Exploring the impact of high-altitude de-acclimatization on renal function: The roles of oxidative and endoplasmic reticulum stress in rat models.

BACKGROUND: High-altitude de-acclimatization (HADA) significantly impacts physiological functions when individuals acclimatize to high altitudes return to lower altitudes. This study investigates HADA's effects on renal function and structure in rats, focusing on oxidative and endoplasmic reticulum stress as potential mechanisms of renal injury. OBJECTIVE: To elucidate the pathophysiological mechanisms of renal damage in HADA and evaluate the efficacy of antioxidants Vitamin C (Vit C) and tauroursodeoxycholic acid (TUDCA) in mitigating these effects. METHODS: 88 male Sprague-Dawley rats were randomly divided into a control group, a high-altitude (HA) group, a high-altitude de-acclimatization (HADA) group, and a treatment group. The control group was housed in a sea level environment (500 m), while the HA, HADA, and treatment groups were placed in a simulated high-altitude chamber (5000 m) for 90 days. After this period, the HA group completed the modeling phase; the HADA group was further subdivided into four subgroups, each continuing to be housed in a sea level environment for 3, 7, 14, and 30 days, respectively. The treatment group was split into the Vit C group, the TUDCA group, and two placebo groups, receiving medication for 3 consecutive days, once daily upon return to the sea level. The Vit C group received 100 mg/kg Vit C solution via intravenous injection, the TUDCA group received 250 mg/kg TUDCA solution via intraperitoneal injection, and the placebo groups received an equivalent volume of saline similarly. Serum, urine, and kidney tissues were collected immediately after the modeling phase. Renal function and oxidative stress levels were assessed using biochemical and ELISA methods. Renal histopathology was observed with H&E, Masson's trichrome, PAS, and PASM staining. Transmission electron microscopy was used to examine the ultrastructure of glomeruli and filtration barrier. TUNEL staining assessed cortical apoptosis in the kidneys. Metabolomics was employed for differential metabolite screening and pathway enrichment analysis. RESULTS: Compared to the control and HA groups, the HADA 3-day group (HADA-3D) exhibited elevated renal function indicators, significant pathological damage, observable ultrastructural alterations including endoplasmic reticulum expansion and apoptosis. TUNEL-positive cells significantly increased, indicating heightened oxidative stress levels. Various differential metabolites were enriched in pathways related to oxidative and endoplasmic reticulum stress. Early intervention with Vit C and TUDCA markedly alleviated renal injury in HADA rats, significantly reducing the number of apoptotic cells, mitigating endoplasmic reticulum stress, and substantially lowering oxidative stress levels. CONCLUSION: This study elucidates the pivotal roles of oxidative and endoplasmic reticulum stress in the early-stage renal injury in rats undergoing HADA. Early intervention with the Vit C and TUDCA significantly mitigates renal damage caused by HADA. These findings provide insights into the pathophysiological mechanisms of HADA and suggest potential therapeutic strategies for its future management.

Evaluating Modified Ultrasound-Guided Serratus Anterior Plane Block for Enhanced Postoperative Recovery in Thoracoscopic Lobectomy Patients.

BACKGROUND Thoracoscopic lobectomy is accompanied by intense trauma and pain due to impaired chest wall integrity. We aimed to introduce a modified ultrasound-guided serratus anterior plane block (MUG-SAPB) for postoperative analgesia in patients who underwent thoracoscopic lobectomy, and to determine whether it could effectively alleviate postoperative pain and improve recovery quality. MATERIAL AND METHODS Overall, 78 patients randomly received either combined MUG-SAPB (0.25% ropivacaine, 10 mg dexamethasone, 40 mL) with patient-controlled intravenous analgesia (PCIA) or received PCIA alone. The primary outcomes were visual analog scale (VAS) scores at rest and during movement at 4, 8, 12, 20, 24, 48, and 72 h postoperatively. The secondary outcomes included use of opioids during surgery, numbers of rescue analgesics (butorphanol), frequency of patient-controlled analgesia (PCA), comfort score within 24 h postoperatively, and postoperative complications within 72 h. RESULTS Compared to the PCIA group, in the MUG-SAPB group, resting VAS scores at 4-24 h (P<0.05) and movement VAS scores at 4-12 h postoperatively (P<0.05) were lower; intraoperative use of sufentanil and frequency of PCA were less, and less rescue analgesia was used (P=0.02, P=0.04 and P=0.03, respectively). Patients in the MUG-SAPB group had faster first mobilization (P=0.04). The MUG-SAPB group had higher comfort scores than the PCIA group (P=0.03). None of the MUG-SAPB patients had any SAPB-related complications. CONCLUSIONS MUG-SAPB effectively relieved postoperative pain, reduced opioid consumption, and accelerated early ambulation in comparison with PCIA alone in patients who underwent thoracoscopic lobectomy.

Administration of combined spinal epidural anesthesia with ultrasound-assisted positioning in obese patients undergoing open hysterectomy: A randomized controlled trial.

BACKGROUND: Administration of combined spinal epidural anesthesia (CSEA) with traditional landmark-guided positioning can be challenging in patients with high body mass index (BMI). The popularization of ultrasound technology may effectively solve these problems. However, reports on the administration of CSEA ultrasound-assisted positioning in obese populations are relatively limited and have made inconsistent conclusions. We aimed to investigate the ability of ultrasound-assisted positioning to improve the success rate of CSEA in obese patients. METHODS: Overall, 118 adult women with a BMI ≥ 30 kg/m2 who scheduled to undergo open hysterectomy and received CSEA were recruited. Finally, 108 patients were enrolled and randomly assigned to 2 groups: the ultrasound-assisted positioning group (group A) and traditional landmark-guided positioning group (group B). Ultrasound-assisted or landmark-guided positioning was employed to locate the puncture interspace before anesthesia. The primary outcomes were the success rate of first attempt and number of attempts. The secondary outcomes were the patient positioning accuracy, positioning time, CSEA operation time, patient-satisfaction scores, anesthesia characteristics, and complications of CSEA. RESULTS: The success rate of patient first puncture attempt in group A was significantly higher than that in group B (78.4% vs 52.9%, P = .007). The total number of punctures was lower in group A than that in groups B (average rank 44.54 vs 58.46, P = .005). Using ultrasound positioning as the gold standard, the accuracy of landmark-guided location was only 67%. Positioning time in croup A was longer in group A than that in group B (P = .004), while CSEA operation time spent in Group A was less than that in Group B (P < .001). Patient satisfaction score in group A was significantly higher than that in group B (P = .002). The successful puncture interspace in group A were more likely at L3-4 than that in group B (P = .02). CONCLUSION: The success rate of first puncture attempt and positioning accuracy in CSEA with ultrasound-assisted is significantly higher than those based on landmark-guided location in obese patients.