MONTREAL — Half of abnormal preoperative coagulation results normalize on repeat testing in children undergoing tonsillectomy and adenoidectomy—and among the other half that remain abnormal, 93% of the abnormalities are clinically insignificant, according to a retrospective chart review.
Despite this finding, relying on patient and family bleeding history alone is not sufficient for identifying potentially life-threatening bleeding abnormalities, said Dr. Neha Bhasin and her coauthor, who presented the findings in a poster.
The review included charts from 791 patients who were referred for further work-up over a 15-year period because routine presurgical coagulation tests revealed an elevated prothrombin time (PT) and/or activated partial thromboplastin time (aPTT), said Dr. Bhasin of Stony Brook (N.Y.) University Medical Center. On follow-up, only 3.4% of the cohort had an acute bleeding disorder, and of these patients 40% would have been missed based on personal or family bleeding history alone, she said.
“So we can't say family history is the sole criteria on which we should base an abnormal PT/PTT work-up,” Dr. Bhasin said in an interview. “You should repeat the PT/PTT before you go on a vast search. And if it is still abnormal, a full work-up is a good adjunct to family history to find out why.”
The study revealed no diagnosis for 394 (50%) of the 791 patients. For most in this subgroup, repeat testing showed their values had normalized, while for 131 the results remained abnormal for no apparent reason. “A transient lupus anticoagulant can sometimes cause an elevated PT/PTT temporarily,” she suggested.
Specific diagnoses were found to explain the abnormal results in the remaining 397 patients, but only 27 of these patients had clinically significant conditions: mild to moderate von Willebrand's disease (21), low Factor VII (3), hemophilia (2), and liver disease (1).
In the remaining 370 patients with clinically insignificant abnormalities, the most common explanation was a lupus anticoagulant (29.5%) or presumed lupus anticoagulant (36.5%), she said. Even though these findings had no acute clinical relevance to the patients, a persistent lupus anticoagulant “may be a predictor of an autoimmune process, and has been shown to represent a risk for thrombosis,” wrote the authors. “Therefore, identifying this abnormality on work-up may potentially be of future clinical significance.”
A personal or family bleeding history was documented in 256 (32%) of the 791 patients, but only 107 of them had an abnormality identified on further work-up, and only 16 of these abnormalities were clinically significant.
Additionally, 11 patients with no bleeding history were found to have clinically significant abnormalities. Therefore, relying solely on patient or family history of bleeding would have missed 41% of the 27 that were found, Dr. Bhasin said. “The presence of a positive personal and/or family history of bleeding is a strong but not absolute predictor of identifying a clinically significant bleeding disorder on further evaluation,” wrote the authors. “Therefore, routine preoperative coagulation testing serves as useful adjunct to clinical history.”
The clinical utility of performing routine preoperative coagulation testing on all children when just 3.4% will have clinically significant results “must be weighed against the risk to the patient of not identifying a hemostatic defect preoperatively,” they concluded.
Disclosures: The investigators did not report any financial conflicts of interest.