Accuracy testing of a novel obstetric blood loss quantifying device: A pilot study

The Stryker® system is accurate in detecting hemoglobin levels in fluid mixtures, which may assist professionals in assessing birth waste and diagnosing postpartum hemorrhage.

Methods of Blood Loss Quantification in Major Abdominal Surgery: A Narrative Review

Blood loss in major abdominal surgery is an essential parameter in the evaluation of strategies aimed at reducing perioperative bleeding. It is also an important parameter of quality of the surgical procedure, along with postoperative morbidity and mortality, radicality of the surgical resection, etc. However, blood loss quantification remains unreliable and inaccurate. The methods used to measure blood loss can be categorized as visual estimation, gravimetric method, direct measurement, spectrophotometry, calculation methods, colorimetric analysis, and miscellaneous. The aim of this work is to review up-to-date knowledge about the various methods of blood loss quantification and then to introduce study, which should compare more methods of blood loss quantification in a real surgical setting.

Workshop on Blood Loss Quantification in Obstetrics: Improving Medical Student Learning through Clinical Simulation

PURPOSE

To assess whether a clinical simulation-based obstetric blood loss quantification workshop for medical undergraduate trainees improves theoretical-practical knowledge, along with self-assurance and self-confidence.

METHODS

This was a quasi-experimental pre-post learning study conducted at the Gynaecology and Obstetrics Unit of the Hospital Gregorio Marañón, Madrid, Spain. Participants were volunteer students in their fourth year of a 6-year degree course in Medicine. The study period was divided into the stages: pre-workshop, intra-workshop, 2 weeks post-workshop and 6 months post-workshop. In the pre-workshop stage, students completed a brief online course in preparation for the workshop. The effectiveness of the workshop was assessed through multiple choice tests and self-administered questionnaires. Data were compared between time-points using statistical tests for paired samples.

RESULTS

Of the 142 students invited (age 21.94 ± 3.12 years), 138 accepted the offer of the workshop (97.2%), and 85.4% had no experience in managing blood loss. Between the stages pre- and 2 weeks post-workshop, significant improvements were observed in theoretical-practical knowledge (μ = 1.109), self-assurance and self-confidence. At the 6 months post-workshop stage, theoretical-practical knowledge diminished compared with 2 weeks post-workshop, returning to pre-workshop levels, while self-assurance and confidence failed to vary significantly in the longer term.

CONCLUSIONS

The obstetric workshop improved theoretical-practical knowledge and the self-assurance and confidence of the medical students. Results 2 weeks post-workshop were maintained up until 6 months after the training intervention. The clinical simulation-based workshop was perceived by the students as useful and necessary.

Limitations of Gravimetric Quantitative Blood Loss during Cesarean Delivery

Objective  This study examined the accuracy, sources of error, and limitations of gravimetric quantification of blood loss (QBL) during cesarean delivery. Study Design  Blood loss determined by assays of the hemoglobin content on surgical sponges and in suction canisters was compared with QBL in 50 parturients. Results  QBL was moderately correlated to the actual blood loss ( r  = 0.564; p  < 0.001). Compared with the reference assay, QBL overestimated blood loss for 44 patients (88%). QBL deviated from the assayed blood loss by more than 250 mL in 34 patients (68%) and by more than 500 mL in 16 cases (32%). Assayed blood loss was more than 1,000 mL in four patients. For three of these patients, QBL was more than 1,000 mL (sensitivity = 75%). QBL was more than 1,000 mL in 12 patients. While three of these had an assayed blood loss of more than 1,000 mL, 9 of the 46 patients with blood losses of less than 1,000 mL by the assay (20%) were incorrectly identified as having postpartum hemorrhage by QBL (false positives). The specificity of quantitative QBL for detection of blood loss more than or equal to 1,000 mL was 80.4%. Conclusion  QBL was only moderately correlated with the reference assay. While overestimation was more common than underestimation, both occurred. Moreover, QBL was particularly inaccurate when substantial bleeding occurred. Key Points QBL is inaccurate in cesarean delivery.QBL deviated from the assay result by more than 500 mL in 32% of cases.QBL sensitivity and specificity for hemorrhage is 75.0% (95% confidence interval [CI]: 0.19-0.93) and 80.4% (95% CI: 0.69-0.92), respectively.