Injury and Liability Associated with Implantable Devices for Chronic Pain.

BACKGROUND: Due to an increase in implantable device-related anesthesia pain medicine claims, the authors investigated anesthesia liability associated with these devices. METHODS: After institutional review board approval, the authors identified 148 pain medicine device claims from 1990 or later in the Anesthesia Closed Claims Project Database. Device-related damaging events included medication administration events, infections, hematomas, retained catheter fragments, cerebrospinal fluid leaks, cord or cauda equina trauma, device placed at wrong level, stimulator incorrectly programmed, delay in recognition of granuloma formation, and other issues. RESULTS: The most common devices were implantable drug delivery systems (IDDS; 64%) and spinal cord stimulators (29%). Device-related care consisted of surgical device procedures (n = 107) and IDDS maintenance (n = 41). Severity of injury was greater in IDDS maintenance claims (56% death or severe permanent injury) than in surgical device procedures (26%, P < 0.001). Death and brain damage in IDDS maintenance claims resulted from medication administration errors (n = 13; 32%); spinal cord injury resulted from delayed recognition of granuloma formation (n = 9; 22%). The most common damaging events for surgical device procedures were infections, inadequate pain relief, cord trauma, retained catheter fragments, and subcutaneous hygroma. Care was more commonly assessed as less than appropriate (78%) and payments more common (63%) in IDDS maintenance than in surgical device procedure claims (P < 0.001). CONCLUSIONS: Half of IDDS maintenance claims were associated with death or permanent severe injury, most commonly from medication errors or failure to recognize progressive neurologic deterioration. Practitioners implanting or managing devices for chronic pain should exercise caution in these areas to minimize patient harm.

National Perioperative Outcomes for Intrathecal Pump, Spinal Cord Stimulator, and Peripheral Nerve Stimulator Procedures.

BACKGROUND: There is abundant literature on the long-term complications of intrathecal pumps (ITP), spinal cord stimulators (SCS), and peripheral nerve stimulators (PNS) used in the treatment of chronic pain. There is less information, however, on the perioperative complications of these procedures. OBJECTIVE: Exploration of the perioperative outcomes of implantable pain devices. STUDY DESIGN: Observational study. SETTING: University hospitals, community hospitals, specialty hospitals, attached surgery centers, and freestanding surgery centers METHODS: Data were obtained from the National Anesthesia Clinical Outcomes Registry (NACOR) of the Anesthesia Quality Institute (AQI). Information was collected on patient demographics, procedure information, anesthetic administered, diagnosis linked to the procedure, and perioperative outcomes. RESULTS: The search yielded 12,611 ITP, 19,276 SCS, and 15,184 PNS cases from 2010 to 2014. In this sample, the majority of procedures were performed at community hospitals, not university medical centers. The most common diagnosis cited for an ITP was an implant complication (n = 2,570), followed by spasticity, and non-malignant back pain. For SCS, the most common diagnoses were lower back pain (n = 5,515) or radiculopathy (n = 2,398). For PNS, by far the most common diagnosis related to urinary dysfunction (n = 8,745), with painful bladder syndrome a small minority (n = 133). General anesthetics were more often performed for ITP than for SCS and PNS procedures (60.6% vs. 31.8% and 32.2%, respectively). Hemodynamic instability was a common outcome (13.9% for ITP procedures); other common outcomes for all the procedures included case delays, inadequate pain control, and extended PACU stays. LIMITATIONS: Despite the large sample size in this study, not all medical centers transmit their outcome data to NACOR. Furthermore, some institutions do not report clinical outcomes for every case to NACOR, making the sample size of assessing complications smaller and potentially more biased. Finally, procedures identified in the NACOR database using CPT may be similar but not identical and therefore potentially influence outcomes. CONCLUSIONS: Databases such as NACOR can provide rich information on ITP, SCS, and PNS for physicians performing these procedures. In this sample, ITP procedures, performed on the patients with the most severe cormobidities and often-requiring general anesthesia, were the most likely to be associated with hemodynamic instability, inadequate pain control, and extended PACU stays. Complications relating to the ITP are also the most common reason for an operation. These findings underscore the importance of proper patient selection for ITP and other implantable pain devices, in particular for patients with malignant pain or multiple co-morbidities. To identify the root causes of complications, additional information is needed on the procedure performed (e.g., an implant vs a revision), the surgical technique used, and the device implanted, as well as on specific patient comorbidities. Such information will likely become more available as resources like NACOR expand and as electronic medical record systems and coding become more integrated.

The subjective psychoactive effects of oral dronabinol studied in a randomized, controlled crossover clinical trial for pain.

BACKGROUND: Many cannabinoid medications are approved in North America or in phase III trials, such as dronabinol, nabilone, or nabiximols. Little is known about their subjective psychoactive effects when used for pain management. We hypothesized that when used for pain, dronabinol has psychoactive effects in a dose-response relationship, whose peak effects are comparable with smoking marijuana. METHODS: This was a randomized controlled trial of single dose placebo, 10 or 20 mg dronabinol in 30 chronic noncancer pain patients taking opioids and not using marijuana. Participants completed the Addiction Research Center Inventory (ARCI) hourly for 8 hours during 3 monitored sessions. Comparison sample was the ARCI ratings in participants with no pain (N=20), monitored every 30 minutes after smoking a 1.99% THC (low) and a 3.51% (high strength) marijuana cigarette. RESULTS: The 10 and 20 mg dronabinol doses had significantly elevated scores over time on 4/5 subscales versus placebo (P<0.05). Average daily morphine use, total pain relief (TOTPAR), age, sex, and baseline pain level were not significant covariates. ARCI peak effects at 2 hours were similar to peak effects of smoked marijuana at 30 minutes (P=0.80, 10 mg=low strength, 20 mg=high strength). CONCLUSIONS: In pain patients, oral dronabinol has similar psychoactive effects to smoking marijuana. This risk must be considered in any decision to prescribe cannabinoid medications for pain.

Evolution of a protocol for ketamine-induced sedation as an alternative to general anesthesia for interventional radiologic procedures in pediatric patients.

PURPOSE: To establish a protocol for credentialed pediatric radiology nurses, with radiologist supervision, to administer ketamine to induce sedation and analgesia during interventional radiologic procedures. MATERIALS AND METHODS: This study was conducted in two phases. The goal of the first phase was to develop a sedation protocol to replace that of using general anesthesia for specified pediatric interventional procedures. Ketamine was administered intravenously (with intermittent bolus or continuous infusion) or intramuscularly. Sedation induction times, adverse events, doses, and sedation and recovery durations were recorded. In phase 2, the results of phase 1 were reviewed and a formal ketamine protocol was developed. RESULTS: Neither sedation failures nor substantial adverse events occurred in phase 1. Mean duration of all sedations was 52 minutes, and median recovery room time was 0 minutes. In phase 2, the results of phase 1 were reviewed and a sedation protocol was proposed to a hierarchy of hospital committees before final approval from the medical staff executive committee. Subsequently, standard order forms for radiology nurse administration of ketamine with radiologist supervision were prepared for exclusive use by the pediatric interventional radiology department. CONCLUSION: Ketamine-induced sedation may be a safe and effective alternative to general anesthesia for some interventional radiologic procedures in pediatric patients. Collaboration between anesthesia and radiology departments is important for development of a safe and successful ketamine sedation program. To the authors' knowledge, this is the first report describing the intravenous infusion of ketamine for sedation in pediatric patients and the only report describing the establishment of a protocol for ketamine administration by credentialed radiology nurses with radiologist supervision.