document: autosomal dominant polycystic kidney disease ( adpkd ) affects between 1 in every 500 and 1 in every 1000 individuals and is found in all racial and ethnic groups 
   . the disease may not be clinically apparent until the third or fourth decade of life and only about half of the patients will progress to renal failure . in young patients , there is no way to predict whether or when renal failure will develop , although several risk factors such as hypertension , renal hemorrhage , multiple pregnancies , male gender , and pkd1 disease genotype have been associated with a more rapid course . 
   complications associated with pregnant subjects with chronic renal failure undergoing dialysis include maternal hypertension , preeclampsia , anemia , infected renal and hepatic cysts , pyelonephritis , and rupture of cerebral artery aneurysm during labor with subarachnoid hemorrhage 
   . however , with careful and effective perioperative monitoring spinal anesthesia can be safely performed for cesarean section in patients undergoing hemodialysis . 
   an 80 kg 35-year - old full term primigravida with oligohydramnios was scheduled for emergency lower segment cesarean section ( lscs ) . 
   she was diagnosed to have adpkd in the seventh month when she complained of flank pain , generalized swelling , and decreased urine output . 
   she was hospitalized and hemodialyzed thrice a week for the next 2 months to maintain blood urea nitrogen ( bun ) , serum creatinine , and potassium values within acceptable limits . 
   the nephrologists and obstetricians decided to proceed with an emergency lscs as she was full term . 
   clinical parameters were heart rate of 102/ min regular , systemic blood pressure of 120/74 mm hg in supine position , central venous pressure ( cvp ) 1 - 2 cm h2o . 
   preoperative investigations showed hemoglobin ( hb ) of 10.2 gm% , normal leucocyte count , and mild proteinurea and pus cells in urine . 
   her biochemical profile revealed bun of 30 mg / dl , serum creatinine 3.7 mg% , serum sodium 140 mmol l , serum potassium 5 mmol l , and normal liver function tests . 
   coagulation profile was bleeding time 3 min , clotting time 9 min , activated partial thromboplastin time ( aptt ) 30 s , platelet count 150  10l , prothrombin time 13 s , and international normalized ratio 1:2 . 
   arterial blood gas on air showed ph 7.41 , pco2 30.8 mm hg , po2 93.3 mm hg , spo2 98% , and hco3 22 meq . after obtaining informed written consent , patient 
   monitoring included pulse oximeter , cardioscope , noninvasive blood pressure ( nibp ) , cvp , and urine output measurement . 
   a peripheral line of 18 g in the left arm was used to preload her with 500 ml of normal saline till cvp was 5 cm h2o . 
   spinal anesthesia was successfully given in the l3 - 4 intervertebral space using 1 ml of 0.5% hyperbaric bupivacaine ( 5 mg ) with 25 mcg fentanyl in the left - lateral position with a 25 g spinal needle . 
   intraoperatively , bp was in the range of 100 - 120 mm hg systolic , hr 70 - 100/ min , cvp 5 - 6 cm h2o and urine output of approximately 1 
   a 2.0 kg live male child was delivered ( apgar score of 9 at 5 min ) . 
   patient did not complain of pain for about 4 h ; thereafter , she was given intravenous tramadol 8 hourly . 
   postoperatively , she maintained normal hemodynamic and biochemical parameters and did not require any hemodialysis . 
   there was no neurological deficit ; she was shifted to the nephrology unit after 72 h and discharged on day 7 . 
   women with moderate or severe antenatal renal insufficiency often experience deterioration of their renal functions during pregnancy . the pathophysiology by which pregnancy exacerbates renal disease is unknown . 
   one hypothesis is that increased glomerular perfusion which normally accompanies pregnancy paradoxically causes further injury to the kidneys in patients with preexisting impairment of function . 
   however , this hypothesis is not supported by published data , which reveal no evidence of hyperfiltration . 
   epstein outlined an alternative hypothesis in which preexisting renal disease may induce a cascade of platelet aggregation , microvascular fibrin thrombus formation , and endothelial dysfunction that leads to microvascular injury in the already tenuous kidneys . increased cardiac output and decreased intrarenal vascular resistance in pregnancy cause an 80% increase in renal blood flow and a 50% increase in glomerular filtration rate ( gfr ) . 
   because of the increased gfr , a serum creatinine concentration greater than 0.8 mg / dl and a bun concentration greater than 13 mg/ dl ( which are normal values for the nonpregnant patient ) suggest renal insufficiency . 
