Use of non-invasive cardiac out monitoring for optimization of hemodynamic parameters versus standard care in geriatric patients with hip fractures undergoing surgery under spinal anaesthesia. A Pilot Study

Hip fractures among the geriatric population are a major cause of morbidity and mortality, and the one-year mortality rate after hip fractures estimated to be as high as 30%. The worldwide annual incidence of hip fractures is estimated to be about 1.6 million and is expected to increase to 2.6 million by the year 2025 and 4.5 million by 2050 due to the aging population. The true figures on the incidence of hip fractures in India is lacking, though the annual incidence is estimated to be over 120 fractures per 100,000 persons over the age of 50, with higher rates in women.

Anesthetists play a very important role in the perioperative care of these patients. Intertrochanteric fractures carry distinctive challenges for the anesthetists as geriatric patients might harbor significant comorbidities, moreover, the incidence of these comorbidities has increased during the past years. After hip fracture, in-hospital mortality ranges from 2.3 to 13.9%, but the risk persists beyond the immediate surgical period with 6-month mortality rates ranging from 12 to 23%.Three in four hip fracture-associated deaths may be causally related to preexisting medical conditions rather than the fracture itself. This indicates that the hip fracture destabilizes a frail elderly population with a high burden of preexisting morbidities, thereby resulting in excess mortality.

Many improvements have been introduced in the care of these patients, including improved surgical devices, earlier mobilization, prophylactic administration of antibiotics and anticoagulant, as well as increased rate of admission into rehabilitation unit. A careful preoperative assessment is usually recognized as essential in these patients to stabilize coexisting medical conditions and to optimize cardiovascular and respiratory functions**.** The anesthesiologist should distinguish the preoperative elements that required correction (dehydration, occult hypovolemia, anemia, hypoxia, electrolyte disturbances, and arrhythmias) and those that could modify the postoperative course of the patient (cognitive disorders, chronic cardiac, respiratory, and renal failure).

Various studies attempting to improve outcome through fluid optimization protocol has shown conflicting results. White et al demonstrated that the incidence of hypotension was significant with 56% of patients undergoing neck of femur (NOF) repair having a systolic blood pressure of less than 90 mmHg, and one third having a mean arterial pressure (MAP) of less than 55 mmHg.  Since intraoperative hypotension is associated with adverse events, optimization of hemodynamics using noninvasive cardiac output monitoring may be a valid treatment strategy in this group. Therefore, the aim of the study is to investigate the role of hemodynamic optimization in geriatric patients undergoing surgical repair of inter-trochanteric femoral fractures and the effects of this on length of stay. Secondary outcomes included post operative complications, ICU admission rate, the length of ICU stay, the incidence of hypotension and the use of vasopressors and fluids.