Michal Prusak

Background: Postoperative pain levels and opioid requirements vary considerably, even among patients undergoing similar surgical interventions. The pupillary pain index—a pupillometry-derived measure of nociception-antinociception balance—may help individualize postoperative analgesia. We therefore tested the hypothesis that a pupillary pain index-guided opioid titration at the end of surgery reduces postoperative pain and opioid consumption compared with standard care. Methods: At the end of surgery, a portable infrared pupilometer was used to measure pupillary dilation reflex during stepwise tetanic stimulation (10–60 mA), generating a pupillary pain index score. Adult patients undergoing elective ear-nose-throat surgery under general anesthesia were randomized to pupillary pain index-guided opioid therapy or standard care. Opioid administration in the pupillary pain index group followed predefined pupillary pain index cutoffs; in the control group, analgesia was managed per routine practice. Postoperative opioid consumption and pain—assessed using a numerical rating scale (NRS, 0–10)—were recorded every 30 min for 2 h in the post-anesthesia care unit. Linear models with covariates including remifentanil, weight, nose surgery, and sex were calculated to compare outcomes between groups. Results: Mean (±SD) opioid consumption during the first 2 postoperative hours was 4.9 ± 4.3 mg in the pupillary pain index-guided group and 6.5 ± 4.3 mg in the control group (adjusted p = 0.12). Mean pain scores were 2.0 ± 1.1 and 2.6 ± 1.4, respectively (adjusted p = 0.10). Conclusions: Pupillary pain index-guided analgesia resulted in a nearly 25% reduction in opioid consumption and lower pain scores, although not statistically significant. This suggests that PPI-guided analgesia is not inferior to standard care in terms of pain management.

Background: Mitochondrial DNA (mtDNA), normally enclosed within mitochondria, can be released into circulation in response to cellular stress, hypoxia, or inflammation. Its detection in plasma has been proposed as a marker of cellular injury, particularly in the context of mechanical ventilation. High-frequency jet ventilation is a specialized approach of open-airway ventilation, delivering small tidal volumes through jet gas streams, applied with high pressure and oxygen fraction. It remains unclear whether this mode of ventilation contributes to mitochondrial stress. We therefore hypothesized that circulating mtDNA levels would increase after jet ventilation due to the combined effects of high oxygen exposure and mechanical strain. Furthermore, we explored whether the magnitude of mtDNA change correlates with the duration of ventilation and arterial oxygenation levels. Methods: Plasma levels of cell-free circulating mitochondrial DNA were measured in 30 patients before and following jet ventilation in laryngotracheal surgery. Post hoc analysis of a primary monocentric, randomized cross-over study was conducted to investigate ventilation distribution in high-frequency jet ventilation techniques. Results: Mitochondrial DNA levels significantly decreased after jet ventilation (median T0: 13.57; T1: 6.78; p = 0.0087). No significant associations were found between mtDNA change and jet ventilation duration, type of surgery, or ASA classification. Despite variable air entrainment in the open-jet ventilation system, the arterial partial pressure of oxygen increased significantly during the procedure. Conclusions: Jet ventilation was associated with a significant decrease in circulating mtDNA levels. This contrasts with our initial hypothesis of mtDNA elevation under ventilation-induced stress. These findings suggest that jet ventilation may exert less mitochondrial damage than previously expected.

Background: Glycyrrhiza glabrata (licorice) is used in traditional medicine and herbal remedies and reduces sore throats consequent to intubation, but whether it is protective for more intense pain after oropharyngeal surgery remains unclear. We thus tested the joint hypothesis that gargling with licorice, which has anti-inflammatory and antioxidant properties, reduces postoperative pain and morphine consumption. Methods: We enrolled patients having elective oropharyngeal surgery. Participants were randomly allocated to gargle with either 1 g licorice or a sugar placebo before and for up to three days after surgery. A numerical rating scale (NRS) for pain along with morphine consumption was evaluated every 30 min during the post-anesthesia care unit (PACU) stay and then three times daily for three days. We pre-specified that licorice gargling would be deemed better than sugar gargling only if found non-inferior on both morphine consumption and pain score and superior on at least one of the two. Results: 65 patients were randomized to the licorice group and 61 to placebo. We found noninferiority (NI) in pain scores with an estimated mean difference of −0.09 (95.2% CI: −0.88, 0.70; p = 0.001; NI delta = 1) between licorice and placebo gargling. There were no adverse events reported in either group that required treatment discontinuation. Conclusions: Gargling with licorice did not significantly or meaningfully reduce postoperative pain or morphine consumption in patients recovering from oropharyngeal surgery. While higher doses might prove more effective, our results suggest that other topical analgesics should be considered.

Background and Objectives: Pain is a multidimensional phenomenon with a wide range regarding the location, intensity and quality. Patients with chronic pain, in particular those suffering from mixed pain, often present a special challenge. The PainDETECT questionnaire (PD-Q) is a screening instrument designed to classify whether a patient has neuropathic pain (NP), often rated as more distressing compared to nociceptive pain. The objective of this study was to investigate whether the PD-Q score correlates with pain intensity, measured with the numeric rating scale (NRS), in chronic pain patients in an outpatient setting. Materials and Methods: A questionnaire-based study was conducted to identify the associations between the unidimensional NRS scale for pain intensity and the PD-Q score for screening of an NP component in an outpatient setting. Participants were asked to fill in the questionnaire themselves. Results: One hundred seventy-six participants completed the PD-Q questionnaire and rated pain on the NRS scale at the baseline visit. The PD-Q and NRS scores significantly correlated at the baseline visit and the 1-month follow-up visit in chronic pain patients. The identification of a neuropathic component in chronic pain may permit more targeted and effective pain management. Conclusions: The findings of our questionnaire suggest that a significant proportion of chronic pain patients had manifested features of NP at the first visit to the outpatient clinic. The PD-Q is a useful screening tool to alert clinicians of NP that may need further diagnostic evaluation or therapeutic intervention and may also help to predict treatment response. Further research is needed to investigate if a correlation is predictive of treatment response when pain therapy targets NP.