Viscoelastic Testing in an Obstetric Population at High Risk of Hemorrhage

INTRODUCTION

 Rotational thromboelastometry (ROTEM) is a point-of-care viscoelastic test used in trauma for goal-directed transfusion. However, there are limited data on baseline ROTEM parameters in the U.S. obstetric population. Obtaining baseline parameters is a first step in implementing a goal-directed massive transfusion protocol in obstetric hemorrhage.

OBJECTIVE

 Our study aimed to establish pre- and postdelivery baseline parameters in a high-risk obstetric population and determine their association with postpartum hemorrhage (PPH).

STUDY DESIGN

 Prospective observational study of patients ≥34 weeks' gestation, at high risk of PPH, admitted for delivery. INTEM, EXTEM, FIBTEM, and APTEM assays were performed at the time of admission to labor and delivery and then 2 hours after delivery. Primary outcome was pre- and postdelivery ROTEM parameters among women without PPH. A sample size of 60 women was needed for >90% power to detect at least 50% correlation between pre- and postdelivery assuming a loss of 10% of participants to follow-up.

RESULTS

 Of 60 women in the study, 10 (17%) had PPH. Baseline characteristics were not different between those with or without PPH. Pre- and postdelivery ROTEM parameters were not significantly different except for APTEM. None of the patients who had PPH, compared with 4 (10%) of those who did not, had shortened clotting time and higher maximum clot firmness in postdelivery APTEM compared with EXTEM, a pattern suggestive of hyperfibrinolysis (p = 0.4).

CONCLUSION

 In this study, we describe baseline ROTEM parameters in women at high risk of PPH. The majority of patients did not have a ROTEM pattern that is suggestive of hyperfibrinolysis, for which tranexamic acid is thought to be beneficial. Based on our findings, previously established obstetric transfusion thresholds for goal-directed massive transfusion protocols are likely valid for the majority of the obstetric population regardless of the presence of comorbidities or pregnancy complications.

KEY POINTS

· ROTEM parameters do not vary significantly before and after delivery.. · Most patients did not have a hyperfibrinolysis pattern, for which tranexamic acid is thought to be beneficial.. · Previous goal-directed obstetric transfusion thresholds are likely valid in most populations..

Assessment of the feasibility of same-day discharge following minimally invasive hysterectomy in the elderly population

Objective

To determine the safety and feasibility of same-day discharge (SDD) following minimally invasive hysterectomy (MIH) for elderly patients and to evaluate associations between age, frailty, and postoperative outcomes.

Methods

Retrospective review was conducted of patients aged ≥ 70 who underwent MIH within a single gynecologic oncology institution from 2018 to 2020. Demographics, peri-operative factors, postoperative complications, and 30-day readmission rates were collected. Frailty was determined by an 11-point modified frailty index ≥ 2. Outcomes were compared between SDD and observation groups using Fisher's exact and Wilcoxon rank-sum tests.

Results

Of 169 patients included in the analysis, 8.9% (n = 15) underwent SDD, and 91.1% (n = 154) were admitted for OBS following MIH. Demographics, peri-operative factors, and frailty rates (33% SDD vs 43.5% observation; p = 0.59) were similar between groups. 86.7% (n = 13) of SDD cases were completed before 12PM, and none were completed after 6PM. No SDD patients had early post-operative complications or hospital readmissions. Early postoperative complications were diagnosed in 9 (5.8%) patients admitted for OBS, and the 30-day hospital readmission rate for patients who underwent OBS was 8.4% (n = 13). While elderly patients who met objective frailty criteria (n = 72) did not have a higher likelihood of early post-operative complications (44.4% vs 55.6%; p = 0.909), they did have a higher likelihood of ED visit within 30 days of discharge (15.3 vs 3.1%; p = 0.009), and a trend was noted toward a higher rate of 30-day hospital readmission (12.5% vs 4.1%; p = 0.080).

Conclusions

Elderly patients undergoing SDD following MIH did not have increased morbidity or mortality. Elderly patients who meet objective criteria for frailty, however, represent a more vulnerable population.

Safety and feasibility of same-day discharge following minimally invasive hysterectomy in the morbidly obese patient population

OBJECTIVES

To determine whether morbid obesity should serve as an independent factor in the decision for same day discharge following minimally invasive hysterectomy.

METHODS

Retrospective review was performed of patients with BMI ≥ 40 who underwent minimally invasive hysterectomy within a single comprehensive cancer center between January 2018 - August 2020. Demographics, perioperative factors, post-operative monitoring, complications, and readmissions were compared between patients who underwent same day discharge and overnight observation using Fisher's exact tests and Wilcoxon rank-sum tests.

