BACKGROUND: A rapid response system triggered by single parameter criteria has been introduced in our hospital since 2015 with the aim of early identification of patient deterioration. Although the criteria is designed for non-obstetric hospitalized patients, the RRS concept can be applied to inpatient obstetric care. This study was aimed to assess the trigger criteria of the RRS at Kitasato University Hospital as a bedside screening tool in correlation with obstetric morbidity by comparing it with the MEOWS criteria. METHOD: We retrospectively reviewed the medical records of women admitted to MFICU at Kitasato University Hospital from January to December 2015. Based on the recorded physiological parameters, the researcher (YH) investigated all cases whether they met the trigger criteria of the Kitasato RRS (KRRS) and MEOWS criteria. Additionally, obstetric morbidity of each case was determined by YH. The sensitivity and specificity of the KRRS and MEOWS for diagnosing obstetric morbidity were evaluated. RESULTS: Out of 377 patients who admitted to MFICU over the study period, 69 (18%) met the criteria of obstetric morbidity which included hypertensive disorder of pregnancy (HDP) in 43, massive hemorrhage in 14, and others in 4, respectively. KRRS criteria for diagnosing obstetric morbidity was found to be 47% sensitive, 77% specific. Out of 34 patients who had morbidity but did not trigger on KRRS criteria, 26 cases were diagnosed HDP. Of 76 cases which didn’t have morbidity but triggered KRRS criteria, half of cases were tachycardia due to ritodrine. DISCUSSION: The sensitivity of the KRRS trigger criteria (47%) was lower than that of the MEOWS criteria (93%) in this and a previous study (89%). Lower sensitivity could be attributed to the KRRS trigger criteria not detecting obstetric-specific conditions, including HDP and obstetric hemorrhage, which obstetricians frequently encounter. The RRS has originally focused on the early prediction of critical conditions that require intensive care, suggesting that the criteria can trigger prompt resources. The KRRS was triggered in non-morbidity conditions, particularly with ritodrine, a beta-agonist, which suggests the KRRS is not adopted to physiological changes in obstetric patients. It is imperative to inform RRS members about the specific conditions of obstetric patients. CONCLUSION: The KRRS criteria can be introduced to the obstetric ward. To inform RRS members about the specific conditions of obstetric patients is imperative.

05 / Retrospective evaluation of trigger criteria of rapid response system in an obstetric ward