Mechanisms of myocardial protection by adenosine-supplemented cardioplegic solution: myofilament and metabolic responses

OBJECTIVE: Adenosine supplementation of cardioplegic solutions in cardiac operations improves postarrest myocardial recovery after cardioplegic arrest and reperfusion; however, the mechanism of the action of adenosine remains unknown. We tested the hypotheses that adenosine-supplemented cardioplegic solution improves myofibrillar protein cooperative interaction and increases myocardial anaerobic glycolysis. METHODS: The hearts of male Sprague-Dawley rats were randomized to undergo 120 minutes of cardioplegic arrest with 1 of 3 cardioplegic solutions: (1) St Thomas' Hospital No. 2 cardioplegic solution (St Thomas group), (2) St Thomas' Hospital No. 2 cardioplegic solution plus adenosine (100 micromol/L) (adenosine group), and (3) St Thomas' Hospital No. 2 cardioplegic solution plus adenosine (100 micromol/L) plus the nonspecific adenosine receptor antagonist 8-p -sulfophenyltheophylline (50 micromol/L) (sulfophenyltheophylline group). A fourth group of hearts underwent no cardioplegic arrest. RESULTS: Systolic and diastolic functional recovery was improved in the adenosine group compared with that in the other two groups, independent of coronary flow. Adenosine supplementation of cardioplegic solution prevented the decrease in myofibrillar protein cooperative interaction seen after cardioplegic arrest and reperfusion (St Thomas and sulfophenyltheophylline groups). Adenosine-supplemented cardioplegic solution also caused significantly increased anaerobic glycolysis during cardioplegic arrest. These responses were blocked in the sulfophenyltheophylline group. CONCLUSIONS: The changes in myocardial glycolytic activity and myofilament cooperativity coincided with functional recovery in the three cardioplegia groups and may represent mechanisms underlying protection with adenosine-supplemented cardioplegic solution.     

The Predictive Validity of OMPQ on the Rehabilitation Outcomes for Patients with Acute and Subacute Non-Specific LBP in a Chinese Population

Introduction Early screening of physical and psychosocial risk factors has been advocated as a way to identify low back pain (LBP) patients who may develop chronic disability. This study evaluated the predictive validity of a Chinese version of the Orebro Musculoskeletal Pain Questionnaire (OMPQ) in identifying LBP patients at risk of developing poor return-to-work (RTW) outcomes. Methods Altogether 241 patients with acute or subacute non-specific LBP agreed to participate, and they were screened at baseline with OMPQ, and evaluated after discharge from physiotherapy (n = 173) with outcome measures including the Roland–Morris Disability Questionnaire (RMDQ), numerical pain score (0–10) and global recovery (0–10). At 1-year follow-up, information on RTW status as well as sick leave duration were obtained. Results At baseline the OMPQ had a mean score of 112.0 (SD = 26.5). The receiver operator characteristic (ROC) curves of OMPQ scores at 1-year follow-up recorded values of area under the curve of 0.693 for RTW and 0.714 for sick leave duration, which are comparable to those reported in European studies. OMPQ was the only factor that could significantly predict the RTW outcomes, compared to other variables such as the RMDQ scores. Conclusion The results confirmed the predictive validity of the Chinese version of OMPQ in screening LBP patients at risk of developing poor occupational outcomes, and appropriate interventions can be arranged for these high-risk individuals in the rehabilitation process.     

ALEXIS O‐Ring wound retractor vs conventional wound protection for the prevention of surgical site infections in colorectal resections1

Aim Surgical site infection (SSI) remains a common postoperative morbidity, particularly in colorectal resections, and poses a significant financial burden to the healthcare system. The omission of mechanical bowel preparation, as is performed in enhanced recovery after surgery programmes, appears to further increase the incidence. Various wound protection methods have been devised to reduce the incidence of SSIs. However, there are few randomized controlled trials assessing their efficacy. The aim of this study is to investigate whether ALEXIS wound retractors with reinforced O‐rings are superior to conventional wound protection methods in preventing SSIs in colorectal resections. Methodology Patients undergoing elective open colorectal resections via a standardized midline laparotomy were prospectively randomized to either ALEXIS or conventional wound protection in a double‐blinded manner. A sample size of 30 in each arm was determined to detect a reduction of SSI from 20% to 1% with a power of 80%. Secondary outcomes included postoperative pain. The operative wound was inspected daily by a specialist wound nurse during admission, and again 30 days postoperatively. Statistical analysis was performed using spss version 13 with P < 0.05 considered significant. Results Seventy‐two patients were recruited into the study but eight were excluded. There were no SSIs in the ALEXIS study arm (n = 34) but six superficial incisional SSIs (20%) were diagnosed in the control arm (P = 0.006). Postoperative pain score analysis did not demonstrate any difference between the two groups (P = 0.664). Conclusion The ALEXIS wound retractor is more effective in preventing SSI in elective colorectal resections compared with conventional methods.