Commissioner Scott Gordon ordered another hearing to be held Jan. 14.
Federline had previously been awarded temporary custody of 2-year-old Sean Preston and 1-year-old Jayden James because Spears has defied court orders, resulting in limitations on her visitation.
"I'm not happy about any of these events," Federline attorney Mark Vincent Kaplan said when he left a closed-door emergency hearing Friday afternoon. "There's no winners here."
Federline was not in court for the hearing, Kaplan said.
The attorney had said he did not expect the ruling to be released until Monday, but it was issued shortly after the hearing concluded.
Law professor Steve Cron, who is not involved in the Spears-Federline matter, predicted that Spears will face sanctions from the court for her behavior.
"My guess is that she won't be seeing her kids for a while," said Cron, who teaches at Pepperdine University in Malibu.
Gordon has little option other than to further reduce the time Spears can legally spend with her children, Cron said, "at least for the time being until she gets some help. She's obviously a very troubled person."
The 26-year-old pop star remained hospitalized Friday.
Her latest troubles began around 8 p.m. Thursday when officers were called to her home to help resolve a dispute over her refusal to turn the children over to Federline, as dictated by their custody agreement.
It took two to three hours to resolve the conflict, said Officer Ana Aguirre.
"There was a time where she was within the residence and wasn't available to be speaking to the officers, apparently," she said. "There was no threat to the children."
"Police resolved the conflict," Aguirre said. "Both children were turned over to her ex-husband Kevin Federline for custody, and she was in fact taken to a local hospital for medical treatment."
Early police reports said officers thought Spears might have been under the influence of some substance, but Aguirre said there was no evidence of that.
"Our understanding is that was not the case," she said.
Officers at the scene determined that paramedics "needed to be called" but it was unclear why, she said.
"We're not aware of any type of injuries that she sustained" and she was not combative with authorities, Aguirre said.
Spears wasn't arrested in connection with the custody dispute, Aguirre said.
"There was no actual crime that was involved," the police spokeswoman said.
Spears and Federline were married in October 2004. Her life has spiraled downward since their divorce in July. She has been photographed without underwear and appeared to be drunk and out of control in public. She shaved her head, beat a car with an umbrella and spent a month in rehab.
She had hoped to regain her pop crown with a much-hyped performance at MTV's Video Music Awards in September, but it was universally panned by fans and critics.
Still, Spears' latest album, "Blackout," earned positive reviews when it was released in October and brought Spears her first No. 1 hit in years, "Gimme More."
However, Spears remains a paparazzi target for her bizarre antics, which include frequent stops at gas-station bathrooms and holing up in a hotel room with a paparazzo.
Her 16-year-old sister, Jamie Lynn, made headlines last month when she announced that she is pregnant.
