Hip fracture is the most common serious injury in the elderly and the one that causes the greatest functional impairment and loss of mobility in the short and long term (6). It is also associated with the occurrence of post-surgical morbidities (15) and, to a lesser extent, hospital mortality, although hospital mortality may have increased during the years 2020–2021 due to the COVID-19 pandemic (16). However, there are few studies that evaluate complications prior to surgery in this population. This is because there is an early surgical treatment standard of 36 hours established by the National Institute for Health and Care Excellence (NICE) in 2014 (6,17) that is not adequately met in our country due to the current socio-sanitary condition (12).
Prevalence of preoperative complications in older adults with hip fractures.
Preoperative complications occurred in 26.9% of adults. This prevalence is lower than that reported by Palomino in Lima with 62% (12) and Barrios in Mexico with 67% (11). Additionally, the reported complications are mostly post-surgical, as the Spanish study by Bielsa found 71% (9) and the Spanish registries in 2019 considered the prevalence of pressure injuries at 7.2% (14) and the English NHFD registry found 38% of post-surgical delirium in 2022 (13). This prevalence could be explained by under-reporting of these complications due to prolonged emergency waiting time, and especially under-reporting of delirium as a pre-surgical complication.
Among the main pre-surgical complications, infectious complications are the most frequent. Pneumonia and sepsis were the most frequent major complications, and urinary tract infections were the most frequent minor ones. Similar results were found in a study from the United Kingdom, where the complications, in this case post-surgical, were infectious, followed by cardiovascular complications. The diagnosis of delirium was less frequent at 7.6% than in our study with 10.3% (15). However, only septic complications were associated with delayed surgery (18).
Clinical factors are associated with preoperative complications in older adults with hip fractures.
Our study found an increased risk of developing a surgical complication in patients with functional red cross > = 3 points, glucose on admission, and minimally in females in older adults with hip fracture.
Age and gender have been evaluated as predictors of mortality and post-surgical complications in several studies. A study in the USA considered male sex and especially age as predictors of mortality (19), as did a study in Japan where age over 90 years was associated with major postoperative complications overall (20). Higashikawa, in another study with a Japanese population, attributed female sex as a predictor of aspiration pneumonia (21). Although our study found no association between age and the presence of complications in both bivariate and multivariate analyses, our population was mostly older than 80 years, which demographically may lead to a higher frequency of female sex or the greater presence of an unstudied entity such as frailty.
The presence of comorbidities impacts the development of post-surgical complications. Chronic kidney disease has been associated with mortality from post-surgical pneumonia, with follow-ups up to 8 months (22). Chronic obstructive pulmonary disease, heart failure, and advanced cancer also appear to increase the risk of major complications (pulmonary, renal, cardiac, and sepsis) (18). Although our study did not find a clinical association in the adjusted analysis with any comorbidity, nor with multimorbidity, an Italian study, where in-hospital mortality was assessed as an outcome, found that multimorbidity was associated with this event (23).
Although a high body mass index (BMI) has not been associated with complications, it may increase preoperative time and hospital stay (24), with the exception of BMI greater than 40, where increased respiratory and dermal complications have been reported (25).
Our study found an association between the number of geriatric syndromes present in each patient and pre-surgical complications, without finding a clinical association in the adjusted model or a specific association with depression, visual deprivation, dependence, or mobility. However, our study finds that a mental red cross scale score > = 3 points equating to moderate to severe dementia increased the risk of pre-surgical complications by more than 4-fold. Several studies have assessed geriatric syndromes such as cognitive impairment and disability in hip fracture patients. A Japanese study found that a history of cognitive impairment and dependence on basic activities, as measured by the Barthel index, can predict the occurrence of aspiration pneumonia (21). Functional dependence and impaired mobility have also been associated with increased mortality at 30 days and 3 months, respectively (18,23), but not with preoperative complications. Mosk et al., in a Dutch population study, found that dementia and a previous history of delirium were predictors of perioperative delirium and that the presence of dementia was associated with more than one complication (26). This association could be due to the fact that, although delirium was the third most frequent preoperative complication found in our study, the presence of dementia increases the risk of developing delirium by being a predisposing factor and making these patients more vulnerable even to other complications due to their poor nutritional status and functional dependence.
Laboratory factors associated with preoperative complications in older adults with hip fractures.
Laboratory parameters may play a role in the development of pre- and post-surgical complications. Although we did not find an association between the parameters of the leukocyte formula, glycemia on admission may increase the risk of developing pre-surgical complications in a minimal (1%) but significant way. Other authors, such as Shuai, determined that a neutrophil/lymphocyte index greater than 4.85 is related to post-surgical delirium (27).