New Bupivacaine Implants Show Benefit for Postsurgical Pain
A new approach to postsurgical pain control involves absorbable collagen implants containing 600-mg bupivacaine HCl, which are placed into the surgical site.
The manufacturer, Innocoll Pharmaceuticals Ltd, has provided data on the implants, which are produced and sold in sterile, ready-to-use packages.
In 2018, a poster presented at the World Congress on Regional Anesthesia and Pain Medicine reported that among participants, pain relief was complete at 24 hours, and that a significant decrease in opioid use was demonstrated at 48 and 72 hours. (See 1. Data on File. Innocoll Pharmaceuticals Ltd; http://www.innocoll.com. 2. Leiman D, Niebler G, Minkowitz H. Pharmacokinetics and safety of the bupivacaine collagen-matrix implant (INL-001) compared to liquid bupivacaine infiltration after open inguinal hernia repair. Poster presented at: World Congress on Regional Anesthesia & Pain Medicine; April 19-21, 2018; New York, NY. https://epostersonline.com/ASRAWORLD18/node/1154. 3. Velanovich V, Rider P, Deck K, et al. Safety and efficacy of bupivacaine HCl collagen-matrix implant (INL-001) in open inguinal hernia repair: results from two randomized controlled trials. Adv Ther. 2019;36:200-216.)
Children May Have More Pain Than Parents Realize
Researchers conducted a prospective study of 5639 children from a Portuguese birth cohort-Generation XXI. Parents and their 7-year-old children answered the same questions at the same time. The accuracy of parental report was assessed, considering children's self-reporting as the gold standard.
At 7 years of age, 499 children [8.8%; 95% confidence interval (CI), 8.1-9.6] reported having pain at the time of the interview. Of the entire sample, 44.1% had high-intensity pain (3.9%; 95% CI, 3.4-4.4) and 12.4% reported pain in 2 or more sites (1.1%; 95% CI, 0.8-1.4). Pain prevalence and intensity were lower when information was collected from parents. Parental report exhibited sensitivity below 20% and specificity above 95%, but its positive predictive value was, at most, 25%.
The authors suggest that their findings support that, outside acute care, parents have a specific but not sensitive report of children's pain at the age of 7 years. The data seemed useful to exclude major complaints but limited to screening children's pain. This limitation was higher for more severe pain-that is, 2 or more sites or high-intensity pain. Children should be asked directly about pain to avoid underestimating pediatric pain. (See Gorito V, Monjardino T, Azevedo I, et al. Potentially unrecognised pain in children: population-based birth cohort study at 7 years of age [published online ahead of print September 23, 2021]. J Paediatr Child Health. doi:10.1111/jpc.15749.)
A Review of Mechanisms and Assessment of Cervical Dystonia
Pain is a major contributor to disability and social isolation in patients with cervical dystonia (CD) and is often the main reason patients seek treatment. Surveys evaluating patient perceptions of their CD symptoms consistently highlight pain as a troublesome and disabling feature of their condition with significant impact on daily life and work.
In this article, the authors review the epidemiology, assessment, possible mechanisms, and treatment of pain in CD, including a meta-analysis of randomized controlled trial data with botulinum toxin.
Mechanisms of pain in CD may be muscle-based and non-muscle-based. Accumulating evidence suggests that non-muscle-based mechanisms (such as abnormal transmission and processing of nociceptive stimuli, dysfunction of descending pain inhibitory pathways and structural and network changes in the basal ganglia, cortex, and other areas) may also contribute to pain in CD alongside prolonged muscle contraction.
Chemodenervation with botulinum toxin is considered the first-line treatment for CD. Treatment with botulinum toxin is usually effective, but optimization of the injection parameters should include consideration of pain as a core symptom in addition to the motor problems. (See Rosales RL, Cuffe L, Regnault B, et al. Pain in cervical dystonia: mechanisms, assessment and treatment. Expert Rev Neurother. 2021;21(10):1125-1134.)
Medical Cannabis Shows Minimal Effect on Relieving Chronic Pain
A recent study reports data indicating that noninhaled medical cannabis or cannabinoids leads to a small to very small improvement in pain relief.
The authors reviewed 32 trials with 5174 patients, 29 of whom compared medical cannabis or cannabinoids with placebo.
Medical cannabis was administered orally (n = 30) or topically (n = 2). Clinical populations included chronic noncancer pain (n = 28) and cancer-related pain (n = 4). Length of follow-up ranged from 1 to 5.5 months.
Compared with placebo, noninhaled medical cannabis resulted in a small increase in the proportion of patients experiencing at least the minimally important difference (MID) of 1 cm [on a 10-cm visual analog scale (VAS) in pain relief, modeled risk difference (RD) of 10% (95% confidence interval, 5% to 15%), based on a weighted mean difference (WMD) of -0.50 cm (95% CI, -0.75 to -0.25 cm, moderate certainty)].
Medical cannabis taken orally showed a very small improvement in physical functioning (4% modeled RD (0.1% to 8%) for achieving at least the MID of 10 points on the 100-point 36-item Short Form Health Survey (SF-36) physical functioning scale, WMD of 1.67 points (0.03 to 3.31, high certainty).
Oral medical cannabis also showed a small improvement in sleep quality [6% modeled RD (2% to 9%) for achieving at least the MID of 1 cm on a 10 cm VAS, WMD of -0.35 cm (-0.55 to -0.14 cm, high certainty)].
Medical cannabis taken orally does not improve emotional, role, or social functioning (high certainty) but does result in a small increase in cognitive dysfunction, vomiting, and inattention. High certainty evidence showed greater increased risk of dizziness.
The author concluded that moderate- to high-certainty evidence showed that noninhaled medical cannabis or cannabinoids resulted in a small to very small improvement in pain relief, physical functioning, and sleep quality among patients with chronic pain, along with several transient adverse side effects, compared with placebo. (See Wang L, Hong PJ, May C, et al. Medical cannabis or cannabinoids for chronic non-cancer and cancer related pain: a systematic review and meta-analysis of randomized clinical trials [published online ahead of print September 8, 2021]. BMJ. doi:10.1136/bmj.n1034.)