Weight-based thyroid dosing vs fixed dosing during pregnancy for subclinical hypothyroidism: A retrospective cohort study

OBJECTIVE

Thyroid hormones play a crucial role in foetal growth and neurocognitive development. Our aim was to compare a weight-based dosing method of starting thyroxine to a fixed-dose method in newly diagnosed women with subclinical hypothyroidism during pregnancy.

DESIGN

We performed a retrospective cohort study of consecutive women with newly diagnosed subclinical hypothyroidism during pregnancy seen at Mount Sinai Hospital and Women's College Hospital, Toronto, Canada 2015-2018.

PATIENTS

We identified women that were treated based on pre-pregnancy weight and those that were given a fixed dose of 50 mcg/day.

MEASUREMENTS

The percent of women who reached the target TSH of <2.5 mIU/L within 4-8 weeks was compared using a chi-squared test and a logistic regression model, adjusting for age, initial TSH and gestational age treatment was started.

RESULTS

393 women were included: 252 treated using a fixed-dose approach; 141 treated based on pre-pregnancy weight. In the unadjusted analysis, there was no difference between the groups in the percentage of women in the target range within 4-8 weeks (89.6% in the fixed-dose group vs 88.8% in the weight-based group (p = .954)). However, after adjustment for between-group differences in age, initial TSH and gestational age treatment was started, there was a significantly greater odds of achieving the target range using the weight-based dosing (OR 4.26 (1.60-11.7), p = .004).

CONCLUSIONS

Treating women with newly diagnosed subclinical hypothyroidism during pregnancy with a weight-based strategy increased the odds of reaching the target TSH range within 4-8 weeks. Clinicians caring for these women should consider this approach when starting treatment during pregnancy.

Chloride-liberal fluids are associated with acute kidney injury after liver transplantation

Introduction

Acute kidney injury (AKI) occurs frequently after liver transplantation and is associated with significant morbidity and mortality. Recent evidence has linked the predominant usage of ‘chloride-liberal’ intravenous fluids, such as 0.9% saline to the development of renal dysfunction in general critically ill patients. We compared the effects of perioperative fluid types on AKI in liver transplant recipients.

Methods

An observational analysis of liver transplant recipients over a 33-month period, between January 2010 and September 2013, was performed. Intensive care unit database and patient records were analyzed for determinants of early postoperative AKI. Univariate and multivariate regression analysis was carried out using a two-tailed P value less than 0.05 to establish significance. The institutional Research Ethics Committee approved the study methodology (RAC no. 2131 073).

Results

One hundred and fifty-eight liver transplants were performed, AKI developed in 57 (36.1%) patients: 39 (68.4%) fully recovered, 13 (22.8%) developed chronic renal failure and 10 (17.5%) required long-term hemodialysis. On univariate regression analysis, AKI was significantly associated with greater than 3,200 ml of chloride-liberal fluids infused within the first postoperative day (HR 5.9, 95% CI 2.64, 13.2, P <0.001), greater than 1,500 ml colloids received in the operating room (hazard ratio (HR) 1.97, 95% CI 1.01, 3.8, P = 0.046), vasopressor requirement for 48 hours posttransplant (HR 3.34, 95% CI 1.55, 7.21, P = 0.002), hyperchloremia at day 2 (HR 1.09, 95% CI 1.01, 1.18, P = 0.015) and preoperative model for end-stage liver disease (MELD) score (HR 1.08, 95% CI 1.03, 1.13, P <0.001).

After stepwise multivariate regression, infusion of greater than 3,200 ml of chloride-liberal fluids (HR 6.25, 95% CI 2.69, 14.5, P <0.000) and preoperative MELD score (HR 1.08, 95% CI 1.02, 1.15, P = 0.004) remained significant predictors for AKI.

Conclusions

In a sample of liver transplant recipients, infusion of higher volumes of chloride-liberal fluids and preoperative status was associated with an increased risk for postoperative AKI.