The impact of hospital length of stay
Understanding the relationship between anaemia and surgical outcomes is a complex model to comprehend with the multiple covariates that come associated with low haemoglobin levels. For example, Table 2 shows the increase incidence of anaemia with increasing age (P < 0.001), but it is possible that increasing age alone could bring its own challenges when considering co-morbidities (such as coronary artery disease), frailty and social circumstances. Consequently, when interpreting the results, it is perhaps fair to suggest that the relationships be considered more as an additive contribution rather than a stand-alone single causative characteristic[8].
Considering the LOS in this study, the evidence concludes that non-anaemic patients had a statistically significant reduced hospital length of stay than the anaemic patients undergoing major lower limb surgery (primary hip and knee replacements). Studies have shown that an enhanced recovery programme (ERP) can reduce length of stay[20,21], and many hospitals within the UK now deploy an enhanced recovery programme which include a multidisciplinary approach to the patient’s overall care. This includes pre-operative assessment to optimise patients medically, looking at anaesthetic techniques to reduce post-operative pain, early mobilisation with the aid of physiotherapists, and surgical techniques. This study focuses on the pre-optimisation of anaemia, just one significant aspect of the ERP given the population that present with anaemia in this cohort.
However, as stated previously, this particular characteristic cannot be taken in isolation, and must be considered as an additive variable. Studies have shown that anaesthetic technique for lower limb joint replacements can alter the patient experience and the surgical outcomes as well[21]. For example, the use of general anaesthesia has shown to increase the requirements of post-operative opiate use for analgesia[22], which can lead to an increase incidence of post-operative nausea and vomiting as well as a reluctance and difficulty in early mobilisation due to pain – both of which can increase hospital length of stay[23]. In this study, we did not examine the type of anaesthesia used in all patients, the type of opiate used intrathecally for regional techniques (short acting fentanyl vs longer acting diamorphine) and the dose it was used in, and nor did we evaluate the concomitant use of non-steroidal anti-inflammatory drugs (NSAIDs) which may often be omitted in patients whose conditions may contraindicate its use. Likewise, taking into consideration surgical techniques, we did not review the use of local anaesthetic infiltration into the surgical site as recommended by the Hillingdon and Mount Vernon rapid recovery programme anaesthesia and analgesia guideline published in 2014 (Figure 2).
Figure 2: