**12. References**

60 Novel Insights on Chronic Kidney Disease, Acute Kidney Injury and Polycystic Kidney Disease

be extended to those without clinical cerebral disease. This diagnostic and dependent therapeutic dilemma will persist until we have a mindset to consider RSW in these patients and develop a better diagnostic approach to solving this dilemma. Recommendations to determine FEurate in normonatremic patients have not been resolved except to include it as a routine measurement in any patient with acute brain disease and demented patients with

In patients with symptomatic hyponatremia such as muscular irritability, altered mental status or seizures, the patient should be treated with hypertonic saline to increase serum sodium by 4-6 mmol/l over 4 hours and then slowly thereafter. (Sterns & Silver, 2008) Although it is safe to increase serum sodium to normal values in conditions such as in acute and documented water intake, marathon runners, that cause acute hyponatremia, we recommend gradual improvement in all patients with hyponatremia to avoid any contributions rapid correction might add to circumstances in which osmotic demyelination might occur irrespective of their sodium, such as in malnourished patients or those with liver disease. (Almond et al, 2005, Sterns & Silver, 2008) We favor a conservative approach to the correction of chronic hyponatremia by increasing serum sodium <10 mmol/l/24 hrs with slower rates for patients with severe malnutrition and cirrhosis to avoid osmotic

The present chapter hopefully provided the following important insights and new

1. an appreciation of the diagnostic and therapeutic dilemma that exists for SIADH and

2. provided an objective review of how the controversy over the relative prevalence of

3. emphasized our inability to assess accurately the state of ECV as being the root of this enigmatic controversy and how the overlapping features of both syndromes make it

5. RSW is much more common than SIADH in neurosurgical patients and RSW can occur

6. although FEurate is increased in both SIADH and RSW, FEurate can differentiate one syndrome from the other by reverting to normal in SIADH and being persistently

7. the demonstration of natriuretic activity in plasma of neurosurgical and in the plasma and urine of Alzheimer disease patients with increased FEurate and normonatremia introduces the possibility that an increased FEurate with normonatremia might be

8. the natriuretic factor probably contributes to RSW, has its major effect in the proximal

9. a normal FEurate in patients with nonedematous hyponatremia is highly suggestive of

10. the normal FEurate and predictability of ADH responses suggest that RO might

tubule where urate is exclusively transported and is not A/BNP.

represent a group that is pathophysiologically different from SIADH.

RO and identifies a common and overlooked disorder.

virtually impossible to differentiate SIADH from RSW on first encounter.

4. reviewed the relative merits by which we determine ECV.

AD.

demyelination.

**11. Summary** 

RSW.

directions in our understanding of RSW:

SIADH and RSW evolved.

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**4** 

**Epidemiology, Causes and Outcome** 

Acute kidney injury (AKI) is a clinical syndrome denoted by an abrupt decline in glomerular filtration rate (GFR) sufficient to decrease the elimination of nitrogenous waste products (urea and creatinine) and other uremic toxins (Jefferson et al, 2010). AKI is a not very common yet serious complication occurring in pregnancy. The incidence and the mortality rates associated with obstetric acute kidney injury (also known as pregnancy related acute renal failure; PRARF) have decreased over the last few decades especially in developed countries (Prakash et al, 2007; Stratta et al, 1996). There are several factors which lead to this improvement and will be discussed later in the chapter. Since the term AKI is now widely used in place of acute renal failure (Ricci et al, 2011); for the ease of description

Obstetric AKI can occur at any stage of pregnancy; ante-partum or post-partum and may be AKI occurring as a coincidence during pregnancy or AKI due to causes specific to

Although obstetric AKI is vanishing from developed world (Stratta et al, 1996), it is still a frequent cause of maternal morbidity and mortality in the developing nations. Poverty, lack of awareness and difficulties (e.g. lack of transport) accessing obstetric care all are responsible for this additional burden (World Health Organization [WHO], 2009). This also increases the disparity in reported number of cases and its actual occurrence contributing to

Insight into the occurrence and consequences of kidney disease has rapidly progressed. More than 30 different definitions have been used for defining AKI in the literature, creating much confusion and making comparisons difficult (Bellomo et al, 2001). Recently, consensus

**1.1 Definition and epidemiology of Acute Kidney Injury (AKI) and obstetric AKI** 

we have used obstetric AKI in place of PRARF in this chapter.

scarcity of literature even in recent time.

**1. Introduction** 

pregnancy.

\* Corresponding Author

**of Obstetric Acute Kidney Injury** 

Namrata Khanal1\*, Ejaz Ahmed2 and Fazal Akhtar2

*Sindh Institute of Urology and Transplantation, Karachi,* 

*1Middlemore Hospital, Auckland, 2Department of Renal Medicine,* 

> *1New Zealand 2Pakistan*

