Association of Preoperative Hyponatremia With Surgical Outcomes: A Systematic Review and Meta-analysis of 32 Observational Studies.

BACKGROUND: Preoperative hyponatremia is prevalent in patients undergoing surgical procedures, but it is uncertain if hyponatremia will lead to increased risk of surgical mortality and morbidity. METHODS: A systematic search of Medline (PubMed), Embase, and Cochrane Library from inception through July 2, 2021, was performed. Full-length articles that reported on the association between surgical outcomes among adults aged ≥18 years with documented preoperative hyponatremia were included. FINDINGS: We identified 32 observational studies comprising 1 301 346 participants. All studies had low risk of bias. When adjusted for covariates, patients with hyponatremia had significantly higher odds of developing major complications (defined as a composite measure of 9 major complications) compared with patients with normal sodium concentrations (adjusted odds ratio = 1.37; 95% CI, 1.23-1.53; I2 = 78%; N = 10). Additionally, patients with preoperative hyponatremia also significantly higher hazards of early mortality (<90 days) compared with patients with normonatremia (adjusted hazard ratio = 1.27; 95% CI, 1.13-1.43; I2 = 97%; N = 10) after adjustment for covariates. Preoperative hyponatremia also had significant associations with respiratory, renal, and septic complications. In terms of prognostic performance, preoperative hyponatremia performed adequately in predicting major complications in surgical patients (area under the curve = 0.70; negative likelihood ratio, 0.90) with a specificity of 88% and a sensitivity of 25%. INTERPRETATION: Our meta-analysis suggests that preoperative hyponatremia is associated with poorer early mortality and major morbidity outcomes in surgical patients. Hyponatremia is also a specific prognosticator for major complications in surgical patients, reiterating its potential use as a clinical indicator of poor outcomes.

Pentacyclic Triterpenoids as Antibiofilm Agents against Methicillinresistant and Biofilm-forming Staphylococcus aureus (MRSA).

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) has been constantly evolv-ing and developing resistance against conventional antibiotics. One of the key features of MRSA that enables it to develop resistance to antibiotics and host immune system is its ability to form biofilm in indwelling medical devices. In previous studies, the antimicrobial activity and mechanisms of action of three known pentacyclic triterpenoids α-amyrin, betulinic acid and betulinaldehyde against planktonic cells of MRSA were determined and elucidated. OBJECTIVE: This study was carried out to evaluate the ability of the three compounds to significantly reduce the biomass of pre-formed biofilms of MRSA and metabolic activity of the bacterial cells in the biofilm. METHODS: The anti-biofilm activity of α-amyrin, betulinic acid and betulinaldehyde, individually and in combination with oxacillin or vancomycin, against reference strain of MRSA in pre-formed biofilm were evaluated using the crystal violet and resazurin assays. RESULTS: α-amyrin and betulinic acid significantly reduced the biomass of pre-formed biofilms of MRSA as individual compounds and in combination with oxacillin or vancomycin. Although betulinaldehyde individually increased the biomass, selected combinations with oxacillin and vancomycin were able to reduce the biomass. All three compounds did not show cytotoxic properties on normal mammalian cells. CONCLUSION: The three pentacyclic triterpenoids could significantly reduce pre-formed biofilm of MRSA with no cytotoxic effects on normal mammalian cells. These findings demonstrated that pentacyclic triterpenoids have the potential to be developed further as antibiofilm agents against MRSA cells in bio-films, to combat infections caused by multidrug-resistant and biofilm-forming S. aureus.