Investigating the Association of Shock Index and Hemoglobin Variation With Postpartum Hemorrhage After Vaginal Deliveries

Investigating the Association of Shock Index and Hemoglobin Variation With Postpartum Hemorrhage After Vaginal Deliveries: A Prospective Cohort Study

Postpartum hemorrhage (PPH) is a leading cause of maternal mortality and morbidity, and is most commonly caused by poor uterine tone after delivery of the baby and placenta. Currently, a lack of early identification of PPH also results in delayed treatment, with an increase in morbidity. The investigators propose that 2 non-invasive methods may provide monitoring for early and accurate detection of PPH. These methods include shock index (SI) and continuous hemoglobin (Hb) monitoring. SI is defined as heart rate divided by systolic blood pressure, and can be used as a marker to predict the severity of hypovolemic shock. Continuous Hb monitoring can now be done using a non-invasive probe that is placed on the patient's finger. It provides real-time Hb values, rather than having to draw blood and wait for a lab test.

The investigators hypothesize that SI will have a stronger association with postpartum blood loss than Hb variation.

The investigators believe that trends in patient-specific SI combined with continuous SpHb monitoring, will be useful to identify PPH and the immediate need for pharmacotherapy, as well as the need for transfusion in obstetric patients undergoing vaginal deliveries. The investigators expect shock index to increase and SpHb levels to decrease with increasing blood loss after delivery. The compensatory hemodynamic response may start early, however, Hb variation may be delayed unless the patient is transfused with crystalloids. Also autotransfusion after delivery may influence these measures. It is unknown which one of the two indicators, SI or SpHb, has a stronger association with blood loss after vaginal delivery.

It is already established that both SI and SpHb are independent, clinically useful markers indicating significant blood loss in elective cesarean delivery and trauma. This study would assess their utility in the recognition and management of obstetric hemorrhage following normal vaginal delivery, where early recognition and resuscitation reduces the risk of progressing to hemorrhagic shock, disseminated intravascular coagulation and death.

Inclusion Criteria:

• patients who give written consent to participate in this study
• all term laboring patients including spontaneous and induced labor (gestational age >37 weeks) undergoing spontaneous vaginal delivery or instrumental delivery

Exclusion criteria

• patients who refuse to give written informed consent
• patients with cardiac rhythm abnormalities or cardiac diseases
• patients undergoing elective/emergency CD
• patients with jaundice
• patients with abnormal Hb-->Such as Sickle cell disease and Thalassemia
• patients with peripheral vascular disease
• patients with hypertension and preeclampsia
• patients on medications affecting blood pressure such as anti hypertensives (including Magnesium Sulphate), and those affecting HR (including beta blockers)