Archive | 2019
Illusive Dynamic Nadirs and Masks of Postoperative Hyponatraemia and the TURP Syndrome: Volumetric Overload Over Time (VO/T) Concept for Resolving its Puzzle
Abstract
Introduction and Objective Postoperative hyponatraemia (HN) causes serious morbidity and mortality, of which the transurethral resection of the prostate (TURP) syndrome is a unique model. It is an illusive puzzle with unclear definition, unknown aetiology, difficult diagnosis and disputed therapy. Clinical presentation ranges from prodromal symptoms to severe signs of circulatory shock and multiple vital organ dysfunction/ failure (MVOD/F) or death. All severe cases were reported retrospectively and attributed to multiple toxic/ dilution hypotheses interchangeably with recognized clinical conditions. The overlooked VO/T causes dynamic HN nadirs and masks making it a complex clinical/biochemical jigsaw puzzle with false and missing pieces. The objective here is to resolve this puzzle. \n \nPatients and Methods: Investigations based on clinical observations, critical literature analysis, physics-physiological and clinical prospective studies done over the past 32 years. Observations and deductive analysis identified VO/T insult, HN nadirs, clinical paradoxical masks of shock and MVOD/F. Documented evidence provided correct puzzle pieces and stepping-stones that led to new understanding, rejecting false and discovering missing ones. Prospective studies verified and quantified VO/T insult causing secondary, tertiary HN nadirs and osmotic gaps. Severity depends on VO over T and fluid type of sodium-free (VO1) and sodium-based (VO2) fluids and tonicity as well as patient’s variables of body weight and hormones. The results of all prospective studies on VO, HN nadirs, and clinical severity grades have contributed to resolving the puzzle that is impossible to resolve using a single prospective study. \n \nResults: “VO over T” causes the biochemical and clinical features of HN and the TURP syndrome. Dilutional HN “shock” and “VO” concepts were reported 45 and 11 years ago but VO insult remained invisible. The puzzle was resolved after unraveling the dynamic role of T in HN nadirs, discovering missing pieces and refuting unduly incriminated dilutional and toxic hypotheses. 3.5l of VO1 (5% body weight) infused in 1h causes HN shock and MVOD/F syndrome. The immediate postoperative secondary HN nadir is proportional to VO1 and clinical severity but shock mask is confused with haemorrhage or sepsis. The late tertiary HN nadir is disproportional to both but osmotic fluid shift into cell “Missing VO” confuses VO1 cell oedema and necrosis with cerebral or cardiac infarction. Inappropriate therapeutic response with “aggressive vascular expansion” erases HN, makes shock irreversible and establishes MVOD/F. \n \nConclusions \n \nThe concept of “VO over T’ insult explains the aetiology of HN and the TURP syndrome and pathophysiology of HN nadirs unveiling its paradoxical presentation masks and refuting dilutional and toxic hypotheses. It exposes the biochemical, clinical and therapeutic illusions, resolving HN puzzle and paving the way to identify “VO shock”, “optimize” fluid therapy and precise life-saving hypertonic sodium therapy. The new capillary-interstitial hypothesis based on G tube dynamic makes resolving MVOD/F puzzle neither difficult nor distant.