom limb sensations were present in 39% of patients at the end of the 12-month evaluation period. All patients were able to manage the elastomeric catheter infusion system at home. CONCLUSION: Use of a prolonged postoperative perineural infusion of ropivacaine 0.5% seems to be an effective therapy for the treatment of phantom limb pain and sensations after lower extremity amputation.

Postoperative Pain Management After Ambulatory Surgery: Role of Multimodal Analgesia

Multimodal (or balanced) analgesia represents an increasingly popular approach to preventing postoperative pain. The approach involves administering a combination of opioid and nonopioid analgesics. Nonopioid analgesics are increasingly being used as adjuvants before, during, and after surgery to facilitate the recovery process after ambulatory surgery. Early studies evaluating approaches to facilitating the recovery process have demonstrated that the use of multimodal analgesic techniques can improve early recovery as well as other clinically meaningful outcomes after ambulatory surgery. The potential beneficial effects of local anesthetics, NSAIDs, and gabapentanioids in improving perioperative outcomes continue to be investigated.

Intrathecal transplantation of bone marrow stromal cells attenuates blood-spinal cord barrier disruption induced by spinal cord ischemia-reperfusion injury in rabbits

OBJECTIVE Intrathecal administration of bone marrow stromal cells has been found to produce beneficial effects on ischemia-reperfusion injury to the spinal cord. The blood-spinal cord barrier is critical to maintain spinal cord homeostasis and neurologic function. However, the effects of bone marrow stromal cells on the blood-spinal cord barrier after spinal cord ischemia-reperfusion injury are not well understood. This study investigated the effects and possible mechanisms of bone marrow stromal cells on blood-spinal cord barrier disruption induced by spinal cord ischemia-reperfusion injury. METHODS This was a prospective animal study conducted at the Central Laboratory of the First Affiliated Hospital, China Medical University. The study used 81 Japanese white rabbits (weight, 1.8-2.6 kg). Spinal cord ischemia-reperfusion injury was induced in rabbits by infrarenal aortic occlusion for 30 minutes. Two days before the injury was induced, bone marrow stromal cells (1 × 10(8) in 0.2-mL phosphate-buffered saline) were transplanted by intrathecal injection. Hind-limb motor function was assessed using Tarlov criteria, and motor neurons in the ventral gray matter were counted by histologic examination. The permeability of the blood-spinal cord barrier was examined using Evans blue (EB) and lanthanum nitrate as vascular tracers. The expression and localization of tight junction protein occludin were assessed by Western blot, real-time polymerase chain reaction, and immunofluorescence analysis. Matrix metalloproteinase-9 (MMP-9) and tumor necrosis factor-α (TNF-α) expression were also measured. RESULTS Intrathecal transplantation of bone marrow stromal cells minimized the neuromotor dysfunction and histopathologic deficits (P < .01) and attenuated EB extravasation at 4 hours (5.41 ± 0.40 vs 7.94 ± 0.36 μg/g; P < .01) and 24 hours (9.03 ± 0.44 vs 15.77 ± 0.89 μg/g; P < .01) after spinal cord ischemia-reperfusion injury. In addition, bone marrow stromal cells treatment suppressed spinal cord ischemia-reperfusion injury-induced decreases in occludin (P < .01). Finally, bone marrow stromal cells reduced the excessive expression of MMP-9 and TNF-α (P < .01). CONCLUSIONS Pre-emptive intrathecal transplantation of bone marrow stromal cells stabilized the blood-spinal cord barrier integrity after spinal cord ischemia-reperfusion injury in a rabbit model of transient aortic occlusion. This beneficial effect was partly mediated by inhibition of MMP-9 and TNF-α and represents a potential therapeutic approach to mitigating spinal cord injury after aortic occlusion. CLINICAL RELEVANCE Clinical thoracoabdominal aorta surgery may trigger spinal cord ischemia-reperfusion injury, resulting in paraplegia as well as bladder, bowel, and sexual dysfunction. Transplantation of bone marrow stromal cells has attracted increasing attention in the field of nervous system protection, but its mechanisms have not been elucidated completely. The blood-spinal cord barrier plays a crucial role to maintain normal spinal cord function. This study suggested that intrathecal transplantation of bone marrow stromal cells stabilized blood-spinal cord barrier integrity through inhibiting the upregulation of matrix metalloproteinase-9 and tumor necrosis factor-a and ameliorated spinal cord ischemia-reperfusion injury. This may provide a novel train of thought to enhance the protective effects of bone marrow stromal cells on spinal cord injury.