RESULTS

374 patients with BMI ≥ 40 were included. Eighty-three (22.2%) patients underwent same day discharge, and 291 (77.8%) patients underwent overnight observation. Factors associated with increased likelihood of same day discharge included younger age (median age 53 vs 58; p = 0.001), lower BMI (median BMI 45 vs 47; p = 0.005), and fewer medical co-morbidities (Charlson Co-Morbidity Index 2 vs 3; p < 0.001). On multivariate regression analysis, frailty (OR 2.16 [1.14-4.11], p = 0.019) and surgical completion time after 12 PM (OR 3.67 [2.16-6.24], p < 0.001) were associated with increased risk of overnight observation. Few patients admitted for routine overnight observation required medical intervention (n = 14, 4.8%); most of these patients were frail (64.3%). The overall hospital readmission rate within 30 days of discharge was 3.2% (n = 12), with no patients discharged on the day of surgery being readmitted.

CONCLUSIONS

Morbid obesity alone should not serve as a contraindication to same day discharge following minimally invasive hysterectomy. Admission for observation was associated with low rates of clinically meaningful intervention, and patients who underwent same day discharge were not at increased risk of adverse outcome.

Effective Structure Factor of Osmotically Deformed Nanoemulsions

Extreme osmotic compression of nanoemulsion droplets, achieved by ultracentrifugation, can create solidlike biliquid foams without causing significant droplet coalescence. Using small-angle neutron scattering (SANS), we probe the structure of a uniform silicone oil-in-water nanoemulsion stabilized by sodium dodecyl sulfate over a wide range of volume fractions, phi, up to and beyond the limit associated with maximal random jamming of spheres, phiMRJ = 0.64. Although some features in the structure can be understood at lower phi using simple predictions for hard spheres, the anionic repulsion and deformability of the droplet interfaces creates departures from these predictions at higher phi. For phi near and beyond phiMRJ, the effective structure factor, Seff, as a function of wavenumber, q, exhibits a primary peak that is subunity. We speculate that this striking feature is due to the deformation of the droplets into nonspherical shapes as the system begins to approach the limit of a random array of nanoscopic thin films, Plateau borders, and vertexes characteristic of a polyhedral foam.

Dense cluster formation during aggregation and gelation of attractive slippery nanoemulsion droplets

Using time-resolved small angle neutron scattering, we have measured the wave-number-dependent structure factor S(q) of monodisperse nanoemulsions that aggregate and gel after we suddenly turn on a strong, short-range, slippery attraction between the droplets. At high q, peaks in S(q) appear as dense clusters of droplets form, and S(q) increases strongly toward low q, as these dense clusters become locked into a rigid gel network, despite the fluidity of the films between the droplets. The long-time high-q structure of nanoemulsion gels formed by slippery diffusion-limited cluster aggregation is universal in shape and remarkably independent of the droplet volume fraction, phi.

0.9% sodium chloride injection with and without heparin for maintaining peripheral indwelling intermittent-infusion devices in infants

The use of 0.9% sodium chloride injection with and without heparin sodium for maintaining peripheral indwelling intermittent-infusion devices (PIIIDs) in infants was studied. In this double-blind study, children up to one year of age who had a 24-gauge PIIID through which a continuous i.v. infusion was no longer running were randomly assigned to have their PIIID capped with 0.9% sodium chloride injection with or without heparin sodium 10 units/mL. PIIIDs were capped every eight hours if no medications were administered; otherwise, they were capped after each dose of an i.v. drug. The heparin group had 26 patients with 28 evaluable PIIIDs, and the 0.9% sodium chloride injection group had 32 patients with 46 evaluable PIIIDs. The two groups did not differ significantly in variables assessing the duration of PIIID use, reasons for removal of PIIIDs, mean number of cappings, irritant potential of administered drugs, or severity of medication-related irritation. There was no significant difference between 0.9% sodium chloride injection with and without heparin sodium 10 units/mL in maintaining 24-gauge PIIIDs in children younger than one year.

Klippel-Trenaunay-Weber syndrome

Klippel-Trenaunay-Weber syndrome exhibits vascular anomalies including hemangiomas and varicose veins that commonly appear in the facial area. Characteristic findings involving the oral cavity include an enlarged maxilla, displacement of teeth, and malocclusions. Two cases are presented, with generalized and oral findings ranging from a mild to a very severe form of the syndrome.