Intraoperative Management: Anaesthesia, Tourniquet, Tranexamic Acid, Blood Loss and Fluid Management

Introduction

The cases of patients suffering from complex knee injuries vary in complexity and severity. These patients may have isolated lower extremity injuries or can present with more complex injury patterns involving multiple organ systems. This dichotomy presents challenges to both the surgical team and the anaesthesia team because patients may be stable for treatment in an outpatient setting with surgical intervention performed on a semielective basis, or they may present in a more urgent manner and require anaesthesia for emergent reduction of a knee dislocation, fasciotomy, vascular repair or early stabilisation with damage control orthopaedics and delayed reconstruction after initial evaluation.

This chapter discusses the perioperative approach to the patient with a complex knee injury and reviews options for anaesthesia (including regional and general anaesthesia), techniques to mitigate blood loss and techniques to maintain appropriate fluid management.

Anaesthesia Considerations for Patients with Knee Injuries

Because of the potential variability of patients receiving care for complex knee injuries, careful coordination between the surgical team and the anaesthesia team must be achieved. Anaesthesia care for complex knee surgery requires increased skill and an orthopaedic anaesthesia provider with proficiency in a wide range of techniques, including general anaesthesia, central neuraxial anaesthesia and peripheral regional anaesthesia. Although many complex knee surgeries are performed on an elective basis, these patients may also present emergently after a polytraumatic injury, and therefore providers must also be comfortable with managing a challenging airway in a wide age range, caring for patients at increased risk for haemodynamic instability and deep venous thrombosis (DVT) or fat emboli, and must be willing to participate in a range of highly variable operative procedures. ^,

When required, patients with complex knee injuries should be evaluated for life-threatening injuries via the advanced trauma life support (ATLS) protocol. If required, preoperative cardiac evaluations (such as electrocardiography) should be considered, and all providers must maintain a high index of suspicion for associated injury patterns in other organ systems in the polytraumatised patient. In all patients the injury history, injury pattern, medical history, anaesthesia history, pertinent imaging related to the injury and any associated comorbid conditions should be reviewed in preparation for appropriate anaesthesia.

Both in the acute setting and at times when surgical intervention can be delayed, surgical coordination is paramount between the surgical and anaesthesia teams. It is important to for the surgeon to communicate with the anaesthesia provider regarding the planned surgical positioning, expected blood loss, potential use of a tourniquet, the nature of the procedure and the pertinent steps, the expected surgical duration and the need for pre- or postoperative regional anaesthesia. When this early communication is accomplished, it allows for appropriate choice of anaesthesia and minimises complications before, during and after surgery.