scholarly journals Improving on the Adrogué-Madias Formula

Kidney360 ◽  
2020 ◽  
pp. 10.34067/KID.0005882020
Author(s):  
Sheldon Chen ◽  
Michael Shieh ◽  
Robert Chiaramonte ◽  
Jason Shey
Keyword(s):  
Serum Sodium ◽  
Fluid Volume ◽  
Linear Scaling ◽  
Non Linear ◽  
Actual Volume ◽  
New Equation ◽  
Sodium Correction ◽  
Approximate Answer ◽  
Original Formula ◽  
Negative Volume

The Adrogué-Madias (A-M) formula is correct as written, but technically it only works when adding one liter of an intravenous (IV) fluid. For all other volumes, the A-M algorithm gives an approximate answer, one that diverges further from the truth as the IV volume is increased. If one liter of an IV fluid is calculated to change the serum sodium by some amount, then it was long assumed that giving a fraction of the liter would change the serum sodium by a proportional amount. We challenged that assumption and now prove that the A-M change in [sodium] is not scalable in a linear way. Rather, the delta [Na] needs to be scaled in a way that accounts for the actual volume of IV fluid being given. This is accomplished by our improved version of the A-M formula in a mathematically rigorous way. Our equation accepts any IV fluid volume, eliminates the illogical infinities, and, most importantly, incorporates the scaling step so that it cannot be forgotten. However, the non-linear scaling makes it harder to obtain a desired delta [Na]. Therefore, we reversed the equation so that clinicians can enter the desired delta [Na], keeping the rate of sodium correction safe, and then get an answer in terms of the volume of IV fluid to infuse. The improved equation can also unify the A-M formula with the corollary A-M loss equation wherein one liter of urine is lost. The method is to treat loss as a negative volume. Since the new equation is just as straightforward as the original formula, we believe that the improved form of A-M is ready for immediate use, alongside frequent [sodium] monitoring.

A New Resuscitation Formula Based on Burn Index Provides More Reliable Prediction for Fluid Requirement in Adult Major Burn Patients

2021 ◽  
Author(s):  
Jianglin Tan ◽  
Junyi Zhou ◽  
Ning Li ◽  
Lili Yuan ◽  
Gaoxing Luo
Keyword(s):  
Fluid Resuscitation ◽  
Linear Regression Analysis ◽  
Fluid Volume ◽  
Multivariate Linear Regression Analysis ◽  
Burn Patients ◽  
Full Thickness ◽  
Burn Wound ◽  
Major Burn ◽  
Fluid Requirement ◽  
Actual Volume

Abstract The Third Military Medical University (TMMU) formula is widely used in fluid resuscitation in China. However, the actual volume needs usually exceed the prediction provided by the TMMU formula in major burn patients with a high proportion of full-thickness burn wounds. This retrospective study included 149 adult major burn patients (≥40% TBSA) who were admitted to the Burn Department, Southwest Hospital from 2014 to 2020 and received appropriate fluid resuscitation by the TMMU protocol. The actual volume infused in the first 48 hours postburn was compared to the estimation by the TMMU formula. A new fluid volume prediction formula was developed by multivariate linear regression analysis. The mean fluid requirements were 2.35 ml/kg/% TBSA and 1.75 ml/kg/% TBSA in the first and second 24 hours postburn, respectively. The TMMU formula underestimated the fluid requirement, and its prediction accuracy was 54.1% and 25.8% for the first and second 24 hours, respectively. The proportion of full-thickness burn wound was found to be associated with the fluid requirements postburn. A revised multifactorial formula consisting of the burn index, body weight, and inhalation injury was developed. Using the revised formula, the prediction reliability of resuscitation fluid volume improved to 65.3% and 61.1% in the first and second 24 hours, respectively. The TMMU formula showed low accuracy in predicting fluid requirements among major burn patients. A revised formula based on burn index was developed to provide better guidance for initiative fluid resuscitation for major burns by the TMMU protocol.

Confirmation Bias Affects Estimation of Blood Loss and Amniotic Fluid Volume: A Randomized Simulation-Based Trial

2020 ◽  
Author(s):  
Fouad Atallah ◽  
Rafine Moreno-Jackson ◽  
Rodney McLaren ◽  
Nelli Fisher ◽  
Jeremy Weedon ◽  
...  
Keyword(s):  
Blood Loss ◽  
Amniotic Fluid ◽  
Confirmation Bias ◽  
Fluid Volume ◽  
The Other ◽  
Chronic Hypertension ◽  
Convenience Sample ◽  
Amniotic Fluid Volume ◽  
Simulation Based ◽  
Actual Volume

