Six days after Thanksgiving last year, a 73-year-old woman showed up at Baylor St. Luke’s Medical Center in Houston. Her body was retaining too much fluid after a dialysis treatment, and she was in need of emergency medical care.

What happened next could have killed her.

Hospital staff put in a request to give the woman a blood transfusion, but the order was meant for another patient with a different blood type. Fortunately, the St. Luke’s laboratory caught the error, sparing the woman from harm.

Four days later, however, hospital staff committed a similar mistake, only this time workers in the lab didn’t notice when a blood sample arrived with another patient’s blood in it. As a result, a 75-year-old woman was given the wrong blood, mistaken for a patient who had been in her ER room immediately before her.

She died the next day after repeated bouts of cardiac arrest.

The fatal mistake followed a pattern of blood labeling errors at St. Luke’s during the past year, according to a scathing report issued last month by the Centers for Medicare and Medicaid Services and made public Tuesday by the hospital. The government report came after a yearlong investigation by the Houston Chronicle and ProPublica that documented numerous lapses in patient care at a hospital once regarded as among the nation’s best for cardiac care.

St. Luke’s leaders released the 99-page inspection report on Tuesday, along with a document detailing the hospital’s efforts to correct the problems. In a letter posted on the hospital’s website, St. Luke’s CEO Doug Lawson called the government’s findings “deeply disappointing.” He also wrote that he expects regulators to find additional problems when they return to the hospital for a comprehensive audit of patient care practices in the coming weeks.

Lawson said newly hired St. Luke’s executives have already made several changes to bring the hospital into compliance with federal standards, including an improved training program to ensure blood samples are labeled properly. The hospital has also enhanced its quality improvement program, Lawson wrote, and officials have made it easier for staff to report patient safety concerns to senior leadership.

“It is our responsibility to learn from these mistakes, and we take this responsibility very seriously,” Lawson wrote. “An incident like this should never happen.”

Dr. Ashish Jha, an expert in hospital quality, reviewed the government’s findings and said it appeared St. Luke’s was struggling to meet basic care standards. The labeling mistakes, he said, seemed indicative of “a broader systemic problem.”

“These are really basic errors that I didn’t really think happened that often anymore,” said Jha, who directs Harvard University’s Global Health Institute.

St. Luke’s appeared to miss warning signs in the months prior to the deadly mistake, according to the government report.

An internal hospital committee identified problems with the way staff had been labeling blood samples a year ago, according to the federal report, but the unsafe practices continued. In total, regulators identified 122 incidents from a recent four-month period, from September to January, in which St. Luke’s staff made blood labeling errors, some more serious than others.

These problems were compounded by a short-staffed nursing crew that lacked training in how to detect adverse reactions during transfusions and a hospital laboratory with too few workers on staff to always catch potentially fatal labeling mistakes, according to the government report.

The violations are the latest in a series of setbacks for St. Luke’s. The Medicare agency cut off funding for heart transplants at St. Luke’s last year after the Chronicle-ProPublica investigation documented an outsized number of patient deaths and unusual surgical complications following the procedure in recent years.

The news organizations also reported on poor outcomes following heart bypass surgery, repeated complaints about inadequate nursing care, a recent rise in the number of deaths after liver and lung transplants, and a physician’s lawsuit alleging that he was retaliated against after raising concerns that some of his patients had received unnecessary medical treatments in intensive care units.

Hospital officials said repeatedly that problems identified by reporters had already been corrected, and they denied retaliating against the physician.

After the botched blood transfusion, hospital leaders have taken a different tack. Days after the inspection, the hospital’s board of directors announced it had dismissed CEO Gay Nord and three other top executives.

The report released Tuesday details how the fatal mistake occurred.

Medical staff had drawn blood from an ER patient on Dec. 2 but failed to discard the sample after that patient was discharged. The vial of blood was still in the hospital room when staff brought in a 75-year-old woman who had been rushed to St. Luke’s by ambulance. When a doctor ordered a transfusion, staff mistakenly sent the tube containing the prior patient’s blood sample, placing a new label over the original.

Jha, the quality expert, said the double-labeling error was an egregious mistake, but with the proper checks in place, it shouldn’t have led to the woman’s death.

“A lab should never accept a specimen that has two labels of two different patients,” he said.

Government inspectors found that the lab at St. Luke’s did not have a policy on whether technicians should accept blood samples with multiple labels.

The situation was made worse by poor nursing care, regulators wrote. Many nurses at St. Luke’s had not been trained on how to identify signs of a blood transfusion gone wrong. Staff continued to give the 75-year-old woman the wrong blood despite a worsening adverse reaction, according to the report.

The government report details numerous incidents in which St. Luke’s nurses failed to track patient vital signs while administering transfusions, making it impossible to detect problems.

“The findings present a likelihood that serious blood transfusion reactions may not be detected in an expeditious manner, which could delay appropriate response and treatment, and could result in death or injury to a patient,” inspectors wrote.

The hospital did not make changes in the weeks that followed, according to the report. In a meeting at St. Luke’s on Jan. 10, more than a month after the death, hospital leaders acknowledged they still were not tracking labeling mistakes.

The hospital has since hired several new officials to guide St. Luke’s on its “journey back to excellence,” Lawson wrote in his letter Tuesday.

“This is a challenging time for our hospital,” he wrote. “While we cannot go back and change the past, we can focus our efforts on recreating the Baylor St. Luke’s you have known and trusted.”