Effect of local anaesthetic infiltration with bupivacaine and ropivacaine on wound healing: a placebo‐controlled study

Infiltration of surgical wounds with long‐acting local anaesthetics (LA) is used to reduce postoperative incisional pain. We hypothesised that infiltration with LA interferes with wound healing in rats. Seventy‐two rats were allocated into nine groups. After intraperitoneal anaesthesia, the interscapular dorsal region was infiltrated with equivolumes of saline, 0·5% bupivacaine or ropivacaine, in a randomised double‐blind fashion. A standardised incision was performed in the infiltrated area and sutured closed. The rats were euthanised on the 3rd or 14th day after the operation and tissue from the incision site was subjected to histochemical analyses and mechanical testing (MT). Compared with the control group, bupivacaine displayed a significant increase in the macrophage number on day 3 (+63% versus +27% for ropivacaine). The transforming growth factor β‐1 expression had a significant increase in the LA (versus saline) groups, +63% in ropivacaine group and +115% in bupivacaine group on day 3 (P < 0·05). The collagen fibres as measured by dyed area were significantly higher in the bupivacaine group on day 3 (+56%, P < 0·01 versus +15% for ropivacaine). CD34 was reduced in bupivacaine group (−51%, P < 0·05 versus +3% for ropivacaine). On day 14, no statistical differences were observed in either LA group (versus saline) with respect to histopathologic or inflammatory mediators. MT on day 14 showed no differences between the LA and saline groups. The LA‐induced increases in histological markers did not extend beyond the third day, suggesting that wound infiltration with long‐acting LA does not impair the wound healing process in rats.

Age exacerbates surgery-induced cognitive impairment and neuroinflammation in Sprague-Dawley rats: the role of IL-4

Age is the most prominent risk factor for the development of postoperative cognitive dysfunction. This study investigated the potential role of anti-inflammatory interleukin (IL)-4 in age-related differences of surgery-induced cognitive deficits and neuroinflammatory responses. Both adult and aged Sprague-Dawley male rats were subjected to partial hepatectomy or partial hepatectomy with a cisterna magna infusion of IL-4. On postoperative days 1, 3, and 7, the rats were subjected to a reversed Morris water maze test. Hippocampal IL-1β, IL-6, IL-4, and IL-4 receptor (IL-4R) were measured at each time point. Brain derived neurotrophic factor (BDNF), synaptophysin, Ionized calcium-binding adapter molecule 1 (Iba-1), microglial M2 phenotype marker Arg1, and CD200 were also examined in the hippocampus. Age induced an exacerbated cognitive impairment and an amplified neuroinflammatory response triggered by surgical stress on postoperative days 1 and 3. A corresponding decline in the anti-inflammatory cytokine IL-4 and BDNF were also found in the aged rats at the same time point. Treatment with IL-4 downregulated the expression of proinflammatory cytokines (e.g., IL-1β and IL-6), increased the levels of BDNF and synaptophysin in the brain and improved the behavioral performance. An increased Arg1 expression and a high level of CD200 were also observed after a cisterna magna infusion of IL-4. An age-related decrease in IL-4 expression exacerbated surgery-induced cognitive deficits and exaggerated the neuroinflammatory responses. Treatment with IL-4 potentially attenuated these effects by enhancing BDNF and synaptophysin expression, inhibiting microglia activation and decreasing the associated production of proinflammatory cytokines.

A novel treatment for chronic opioid use after surgery

In a recent article from the Center for Disease Control, the authors addressed the current opioid epidemic in America and emphasized the importance of utilizing non-opioid analgesic alternatives to opioid medication for treating chronic pain. In cases where non-opioid analgesic drugs alone have failed to produce adequate pain relief, these authors suggested that non-pharmacologic therapies should also be considered. This Case Series describes a pilot study designed to evaluate a novel non-pharmacologic approach to treating long-standing (>1year) opioid dependency. The therapy involved the use of a high intensity cold laser device to treat three patients who had become addicted to prescription opioid-containing analgesic medication for treating chronic (residual) pain after a major operation. After receiving a series of 8-12 treatment sessions lasting 20-40min to the painful surgical area over a 3-4week period of time with the high intensity (42W) Phoenix Thera-lase laser device, an FDA-approved Class IV cold laser, these patients were able to discontinue their use of all oral opioid-containing analgesic medications and resume their normal activities of daily living. At a follow-up evaluation 1-2months after their last laser treatment, these patients reported that they have been able to control their pain with over-the-counter non-opioid analgesics and they have remained largely opioid-free. Further larger-scale studies are needed to verify these preliminary findings with this powerful cold laser in treating opioid-dependent patients.

An update on the management of postoperative nausea and vomiting

Postoperative nausea and vomiting (PONV) and postdischarge nausea and vomiting (PDNV) remain common and distressing complications following surgery. PONV and PDNV can delay discharge and recovery and increase medical costs. The high incidence of PONV has persisted in part because of the tremendous growth in ambulatory surgery and the increased emphasis on earlier mobilization and discharge after both minor and major operations. Pharmacological management of PONV should be tailored to the patients’ risk level using the PONV and PDNV scoring systems to minimize the potential for these adverse side effects in the postoperative period. A combination of prophylactic antiemetic drugs should be administered to patients with moderate-to-high risk of developing PONV in order to facilitate the recovery process. Optimal management of perioperative pain using opioid-sparing multimodal analgesic techniques and preventing PONV using prophylactic antiemetics are key elements for achieving an enhanced recovery after surgery. Strategies that include reductions of the baseline risk (e.g., adequate hydration, use of opioid-sparing analgesic techniques) as well as a multimodal antiemetic regimen will improve the likelihood of preventing both PONV and PDNV.

