Body surface area: a predictor of response to red blood cell transfusion

Impact of Significant Hemoglobin Drop Without Bleeding in Patients Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND

Hemoglobin (Hgb) drop without bleeding is common among patients undergoing transcatheter aortic valve replacement; however, the clinical implications of significant Hgb drop have not been fully evaluated.

METHODS AND RESULTS

Consecutive patients undergoing transcatheter aortic valve replacement at our institution from 2011 to 2021 were retrospectively reviewed. Three groups were assessed: no Hgb drop and no bleed (NoD-NoB [reference group]), Hgb drop with bleed, and Hgb drop and no bleed (D-NoB). Hgb drop was defined as ≥3 g/dL decrease from pre- to post-transcatheter aortic valve replacement. Outcomes of interest were in-hospital death and 1-year all-cause mortality. A total of 1851 cases with complete Hgb data were included: NoD-NoB: n=1579 (85.3%); D-NoB: n=49 (2.6%); Hgb drop with bleed: n=223 (12.6%). Compared with NoD-NoB, the D-NoB group was older (81.1 versus 78.9 years of age) with higher preprocedure Hgb (12.9 versus 11.7 g/dL). In-hospital death rate was higher among patients with D-NoB versus NoD-NoB (4.5% versus 0.8%, P<0.001) and similar to Hgb drop with bleed (4.5% versus 4.1%, P=0.999). Predictors of in-hospital death were D-NoB (odds ratio [OR], 3.45 [95% CI, 1.32-8.69]) and transfusion (OR, 10.6 [95% CI, 4.25-28.2]). Landmark survival analysis found that D-NoB experienced 1-year mortality rate comparable to NoD-NoB, whereas Hgb drop with bleed had higher midterm mortality (hazard ratio [HR], 3.2 [95% CI, 1.83-5.73]), and transfusion continued to impact mortality (HR, 2.5 [95% CI, 1.79-3.63]).

CONCLUSIONS

Hgb drop without bleeding is common among patients undergoing transcatheter aortic valve replacement and may represent a higher risk of periprocedural death. Blood transfusion increases short- and midterm mortality risk in patients with and without bleeding, supporting a restrictive transfusion strategy.

Efficacy of packed red blood cell transfusions based on weight versus formula in thalassemic children: An open-label randomized control trial

BACKGROUND

Protocols for transfusion therapy in transfusion-dependent thalassemia (TDT) children differ among various medical centers. In India, most centers consider only the patient's weight while calculating the volume of packed red blood cells (PRBCs) to be transfused. This study aimed to compare the efficacy of PRBC transfusions of different volumes calculated either by weight or by a formula using weight and pretransfusion hemoglobin of patient and hematocrit of PRBC.

STUDY DESIGN AND METHODS

Sixty TDT patients in the age group of 3-9 years were enrolled and randomly allocated to two groups. Group A received PRBC transfusion volume based on the patient's weight, and Group B received PRBC volume calculated using a formula for 6 months.

RESULTS

Average pretransfusion hemoglobin in Group A and Group B (9 ± 0.4 vs. 8.9 ± 0.4 g/dl) was not significantly different (p = .353). Although the average number of visits in 6 months was less for Group A compared to Group B (7 ± 1 vs. 8 ± 1; p = .001); the average volume transfused per visit was more (351 ± 78 vs. 287 ± 68 ml; p = .003). The calculated average annual pure red cell requirement of the patients was 178 ml/kg/year for Group A and 154 ml/kg/year for Group B (p = .000). Total donor exposures were significantly lower in Group B than Group A (11 ± 3 vs. 14 ± 3; p = .006).

CONCLUSION

The number of donor exposures and annual pure red cell requirement was significantly lower in the formula-based group. Transfusions based on formula are recommended in TDT patients.

Post-kidney transplant soluble Klotho levels are determined by pretransplant soluble Klotho levels in both living donors and recipients

BACKGROUND

Soluble Klotho (sKl), the free form of membrane-bound Klotho predominantly expressed in the kidney, is detectable in serum and may have multiple pleiotropic effects. Patients with end-stage kidney disease are possibly sKl deficient, and kidney transplantation is the treatment of choice in these patients; however, little is known about changes in posttransplant sKl level and the factors influencing these changes.

METHODS

We conducted a prospective longitudinal study to examine changes in posttransplant sKl level in recipients for 12 months after living-donor kidney transplantation and analyzed correlations between posttransplant changes in sKl levels and various influencing factors in both recipients and donors.

RESULTS

29 kidney transplant recipients and their living donors were included for analysis. The results showed that sKl levels transiently decreased at 1 week posttransplant but progressively increased thereafter for 12 months. Multivariable linear regression analysis showed that body surface area-adjusted donor sKl levels were associated with posttransplant increases in recipient sKl levels at 12 months. In addition, pretransplant recipient sKl levels and body surface area-adjusted donor sKl levels were identified as an independent predictor of 12-month posttransplant sKl levels.

CONCLUSION

Pretransplant sKl levels in both kidney recipients and living donors are a strong determinant of sKl levels after kidney transplantation.

Sex-based differences in transfusion need after severe injury: Findings of the PROPPR study

BACKGROUND

Women are underrepresented in trauma research, and aggregated results of clinical trials may mask effects that differ by sex. It is unclear whether women respond differently to severe hemorrhage compared with men. We sought to evaluate sex-based differences in outcomes after severe trauma with hemorrhage.

METHODS

We performed a secondary analysis of the Pragmatic Randomized Optimal Platelet and Plasma Ratios trial. Trauma patients predicted to require massive transfusion were randomized to a 1:1:1 vs 1:1:2 plasma to platelet to red blood cell transfusion ratio. Analysis was performed according to sex, controlling for clinical characteristics and transfusion arm.

RESULTS

A total of 134 women and 546 men were analyzed. In multivariable analysis, there was no difference in mortality at 24 hours (hazard ratio for women 0.64, 95% confidence interval 0.34-1.23, P = .18) or in time to hemostasis (hazard ratio 1.10, 95% confidence interval 0.84-1.42, P = .49) by sex. We observed no difference between sexes in volume of blood products transfused during active hemorrhage. However, after anatomic hemostasis, women received lower volumes of all products, with a 38% reduction in fresh frozen plasma (mean ratio 0.62 (95% confidence interval 0.43-0.89, P = .01), 49% reduction in platelets (mean ratio 0.51, 95% confidence interval 0.33-0.79, P < .01) and 49% reduction in volume of red blood cells (mean ratio 0.51, 95% confidence interval 0.33-0.79, P < .01).

CONCLUSION

Mortality and time to hemostasis of trauma patients with hemorrhage did not differ by sex. Although there was no difference in transfusion requirement during active hemorrhage, once hemostasis was achieved, women received fewer units of all blood products than men. Further research is required to determine whether women exhibit differences in coagulation during and after severe traumatic hemorrhage.