Medical emergencies occur about once every 604 flights, according to a study in 2013 in The New England Journal of Medicine of 11,920 emergencies from 2008 to 2010. The most common ailments were loss of consciousness, respiratory problems, nausea or vomiting.
Physician passengers provided assistance in nearly half (48%) of the emergencies, according to the study. Flights diverted for emergency landings in 7.3% of cases, according to the study.
"Few in-flight medical emergencies resulted in diversion of aircraft or death; one-fourth of passengers who had an in-flight medical emergency underwent additional evaluation in a hospital," the study said.
The Federal Aviation Administration requires airliners to carry lifesaving equipment, including an automated defibrillator to shock a person's heart back into regular rhythm, CPR masks to assist breathing and an IV set to administer medicine. The emergency medical kit should contain aspirin, dextrose for diabetics, epinephrine for allergic reactions and nitroglycerine for heart problems.
Flight attendants are trained in CPR. Congress approved legislation in 1998 to protect Good Samaritans aboard flights from lawsuits if they help an ill passenger.
The lawsuit for Oswell alleges a series of problems aboard the American Airlines flight.
About three hours after departing Honolulu, Oswell became dizzy and disoriented. Her husband paged flight attendants, who heard her slurring her speech before she fainted.
A doctor on board examined Oswell, and she regained consciousness. The doctor initially thought she had a panic attack and didn't administer oxygen.
A couple of hours later, Oswell went to a lavatory, where she collapsed, vomited and defecated on herself.
The doctor was summoned again, and he urged the crew to land at the nearest airport for medical care, according to the lawsuit.
Flight attendants brought Oswell to the galley, where she received oxygen. The doctor tried to take Oswell's blood pressure, but one cuff registered an error and the other was broken, according to the lawsuit.
Oswell's pulse stopped, and the doctor and flight attendants tried to apply the defribrillator, but no shock was administered despite three attempts, according to the lawsuit.
The doctors and flight attendants took turns administering cardio-pulmonary resuscitation.
The flight didn't divert and landed in Dallas about two hours after the lavatory incident, according to the lawsuit.
"We absolutely felt like this was not taken very seriously," Tina Starks told ABC News. "She's no longer here to do anything with us, and it's all because someone made a business decision to keep flying a plane when she needed emergency medical help that they could not provide because of inadequacies on board the flight."