   tubular sodium reabsorption and osmoregulation are reset , allowing a  physiologic hypervolemia  during gestation . 
   modest proteinuria also occurs during pregnancy ( up to 300 mg in 24 h ) . 
   when serum creatinine concentration exceeds 2.0 mg / dl there is a one in three chance of developing dialysis - dependent end stage renal disease during or shortly after pregnancy . our patient presented with symptoms of renal insufficiency only in the seventh month of gestation , it is difficult to opine whether her disease progressed during pregnancy or the diagnosis was missed earlier . on presentation , 
   the blood erythrocyte count and hematocrit may be increased above normal possibly because of abnormal erythropoietin production by the cysts ; hence , they do not have anemia as profound as that occurring in other types of terminal renal disease . for ambulatory chronic renal failure patients , hb of 11 - 12 g / dl 
   blood coagulation studies and platelet counts are usually normal in patients of adpkd , as was the case in our patient . 
   hypertension an early symptom , occurring in approximately 60% of patients secondary to stretching of arterioles across expanding cysts leading to increased secretion of renin and angiotensin . 
   although the patient was not anuric and did not have ecg changes due to hyperkalemia , it was decided to dialyze her at least thrice a week . during pregnancy early dialysis 
   is recommended ( when the gfr is approximately 10 ml / min , rather than waiting until it falls further ) and treating with more frequent and longer hemodialysis sessions . 
   problems occurring in a pregnant patient on hemodialysis are need for vascular access , cardiovascular instability , large fluid , and electrolyte shifts , need for anticoagulation of extracorporeal circuit and risk of hepatitis . 
   fetal heart rate monitoring is recommended , even when hypotension and major fluid shifts are avoided , as doppler examination of uterine and umbilical artery flow during hemodialysis suggest redistribution of arterial flow away from the uteroplacental vascular bed . 
   bun levels are kept below 80 mg / dl predialysis and 30 mg / dl postdialysis . at birth , 
   the increase in concentration of most coagulation factors is associated with a shortening of the prothrombin and aptt during pregnancy . 
   there are reports of safe administration of epidural anesthesia , without any neurologic complications , in thrombocytopenic ( platelet count < 100 000/cumm ) healthy pregnant women , preeclampsia , and women with autoimmune thrombocytopenic purpura . 
   they state that in the absence of clinical evidence of bleeding , regional anesthesia should not necessarily be withheld in pregnant women with a platelet count of less than 1 00 000/cu mm . 
   no hemorrhagic complications were observed in 24 women with unsuspected thrombocytopenia ( platelet counts of 15 - 99  10/l ) who received spinal anesthesia or in 24 children with acute lymphoblastic leukemia and platelet counts below 20  10/l . 
   intravenous unfractionated heparin should be stopped 4 - 6 hrs before neuroaxial blockade and a normal aptt should be confirmed . since our patient had been dialyzed the previous day and her electrolytes , aptt , platelet counts , bleeding time and hemoglobin values were within acceptable limits , we decided to proceed with spinal anesthesia . 
   high degree of suspicion for any neurological complications should be maintained in the postoperative period . 
   preservation of renal function intraoperatively depends on maintaining an adequate intravascular fluid volume and minimizing drug - induced cardiovascular depression . 
   we used low dose of local anesthetic with intrathecal opioid in an effort to preserve renal and uterine blood flow . 
   low dose of spinal anesthesia has the advantage of providing cardiovascular stability and it is advocated that 8 mg of 0.5% hyperbaric bupivacaine is the optimal dose for cesarean section . 
   we were able to achieve a sensory level of t6 with 5 mg of 0.5% bupivacaine combined with fentanyl 25 mcg . 
   bogra j et al . studied the synergistic , potentiating effect of fentanyl on bupivacaine in spinal anesthesia for cesarean section , on comparing the hemodynamic stability of equipotent doses of bupivacaine and bupivacaine fentanyl , they found the latter to be more stable .
summary: renal disease , either preexisting or occurring during gestation may impair maternal and fetal health . a 35-year - old primigravida with autosomal dominant polycystic kidney disease on hemodialysis was scheduled for emergency cesarean section . 
   she was managed successfully with low - dose intrathecal bupivacaine and fentanyl . in the case of pregnancy in such a patient , early involvement of the nephrologists along with the obstetrician 
   can improve maternal and fetal outcome .