Delirium after cardiac surgery: have we overlooked obstructive sleep apnea?

Overexpression of TRPM7 contributes promotesto the therapeutic effect of curcumin in treatmentprocess of wound healing through STAT3/SMAD3 signaling pathway in human fibroblasts

OBJECTIVE

Curcumin, a natural extract from the rhizomes of Curcuma longa, is also known as a curcuminoid. Curcumin has been studied as a therapeutic drug for wound healing because of its anti-inflammatory, anti-oxidant, and anti-bacterial activities. However, the detailed mechanism of curcumin in wound healing is not clear. It is well-known that the skin is the largest organ in humans and prevents tissues from damage, including infection, radiation, and mechanical damage. Wound healing of the skin is a complex physiological regulation process requiring various cell types and cytokines; hence, wound healing, including surgery and care, incurs a huge expenditure each year. Transient receptor potential cation channel subfamily M member 7 (TRPM7) regulates multiple physiological and pharmacological processes through its channel and kinase activities. In addition, TRPM7 regulates cell adhesion, migration, and anti-oxidative activity, thereby playing a regulatory role in the wound healing process. This study aimed to explore the function of curcumin in the wound healing process.

METHODS

We first established TRPM7 overexpression and knockdown models in fibroblasts using lentivirus. CCK-8 and wound healing assays were used to clarify whether overexpression of TRPM7 promoted proliferation and migration in fibroblasts. Expression of target genes and proteins was detected using qPCR and western blotting. Concentrations of migration-related cytokines were measured using ELISA.

RESULTS

Proliferation and migration of fibroblasts increased after curcumin treatment and was further enhanced after overexpression of TRPM7. In addition, expression of proliferation-related genes and proteins was elevated after TRPM7 overexpression. Further, the secretion of migration-related cytokines was elevated after TRPM7 overexpression.

CONCLUSION

Curcumin treatment promoted proliferation and migration of fibroblasts, and these effects were mediated by the signal transducer and activator of transcription 3 (STAT3)/SMAD family member 3/hypoxia-inducible factor 1 subunit alpha signaling pathway. Thus, we conclude that overexpression of TRPM7 might contribute to wound healing.

A prospective five-year cohort study of undiagnosed sleep apnea in patients undergoing coronary artery bypass graft surgery

BACKGROUND

We aimed to study prospectively the nature and effect of sleep apnea-hypopnea syndrome (SAHS) in patients undergoing coronary artery bypass graft (CABG) surgery over five years of follow-up.

METHODS

Patients undergoing CABG surgery (N.=145) were assessed longitudinally (baseline, 1 year, and 5 years post-surgery) using the 'STOP-BANG' screen of sleep apnea risk. Additionally, all patients had a preoperative multiple-channel sleep-study, providing acceptable data for an obstructive and central apnea, and desaturation index in 97 patients.

RESULTS

Preoperatively, over half (63%) of patients obtained an apnea-hypopnea index score (combining apnea types) in the moderate-severe range for SAHS, and STOP-BANG threshold score (>3/8) was reached by most (95%) patients. Despite some improvement in 'STOP symptoms' at 1-year follow-up, most patients (98%) remained at risk of SAHS at 5 years post-surgery. There was an underlying and chronic relationship between STOP-BANG score and cardiac symptoms at both baseline and 5-year follow-up. Additionally, SAHS variables were associated with greater incidence of acute postoperative events, and generally with increased length of stay on the intensive care unit.

CONCLUSIONS

We confirm that SAHS is common in CABG-surgery patients, presenting additional clinical challenges and cost implications. The underlying pathophysiology is complex, including upper airway obstruction and cardiorespiratory changes of heart failure. In patients presenting for CABG-surgery, we show chronic susceptibility to SAHS, likely associated with traditional risk factors e.g. obesity but perhaps also with gradual decline in heart function itself. Superimposed on this, there is potential for exacerbated risk of morbidity at the time of CABG surgery itself.

Obstructive sleep apnea as an independent predictor of postoperative delirium and pain: protocol for an observational study of a surgical cohort

Introduction: Postoperative delirium and pain are common complications in adults, and are difficult both to prevent and treat. Obstructive sleep apnea (OSA) is prevalent in surgical patients, and has been suggested to be a risk factor for postoperative delirium and pain. OSA also might impact pain perception, and alter pain medication requirements. This protocol describes an observational study, with the primary aim of testing whether OSA is an independent predictor of postoperative complications, focusing on (i) postoperative incident delirium and (ii) acute postoperative pain severity. We secondarily hypothesize that compliance with prescribed treatment for OSA (typically continuous positive airway pressure or CPAP) might decrease the risk of delirium and the severity of pain. Methods and analysis: We will include data from patients who have been enrolled into three prospective studies: ENGAGES, PODCAST, and SATISFY-SOS. All participants underwent general anesthesia for a non-neurosurgical inpatient operation, and had a postoperative hospital stay of at least one day at Barnes Jewish Hospital in St. Louis, Missouri, from February 2013 to May 2018.  Patients included in this study have been assessed for postoperative delirium and pain severity as part of the parent studies. In the current study, determination of delirium diagnosis will be based on the Confusion Assessment Method, and the Visual Analogue Pain Scale will be used for pain severity. Data on OSA diagnosis, OSA risk and compliance with treatment will be obtained from the preoperative assessment record. Other variables that are candidate risk factors for delirium and pain will also be extracted from this record. We will use logistic regression to test whether OSA independently predicts postoperative delirium and linear regression to assess OSAs relationship to acute pain severity. We will conduct secondary analyses with subgroups to explore whether these relationships are modified by compliance with OSA treatment.

Association between Serum IGF-I levels and Postoperative Delirium in Elderly Subjects Undergoing Elective Knee Arthroplasty

Evidence is mixed for an association between serum insulin-like growth factor-I (IGF-I) levels and postoperative delirium (POD). The current study assessed preoperative serum IGF-I levels as a predictor of incident delirium in non-demented elderly elective knee arthroplasty patients. Preoperative serum levels of total IGF-I were measured using a commercially available Human IGF-I ELISA kit. POD incidence and severity were determined using DSM-IV criteria and the Delirium Rating Scale-Revised-98 (DRS-R98), respectively. Median IGF-I levels in delirious (62.6 ng/ml) and non-delirious groups (65.9 ng/ml) were not significantly different (p = 0.141). The ratio (95% CI) of geometric means, D/ND, was 0.86 (0.70, 1.06). The Hodges-Lehmann median difference estimate was 7.23 ng/mL with 95% confidence interval (−2.32, 19.9). In multivariate logistic regression analysis IGF-I level was not a significant predictor of incident POD after correcting for medical comorbidities. IGF-I levels did not correlate with DRS-R98 scores for delirium severity. In conclusion, we report no evidence of association between serum IGF-I levels and incidence of POD, although the sample size was inadequate for a conclusive study. Further efforts to investigate IGF-I as a delirium risk factor in elderly should address comorbidities and confounders that influence IGF-I levels.