Walking, Climbing Capacity Predicts PH Patients at Higher Risk of Postsurgical Complications, Study Suggests

Ana Pena, PhD avatar

by Ana Pena, PhD |

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For patients with pulmonary hypertension (PH) who have undergone nonheart surgeries, self-reporting of walking and stair climbing ability can predict the risk of postsurgical complications, a study found.

Researchers say this simple and noninvasive assessment can help identify PH patients at high risk of complications, help the medical team decide which patients should be further examined before surgery, and if additional measures need to be taken to minimize the perils from the procedure.

The findings were described in the study, “Self-reported functional status predicts post-operative outcomes in non-cardiac surgery patients with pulmonary hypertension,” published in the journal PLOS ONE.

People with PH undergoing any type of surgery can have a higher risk of complications, including a higher chance of dying. Doctors usually perform heart scans by echocardiography to evaluate these patients prior to surgery, but its accuracy in predicting postsurgical outcomes remains unproven.

Researchers decided to test whether another type of assessment, namely patient-reports of their exercise resistance, could represent a better and simpler predictor of postsurgical problems.

The team asked patients a specific question: “Can you walk up two flights of stairs without stopping for shortness of breath?”

“Asking a person a question is a pretty inexpensive test that yields an immediate answer, compared with echocardiography, a standard screen used to detect that level of risk, which costs more than $3,000 and which needs to be scheduled,” Gail Van Norman, a University of Washington Medicine anesthesiologist and senior author of the study, said in a UW news release.

In the study, researchers reviewed 550 noncardiac, nonobstetric surgeries performed on 370 PH patients at the UW Medical Center. Other coexisting diseases (comorbidities) and echocardiography scans were collected before surgery.

The functional status of patients was evaluated during the pre-anesthesia clinical visit by asking patients to estimate the number of blocks they could walk and flights of stairs they could climb without getting too tired and stopping for shortness of breath.

Exercise tolerance of patients who could not walk four blocks or climb two flights of stairs was considered “poor.”

Results showed that compared with patients with a better functional condition, those with a poor exercise capacity stayed significantly longer in the hospital (more than seven days), and were more likely to experience a major postsurgical complication (29.8% vs. 20.3%).

Most common complications reported were arrhythmias, acute kidney failure, and delirium.

Other predictors of a prolonged hospital stay were a worse American Society of Anesthesiologists (ASA) classification, an open surgical approach, a procedure lasting longer than two hours, and the absence of systemic hypertension.

Based on these criteria (except ASA classification), plus the patient-reported walking and climbing abilities, researchers created a PH outcome risk score model.

This tool was able to accurately predict the risk of postsurgical complications. A score equal or higher than 2 was associated with an increased rate of major complications in the first 30 days following surgery and intensive care unit admission rates, but no differences in hospital readmissions or mortality.

In contrast, the preoperative echocardiography results did not aid in identifying whose patients were likely to need longer hospitalization,  nor did they improved the accuracy of the model predictions.

According to the team, if a patient answers negatively to the question of whether he/she is able to walk up two flights of stairs without stopping for shortness of breath, that helps anesthesiologists decide about further preoperative testing and to ensure that all precautionary measures are in place for that patient’s surgery.

“Say you’re an anesthesiologist in Coeur d’Alene [Idaho] and a patient who you know with severe pulmonary hypertension is supposed to undergo a laparoscopic gallbladder removal. Are they at such high risk that you should refer them to a large medical center? If they can walk up two flights of stairs, you probably can do that case and reassure them that their risks of complications are pretty low,” Van Norman said.

The researchers noted that a risk assessment model in conjunction with the surgeon’s team and a PH specialist can identify higher risk patients “who might reasonably need to undergo further testing, including repeat ECHO [echocardiography], and optimization prior to elective surgery,” they wrote.

Still, researchers acknowledge the importance of including previous ECHO data and assessing the underlying cause of PH before surgery to improve risk stratification of patients.