“I had tried many treatment options, but the pain was still interfering with my day-to-day life,” Makkar said.

Makkar, 73, underwent conventional knee replacement surgery for his right knee in 2023. While the procedure ultimately relieved his pain and helped him regain mobility, the recovery was long and difficult. For weeks, he relied on a walker, needed prescription pain medication and avoided social activities as he slowly worked his way back to daily life.  

However, for Makkar’s second knee replacement—this time for his left knee—he benefited from a new approach to the procedure intended to speed recovery and lessen pain.

The new approach worked. This time, Makkar used a walker for only two days, met up with his friends within days and relied on Tylenol instead of prescription painkillers.

“This recovery felt so much easier,” Makkar said.

People are living longer and outliving their joints. However, many patients avoid much-needed surgery because they expect a tough recovery, said Sean Rajaee, MD, chief of Arthroplasty at Cedars-Sinai Orthopaedics, and Makkar’s surgeon for both of his procedures.

To help patients recover faster and walk sooner after surgery—which can reduce the risk of complications, such as blood clots, pneumonia and urinary tract infections—Cedars-Sinai launched an enhanced joint replacement recovery effort. As a result, nearly 80% of total joint replacement patients are walking and going home within 24 hours, up from 68% in 2022.

“Now that patients are hearing about improved techniques and smoother recoveries, there is a growing demand for faster care—and Cedars-Sinai is committed to meeting that need,” Rajaee said.

Building a Better Recovery

To speed recovery time for total joint replacement patients, Cedars-Sinai leaders developed guidelines to identify patients best suited for an enhanced recovery regimen. Surgeons consider factors such as overall health and age. Nurses screen patients to assess their home environment and whether they have reliable support after surgery.

Collaboration among surgeons, anesthesiologists, nurses and physical therapists is another key element of the program. Anesthesiologist Michael Kissen, MD, said teams regularly meet to discuss optimal treatment plans, including medication use, procedure timing and wound dressings, with the shared goal of getting patients up and moving within hours after joint replacement surgery.

“Every part of this pathway has existed for a while on its own, but coordinating all these processes and fine-tuning what we do through constant feedback and regular meetings is the novel concept behind creating this pathway,” Kissen said.

Rajaee said educating patients also helps. During presurgical appointments, setting expectations about the recovery plan and explaining the benefits of the approach prepares patients mentally.

The new approach has worked so well that plans are underway to expand the approach to other procedures, beginning with robotic prostate surgeries.

Medical Advances Speed Healing

Advances in pain management play a major role in helping patients walk soon after surgery. Rather than relying solely on general anesthesia, anesthesiologists often use spinal anesthesia, a form of neuraxial anesthesia that numbs the lower body while avoiding many side effects of general anesthesia. Compared with general anesthesia, spinal anesthesia is linked with fewer respiratory complications, less postoperative pain and nausea, reduced need for narcotics, and earlier mobilization.

“Spinal anesthesia has been used safely for years,” Kissen said. “What’s changed is our shift to shorter-acting medications that last through surgery but wear off quickly, so patients can move and start therapy much sooner.”

In addition to spinal anesthesia, anesthesiologists use regional anesthesia techniques, such as peripheral nerve blocks and nerve catheters, to provide longer-lasting pain control after surgery while minimizing opioid use. One commonly used approach for knee surgery is the adductor canal nerve block, which targets sensory nerves while sparing motor function. This allows patients to experience pain relief around the knee without limiting their ability to walk immediately after surgery. In some cases, a catheter is placed near the nerve so a pump can deliver local anesthetic continuously for two to three days after surgery.

Rajaee said robotic-assisted surgery also helps patients walk sooner by reducing tissue trauma and preserving healthy muscle.

Second Surgery, With Less Pain

When Rajaee performed Makkar’s first knee replacement, he used a tourniquet, a common technique that reduces blood flow to the knee to allow surgeons to place an implant.

However, during the second procedure, Rajaee opted for a tourniquet-free approach, a newer method shown to reduce pain after surgery. He also used what’s called a quadriceps-sparing midvastus approach, which avoids cutting through the main tendon attached to the large muscle on the front of the thigh, preserving the tissue.

Anesthesiologists added a low dose of ketamine to target pain pathways not relieved by narcotics during the second surgery. Makkar experienced a smoother recovery and was thrilled with his results.

“At my age, I am super happy I’m walking,” he said. 

