Postoperative Orthostatic Intolerance and Hypotension in Unilateral TKA

Study Overview
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Brief Summary
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Incidence of Postoperative Orthostatic Intolerance and Postoperative Orthostatic Hypotension in Patients Undergoing Unilateral Total Knee Arthroplasty

Detailed Description
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Early postoperative mobilization is a cornerstone in the so-called fast track multimodal perioperative approach and is essential in preventing postoperative morbidity and reducing hospital length-of-stay. Intact orthostatic blood pressure regulation is essential for early postoperative mobilization. However, early postoperative mobilization can be delayed due to postoperative orthostatic hypotension (POH) defined as a fall in systolic pressure > 20 mmHg and/or diastolic pressure > 10 mmHg or due to postoperative orthostatic intolerance (POI), characterized by dizziness, nausea, vomiting, blurred vision or syncope during mobilization. Previous prospective studies of major surgery have reported that OI and OH are common problem during early postoperative mobilization, with a prevalence of 42-50%. Retrospective studies with a less-defined mobilization protocols have reported am OI prevalence in the range of 12-60 % across surgical procedures. The aim of our study is to determine the incidence of OI during early postoperative mobilization in fast track unilateral total knee arthroplasty.

Official Title
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Incidence of Postoperative Orthostatic Intolerance and Postoperative Orthostatic Hypotension in Patients Undergoing Unilateral Total Knee Arthroplasty

Conditions
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Orthostatic Intolerance, Orthostatic Hypotension, Postoperative Complications

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥ 18 Written informed consent Patients that speak and understand Danish Patients undergoing primary unilateral total knee arthroplasty in spinal anesthesia and standardized fast-track setting Exclusion Criteria: Alcohol or drug abuse Cognitive dysfunction Known orthostatic hypotension Use of anxiolytic drugs

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Orthostatic intolerant (OI)<br>Patients that experience symptoms of orthostatic intolerance (dizziness, nausea, vomiting, blurry vision or syncope) or orthostatic hypotension (fall in systolic pressure > 20 mmHg and/or diastolic pressure > 10 mmHg) during mobilisation | |
| Orthostatic tolerant (OT)<br>Patients that do not experience symptoms of orthostatic intolerance (dizziness, nausea, vomiting, blurry vision or syncope) or orthostatic hypotension (fall in systolic pressure > 20 mmHg and/or diastolic pressure > 10 mmHg) during mobilisation | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of orthostatic intolerance | Symptoms of orthostatic intolerance: dizziness, nausea, vomiting, blurry vision or syncope during mobilization | 6 hours postoperatively | 
| Incidence of orthostatic hypotension | Orthostatic hypotension is defined as a fall in systolic pressure > 20 mmHg and/or diastolic pressure > 10 mmHg during mobilization | 6 hours postoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in systolic arterial pressure (SAP) during mobilization | Measured in mmHg | Preoperatively, 6 and 24 hours postoperatively | 
| Changes in diastolic arterial pressure (DAP) during mobilization | Measured in mmHg | Preoperatively, 6 and 24 hours postoperatively | 
| Changes in mean arterial pressure (MAP) during mobilization | Measured in mmHg | Preoperatively, 6 and 24 hours postoperatively | 
| Changes in systemic vascular resistance (SVR) during mobilization | Measured in mmHg⋅min⋅mL-1 | Preoperatively, 6 and 24 hours postoperatively | 
| Changes in cardiac output (CO) during mobilization | Measured in mL/min | Preoperatively, 6 and 24 hours postoperatively | 
| Changes in stroke volume (SV) during mobilization | Measured in mL | Preoperatively, 6 and 24 hours postoperatively | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Orthostatic Intolerance, Orthostatic Hypotension, Knee arthroplasty