Abstract Objective This study was aimed to determine if confirmation bias affects diagnoses in obstetrics, specifically estimation of blood loss and amniotic fluid volume. Study Design We performed a randomized simulation-based trial. Participants went through the following three consecutive scenarios: (1) the first involved estimating the volume of blood (actually a blood-like substance) in a container at the simulation model's perineum. The actual volume was either 500 or 1,500 mL. Participants were told it was blood seen after a vaginal delivery. One group was told that the “patient” was normotensive, the other was told that the “patient” was hypotensive. (2) The second scenario involved estimation of amniotic fluid from an ultrasound picture of four quadrants, with one group told that the patient was normotensive and the other group told that the patient had chronic hypertension. (3) The third scenario was a “negative image” of the first (i.e., if they had been randomized to the 500 mL/normotensive in scenario one, then they would be presented with the 1,500 mL/hypotensive). They also filled a survey including demographics and tolerance of ambiguity and confirmation bias scales. Results From April 2018 through May 2018, a convenience sample of 85 providers was recruited. Participants were more likely to overestimate blood loss when they were told that the patient was hypotensive (p = 0.024), in comparison to when they were told the patient had normal blood pressure. They were also less likely to estimate the amniotic fluid as normal when they were told that the patient was hypertensive (p = 0.032). Conclusion Confirmation bias affects estimates of blood loss and amniotic fluid.

330: Low Frequency of Overly Rapid Serum Sodium Correction During Treatment of Euvolemic or Hypervolemic Hyponatremia With Conivaptan

2007 ◽  
Vol 50 (3) ◽  
pp. S104
Author(s):  
L.E. Wagoner ◽  
S. Rosansky ◽  
D. Zeltser ◽  
J.G. Verbalis ◽  
B. McNutt ◽  
...  
Keyword(s):  
Serum Sodium ◽  
Low Frequency ◽  
Sodium Correction

Linear and non-linear scaling of the Yangtze River flow

2008 ◽  
Vol 22 (10) ◽  
pp. 1532-1536 ◽  
Author(s):  
Guojie Wang ◽  
Buda Su ◽  
Zbigniew W. Kundzewicz ◽  
Tong Jiang
Keyword(s):  
Yangtze River ◽  
River Flow ◽  
Linear Scaling ◽  
The Yangtze River ◽  
Non Linear

scholarly journals Multifactorial diabetes insipidus during pregnancy: a challenging diagnosis

2021 ◽  
Vol 14 (3) ◽  
pp. e238410
Author(s):  
Alexandra Novais Araújo ◽  
Maria Cunha ◽  
Tiago Marques ◽  
Maria João Guerreiro Martins Bugalho
Keyword(s):  
Diabetes Insipidus ◽  
Serum Sodium ◽  
Antiretroviral Treatment ◽  
Growth Restriction ◽  
Obstetric Ultrasound ◽  
Adequate Treatment ◽  
Foetal Growth ◽  
Foetal Growth Restriction ◽  
Underlying Disorder ◽  
Sodium Correction

Diabetes insipidus (DI) is characterised by thirst and polydipsia with hypotonic polyuria. Several forms exist, namely, central or pituitary, nephrogenic and gestational and must be differentiated for adequate treatment. We describe the case of a 41-year-old woman chronically infected with HIV who had been recently medicated with a tenofovir-based antiretroviral treatment and who, at 22 weeks of pregnancy, presented with transient gestational DI. Obstetric ultrasound revealed oligohydramnios and foetal growth restriction that did not improve despite serum sodium correction. The severity of the case suggested the presence of an underlying disorder and elevated copeptin levels indicated that an underlying subclinical form of nephrogenic DI, possibly induced by HIV-related nephropathy or tenofovir use, was present and rendered clinically overt during pregnancy.

Osmotic demyelination syndrome following slow correction of hyponatraemia

2021 ◽  
Vol 14 (8) ◽  
pp. e241407
Author(s):  
Isabel Saunders ◽  
David M Williams ◽  
Aliya Mohd Ruslan ◽  
Thinzar Min
Keyword(s):  
Antidiuretic Hormone ◽  
Serum Sodium ◽  
Inflammatory Markers ◽  
Urine Osmolality ◽  
Fluid Restriction ◽  
Osmotic Demyelination Syndrome ◽  
Electrolyte Disturbance ◽  
Osmotic Demyelination ◽  
Sodium Correction ◽  
Hospital Inpatients

Hyponatraemia is the most common electrolyte disturbance observed in hospital inpatients. We report a 90-year-old woman admitted generally unwell following a fall with marked confusion. Examination revealed a tender suprapubic region, and investigations observed elevated inflammatory markers and bacteriuria. Admission investigations demonstrated a serum sodium of 110 mmol/L with associated serum osmolality 236 mmol/kg and urine osmolality 346 mmol/kg. She was treated for hyponatraemia secondary to syndrome of inappropriate antidiuretic hormone (SIADH) and urosepsis. However, her serum sodium failed to normalise despite fluid restriction, necessitating treatment with demeclocycline and hypertonic saline. Despite slow reversal of hyponatraemia over 1 month, the patient developed generalised seizures with pontine and thalamic changes on MRI consistent with osmotic demyelination syndrome (ODS). This case highlights the risk of ODS, a rare but devastating consequence of hyponatraemia treatment, despite cautious sodium correction.

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