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When Evelyn visited her mother Georgia, who was in the hospital recovering from hip replacement surgery, she knew something was desperately wrong.
Even at the age of 88, Georgia was usually mentally alert. After the surgery, she just didn't seem to be "with it." The nursing staff seemed to think it was just age, but daughter Evelyn knew it was more than that.
Never one to get headaches, Georgia had been asking for pain medication. And even though hip replacement is a traumatic experience and a certain reluctance to get up and get moving is only to be expected, Georgia just didn't want to do anything at all. And she seemed a little puffy all over, not something to be expected in a woman of 88.
Fortunately, Evelyn, herself a doctor, asked to see her mother's labs. The problem was immediately clear.
Hospitals Are Hotbeds of Hyponatremia
Hyponatremia is a common condition among hospital patients, particularly those who have high blood pressure or cardiovascular disease. Accepting the nutritional dictum that sodium is always bad, many hospitalists automatically put patients with any kind of cardiovascular indication on a sodium-restricted diet.
Studies find that between 15 and 30% of all hospital patients develop moderate hyponatremia. Used to eating a higher-salt diet, sodium levels fall when eating hospital food. Usually the hyponatremia is mild, with blood plasma sodium levels ranging from 130 to 135 mg/dl, but in about 10% of all hospitalizations low sodium levels are severe, below 130 mg/dl. And certain surgical procedures, especially hip surgery, are especially likely to cause low sodium levels.
Danger of Low Sodium Levels Especially Acute After Hip Replacement Surgery
Two British researchers, Dr. James Edward Rudge and Dr. Daniel Kim of City Hospital, Sandwell and West Birmingham Hospitals NHS Trust write in their report, published online June 7 in Age and Ageing, reviewed the records of 254 patients who underwent hip surgery after falls in their trauma units in 2012. They found that sodium levels typically fell during surgery, and that 27% of patients developed moderately low sodium levels and 9% developed severely low sodium levels after the procedure.
Patients on proton pump inhibitors for gastroesophageal reflux disease were more likely to develop hyponatremia. Patients taking selective serotonin reuptake inhibitors for depression were more likely to develop hyponatremia. Otherwise, gender, the type of fracture, race, and ethnicity made little or no difference in sodium levels. However, patients who developed low sodium levels had to stay in the hospital on average 9 days longer than those who did not.
Deaths from hyponatremia while in the hospital are rare, but aren't unknown. Problems from low sodium levels, however, are well known:
- When patients come into the hospital with low sodium levels and then have surgery, they are more likely to die of complications. About 10% of patients admitted with low sodium levels who have to have hip surgery right away, for instance, die of complications within 30 days.