Renal Replacement Therapies

Dr Phyo AungEmergency Medicine Registrar

This presentation will includeCauses of renal failure Dialysis Techniques Complications of dialysis Common problems in dialysis patients Download link : will be posted in

Why renal failure talk?

Common patients population 10th leading cause of death (2008 data) : 3224 deaths One in nine Australians over 25 years has reduced renal functionPatients receiving dialysis treatment per year ( 2009)=10341Leading cause of death in Aboriginal populations , 10 times higher than rest of populationEconomic impact of ESKD $ 800 millions per year ( All facts and numbers from Kidney Health Australia )

Acute renal failure defination Acute Kidney Injury Network (AKIN) www.akinnet.org criteriaAbrupt reduction ( within 48 hours ) in renal functionAbsolute increase in serum creatinine (> or = 100 umol/L)Percentage increase in serum creatinine > or = 50% from base line ( 1.5 fold from the base line )Reduction in urine output ( < 0.5 ml/kg per hour for more than six hours)

Causes of Acute Renal FailurePre Renal ( Renal Hypo perfusion)Intravascular volume depletion ( dehydration , blood loss)Severe hypotension ( drug overdose , sepsis , shock )pump failure ( myocardial causes) Renal artery emboli

Renal ATN ( Acute Tubular Necrosis from a/c pancreatitis ,burn ,sepsis , toxins including exogenous and endogenous )Interstitial nephritis / AGN Hepatorenal syndrome

Post Renal Renal vein thrombosis , Ureteric stones , Prostate , retroperitoneal f fibrosis , increased intra abdominal pressure )

ECG Changes

Hyperkalemia TreatmentAgent Dose Onset

/DOAMOA Comments

10%Ca Gluconate or Ca Chloride

10 ml in 10 mins

1-5 mins/ ~1 hr

Antagonizes membrane effects of K

ECG monitoring requiring

Insulin/Glucose

10-20 units IV and 25 to 50 g of 50% dextrose

30 mins Intracellular movement of K

Hypo/Hyperglycaemia

Salbutamol 10-20 mg Neb

30mins/2 hr Intracellular movement of K

Side effects: tremors , tachycardia

NaHCO3 150 mmol/L IV

10-15 mins/1-2 hr

Intracelluar movement of K

Use mainly in Acidotic pt

Resonium 25 g PO or 50 g PR

Hours Exchange of K for Na

Constipation, Na overload

Indications for renal dialysis

Hyperkalemia ( refractory Rx , persistently > 6.5 mmol/L)Pulmonary Odema ( Refractory Rx )Severe Acidosis ( pH < 7.1 )Uraemic complications ( pericarditis , encephalopathy )Anuria or oliguria ( urine < 200ml in 12 hours ) Drug Overdoses Removable drugs ( Lithium , Barbiturates , Salicylates , Methanol , cephalosporins , aminoglycosides ) Non removable drugs ( Digoxin , tricyclic antidepressants , pheyntoin, benzodiazepines , beta blockers , OHAs)

Types of dialysisIHD ( Intermittent Haemodialysis ) : day procedure setting . 3 times per week : mostly for ESRD patients

Peritoneal Dialysis : home dialysis , 4 -5 exchange times per day or overnight procedure . Less effective than HD

Continuous Renal Replacement Therapy CVVH – Continuous Venovenous Hemofiltration CVVHD – Contiouous venovenous Hemodialysis CVVHDF – Continuous venovenous Hemodaifiltration

Different types

Typical dialysis machine

Diffusion Convection

CVVH

CVVHD

CVVHFD

VasCath for dialysis

Mahurkar Double Lumen Catheter Medcomp Duo Flo IJ

Catheter

Advantages and disadvantagesAdvantages Haemodynamic Stability – patients who cannot tolerate IHD are candidate for CRT Slower electrolyte and fluid shifts effective removal of larger molecules

Disadvantagesneeds skills for vascular access continuous anticoagulation => risk of bleedingICU support needed

