The surgery took more than two hours.
The mother of a 9-year-old girl is suing a Michigan hospital after her daughter died in the aftermath of a routine tonsillectomy.
Sonia Gambrell’s daughter, Anyialah Greer, went into cardiac arrest just three hours after leaving Children’s Hospital of Michigan, where she underwent the December 8 surgery, according to her lawyer, Marc Berlin.
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The surgery was to help alleviate her sleep apnea, which was giving her problems breathing and sleeping, the family said.
“She went in for a routine procedure and it took two hours,” Berlin told InsideEdition.com. “The mom is obviously very upset and wants answers and doesn’t believe a routine procedure should end in her daughter’s death.”
According to Gambrell, her daughter never fully regained consciousness despite a doctor saying she would wake up 15 minutes after the surgery.
Doctors also reportedly prescribed oxycodone for Anyialah and while Gambrell was out trying to fill the prescription, which was hard to find due to government regulations on narcotics, she realized something was wrong.
"The child was in the back seat sleeping the whole time and then her mother noticed she wasn’t breathing," Berlin said.
Gambrell rushed her daughter to a nearby hospital but she had no brain activity and later died, according to Berlin.
“It doesn’t seem that the child was ever stable enough to be discharged. We just don’t know what happened and why she was deemed okay to be let go from the hospital,” Berlin said. "We are investigating and trying to obtain justice for this family."
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Children’s Hospital released a statement about the death.
"We were deeply saddened to hear of the passing of Anyialah. We take the care and service we provide to our patients very seriously and we are here to support the family during this difficult time."
The autopsy results are still pending.
Watch: 9-Year-Old Boy Dies Just Days After Getting Tonsils Removed