Short-term Effects of Alfacalcidol on Hospital Length of Stay in Patients Undergoing Valve Replacement Surgery: A Randomized Clinical Trial

Role of vitamin D supplementation in modifying outcomes after surgery: a systematic review of randomised controlled trials

BACKGROUND

There is increasing evidence to suggest vitamin D plays a role in immune and vascular function; hence, it may be of biological and clinical relevance for patients undergoing major surgery. With a greater number of randomised studies being conducted evaluating the impact of vitamin D supplementation on surgical patients, it is an opportune time to conduct further analysis of the impact of vitamin D on surgical outcomes.

METHODS

MEDLINE, EMBASE and the Cochrane Trials Register were interrogated up to December 2023 to identify randomised controlled trials of vitamin D supplementation in surgery. The risk of bias in the included studies was assessed using the Cochrane Risk of Bias tool. A narrative synthesis was conducted for all studies. The primary outcome assessed was overall postoperative survival.

RESULTS

We screened 4883 unique studies, assessed 236 full-text articles and included 14 articles in the qualitative synthesis, comprising 1982 patients. The included studies were highly heterogeneous with respect to patient conditions, ranging from open heart surgery to cancer operations to orthopaedic conditions, and also with respect to the timing and equivalent daily dose of vitamin D supplementation (range: 0.5-7500 mcg; 20-300 000 IU). No studies reported significant differences in overall survival or postoperative mortality with vitamin D supplementation. There was also no clear evidence of benefit with respect to overall or intensive care unit length of stay.

DISCUSSION

Numerous studies have reported the benefits of vitamin D supplementation in different surgical settings without any consistency. However, this systematic review found no clear evidence of benefit, which warrants the supposition that a single biological effect of vitamin D supplementation does not exist. The observed improvement in outcomes in low vitamin D groups has not been convincingly proven beyond chance findings.

TRIAL REGISTRATION NUMBER

CRD42021232067.

The effects of vitamin D on all-cause mortality in different diseases: an evidence-map and umbrella review of 116 randomized controlled trials

Purpose

To conduct a solid evidence by synthesizing meta-analyses and updated RCTs about the effects of vitamin D on all-cause mortality in different health conditions.

Methods

Data sources: Pubmed, Embase, Web of Science, the Cochrane Library, Google Scholar from inception until 25th April, 2022. Study selection: English-language, meta-analyses and updated RCTs assessing the relationships between vitamin D and all-cause mortality. Data synthesis: Information of study characteristics, mortality, supplementation were extracted, estimating with fixed-effects model. A Measurement Tool to Assess Systematic Reviews, Grading of Recommendations Assessment, Development and Evaluation, and funnel plot was used to assess risk of bias. Main outcomes: All-cause mortality, cancer mortality, cardiovascular disease mortality.

Results

In total of 27 meta-analyses and 19 updated RCTs were selected, with a total of 116 RCTs and 149, 865 participants. Evidence confirms that vitamin D reduces respiratory cancer mortality (RR, 0.56 [95%CI, 0.33 to 0.96]). All-cause mortality is decreased in patients with COVID-19 (RR, 0.54[95%CI, 0.33 to 0.88]) and liver diseases (RR, 0.64 [95%CI, 0.50 to 0.81]), especially in liver cirrhosis (RR, 0.63 [95%CI, 0.50 to 0.81]). As for other health conditions, such as the general health, chronic kidney disease, critical illness, cardiovascular diseases, musculoskeletal diseases, sepsis, type 2 diabetes, no significant association was found between vitamin D and all-cause mortality.

Conclusions

Vitamin D may reduce respiratory cancer mortality in respiratory cancer patients and all-cause mortality in COVID-19 and liver disorders' patients. No benefits showed in all-cause mortality after vitamin D intervention among other health conditions. The hypothesis of reduced mortality with vitamin D still requires exploration.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=252921, identifier: CRD42021252921.

Strategies for post–cardiac surgery acute kidney injury prevention: A network meta-analysis of randomized controlled trials

Objects

Cardiac surgery is associated with acute kidney injury (AKI). However, the effects of various pharmacological and non-pharmacological strategies for AKI prevention have not been thoroughly investigated, and their effectiveness in preventing AKI-related adverse outcomes has not been systematically evaluated.