Use of electroanalgesia and laser therapies as alternatives to opioids for acute and chronic pain management

The use of opioid analgesics for postoperative pain management has contributed to the global opioid epidemic. It was recently reported that prescription opioid analgesic use often continued after major joint replacement surgery even though patients were no longer experiencing joint pain. The use of epidural local analgesia for perioperative pain management was not found to be protective against persistent opioid use in a large cohort of opioid-naïve patients undergoing abdominal surgery. In a retrospective study involving over 390,000 outpatients more than 66 years of age who underwent minor ambulatory surgery procedures, patients receiving a prescription opioid analgesic within 7 days of discharge were 44% more likely to continue using opioids 1 year after surgery. In a review of 11 million patients undergoing elective surgery from 2002 to 2011, both opioid overdoses and opioid dependence were found to be increasing over time. Opioid-dependent surgical patients were more likely to experience postoperative pulmonary complications, require longer hospital stays, and increase costs to the health-care system. The Centers for Disease Control and Prevention emphasized the importance of finding alternatives to opioid medication for treating pain. In the new clinical practice guidelines for back pain, the authors endorsed the use of non-pharmacologic therapies. However, one of the more widely used non-pharmacologic treatments for chronic pain (namely radiofrequency ablation therapy) was recently reported to have no clinical benefit. Therefore, this clinical commentary will review evidence in the peer-reviewed literature supporting the use of electroanalgesia and laser therapies for treating acute pain, cervical (neck) pain, low back pain, persistent post-surgical pain after spine surgery (“failed back syndrome”), major joint replacements, and abdominal surgery as well as other common chronic pain syndromes (for example, myofascial pain, peripheral neuropathic pain, fibromyalgia, degenerative joint disease/osteoarthritis, and migraine headaches).

Perioperative Care of Elderly Surgical Outpatients

The ambulatory setting offers potential advantages for elderly patients undergoing elective surgery due to the advancement in both surgical and anesthetic techniques resulting in quicker recovery times, fewer complications, higher patient satisfaction, and reduced costs of care. This review article aims to provide a practical guide to anesthetic management of elderly outpatients. Important considerations in the preoperative evaluation of elderly outpatients with co-existing diseases, as well as the advantages and disadvantages of different anesthetic techniques on a procedural-specific basis, and recommendations regarding the management of common postoperative complications (e.g., pain, postoperative nausea and vomiting [PONV], delirium and cognitive dysfunction, and gastrointestinal dysfunction) are discussed. The role of anesthesiologists as perioperative physicians is important for optimizing surgical outcomes for elderly patients undergoing ambulatory surgery. The implementation of high-quality, evidence-based perioperative care programs for the elderly on an ambulatory basis has assumed increased importance. Optimal management of perioperative pain using opioid-sparing multimodal analgesic techniques and preventing PONV using prophylactic antiemetics are key elements for achieving enhanced recovery after surgery.

Comparison of the C-MAC video laryngoscope to a flexible fiberoptic scope for intubation with cervical spine immobilization

STUDY OBJECTIVE To compare the C-MAC video laryngoscope to the standard flexible fiberoptic scope (FFS) with an eye piece (but without a camera or a video screen) for intubation of patients undergoing cervical spine surgery with manual inline stabilization. The primary end point was the time to achieve successful tracheal intubation. Secondary end points included glottic view at intubation and number of intubation attempts. DESIGN Prospective, randomized, single-blinded study. SETTING Cedars Sinai Medical Center in Los Angeles, CA. PATIENTS One hundred forty patients (American Society of Anaesthesiologists physical status I-III), aged 18 to 80years undergoing elective cervical spine surgery. INTERVENTION Patients were prospectively randomized to undergo tracheal intubation using either an FFS (n=70) or the C-MAC video laryngoscope (n=70). MEASUREMENTS After performing a preoperative airway evaluation, patients underwent a standardized induction sequence. The glottic view was assessed at the time of tracheal tube placement using the Cormack-Lehane and percentage of glottic opening scoring systems. In addition, the time required for successful insertion of the tracheal tube, number of intubation attempts to secure the airway, the need for adjuvant airway devices, hemodynamic changes, adverse events, and any airway-related trauma were recorded. MAIN RESULTS The glottic view at the time of intubation did not differ significantly with the 2 devices; however, the C-MAC facilitated more rapid tracheal intubation compared with the FFS (P=.001). The peak heart rate response following insertion of the tracheal tube was also reduced (P=.004) in the C-MAC (vs FFS) group. CONCLUSION The C-MAC may offer an advantage over the FFS with respect to the time required to obtain glottic view and successful placement of the tracheal tube in patients requiring cervical spine immobilization.