Current depth of anaesthesia monitors: jacks of all trades and masters of none?

Efficacy and tolerability balance of oxycodone/naloxone and tapentadol in chronic low back pain with a neuropathic component: a blinded end point analysis of randomly selected routine data from 12-week prospective open-label observations

Objective

To evaluate the benefit–risk profile (BRP) of oxycodone/naloxone (OXN) and tapentadol (TAP) in patients with chronic low back pain (cLBP) with a neuropathic component (NC) in routine clinical practice.

Methods

This was a blinded end point analysis of randomly selected 12-week routine/open-label data of the German Pain Registry on adult patients with cLBP-NC who initiated an index treatment in compliance with the current German prescribing information between 1st January and 31st October 2015 (OXN/TAP, n=128/133). Primary end point was defined as a composite of three efficacy components (≥30% improvement of pain, pain-related disability, and quality of life each at the end of observation vs baseline) and three tolerability components (normal bowel function, absence of either central nervous system side effects, and treatment-emergent adverse event [TEAE]-related treatment discontinuation during the observation period) adopted to reflect BRP assessments under real-life conditions.

Results

Demographic as well as baseline and pretreatment characteristics were comparable for the randomly selected data sets of both index groups without any indicators for critical selection biases. Treatment with OXN resulted formally in a BRP noninferior to that of TAP and showed a significantly higher primary end point response vs TAP (39.8% vs 25.6%, odds ratio: 1.93; P=0.014), due to superior analgesic effects. Between-group differences increased with stricter response definitions for all three efficacy components in favor of OXN: ≥30%/≥50%/≥70% response rates for OXN vs TAP were seen for pain intensity in 85.2%/67.2%/39.1% vs 83.5%/54.1%/15.8% (P= ns/0.031/<0.001), for pain-related disability in 78.1%/64.8%/43.8% vs 66.9%/50.4%/24.8% (P=0.043/0.018/0.001), and for quality of life in 76.6%/68.0%/50.0% vs 63.9%/54.1%/34.6% (P=0.026/0.022/0.017). Overall, OXN vs TAP treatments were well tolerated, and proportions of patients who either maintained a normal bowel function (68.0% vs 72.2%), reported no central nervous system side effects (91.4% vs 89.5%), or completed the 12-week evaluation period without any TEAE-related treatment discontinuations (93.0% vs 92.5%) were similar for both index medications (P= ns for each comparison).

Conclusion

In daily practice, the BRP of OXN proved to be noninferior to that of TAP in patients with cLBP-NC, but showed a superior efficacy if stricter analgesic response definitions were evaluated.

Closed loop anaesthesia at high altitude (3505 m above sea level): Performance characteristics of an indigenously developed closed loop anaesthesia delivery system

Background:

Closed loop anaesthesia delivery systems (CLADSs) are a recent advancement in accurate titration of anaesthetic drugs. They have been shown to be superior in maintaining adequate depth of anaesthesia with few fluctuations as compared with target-controlled infusion or manual titration of drug delivery.

Methods:

Twenty patients scheduled to undergo general abdominal or orthopaedic procedures under general anaesthesia at Leh (3505 m above sea level) were recruited as subjects. Anaesthesia was delivered by a patented closed loop system that uses the Bispectral Index (BIS™) as a feedback parameter to titrate the rate of propofol infusion. All vital parameters, drug infusion rate and the BIS™ values were continuously recorded and stored online by the system. The data generated was analysed for the adequacy of anaesthetic depth, haemodynamic stability and post-operative recovery parameters.

Results:

The CLADS was able to maintain a BIS™ within ±10 of the target of 50 for 85.0±7.8% of the time. Haemodynamics were appropriately maintained (heart rate and mean arterial blood pressure were within 25% of baseline values for 91.2±2.2% and 94.1±3% of the total anaesthesia time, respectively). Subjects were awake within a median of 3 min from cessation of drug infusion and achieved fitness to recovery room discharge within a median of 15 min. There were no adverse events or report of awareness under anaesthesia.

Conclusions:

The study demonstrates the safety of our CLADS at high altitude. It seeks to extend the use of our system in challenging anaesthesia environments. The system performance was also adequate and no adverse events were recorded.

Pain relief and tolerability balance of immediate release tapentadol or oxycodone treatment for patients with moderate to severe osteoarthritis or low back pain

PURPOSE

Opioid treatment effectiveness may be best compared using definitions of treatment response, which combine measures assessing pain reduction and the occurrence of adverse events (AEs). This analysis of data from two phase III clinical trials was conducted to examine the pain relief and tolerability (PRT) balance of immediate release (IR) tapentadol and oxycodone in patients with moderate to severe osteoarthritis (OA) or low back pain.

METHODS

This was a post hoc analysis of two multicenter, randomized, double-blind studies (10-day and 90-day) that evaluated the efficacy and safety of tapentadol IR in patients with moderate-severe OA pain. PRT was defined as adequate pain reduction (30% or 50% pain intensity improvement from baseline) and no gastrointestinal AE or other type of treatment-emergent AE. The percentage of patients and mean number of days per patient meeting the PRT criteria were summarized.

RESULTS

In the 10-day trial, the percentages of patients meeting PRT criteria (30% reduction) for both tapentadol groups were consistently above that for oxycodone 10 mg, although only significantly different for the 50 mg formulation. The mean number of days per patient meeting the PRT criteria was 3.7, 3.2, and 2.3 days for tapentadol 50 mg, 75 mg and oxycodone 10 mg, respectively. No significant difference between the groups was observed using the 50% pain reduction criterion. For the 90-day trial, using multiple definitions, tapentadol IR showed a significantly higher proportion of days meeting PRT criteria.

CONCLUSION

Pain reduction and tolerability are both important attributes of an effective analgesic treatment. Based on data from two trials, tapentadol IR produced an improved PRT balance compared with oxycodone IR.