Abstract
The letter to the editor suggested several questions regarding the methodology of the recent article by Lam et al who determined effect of multicomponent care bundle on the development of postoperative delirium. This article is published in Geriatric Orthopaedic Surgery & Rehabilitation
In an observational study including 154 geriatric patients with hip fracture surgery, Lam et al 1 assessed effect of multicomponent care bundle (MCB) on the development of postoperative delirium (POD) and showed that MCB effectively reduced POD, postoperative dizziness, opioid consumption, and days to start mobilization. Other than the limitations described by the authors in discussion section, however, there are several issues in this article on which we wish to invite the authors to comment.
First, study subjects are geriatric patients undergoing hip fracture surgery, with a mean age of >80 years and the incidence of preoperative delirium was significantly higher in the control group than in the MCB group (16% vs 4%, P = .014). However, the readers were not provided with the details of preoperative assessment on neurocognitive function, hearing and vision. Other than preoperative delirium, available evidence indicates that preoperative cognitive impairment, dementia, depression, anxiety, poor hearing, and vision are well-established predisposing factors for POD in geriatric patients with hip fracture surgery. 2 We are concerned that not taking these preoperative risk factors into account would have biased the findings of this study.
Second, mode of anesthesia was significantly different between groups, but the authors did not provide the details of anesthetic and intraoperative managements. Thus, it is difficult for readers to determine the extents to which anesthetic and intraoperative managements might have influenced on the development of POD. It has been shown that time between admission and surgery, type of surgery, durations of surgery and anesthesia, intraoperative mass blood loss and blood transfusions, hypoxia, and use of midazolam and vasopressor drugs are significantly associated with an increased risk of POD in geriatric patients with hip fracture surgery.3,4
Third, postoperative pain at rest and during movement was measured by numeric rating scale and median postoperative pain scores were comparable in both groups, but protocol of postoperative analgesia was not provided. As POD occurring within 5 days after surgery was assessed, we believe that analgesic effect of ultrasound-guided fascia iliaca block performed by anesthetic team before surgery may not persist throughout the observed period and other analgesic measures may have been given. In available literature, type and number of drugs used for postoperative analgesia have actually been associated with the development of POD after hip fracture surgery.4,5 In the absence of comparisons of postoperative analgesia protocols and drugs between groups, thus, we argue that findings of this study about postoperative dizziness and opioid consumption must be interpreted with caution as they may have been obtained using incomplete methodology.
Finally, MCB significantly reduced the development of POD and decreased postoperative days to start mobilization, but postoperative medical complications, extended stay in hospital, and length of hospital stay were not significantly different between groups. As POD has been significantly associated with more and worse postoperative adverse outcomes of geriatric patients undergoing hip fracture surgery, 6 the author should reasonably explain this counterintuitive finding why beneficial effect of MCB to decrease the risk of POD cannot be transformed into the improved outcomes of patients.
