آية البقرة 32سورة

Acute Kidney Injury During

Pregnancy, Challenges inDiagnosis & Treatment

Presented by Marwa Medhat Elkaref

M.B., B.ChAlexandria University

Acute kidney injury (AKI) is known as prompt decrease in renal function over a period of several hours to days sufficient enough to result in retention of nitrogenous waste products in body.

The physiologic changes in pregnancy make diagnosis of AKI difficult. So clinicians must be familiar with these changes so they can diagnose any early complication.

Introduction

Is to discuss how to make an early diagnosis

and differentiate between normal

physiological renal changes during

pregnancy and AKI to allow prompt

intervention and to improve morbidity and

mortality in obstetric renal failure.

Aim of the Work

Pregnancy is characterized by significant physiological changes that begin shortly after conception:

Length of both kidneys increase by 1 cm

Dilatation of calicyeal system, renal pelvis and ureters.

GFR and renal blood flow increase by 30-45%.

Serum creatinine fall to 0.4-0.8mg/dl so serum creatinine of 1 mg/dl in pregnant should be considered as abnormal value.

Excretion of glucose, proteins and bicarbonate increase during pregnancy.

Renal physiological changes during pregnancy

It occurs with bimodal distribution.

Etiology of AKI during pregnancy

1st peak: 7th- 8th week

2nd peak:32th- 36th week

Based on trimester of pregnancy AKI can be classified into three groups:

Also AKI known to be traditionally classified into: prerenal, renal and post renal.

First half Second half Postpartum

Hyperemsis gravidurum Septic abortion

PreeclampsiaHELLPAFLP

TTPHUS

Is defined as severe and persistent nausea and

vomiting leading to weight loss, exceeding 5

percent of the pre-pregnancy body weight, and

ketonuria.

These patients present in the first trimester of

pregnancy with acute renal failure associated

with a hypokalemic, metabolic alkalosis.

Hyperemsis gravidarum

Is an infected abortion complicated by fever, endometritis, and parametritis and it remains one of the most serious threats to women’s health worldwide.

WHO defines abortions as unsafe when they are performed by individuals lacking the necessary skills, or in an environment that does not conform to minimal medical standards, or both.

Septic abortion (unsafe abortion)

Preeclampsia is a major cause of renal dysfunction during pregnancy.

It is accompanied by a specific renal lesion known as glomerular endotheliosis, in which the glomeruli enlarge and become ischemic.

Preeclampsia is characterized by general vasoconstriction and hemoconcentration with a reduced intravascular volume.

Preeclampsia

It is defined as combination of hemolysis with a micro-angiopathic blood smear, increased liver enzymes, and low platelets (HELLP).

5-10% of women with pre-eclampsia develop HELLP.

HELLP

It is defined as microvesicular fatty infiltration of hepatocytes during second half of pregnancy (usually third trimester), and it remains a common cause of liver failure in pregnancy.

Recent investigations have found thatAKI occurs in up to 90% in women with AFLP.

Acute fatty liver of pregnancy (AFLP)

TTP is classically characterized by the pentad of microangiopathic-hemolytic-anemia-(MAHA), thrombo-cytopenia, neurologic dysfunction, fever, and renal failure.

Patients with pregnancy-associated TTP are at increased risk for the development of recurrent TTP in subsequent pregnancies.

Thrombtic thrombocytopenic purpura and hemolytic uremic syndrome

TTP occurs due to deficiency of ADAMTS-13

which is usually acquired, resulting from

neutralizing autoantibodies, although congenital

ADAMTS-13 deficiency accounts for a minority

of cases.

Thrombtic thrombocytopenic purpura and hemolytic uremic syndrome

Most patients with HUS have a more prominent component of renal insufficiency than those with TTP, although significant overlap in symptoms/ findings may occur.

Levels of ADAMTS-13 are generally not severely reduced in most patients with HUS.

Thrombtic thrombocytopenic purpura and hemolytic uremic syndrome

There are 3 aspects to be considerd in the

management of AKI during pregnancy:

Renal function supportive measures

Treatment of underlying disease

Dialysis

Management

Restore or maintain fluid balance

Maintenance of electrolyte and acid base balance.

Maintenance of nutritional support.

Prevention of infection.

Avoid renal toxins.

Control continuing blood loss (if present).

Renal function supportive measures:

Avoid over hydration by using diuretics which commonly have been given in attempt to convert the oliguric state to a non-oliguric state.

However diuretics have not been shown to be beneficial and they may worsen outcomes.

Diuretics useful only in management of fluid overload patients.

Renal function supportive measures:

Septic abortion (unsafe abortion):

Prevention of unwanted pregnancy and avoidance

of septic abortion are keys to eliminate abortion-

associated AKI in early pregnancy

Treatment of underlying disease:

Resuscitation goals: Central venous pressure (CVP): 8-12mmHg.

