Characteristics of preterm births during COVID-19 mitigation measures.

BACKGROUND: During the COVID-19 pandemic, mitigation measures were associated with a reduction in preterm birth rates; while not clearly proven, this observation has sparked significant interest. AIM: To understand the cause of this reduction by exploring the characteristics of preterm birth cohorts. MATERIAL AND METHODS: We performed a retrospective cohort study where we compared women who delivered preterm in three Melbourne maternity hospitals and conceived between November 2019 and February 2020 (mitigation measures-exposed cohort) to women who delivered preterm and conceived between November 2018 and February 2019 (non-exposed cohort). We compared maternal characteristics, pregnancy complications, antenatal interventions, intrapartum care, and indications for delivery. RESULTS: In the exposed cohort, 252/3129 women delivered preterm (8.1%), vs 298/3154 (9.4%) in the non-exposed cohort (odds ratio (OR) 0.84, 95% CI 0.70-1.00, P = 0.051). The baseline characteristic of two cohorts were comparable. Rates of spontaneous preterm labour (sPTL) without preterm pre-labour rupture of membranes (PPROM) were lower in the exposed cohort (13.1% vs 24.2%, OR 0.47, P = 0.001) while PPROM occurred more often (48.0% vs 35.6%, OR 1.67, P = 0.003). With a non-statistically significant prolongation of pregnancy in the cohort exposed to mitigation measures for both sPTL without PPROM (35.4 vs 34.9 weeks, P = 0.703) and PPROM (35.6 vs 34.9 weeks, P = 0.184). The rate of spontaneous labour after PPROM was higher in the exposed cohort compared to the non-exposed cohort (40.1% vs 24.1%, OR 2.09, P < 0.001). CONCLUSION: The reduction in preterm delivery during mitigation measures may have been driven by a reduction in spontaneous labour without PPROM, which seemed to result in more PPROM later in pregnancy.

Prehospital Use of Whole Blood for Ill and Injured Patients During Critical Care Transport.

OBJECTIVE: Hemodynamic instability and hemorrhagic shock are frequently encountered by emergency medical services providers managing ill and injured patients during critical care transport. Although many critical care transport services commonly transfuse crystalloids and/or packed red blood cells (PRBCs), the administration of whole blood (WB) in prehospital care is currently limited. WB contains PRBCs, plasma, and platelets in a physiologic ratio to aid in oxygen delivery to tissue as well as hemostasis. This study describes a single critical care transport program's experience using WB for critically ill and injured patients and reports important clinical and safety outcomes. METHODS: This study was a retrospective review of patients who were transported by a single rotor wing-based critical care transport service to 1 of 2 tertiary care receiving hospitals within a single health system. Patients who were transported between November 1, 2018, and November 30, 2019, and who received at least 1 unit of low-titer group O WB during critical care transport were included. The primary outcomes of interest included 24-hour mortality and the total 24-hour transfusion requirement. The safety outcomes included transfusion reactions, acute lung injury, acute kidney injury, and the incidence of venous thromboembolism. RESULTS: During the study period, there were 3,084 total patients transported by our critical care transport service. There were 71 patients who received prehospital WB, 64 of whom met the inclusion criteria. The top 3 indications for WB administration included blunt trauma (n = 27, 42.2%), gastrointestinal hemorrhage (n = 15, 23.4%), and penetrating trauma (n = 11, 17.2%). The median total number of blood components transfused within 24 hours was 4.0 (interquartile range, 2.0-9.5), and the overall 24-hour mortality rate was 21.9%. CONCLUSIONS: The administration of WB by emergency medical services providers to critically ill and injured patients in the prehospital setting is feasible and is associated with low incidences of adverse events and transfusion reactions. Further research is needed to elucidate the benefits of WB relative to current prehospital standards of care.

Preterm Infant Outcomes Following COVID-19 Lockdowns in Melbourne, Australia.

