Safety of Spinal Anesthesia in Patients With Tibial Shaft Fracture

For some of the patients RA may be even more safe than GA. According to a large meta-analysis RA reduces the risk of several complications versus GA.

- Risk of deep vein thrombosis is reduced by 44%

- Risk of pulmonary embolism is reduced by 55 %

- Risk of major bleeding is reduced by 50%

- Risk of post operative pneumonia is reduced by 39%

- Risk of post operative respiratory is reduced by 59%

It is generally thought that RA is safer than GA for example in patients with heart or pulmonary diseases. It is also known that the use of RA reduces postoperative need of opioids, which leads to improved respiratory function and reduced post operative disorientation, delirium and nausea.

Purpose of the study: Our purpose is to gain more information of the safety of RA in patients with tibial fracture. Our hypothesis is that RA is equally safe with GA.

Implementation: Research begins with a pilot study in which RA is compared with GA. There are about 65 tibial fractures operated in our centre every year. We randomize patients to GA group (n=25) and spinal anaesthesia group (n=25). We presume that RA is equally safe with GA. However, power analysis has been made presuming that RA will increase the risk of ACS. We calculated the sample size by assuming that the compartment pressure in RA group is 10 mmHg higher than in the GA group.

GA will be inducted by fentanyl, propofol and rocuronium. GA will be maintained by sevofluran, fentanyl and rocuronium. Spinal-anaesthesia will be performed by using hyperbaric bupivacaine. The dose is 10-15 mg, depending on the needs of the patient. This will maintain RA in lower extremities for 2-4 hours, which is enough to operate a tibial shaft fracture. In both study groups the post-operative pain will be treated by intravenous and peroral oxycodone and paracetamol.

Monitoring and ethics:

- Clinical examination every hour in recovery room (oedema, temperature, cutaneous sensation, distal pulses)

- Continuous pressure-measurement of anterior compartment in the operated leg for 24 hours

- Local oxygen metabolism measured by near-infrared spectroscopy in the operated leg for 24 hours

Patients will be monitored in the recovery room for 24 hours after operation. Blood tests (creatine kinase and myoglobin) will be drawn before operation, when arriving in recovery room, 6 hours and 24 hours after operation in each patient.