With this study, the investigators intend to measure oxygen saturation before and after hip surgery in the context of proximal femur fracture, comparing two types of anesthesia (general or spinal). The investigators also intend to study the effects of the two anesthetic techniques on sleep apnea, delirium, respiratory complications, and length of hospital stay.

This is an observational study, in which oxygen is measured at the fingertip with a sensor and a bracelet, without any intervention, inconvenience, or discomfort for the participant. Data will be collected on: respiratory complications, sleep apnea, delirium, length of hospital stay, and survival.

Data will be collected in the operating room and wards of Santa Maria Hospital, Lisbon, Portugal over a period of approximately 24 hours after the participant's operation. Information about participant's health and co-morbidities will be recorded.

There will be no implication for the participants' clinical care, since the study measurements will not be sent to the health professionals in charge. The operation, recovery, and treatments will not be influenced at any time by participation in the study.

Frailty, comorbidities, medication (anticoagulants and anti-platellet agents) as well as acute and chronic illnesses have an impact on the choice of anesthesia strategy for hip fracture surgery. The choice between general anesthesia (GA) and loco-regional, spinal anesthesia (SA) may have impact on the postoperative period. Despite previous retrospective studies on this topic, it remains uncertain that either is superior in terms of post-operative outcomes, including mortality, delirium and respiratory complications, with conflicting results in the literature.

Postoperative pulmonary complications (PPC) are amongst the commonest complications in geriatric hip fractures, reported to be around 12%. The elder population at Hospital de Santa Maria (Tertiary University Hospital Center) receives the most challenging cases, with pilot data from the past 3 years (2022-2024, n=927) revealing an average risk score for PPC of 32,1%.

Considering that low oxygen saturation is an independent risk factor and a strong predictor for PPC, the investigators seek to compare the oxygenation during the perioperative period between the different anesthesia regimens.

The study hypothesis is that the anesthesia regimen (GA vs SA) has an impact on the oxygenation index during the first 24 postoperative hours.

The secondary objectives are to compare the sleep apnea index between GA and SA, the incidence of PPC, delirium, mortality and the length of stay (LOS) in the PACU and until discharge from the hospital.

Inclusion Criteria:

• hospital admission for hip fracture;
• scheduled for hip fracture surgery;
• age above 65 years, both genders;
• capable of consent or consent by responsible person;

Exclusion Criteria:

• hip fracture during hospitalization (not present upon admission)
• patient refusal to participate

Elder subjects with hip-fracture submitted to surgery.

only anonymised data can be shared after publication and upon reasonable request