Background Community lockdowns during the coronavirus disease 2019 (COVID-19) pandemic may influence preterm birth rates, but mechanisms are unclear. Methods We compared neonatal outcomes of preterm infants born to mothers exposed to community lockdowns in 2020 (exposed group) to those born in 2019 (control group). Main outcome studied was composite of significant neonatal morbidity or death. Results Median gestational age was 35 + 4 weeks (295 infants, exposed group) vs. 35 + 0 weeks (347 infants, control group) (p = 0.108). The main outcome occurred in 36/295 (12.2%) infants in exposed group vs. 46/347 (13.3%) in control group (p = 0.69). Continuous positive airway pressure (CPAP) use, jaundice requiring phototherapy, hypoglycaemia requiring treatment, early neonatal white cell and neutrophil counts were significantly reduced in the exposed group. Conclusions COVID-19 community lockdowns did not alter composite neonatal outcomes in preterm infants, but reduced rates of some common outcomes as well as early neonatal inflammatory markers.

The often forgotten systemic effects of ductus arteriosus: impact on decision-making and future trials.

Respiratory symptomatology and echocardiographic features of pulmonary circulation exclusively guide therapy for a hemodynamically significant patent ductus arteriosus in preterm infants. Interrogations of systemic artery Doppler or the exploration of their links with respective end organ symptomatology is not routine practice. This brief report shows the relevance of 'systemic' symptoms and the assessment of 'systemic hypo-perfusion' (and their resolution with physiologically appropriate therapy) in decision-making. Future trials should include this often-ignored aspect in study designs and/or post-hoc analysis.

Middle-molecule clearance in CRRT: in vitro convection, diffusion and dialyzer area.

Several studies have attempted to compare different doses and modes of therapy in continuous renal replacement therapies in critically ill patients. It is commonly asserted in the literature that convective therapies can achieve higher clearance of middle molecules than achieved by dialysis alone. However, regardless of the actual prescription, most therapies will actually contain a mixture of both diffusive and convective clearance. Molecular transport in purely convective prescriptions may be hindered by clotting and protein interactions with the dialyser. We measured middle molecule clearance using a tracer molecule, Ficoll, in citrated bovine blood. Using a 2 x 2 factorial design, we examined the impact of prescription [postdilution continuous venovenous hemofiltration (CVVH) vs. continuous venovenous hemodialysis (CVVHD)] and membrane area (0.4 m2 vs. 2.0 m2) on blood-side and dialysate-side middle-molecule clearance. In large dialysers, convective and diffusive prescriptions resulted in nearly identical middle molecule clearance from 10 to 100 kDa molecular weight. In the smaller dialyser, middle molecule clearance was higher when a diffusive therapy (CVVHD) was prescribed versus a convective therapy (postdilution CVVH). We hypothesized that high ultrafiltration rates in the smaller dialyzer resulted in a concentration polarization at the membrane that formed a prefilter, limiting middle-molecule clearance. This effect has implications for design and analysis of clinical trials of continuous renal replacement therapy (CRRT).

Arabidopsis mutants lacking long chain base phosphate lyase are fumonisin-sensitive and accumulate trihydroxy-18:1 long chain base phosphate.

The sphingoid long chain bases (LCBs) and their phosphorylated derivatives (LCB-Ps) are important signaling molecules in eukaryotic organisms. The cellular levels of LCB-Ps are tightly controlled by the coordinated action of the LCB kinase activity responsible for their synthesis and the LCB-P phosphatase and lyase activities responsible for their catabolism. Although recent studies have implicated LCB-Ps as regulatory molecules in plants, in comparison with yeast and mammals, much less is known about their metabolism and function in plants. To investigate the functions of LCB-Ps in plants, we have undertaken the identification and characterization of Arabidopsis genes that encode the enzymes of LCB-P metabolism. In this study the Arabidopsis At1g27980 gene was shown to encode the only detectable LCB-P lyase activity in Arabidopsis. The LCB-P lyase activity was characterized, and mutant plant lines lacking the lyase were generated and analyzed. Whereas in other organisms loss of LCB-P lyase activity is associated with accumulation of high levels of LCB/LCB-Ps and developmental abnormalities, the sphingolipid profiles of the mutant plants were remarkably similar to those of wild-type plants, and no developmental abnormalities were observed. Thus, these studies indicate that the lyase plays a minor role in maintenance of sphingolipid metabolism during normal plant development and growth. However, a clear role for the lyase was revealed upon perturbation of sphingolipid synthesis by treatment with the inhibitor of ceramide synthase, fumonisin B(1).