Oral gabapentin premedication for elderly patients undergoing intraocular surgery

Effects of gabapentin on intraocular pressure, tear production and horizontal pupil diameter in New Zealand White rabbits

BACKGROUND

This study aimed to investigate the effects of gabapentin on various ocular parameters in New Zealand White rabbits.

METHODS

A randomised, placebo-controlled crossover study design was employed. Eight New Zealand White rabbits were randomly assigned to receive either oral gabapentin at a dosage of 15 mg/kg or an oral placebo, with a 1-week washout period between treatments. Intraocular pressure, tear production and horizontal pupil diameter were measured at baseline (T0) and at 30, 60, 90, 120, 180, 240 and 360 minutes after drug administration. Physiological and behavioural changes were also recorded for both treatments following drug administration.

RESULTS

The administration of gabapentin did not have any significant effects on the ocular parameters measured in this study. However, the rabbits exhibited some muscle relaxation with partially closed eyes during handling, and they were slightly easier to remove from the cage when treated with gabapentin compared to the placebo treatment.

LIMITATIONS

In this study, the ocular effects of gabapentin were assessed in only a small number of healthy rabbits. These effects may differ in rabbits with pre-existing eye conditions or in those receiving other medications.

CONCLUSIONS

Our findings suggest that gabapentin treatment does not have a significant impact on intraocular pressure, tear production or horizontal pupil diameter in rabbits.

Efficacy and Safety of Anxiolytics in Mohs Micrographic Surgery: A Randomized, Double-Blinded, Placebo-Controlled Trial

BACKGROUND

Patient anxiety can complicate surgical outcomes by elevating blood pressure, increasing the need for postoperative pain management, and reducing overall patient satisfaction. Despite the use of anxiolytic medications in outpatient procedures, there is limited comparative evidence on the efficacy and safety of these agents in Mohs micrographic surgery.

OBJECTIVE

To compare the effectiveness and safety of different preprocedural anxiolytic agents in Mohs surgery on perioperative patient anxiety and patient satisfaction.

MATERIALS AND METHODS

A double-blinded, randomized, placebo-controlled trial was conducted of 6 different preprocedural anxiolytic agents (lorazepam, diazepam, alprazolam, gabapentin, pregabalin, and melatonin) in 350 patients undergoing Mohs surgery. Anxiety and vital signs were recorded.

RESULTS

Diazepam demonstrated a statistically significant, sustained reduction in anxiety levels compared with placebo ( p = .03). Gabapentin significantly reduced early anxiety ( p = .02). Alprazolam showed a trend to early anxiety reduction ( p = .08). Lorazepam ( p = .73), pregabalin ( p = .53), and melatonin ( p = .24) failed to reduce patient anxiety compared with placebo at any time point. No anxiolytic significantly impacted any patient vital sign or cognition.

CONCLUSION

Although short-acting benzodiazepines and gamma-aminobutyric acid medications may have transient anxiolytic effects, a single oral dose of 5 mg of diazepam can provide a sustained anxiolytic effect in Mohs surgery, with excellent patient safety.

Perioperative Anxiety and Depression in Older Adults: Epidemiology and Treatment

The intervals before and after major surgery is a high-risk period for older adults; in this setting, anxiety and depression are common and serious problems. We comprehensively reviewed current evidence on perioperative anxiety and depression in older adults, focusing on epidemiology, impact, correlates, medication risks, and treatment. Principles of perioperative mental healthcare are proposed based on the findings. Prevalence estimates of clinically significant anxiety and depression range from 5% to 45% for anxiety and 6% to 52% for depression, depending on surgical populations and measurement tools. Anxiety and depression may increase risk for surgical complications and reduce patient participation during rehabilitation. Medical comorbidities, pain, insomnia, cognitive impairment, and delirium are common co-occurring problems. Concomitant uses of central nervous system acting medications (benzodiazepines, anticholinergics, and opioids) amplify the risks of delirium and falls. Based on these findings, we propose that anxiety and depression care should be part of perioperative management in older adults; components include education, psychological support, opioid-sparing pain management, sleep management, deprescribing central nervous system active medications, and continuation and optimization of existing antidepressants. More research is needed to test and improve these care strategies.

Patient quality of recovery on the day of surgery after propofol total intravenous anesthesia for vitrectomy: A randomized controlled trial

BACKGROUND

Vitrectomy under general anesthesia is considered as a candidate for ambulatory surgery. An anesthetic method with high quality of postoperative recovery should be selected for successful ambulatory surgery. We thus compared quality of postoperative recovery on the day of vitrectomy using the Quality of Recovery (QoR)-40 questionnaire between propofol total intravenous anesthesia (propofol group) and desflurane inhalation anesthesia (desflurane group) as the 2 representative anesthetic methods.

METHODS

Eighty-four patients (20-80 years old) undergoing elective vitrectomy under general anesthesia were randomized into 2 groups. The propofol group received propofol and remifentanil using effect-site target-controlled infusion (TCI), and the desflurane group received desflurane inhalation and remifentanil using effect-site TCI. We assessed quality of recovery at 6 hours after surgery through interviews using the QoR-40 questionnaire. We also collected data related to recovery and complications during emergence and recovery period.

RESULTS

The median of QoR-40 score on the day of surgery was significantly higher in the propofol group than that in the desflurane group (181.0 vs 169.5, respectively; P = .033). In particular, propofol group had significantly higher scores for physical comfort and physical independence dimensions. The amount of remifentanil administered was significantly higher, and the emergence time was significantly longer in propofol group. However, there were no significant differences in other complications between the 2 groups.

