Medical errors can occur when critical lab values are not properly communicated. A critical lab value is one that is so at odds with normal lab values that it potentially portrays a life threatening condition, unless immediate corrective action is taken. Laboratories can measure a variety of body fluids, including urine, sputum and blood, or process tissue samples with the assistance of a pathologist. Lab values that are generated by testing bodily fluids are measured against reference ranges that are established by a board-certified pathologist.
Generally, reference ranges include a range of values that are considered normal for the population. On either side of normal are abnormal lows and abnormal highs, each of which may carry diagnostic significance depending on the patient’s presenting complaint, history, physical exam and other test results. When an abnormal lab result is critical, another consideration arises: time. Not only must the lab value be used in reaching a diagnosis, but it must be taken into account promptly to avoid life-threatening injury or wrongful death.
Critical lab values can be overlooked for a number of reasons. First, lab results may not be communicated by the lab to the ordering physician. Standard hospital policies require labs to report critical lab values directly to ordering physician, rather than posting them to the chart or handing them off to a nurse. Second, sometimes abnormal lab values are overlooked. Third, lab values can be misinterpreted by lab personnel or equipment. Finally, abnormal lab values can be misinterpreted by inexperienced residents or a sloppy nurse or attending physician.
A good example of medical errors arising out of an abnormal lab result that was ignored occurred in a medical malpractice case that I handled. In that case, a patient was being seen by a number of specialists at a large Cleveland hospital. One urology specialist obtained labs showing critical abnormalities in the patient’s kidney function. However, the urologist only looked at labs relevant to his investigation into whether the patient had prostate cancer (he didn’t). So, the lab value showing abnormal renal function was ignored until many weeks later when it was discovered by the patient’s nephrologist (kidney specialist) and addressed — too late. The patient is now required to be on dialysis.
One study found that laboratory services consume only about 5% of a hospital’s budget, but are relied upon in 60-70% of all critical decisions made. This means that lab work is generally cheap but the results are often very important. An unnecessary delay in considering abnormal lab values may furnish the basis for a medical negligence claim under Ohio law.