Enhancing Postoperative Recovery-Prehabilitation for Frail Patients Undergoing Cardiac Surgery

Frailty is a multidimensional syndrome that leads to excessive vulnerability to stressors and is associated with higher risk of adverse postoperative outcomes and higher healthcare costs. Prehabilitation interventions in frail patients may reduce the risks of adverse events and enhance recovery after surgery. This thesis focused on frail cardiac surgical patients. I explored the relationship between muscle bulk, measured by ultrasonography, and the prediction of frailty. I further evaluated the effect of two prehabilitation interventions, a physical prehabilitation programme, and the use of intravenous iron therapy, on postoperative recovery, and other physiological and functional endpoints.Firstly, a prospective cohort study explored the potential use of rectus femoris muscle ultrasonography to assess frailty. Preliminary results are presented in Chapter 2. Muscle thickness, cross-sectional area and echogenicity assessed with ultrasonography was associated with measures of physical performance, and specifically showed a fair-to-excellent diagnostic performance for predicting gait speed test-defined frailty.Secondly, in Chapter 3, a systematic review, I analysed eight randomised controlled trials (n=929), and summarised current evidence on the effectiveness of physical prehabilitation on perioperative outcomes. Prehabilitation may improve perioperative functional capacity and shorten the hospital stay (MD: -0.66 days, 95% CI: -1.29 to -0.03; low-certainty evidence), with uncertain effects on other outcomes.Thirdly, in Chapter 4, I investigated the effect of a prehabilitation programme (structured exercise training and health promotion) compared with standard care on the quality of recovery for frail patients undergoing elective cardiac surgery in a randomised controlled trial. Preliminary data (currently n=63) showed a non-significant, but suggestive effect of prehabilitation on the shortened mechanical ventilation duration, reduced postoperative disability, and improved frailty peri-operatively was observed.Lastly, in chapter 5, a quasi-experimental study design, measured the prevalence of anaemia and iron deficiency in Hong Kong, and the impact of treating iron deficiency with preoperative iron therapy on postoperative recovery. Preliminary findings (currently n=159) indicated that 31.4% of participants were anaemic, with one-third related to iron deficiency. Twenty iron-deficient patients received single-dose intravenous iron isomaltoside, resulting in a significant improvement in haemoglobin concentration (MD: 0.6 g/dL, 95% CI: 0.2 to 1.0; p=0.01) between baseline and the immediate preoperative period. Ferritin concentration and transferrin saturation also improved. Preliminary data indicated possible beneficial effects of iron therapy on postoperative recovery, including more days (alive and) at home within 30 days, and less reduction in the WHODAS score after surgery.In summary, initial data using muscle ultrasonography for measuring muscle bulk as a frailty indicator for the identification of high-risk patients shows some promise. Following the identification of knowledge gaps through a structured review of the current scientific literature on frailty and perioperative cardiac surgical outcomes, further investigations were informed. Specifically, the potentially positive effects of prehabilitation interventions, including physical prehabilitation and intravenous iron therapy were investigated. While the expected positive physiological and functional outcomes of these interventions were detected in our target group, insufficient data has been collected to date to definitively assess perioperative outcomes. However, ongoing patient recruitment is expected to allow a definitive evaluation of the original research questions.衰弱是一種複雜多元的症狀。衰弱病人接受心臟手術後的事故風險較高̖̖、康復時間較長及醫療開支增加。本論文主要考証術前復康治療能否對接受心臟手術的衰弱患者之術後康復及其它圍術期結果有幫助。第一個項目 (第二章)以前瞻性群組研究的前期數據來探討股直肌超聲波檢查運用於評估擇期心臟手術前衰弱症狀的潛在可能性。前期數據顯示超聲波檢查的結果與身體效能表現有關係，並能合理地判斷 (以5米步速評估)術前衰弱症狀。接著，我以系統化的文獻審查研究 (第三章)，評審了八篇關於心臟手術前的運動復康研究 (n=929)來分析運動復康對術圍術期結果之效果。研究發現術前運動復康能有效提升圍術期之身體功能及減少病人的住院時間 (MD: -0.66日, 95% CI: -1.29 to -0.03)，但對其它圍術期結果之效果則未能確定。因此，我推行了一項平行隨機對照試驗 (第四章)來考証術前運動復康對衰弱的擇期心臟手術病人之康復質素是否比日常護理方案較佳。前期數據 (n=63)初步顯示運動復康於縮短術後機械呼吸輔助的時間、改善圍術期之衰弱情況及減低術後殘疾情況上有不顯著的正面趨勢。最後，我透過一項半實驗性研究 (第五章)來考查本地擇期心臟手術病人圍術期之貧血及缺鐵情況，並考証鐵質補充劑 (Iron isomaltoside)靜脈注射對術後結果的影響。前期數據 (n=159)顯示31.4%的參加者於手術前有貧血情況，當中約三成是由缺鐵問題所引致。20位缺鐵病人在手術前接受了一劑鐵質補充劑靜脈注射。前期數據顯示鐵質補充劑能顯著地提升病人體內手術前的血紅素水平 (MD: 0.6 g/dL, 95% CI: 0.2-1.0; p=0.01)、鐵蛋白濃度及運鐵蛋白飽和度，而且初步顯示出對術後康復的潛在好處。總括而言，肌肉超聲波檢查於評估擇期心臟手術病人之衰弱症狀以識別出當中的高危患者有初步正面數據。通過嚴謹的文獻審查，我進一步推行了關於術前復康治療，包括 : 運動復康及鐵質補充劑靜脈注射的研究。雖然論文結果初步顯示出術前復康治療對一些圍術期結果有幫助，但現時仍需待完成這些研究後，才能提供更多數據來考証術前復康治療對高危病人術後康復的效用。YAU, King Wai.Ph.D. Chinese University of Hong Kong 2021.Includes bibliographical references (leaves )Abstracts in English and Chinese.Title from PDF title page (viewed on ...