How Much Fluid Should TKA Patients Receive Perioperatively?
Orthopaedic surgeons know that not all of the perioperative practices they follow in managing total joint arthroplasty patients are backed by sound evidence. In many cases, these practices have evolved from surgeon preference, the influence of mentors, or a “we’ve always done it that way” mentality.
That’s why studies challenging the status quo in orthopaedic practice are so important: New research can either confirm or debunk common ways of managing patients, contributing to safer care and better patient outcomes.
The latest practice to be examined in a prospective, randomized trial is perioperative fluid management in total knee arthroplasty (TKA) patients. The study explores the optimum amount of perioperative fluids that will ensure hydration without causing complications. Lead author Jason M. Jennings, MD, of Colorado Joint Replacement in Denver, received the James A. Rand Young Investigator’s Award at the 2019 AAHKS Annual Meeting for this study.
Dr. Jennings and his colleagues were prompted to conduct this study by the seemingly arbitrary way in which intraoperative and postoperative fluids are administered in joint replacement patients, as well as the lack of evidence to guide practice.  This can cause problems for surgical patient: The evidence in major abdominal surgery, for example, suggests that large amounts of intravenous (IV) fluid may increase morbidity and hospital length of stay. 
Similar side effects have been observed by Dr. Jennings and his colleagues in joint replacement patients, including fluid overload that led to either prolonged hospitalization or readmission due to medical complications.  Fluid overload can also lead to wound healing complications secondary to fluid shifts, Dr. Jennings said. 
For this study, Dr. Jennings and his colleagues randomized 130 patients age 18 to 75 who were undergoing TKA for degenerative osteoarthritis into 2 groups: 
Traditional Fluid Administration
- NPO clear liquids and food after midnight
- 2 liters of lactated Ringers solution administered by anesthesia intraoperatively
- An additional 2 liters of crystalloid while in the PACU and the inpatient room after surgery (500 mL in the PACU and 1500 mL in the inpatient room), for a total of 4 liters of crystalloid within 24 hours
- Normal diet postoperatively
Oral Perioperative Fluid Administration
- Minimum of 60 ounces of clear liquid consumed per day for the 3 days prior to surgery
- NPO food and milk beginning 8 hours prior to the scheduled procedure time
- 10 ounces of clear liquid consumed 4 hours prior to the scheduled procedure time
- IV of lactated Ringers at a rate of 75 mL/hour started in the preoperative holding area
- IV fluids stopped in the PACU when the patient begins taking fluid orally; total amount of IV fluids limited to 500 mL
The primary outcome measure was change in patient weight from preoperative (baseline) to 2 weeks postoperative. Secondary outcomes measures included: 
- Knee range of motion
- Wound complications
- Pain scores and functional testing results
- Length of hospital stay and readmissions
- Patient-reported outcomes (VR-12, KOOS, KSS)
- Bioelectrical impedance to measure body composition before and after surgery
The study findings demonstrated a benefit for the oral perioperative fluid administration protocol, with patients in the traditional fluid administration group having:
- Higher body weight the evening of surgery and POD1 and POD2
- More limb edema, as measured by bioelectrical impedance
- Greater urinary output on POD1
Dr. Jennings and his colleagues encourage preoperative liquid consumption in their TKA patients while limiting IV fluids in the hospital. This protocol, they said, “may offer short-term benefits with [edema] and [body weight] fluctuations,” which may prevent complications associated with fluid overload and prolonged hospitalization.
Jennings JM, Mejia M, Williams MA, Johnson RM, Yang CC, Dennis DA. The James A. Rand Young Investigator’s Award. Traditional Intravenous Fluid vs. Oral Fluid Administration in Primary Total Knee Arthroplasty: A Randomized Trial. Presented at the 2019 AAHKS Annual Meeting, November 7-9, 2019, in Dallas, Texas.
- Jennings JM. Traditional vs Oral Fluid Management in Total Knee Arthroplasty. ClinicalTrials.gov Identifier: NCT03719378. Accessed November 11, 2019.