Read more on the Cedars-Sinai Newsroom: Cedars-Sinai Slashes Anesthesia Emissions, Reducing Carbon Footprint

felt torn knowing the gases she used to make surgery painless for patients were actually hurting the environment.

“It was disturbing to me and hard to reconcile that here I am as a healthcare provider preserving human health, and yet I create a ton of pollution,” Ma said.

Climate change and air pollution are the biggest threats to human health, according to the World Health Organization, and cause—or worsen—a range of health threats, including infectious diseases spread by mosquitoes, ticks or fleas; respiratory illnesses; and heat exhaustion.

According to a study published in Health Affairs, the healthcare industry may be responsible for up to 8% of greenhouse gas emissions, and anesthetic gases account for more than half of the emissions generated during surgery. These gases are especially harmful because they are released directly into the atmosphere. Using the anesthetic gas desflurane for one hour, for example, produces the same carbon emissions as driving a gasoline-powered car for 190 miles.

Ma launched a Cedars-Sinai Medical Center initiative in 2021 to address anesthesiology’s role in the problem. After four years, she and her colleagues have significantly reduced the output of desflurane as well as nitrous oxide, while still maintaining the highest quality of care and safety for patients.

Caring for Patients, Cleaning the Air

In 2021, Ma and anesthesiologist Michael Kissen, MD, started spreading the word with their colleagues about anesthesiology’s role in climate change, and the environmental benefits of switching to alternative gases.

“Anesthesia is sometimes more of an art than a science,” Kissen said. “Every anesthesiologist has their routine and their medications that they lean on, but we wanted to make our colleagues aware of all the risk profiles of these gases beyond what we learned in an anesthesia textbook.”

Anesthesiologists used to rely on desflurane to provide general anesthesia for patients before surgery, but it has 20 times the carbon impact of its alternative, sevoflurane.

Under Ma’s guidance, Cedars-Sinai Medical Center and other Cedars-Sinai patient care centers moved away from desflurane, and in 2023, the hospital officially removed the gas from its approved list of drugs.

With these changes, Cedars-Sinai went from using 1,200 bottles of desflurane in 2021 to fewer than 12 in 2024—achieving a 99% reduction. Ma said the shift is equivalent to taking 250 cars off the road.

The initiative also targeted nitrous oxide—commonly known as laughing gas—which is frequently used by pediatric and obstetric anesthesiologists and for dental procedures. Experts have found that much of the gas is lost before reaching the patient, posing a hazard to the healthcare workers present during surgery and the environment. Nitrous oxide also lingers in the atmosphere for 100 years.

By gradually phasing out nitrous oxide, Cedars-Sinai reduced emissions from 1,111 metric tons of carbon dioxide in 2021 to 234 in 2024.

Eliminating both gases collectively removed about 2,200 metric tons of carbon dioxide emissions over the past four years—roughly equivalent to the annual emissions of 400 homes. The project has gained a champion in Michael Nurok, MB, ChB, PhD, co-chair of the Department of Anesthesiology.

“This initiative is emblematic of Cedar Sinai's commitment to being at the forefront of medical care and science,” Nurok said. “Beyond delivering excellent patient care and outcomes, our team is thinking about the impact of these gases on the environment, employees, and future generations.”

Expanding Eco-friendly Lens

Nurok has taken up the cause, looking for other ways to minimize pollution. He is working with Robert Kaplan, Marvin Bower Professor of Leadership Development Emeritus at the Harvard Business School, on creating a framework for measuring the impact of healthcare devices on the environment—such as implants, devices and medical equipment—as they are processed and transported through supply chains.

With a better understanding of the environmental costs of different approaches to a procedure, physicians will be able to make informed choices about which materials and processes they choose. Much like a nutrition label helps consumers to make wise decisions about what they eat.

For Anesthesiology’s next project, Nurok and Kissen are collaborating with the Department of Orthopaedics and others to measure and reduce the carbon impact of hip replacement procedures.

Bryan Croft, the medical center’s executive vice president and chief operating officer, said this work encourages Cedars-Sinai staff members to be good stewards of its resources and the environment.

“We are thrilled to be able to support anesthesiologists’ mission to reduce greenhouse gases, bettering the world we live in, and we look forward to continuing to support eco-friendly projects,” Croft said.

Read more on the Cedars-Sinai Blog: Cedars-Sinai Appoints Department of Anesthesiology Co-Chairs