Postoperative Incidence of Orthostatic Intolerance and Hypotension in Primary Unicompartmental Knee Arthroplasty (UKA)

Postoperative Incidence of Orthostatic Intolerance and Hypotension in Patients Undergoing Primary Unicompartmental Knee Arthroplasty (UKA)

Incidence and pathophysiologic hemodynamics of orthostatic intolerance and orthostatic hypotension in patients undergoing UKA

In today's multimodal fast-track perioperative care program (ERAS) early mobilization is an essential cornerstone, and is known to prevent postoperative morbidity and lower length of stay in the hospital. Intact orthostatic blood pressure regulation is necessary to complete mobilization, and postoperative orthostatic hypotension (OH), defined as a drop in systolic arterial pressure (SAP) > 20 mmHg or a drop >10 mmHg in diastolic arterial pressure (DAP) and orthostatic intolerance (OI), characterized by dizziness, nausea, feeling warm and syncope related to orthostatic challenge, are well-known reasons for delayed early mobilization, prolonged bedrest and delayed ambulation.

Former studies have been accessing the postoperative incidence in THA-patients (22%-40%), TKA-patients(36%), colorectal patients(53%), abdominal and cardiothoracic surgery patients(40%), radical prostatectomy patients (50%). One study have been accessing the postoperative incidence of OI in mastectomy patients and found an incidence of 4%, and thereby indicating that postoperative OI is not an issue in minor surgery.

This study is the first, to our acknowledgement, which accesses the postoperative incidence of OI/OH in UKA-patients.

Inclusion Criteria:

• Age >18 years and
• Patients undergoing UKA in spinal anesthesia at Hvidovre Hospital in a standardized fast-track setting.
• Patients that speak and understand Danish
• Written informed consent

Exclusion Criteria:

• Pre-existing orthostatic hypotension or intolerance
• Alcohol or substance abuse
• everyday treatment with either anxiolytic or antipsychotic medicine
• Cognitive dysfunction
• If surgery was converted to general anesthesia or total knee arthroplasty.