Objective: This study explored the risk factors influencing the length of hospital stay (LOS) and establish whether the type of anesthesia is independently associated with the LOS in patients after primary unilateral total knee arthroplasty (TKA). Methods: In this retrospective cohort study, 2309 patients undergoing unilateral TKA were recruited between January 2013 and June 2014 in a tertiary academic medical center in Singapore. Univariate and multivariate linear regression analyses were used to identify the independent risk factors associated with LOS. Besides, subgroup and interaction analyses were performed to evaluate the relationship between the type of anesthesia and LOS. Result: In total, 2309 patients were identified. Out of these, 791 patients underwent general anesthesia, whereas 1518 patients underwent regional anesthesia. Multivariate regression analyses revealed that prolonged LOS was significantly associated with age ≥ 65 years (β = 0.48; 95% CI, 0.09–0.87; P = 0.015), diabetes mellitus (DM) (β = 0.8; 95% CI, 0.33–1.27; P = 0.001), congestive cardiac failure (CCF) (β = 4.1; 95% CI, 2.02–6.17; P < 0.001), perioperative blood transfusion (β = 5.71; 95% CI, 4.86–6.56; P < 0.001), creatinine > 2 mg/dL (β = 4.54; 95% CI, 2.46–6.62; P < 0.001), ASA status (III) (β = 1.72; 95% CI, 0.72–2.71; P = 0.001), general anesthesia (β = 0.78; 95% CI, 0.41–1.66; P < 0.001). The LOS further decreased among participants receiving regional anesthesia at advanced age (age ≥ 65 years) (β = − 1.12; 95% CI, − 1.66 to − 0.58; P < 0.001), patients with BMI ≤ 25 kg/m² (β = − 1.92; 95% CI, − 2.73 to − 1.11; P < 0.001) or ≥ 30 kg/m² (β = − 0.58; 95% CI, − 1.1 to − 0.06; P = 0.029). Conclusion: Our findings demonstrated that age ≥ 65 years, DM, CCF, perioperative blood transfusion, creatinine > 2 mg/dL, ASA status (III), general anesthesia are associated with a prolonged LOS after primary TKA. Elderly patients (age ≥ 65 years) and patients with BMI ≤ 25 kg/m² or ≥ 30 kg/m² receiving regional anesthesia have a further reduced LOS. Therefore, when TKA is performed, priority for regional anesthesia is given to the elderly patients (age ≥ 65 years old) and those with BMI ≤ 25 kg/m² or ≥ 30 kg/m².

Pulmonary arterial hypertension (PAH) is a progressive vascular disease characterized by small artery occlusion, increased pulmonary vascular resistance, and right heart failure. HSPH1, a member of the heat shock protein family, has been shown to inhibit protein aggregation but its role in PAH remains unclear. The purpose of this study was to explore the expression pattern and potential mechanism of HSPH1 in PAH, and to provide new diagnostic markers for PAH. In the study differentially expressed genes from two GEO microarray datasets (GSE53408, GSE113439) were analyzed to identify potential biomarkers for PAH. The expression of HSPH1 in normal lung tissue and pulmonary hypertension tissue was verified by bioinformatics and various experiments. This study also validated the potential mechanism of action of HSPH1 in PAH through transfection techniques. In addition, clinical correlation analysis was used to verify whether HSPH1 was correlated with clinical indicators (age, smoking history, hypertension, SII, NLR, PLR). The results showed that the protein level of HSPH1 was significantly increased in the pulmonary artery tissue of rats with pulmonary hypertension. In the plasma of patients with clinical PAH, the expression of HSPH1 mRNA was also observed to be significantly increased, and its expression was also associated with inflammatory markers such as NLR, PLR and SII. In addition, wet experiments found that HSPH1 could promote the proliferation of pulmonary artery smooth muscle cells, promote epithelial‐mesenchymal transformation and inhibit apoptosis. These findings suggest that HSPH1 plays a crucial role in PAH progression and may serve as a potential diagnostic biomarker for the disease.