Haemodynamic Effects and Complications of Continuous Versus Single-shot Spinal Anaesthesia for HIP Fracture Surgery

Study Flow Diagram.

• Measured Variables, Measurement Scales, and Tools:

• Orthopedic and Anesthesiological Qualification: Conducted according to the standard of care and existing procedures at the participating hospital.
• Baseline Assessment: Performed using the following scales: ASA, Apfel, GCS, RASS, NRS, Bromage, Aldrete, CAM-ICU, and SF-36.
• Baseline Neurological Assessment: Covering all neurological endpoints specified in the point 7
• Anesthesia Method (determined by group randomization):

• Both groups: Ultrasound-guided femoral nerve block with 10 ml of 0.5% ropivacaine.
• Group 1 (Interventional): Continuous spinal anesthesia with titrated doses of 0.5% hyperbaric bupivacaine via an intrathecal catheter. An initial 1 ml induction dose will be administered, followed by 0.5 ml boluses every 15 minutes to achieve a sensory block to the T12 level. Once the block is established, the anesthetic level will be maintained with titrated doses of 0.5-1 ml approximately every hour. The operating table will be kept in a neutral position.
• Group 2 (Control): Single-shot spinal anesthesia with a bolus of 0.5% hyperbaric bupivacaine, with the dose adjusted according to the patient's weight and height to achieve a sensory block to the T12 level. The operating table will be kept in a neutral position.
• Intraoperative Monitoring of Vital Signs:

• Standard Monitoring: Continuous measurement of heart rate (HR) via ECG and arterial oxygen saturation (SpO2) via pulse oximetry, as well as non-invasive blood pressure (NIBP) measured at 3, 5, and 15-minute intervals.
• Advanced Monitoring: Continuous invasive blood pressure (IBP); uncalibrated cardiac output (CO) measurement-calibrated with stroke volume (SV) calculated by echocardiography (LVOT x VTI*); and continuous measurement of stroke volume variation (SVV), pulse pressure variation (PPV), and systemic vascular resistance (SVR) throughout the intraoperative period.

• Calculated as the product of the left ventricular outflow tract (LVOT) area and the velocity time integral (VTI), measured in the parasternal long-axis and apical 5-chamber views, respectively.
• Monitoring in the Post-Anesthesia Care Unit (PACU):

• Continuation of standard vital signs monitoring (HR, BP, SpO2).
• Continuation of advanced hemodynamic monitoring if hemodynamic instability requires a continuous vasopressor infusion; patients will be transferred to the ICU if stabilization is not achieved.
• At discharge from PACU: Assessment using the GCS, RASS, NRS, Aldrete, CAM-ICU, and SF-36 scales, and a neurological assessment covering all endpoints specified in in the point 7 .
• Monitoring on the Orthopedic Ward:

a. At hospital discharge: An SF-36 assessment and a neurological assessment covering all endpoints specified in in the point 7 .

• Assessment of Other Complications: The incidence of other in-hospital complications will be assessed according to established diagnostic criteria if they are suspected to have occurred.
• Follow-up: Conducted at 1, 3, 6, 12, and 24 months post-intervention. A telephone interview will be performed to complete the SF-36 scale and conduct a neurological assessment covering all endpoints specified in the point 7 .
• Complications associated with spinal anesthesia:

• Postoperative nausea and vomiting (PONV)
• Hypothermia
• Total spinal anesthesia
• Cardiac arrest
• Bladder dysfunction
• Back pain
• Transient neurological symptoms (TNS)
• Post-dural puncture headache (PDPH)
• Headache other than PDPH
• Peripheral nerve palsy
• Cauda equina syndrome
• Spinal hematoma or hygroma
• Intracranial hypotension syndrome
• Central nervous system infection
• Other

Inclusion criteria

• Age > 50 years, regardless of gender
• Diagnosis of a proximal femur fracture
• Orthopedic qualification for open reduction and internal fixation of the fracture
• Informed consent for the surgical procedure
• Informed consent for regional anesthesia, i.e., a central neuraxial block (spinal anesthesia)
• Informed consent to participate in the study

Exclusion criteria

• Age < 50 years, regardless of gender
• Refusal to consent to surgical treatment
• Refusal to consent to regional anesthesia
• Refusal to consent to participate in the study
• Inability to provide informed consent
• Allergy to local anesthetic agents
• Severe congenital or acquired coagulation disorders
• Failure to meet the recommended time interval between the last dose of an anticoagulant and central neuraxial blockade, according to the 2022 European Journal of Anaesthesiology (EJA) guidelines
• Infection at the block site or a systemic infection (i.e., sepsis, septic shock)
• Patients with multiple organ dysfunction syndrome requiring hospitalization in the Intensive Care Unit for stabilization of vital functions
• Clinical signs of increased intracranial pressure or suspicion of an intracranial mass on imaging studies
• Other contraindications to spinal anesthesia as judged by the qualifying physician