Complications in IHD patientsVascular ComplicationsAV fistula = lifeline for ESRD patients 1) Bleeding common complication , from minor trauma or after HD Rx : firm gentle pressure x 10 -15 minutes topical gel foam to avoid vigorous pressure IV DDAVP or Protamine sulfate for heparin reversal 2) loss of thrill or bruit over fistula – thrombosis Rx : urgent vascular consult for clot removal Avoid : BP cuff , IV cannula , Central line over access arm 3) Infection over vascular access : common Rx : needs admission for IV anti Single loading dose of Vancomycin and loading dos e of aminoglycoside followed by cephalosporin

Non vascular complications in IHD patientsHypotensionMost common cause = sudden reduction in circulating volume during and after HD

Other important causes Acute haemorrhage from various sited due to qualitative platelet defect , Rx administration of DDAVPOccult GI Bleeding Anaphalytic reaction t o contents in dialysateSevere Hyper kalemiaPericardial tamponade due t o pericardial h’age or worsening pericardial effusion

Dyspnoea in ESRDVolume Overload Congestive Heart Failure 10-30% higher prevalence in dialysis patients ESRD+CHF = 83% mortality at 3 yearsOther Causes of dyspnoea Pleural Effusion Pleural Haemorrhage Air Embolism less common with newer dialysis machines more common in usage of subclavian catheters “ Mill wheel murmur “ crunching sound on auscultation Rx : clamp the catheter and stop dialysis place patient in the left lateral decubitus position if continued decompensation : aspirating air backwards

Altered Mental State in IHD PatientsDialysis Disequilibrium Syndrome e (DDS ) mostly occurred during or immediately after haemodialysis Symptoms included headache , nausea , vomiting , muscle cramps , confusion , seizures or coma . The syndrome is triggered by rapid movement of water into brain cells following the development of transient plasma hypoosmolality as solutes are rapidly cleared from the bloodstream during dialysis . Rx : supportive ( usually self limiting ) resolved after fluid and solutes are re distributed across cell membranes.

Differential Diagnosis of confusion in IHD

Uremia Hypertensive EncephalopathyHypocalcaemiaHypoglycaemiaHyperkalemiaHypovolemiaIntracranial haemorrhage : high risk of spontaneous bleeding Subdural Haemorrhage are common Have a low threshold for CT scan

Dialysis Dementia chronic dialysis patient . Due to aluminium or phosphate binding in brain Rx : Desfuroxamine

Chest Pain in CRF Pericarditis occur 6 to 10 % of ESRD pt usually those who have yet to start dialysis lacks the typical ECG changes * Rx : hemodialysis Acute Coronary Syndrome 50% of all death in ESRD due to cardiovascular disease 25 to 40 % have LV dysfunction risk factor usually present ( DM , HT , hyperlipidaemia ) Silent ischemia is also common chest pain during dialysis is ISCHEMIC until proven otherwise dialysis is like a stress test , should delay HD in patients with unstable angina for at least 24 hours.

TroponinsRegulatory proteins found in cardiac and skeletal musclethree subunits T , I and C Genes encoding for both cardiac and skeletal isoform Tn C is identical : so not useful for TnC.

Theories for elevation Tn in CRF inflammatory response to CRF uremic myopathy subclinical myocardial injury from chronic fluid overload reduced renal clearance CK MB will be elevated up t o 50% of CKD patients

EMCREG RecommendationsEmergency Medicine Cardiac Research &Education Group

Elevations of Tr T or I likely represent myocardial injury and should not be considered non specific due to CRFPatients with elevated Tr , no matter how minor , are at higher risk for cardiovascular mortality and over all mortality.Elevated Tr may not be secondary to ACS , patients with CKD are higher risk . Any elevation in Troponin should warrant further cardiac evaluation.Patient with CKD having chronic low level trop require s measuring a typical rise in Tr over a period of hours improves diagnostic accuracy . ( with serial blood and ECGs)

Peritoneal Dialysis Complications

Peritonitis is the most common complicationPt present with abdomen pain , fever , malaise and dialysis effluent become cloudy.Peritoneal fluid sent for Gram’s stain , culture , Total and DC.Dx : > 100 WBC/mm3 with neutrophils predominant or culture positive.Rx : loading dose of Vancomycin IP +/- gentamicin IP follow ed by once daily dose IP at the time of exchange.

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