California authorities have investigated the November incident in which Dennis Quaid’s newborn twins were accidentally given an overdose of a blood thinner while at Cedars-Sinai Medical Center in Los Angeles, concluding that the institution put them in jeopardy.

The California Department of Public Health said Wednesday in a 20-page deficiency report that the Los Angeles hospital put three children, the newborn twins of Dennis Quaid and wife Kimberly and another baby, in jeopardy by giving them an overdose of heparin, a blood thinner, the Los Angeles Times reports.

The report says the three children were given 1,000 times the intended dosage of heparin on Nov. 18, 2007. The Quaid babies were born on Nov. 8 via a surrogate mother and checked into Cedars-Sinai for an infection.

Zoe Grace and Thomas Boone Quaid each received two 10,000-unit doses over an 8-hour period, when hospital officials initially stated one 10,000-unit dose had been administered to each child.

The babies were supposed to receive only a 10-unit dose each.

A statement from Dennis and Kimberly Quaid released Wednesday to the Los Angeles Times says: “We find it outrageous and totally unacceptable that we are learning for the first time … exactly what transpired.”

The couple adds: “The hospital's lack of candor has left us with the uneasy feeling that we may never know the whole story.”

Cedars-Sinai now has 10 days to respond to the report which states that the hospital’s unsafe medication practices “created a risk of harm for all hospital patients.”

“This violation involved multiple failures by the facility to adhere to established policies and procedures for safe medication use,” state inspectors wrote, adding that the violations “caused, or were likely to cause, serious injury or death to the patients who received the wrong medication.”

While the department has not decided yet whether to fine the medical center for its errors, Kathleen Billingsley, deputy director of the state's Center for Healthcare Quality, said Cedars-Sinai already had taken steps to ensure that patients were no longer in “immediate jeopardy,” as quoted by the Times.

The investigation found that nurses and pharmacy technicians did not check labels on the vials of heparin before using them and did not keep adequate records of when the medication was used. The hospital was found to not have adequately educated its staff about the safe use of heparin.

The Quaid couple has already sued Baxter Healthcare Corp., the Illinois-based makers of heparin, accusing the firm of negligence in using very similar packages for different doses of the drug, thus creating a dangerous situation.

According to the Associated Press, in February Baxter Healthcare Corp. sent a letter warning health care workers to carefully read labels on the heparin packages to avoid confusion.

The couple’s lawyer said in early December that the twins had fully recovered and that it was unlikely for them to suffer long-term effects from the overdose.