Methods

Studies from PubMed, Embase, and Medline and registered trials from published through December 2021 that evaluated strategies for preventing post–cardiac surgery AKI were identified. The effectiveness of these strategies was assessed through a network meta-analysis (NMA). The secondary outcomes were prevention of dialysis-requiring AKI, mortality, intensive care unit (ICU) length of stay (LOS), and hospital LOS. The interventions were ranked using the P-score method. Confidence in the results of the NMA was assessed using the Confidence in NMA (CINeMA) framework.

Results

A total of 161 trials (involving 46,619 participants) and 53 strategies were identified. Eight pharmacological strategies {natriuretic peptides [odds ratio (OR): 0.30, 95% confidence interval (CI): 0.19–0.47], nitroprusside [OR: 0.29, 95% CI: 0.12–0.68], fenoldopam [OR: 0.36, 95% CI: 0.17–0.76], tolvaptan [OR: 0.35, 95% CI: 0.14–0.90], N-acetyl cysteine with carvedilol [OR: 0.37, 95% CI: 0.16–0.85], dexmedetomidine [OR: 0.49, 95% CI: 0.32–0.76;], levosimendan [OR: 0.56, 95% CI: 0.37–0.84], and erythropoietin [OR: 0.62, 95% CI: 0.41–0.94]} and one non-pharmacological intervention (remote ischemic preconditioning, OR: 0.76, 95% CI: 0.63–0.92) were associated with a lower incidence of post–cardiac surgery AKI with moderate to low confidence. Among these nine strategies, five (fenoldopam, erythropoietin, natriuretic peptides, levosimendan, and remote ischemic preconditioning) were associated with a shorter ICU LOS, and two (natriuretic peptides [OR: 0.30, 95% CI: 0.15–0.60] and levosimendan [OR: 0.68, 95% CI: 0.49–0.95]) were associated with a lower incidence of dialysis-requiring AKI. Natriuretic peptides were also associated with a lower risk of mortality (OR: 0.50, 95% CI: 0.29–0.86). The results of a sensitivity analysis support the robustness and effectiveness of natriuretic peptides and dexmedetomidine.

Conclusion

Nine potentially effective strategies were identified. Natriuretic peptide therapy was the most effective pharmacological strategy, and remote ischemic preconditioning was the only effective non-pharmacological strategy. Preventive strategies might also help prevent AKI-related adverse outcomes. Additional studies are required to explore the optimal dosages and protocols for potentially effective AKI prevention strategies.

The Effect of Vitamin D Supplementation on Clinical Outcomes for Critically Ill Patients: A Systemic Review and Meta-Analysis of Randomized Clinical Trials

Purpose: Vitamin D deficiency is a common scenario in critically ill patients and has been proven to be associated with poor outcomes. However, the effect of vitamin D supplementation for critically ill patients remains controversial. Thus, we conducted a meta-analysis to evaluate the effect of vitamin D supplementation among critically ill patients. Methods: Electronic databases PubMed, Embase, Scopus, and the Cochrane Library were searched for eligible randomized controlled trials between 2000 and January 2021. The primary outcome was overall mortality, and the secondary ones were the length of intensive care unit stay, the length of hospital stay, as well as the duration of mechanical ventilation. Subgroup analyses were performed to explore the treatment effect by type of admission, route of administration, dose of supplemented vitamin D, and the degree of vitamin D deficiency. Results: A total of 14 studies involving 2,324 patients were finally included. No effect on overall mortality was found between vitamin D supplementation and control group [odds ratio (OR), 0.73; 95% CI, 0.52-1.03; I ² = 28%]. The vitamin D supplementation reduced the length of intensive care unit stay [mean difference (MD), -2.25; 95% CI, -4.07 to -0.44, I ² = 71%] and duration of mechanical ventilation (MD, -3.47; 95% CI, -6.37 to -0.57, I ² = 88%). In the subgroup analyses, the vitamin D supplementation for surgical patients (OR, 0.67; 95% CI, 0.47-0.94; I ² = 0%) or through parenteral way (OR, 0.42; 95% CI, 0.22-0.82, I ² = 0%) was associated with reduced mortality. Conclusion: In critically ill patients, the supplementation of vitamin D has no effect on overall mortality compared to placebo but may decrease the length of intensive care unit stay and mechanical ventilation. Further trials are necessary to confirm our findings.