Mean arterial pressure (MAP): > 65 mmHg.

Urine output (UOP) : > 0.5ml/kg/h

Central venous or mixed venous oxygen saturation > 70% or >65% respectively.

Treatment of underlying disease:

Fluid therapy: should start immediately and larger amounts may be needed but must be done with careful monitoring to avoid overload.

Antimicrobal therapy: IV antibiotics should be started as early as possible always within first hour of recognizing sepsis.

Blood product administration: if coagulopathy develops.

Treatment of underlying disease:

Fluid and electrolyte replacement:

Avoid dextrose containing fluids which may precipitate Wernicke`s encephalopathy.

Withhold non-essential drugs associated with nausea and vomiting as iron supplementation.

A combination of antiemetic medications may be required.

Hyperemsis gravidarum

Diagnosis:

Blood pressure >140/90 after 20th week in

previously normotensive woman.

Proteinuria >300 mg/24hr.

Severe preeclampsia: blood pressure >160/110 and

involvement of one or more organ.

Preeclampsia: management

Treatment:

Control blood pressure.

Prevention and treatment of eclampsia

Fluid management

Planning of delivery

Preeclampsia: management

Once diagnosis is confirmed decision should be made regarding delivery.

Delivery is an ultimate cure and should be done immediately after 34th week or before 34th week if AKI, multi organ dysfunction, DIC or fetal distress developed.

HELLP

Corticosteroid: used to accelerate fetal lung maturity followed by delivery after 24 hours.

Platelet transfusion: done in actively bleeding patient with thrombocytopenia less than 20.000 to avoid excessive bleeding due to CS.

Platelet transfusion may be required to achieve preoperative platelet count more than 40.000 to 50.0000.

HELLP

It is important to confirm diagnosis because women with AFLP can rapidly develop liver failure and encephalopathy.

Patient must have at least six of the following symptoms.

Nausea, vomiting, hypoglycemia, renal failure, coagulopathy, hyperuricemia, metabolic acidosis and pancreatitis.

Acute fatty liver during pregnancy

Rapid termination must be done.

Plasma exchange and renal replacement

therapy are very effective in treatment of

AFLP complicated by renal failure as they

remove most of toxins, supply coagulation

factor and albumin.

Acute fatty liver during pregnancy

TTP and HUS sharing overlapping features and may be difficult to differentiate from each others.

They both share:

Thrombocytopenia < 150.000 or >25% decrease from baseline

Micro angiopathic Hemolysis : schistocytes and or elevated LDH.

TTP and HUS

Neurological symptoms: confusion or seizures

Renal impairment: elevated creatinine and/or decreased GFR

Gastrointestinal disorder: nausea, vomiting, abdominal pain

But they are different in:

ADAMTS13 activity

TTP and HUS

< 5% activity TTP

> 5% activityHUS

Corticosteriods: used as an adjuvant treatment for ADAMTS13 deficiency related TMA

Plasma exchange: may be done early in pregnancy in women with ADAMTS 13 deficiency to maintain enzymatic activity >10%

Rituximab (B cell depleting antibody): optimal second line therapy if plasma exchange fail to induce or maintain TMA remission

Eculizumab: blocks the common terminal activation step of all three component pathways and was approved by FDA for treatment of aHUS.

Treatment:

If the previous procedures prove to be insufficient, dialysis is the next step.

The indications for dialysis Uremic symptoms (encephalopathy, pericarditis or

neuropathy) Volume overload Hyperkalemia Metabolic acidosis unresponsive to initial medical treatment However, authors recommend starting dialysis earlier, when

GFR falls to below 20 ml/min per 1.73 m2

Dialysis :

Any dialysis modality can be used in pregnancy because there are no randomized studies showing benefits for a specific technique but in most cases, the choice is intermittent hemodialysis.

Heparin and low-molecular-weight heparin are safe in pregnancy because they do not cross the placental barrier.

Dialysis :

Both can be used during hemodialysis treatment.

Dialysis management in a pregnant patient differs slightly from that in a non-pregnant one.

The hours and frequency of dialysis are increased by 50% to maintain a BUN of less than 80 mg/dL, with the ideal range 50 to 60 mg/dL.

Dialysis :

BUN levels of more than 80 mg/dL are associated with an increased risk for fetal demise.

During dialysis, it is important to avoid hypotension and rapid fluctuations in intravascular volume.

Anemia is common in patients receiving dialysis and is exacerbated by pregnancy.

Dialysis :

Approximately 35% of patients need to be transfused before or at delivery.

Giving packed red blood cells during dialysis prevents volume overload and aggravation of hypertension.

Erythropoietin has been shown to be effective in treating anemia in pregnancy.

Dialysis :