Effectiveness of scheduled intravenous acetaminophen in the postoperative pain management of video-assisted thoracic surgery.

PURPOSE: The scheduled administration of intravenous acetaminophen (scheduled-IV-AcA) is one of the more effective multimodal analgesic approaches for postoperative pain in abdominal/orthopedic surgeries. However, there is little evidence concerning scheduled-IV-AcA after general thoracic surgery, especially when limited to video-assisted thoracoscopic surgery (VATS). We investigated the efficacy of scheduled-IV-AcA administration in patients after undergoing VATS. METHODS: Ninety-nine patients who underwent VATS lobectomy or segmentectomy via an 8-cm access window and 1 camera port were retrospectively reviewed by categorizing them into groups either with scheduled-IV-AcA (Group AcA: n = 29) or without it (Group non-AcA: n = 70). Group AcA received 1 g of IV-AcA every 6 h from the end of the operation until the end of POD2. Postoperative pain was measured using a numeric rating scale (NRS) three times per day until discharge. RESULTS: NRS scores were significantly lower in Group AcA with motion (on POD1 to the first point of POD2) than in Group non-AcA. Group non-AcA was also more likely to use additional analgesics than Group AcA (39% vs. 17%, p = 0.058). CONCLUSIONS: Scheduled-IV-AcA administration is a safe and effective multimodal analgesic approach in patients undergoing VATS pulmonary resection via an 8-cm access window.

Prolonged Tachycardia with Higher Heart Rate Is Associated with Higher ICU and In-hospital Mortality.

Tachycardia is common in intensive care units (ICUs). It is unknown whether tachycardia or prolonged tachycardia affects patient outcomes. We investigated the association between tachycardia and mortality in critically ill patients. This retrospective cohort study's primary outcome was patient mortality in the ICU and the hospital. We stratified the patients (n=476) by heart rate (HR) as LowHR, MediumHR, and HighHR groups. We also stratified them by their durations of HR >100 (prolonged HR; tachycardia): MildT, ModerateT, and SevereT groups. We determined the six groups' mortality. The ICU mortality rates of the LowHR, MediumHR, and HighHR groups were 1.0%, 1.5%, and 7.9%, respectively; significantly higher in the HighHR vs. LowHR group. The in-hospital mortality rates of these groups were 1%, 4.5%, and 14.6%, respectively; significantly higher in the HighHR vs. LowHR group. The ICU mortality rates of the MildT, ModerateT, and SevereT groups were 0.9%, 5.6%, and 57.1%, respectively. The mortality of the HRT=0 (i.e., all HR ≤ 100) patients was 0%. The in-hospital mortality rates of the MildT, ModerateT, and SevereT groups were 1.8%, 16.7%, and 85.7%, respectively; that of the HRT=0 patients was 0.5%. Both higher HR and prolonged tachycardia were associated with poor outcomes.

Quercetin Attenuates Neuropathic Pain in Rats with Spared Nerve Injury.

Quercetin is a flavonoid widely found in plants and marketed to the public as a supplement. Several studies have reported its effect on glial cells. This study aimed to examine the effect of quercetin on the development of neuropathic pain and the underlying mechanism in a spared nerve injury (SNI) rat model. Male Sprague-Dawley rats randomly assigned to the control or the quercetin group were subjected to SNI of the sciatic nerve. We measured pain behaviors on the hind paw and glial fibrillary acidic protein (GFAP) in the dorsal root ganglion (DRG) and spinal cord. Oral administration of 1% quercetin, begun before surgery, attenuated mechanical allodynia compared to the control group at days 7 and 10 after SNI. On the other hand, established pain was not attenuated in a post-dose group in which quercetin was begun 7 days after SNI. Quercetin inhibited GFAP in the satellite glial cells of the ipsilateral L5 DRG on day 7 compared to the control group. Quercetin suppressed the development of neuropathic pain through a mechanism partly involving the inhibition of satellite glial cells. As its safety is well established, quercetin has great potential for clinical use in pain treatment.

Antinociceptive effects of intrathecal landiolol injection in a rat formalin pain model.

Perioperative beta-blocker administration has recently been recommended for patients undergoing cardiac or other surgery due to the beneficial cardiovascular effects of these agents. In addition, some studies have reported that perioperatively administered beta-blockers also have analgesic effects. In this study, to investigate the antinociceptive effects and the analgesic profile of landiolol, we examined the effects of intrathecal landiolol administration on nociceptive pain behavior and c-fos mRNA expression (a neural marker of pain) in the spinal cord using a rat formalin model. We found that pain-related behavior was inhibited by intrathecal landiolol administration. Moreover, the increase in c-fos mRNA expression on the formalin-injected side was less pronounced in rats administered landiolol than in saline administered controls. Thus, intrathecal administration of landiolol exhibited antinociceptive effects. Further investigation of the antinociceptive mechanism of landiolol is required.

Radio contrast imaging for continuous epidural infusion in humans: a report of three cases.

There are no reports of human research on continuous epidural contrast injection, and there are no definite methods to investigate the spread of drugs injected continuously into the epidural space. We investigated the feasibility of continuous epidural contrast injection in patients undergoing computed tomography (CT)-guided therapy. In this study, a combination of a contrast agent mixed with 0.75% ropivacaine was used as the test drug. The main outcome evaluated was the feasibility of continuous epidural contrast imaging by CT scan following epidural injection of a contrast agent with 0.75% ropivacaine. We studied three patients who underwent CT-guided procedures and found that continuous epidural contrast injection was possible without any deleterious effects, such as an allergic reaction. The spread of the contrast agent was not consistent with the level of the clinical analgesic effect. Continuous epidural contrast injection is a feasible procedure. The results of our study might contribute to future research on continuous epidural contrast administration, as well as provide patients with superior analgesia.

Up-regulation of brain-derived neurotrophic factor in the dorsal root ganglion of the rat bone cancer pain model.

Metastatic bone cancer causes severe pain, but current treatments often provide insufficient pain relief. One of the reasons is that mechanisms underlying bone cancer pain are not solved completely. Our previous studies have shown that brain-derived neurotrophic factor (BDNF), known as a member of the neurotrophic family, is an important molecule in the pathological pain state in some pain models. We hypothesized that expression changes of BDNF may be one of the factors related to bone cancer pain; in this study, we investigated changes of BDNF expression in dorsal root ganglia in a rat bone cancer pain model. As we expected, BDNF mRNA (messenger ribonucleic acid) and protein were significantly increased in L3 dorsal root ganglia after intra-tibial inoculation of MRMT-1 rat breast cancer cells. Among the eleven splice-variants of BDNF mRNA, exon 1-9 variant increased predominantly. Interestingly, the up-regulation of BDNF is localized in small neurons (mostly nociceptive neurons) but not in medium or large neurons (non-nociceptive neurons). Further, expression of nerve growth factor (NGF), which is known as a specific promoter of BDNF exon 1-9 variant, was significantly increased in tibial bone marrow. Our findings suggest that BDNF is a key molecule in bone cancer pain, and NGF-BDNF cascade possibly develops bone cancer pain.