CONCLUSIONS

Propofol total intravenous anesthesia provided significantly better quality of recovery on the day of surgery than desflurane inhalation anesthesia.

Dose-related beneficial and harmful effects of gabapentin in postoperative pain management - post hoc analyses from a systematic review with meta-analyses and trial sequential analyses

Background

During the last 15 years, gabapentin has become an established component of postoperative pain treatment. Gabapentin has been employed in a wide range of doses, but little is known about the optimal dose, providing the best balance between benefit and harm. This systematic review with meta-analyses aimed to explore the beneficial and harmful effects of various doses of gabapentin administered to surgical patients.

Materials and methods

Data in this paper were derived from an original review, and the subgroup analyses were predefined in an International Prospective Register of Systematic Reviews published protocol: PROSPERO (ID: CRD42013006538). The methods followed Cochrane guidelines. The Cochrane Library’s CENTRAL, PubMed, EMBASE, Science Citation Index Expanded, Google Scholar, and FDA database were searched for relevant trials. Randomized clinical trials comparing gabapentin versus placebo were included. Four different dose intervals were investigated: 0–350, 351–700, 701–1050, and >1050 mg. Primary co-outcomes were 24-hour morphine consumption and serious adverse events (SAEs), with emphasis put on trials with low risk of bias.

Results

One hundred and twenty-two randomized clinical trials, with 8466 patients, were included. Sixteen were overall low risk of bias. No consistent increase in morphine-sparing effect was observed with increasing doses of gabapentin from the trials with low risk of bias. Analyzing all trials, the smallest and the highest dose subgroups demonstrated numerically the most prominent reduction in morphine consumption. Twenty-seven trials reported 72 SAEs, of which 83% were reported in the >1050 mg subgroup. No systematic increase in SAEs was observed with increasing doses of gabapentin.

Conclusion

Data were sparse, and the small number of trials with low risk of bias is a major limitation for firm conclusions. Taking these limitations into account, we were not able to demonstrate a clear relationship between the dosage of gabapentin and opioid-sparing or harmful effects. These subgroup analyses are exploratory and hypothesis-generating for future trialists.

Alpha7 nicotinic acetylcholine receptor agonist promotes retinal ganglion cell function via modulating GABAergic presynaptic activity in a chronic glaucomatous model

Alpha-7 nicotinic acetylcholine receptor (α7-nAChR) agonists can prevent glutamate-induced excitotoxicity in cultured retinal ganglion cells (RGCs). However, the neuroprotective effects and the mechanism of action of PNU-282987, an α7-nAChR agonist, in a chronic in vivo rat glaucoma model are poorly understood. We found that elevated intraocular pressure (IOP) downregulated retinal α7-nAChR expression. Electroretinography revealed that the amplitude of the photopic negative response (PhNR) decreased in parallel with the loss of RGCs caused by elevated IOP. PNU-282987 enhanced RGC viability and function and decreased terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive signals in RGCs. Patch-clamp recordings revealed differences in the baseline frequencies and decay times of the miniature GABAergic inhibitory postsynaptic currents (mIPSCs) of RGCs between control and glaucomatous retinal slices. The results of western blotting and immunostaining showed that glutamic acid decarboxylase 65/67 and GABA deficits persisted in glaucomatous retinas and that these deficits were reversed by PNU-282987. Patch-clamp recordings also showed that PNU-282987 significantly increased the frequency and amplitude of the GABAergic mIPSCs of RGCs. The protective effects of PNU-292987 were blocked by intravitreal administration of selective GABA_A receptor antagonists. The modulation of GABAergic synaptic transmission by PNU-282987 causes de-excitation of ganglion cell circuits and suppresses excitotoxic processes.

Gabapentin for post-operative pain management - a systematic review with meta-analyses and trial sequential analyses

BACKGROUND

Perioperative pain treatment often consist of combinations of non-opioid and opioid analgesics, 'multimodal analgesia', in which gabapentin is currently used. The aim was to document beneficial and harmful effects of perioperative gabapentin treatment.

METHODS

Randomized clinical trials comparing gabapentin vs. placebo or active placebo in adult surgical patients receiving gabapentin perioperatively were included. This review was conducted using Cochrane standards, trial sequential analysis (TSA), and Grading of Recommendations Assessment, Development, and Evaluation (GRADE). The primary outcomes were 24-h opioid consumption and incidence of serious adverse events (SAE).

RESULTS

One hundred and thirty-two trials with 9498 patients were included. Thirteen trials with low risk of bias reported a reduction in 24-h opioid consumption of 3.1 mg [0.5, 5.6] [corrected]. In the analysis of gabapentin as add-on analgesic to another non-opioid analgesic regimen found a mean reduction in 24-h morphine consumption of 1.2 mg [-0.3, 2.6; TSA-adjusted CI: -0.3, 2.6] in trials with low risk of bias. [corrected]. Nine trials with low risk of bias reported a risk ratio of SAEs of 1.61 [0.91; 2.86; TSA-adjusted CI: 0.57, 4.57].

CONCLUSION

Based on GRADE assessment of the primary outcomes in trials with low risk of bias, the results are low or very low quality of evidence due to imprecision, inconsistency, and in some outcomes indirectness. Firm evidence for use of gabapentin is lacking as clinically relevant beneficial effect of gabapentin may be absent and harm is imminent, especially when added to multimodal analgesia.