Nephrology
Seán Keenan
2022
,Urinary Tract Infection
Description
Bacteriuria may be symptomatic or asymptomatic and is not in itself a disease. A UTI is diagnosed on the basis of signs
and symptoms with tests such as urinalysis and culturing providing more information. It should be noted that there is
no standardised bacterial count for urine as it is highly variable per person. A lower UTI involves the bladder (cystitis)
or prostate (prostatitis) whereas an upper UTI involves the kidney / renal pelvis (pyelonephritis). Annual incidence of
UTI in women is 10-20 %. 10 % of men and 20 % of women >65 YO have asymptomatic bacteriuria. Pyelonephritis
occurs 3 per 1000 patient years.
Presentation Investigations
- Lower UTI Features - Urinalysis: CI in Asx pregnancy + catheterised Pt
o Urination: Dysuria; Frequency; Urgency - NB: -ve dipstick ↓ probability of UTI to <20 %
o Urine: Dysuria; Pyuria; Malodorous - MSSU: Cut off >105 CFU/m
o System: Low Grade Fever; Malaise - Systemic: FBC; U&E; CRP; Blood culture
o Pain: Lower Abdominal Pain - NB: BCx only +ve in 15 % of pyelonephritis
o Elderly: Acute confusion is common - Imaging: Cystoscopy; Urodynamics; CT
- Cystitis Features - NB: If Male UUTI; Pyelonephritis; Haematuria
o Urination: Dysuria; Frequency; Urgency Management
o Urine: Dysuria; Haematuria; Polyuria - Non-Pregnant Women
o System: Suprapubic pain o Abx: Trimethoprim or Nitrofurantoin for 3 d
- Acute Pyelonephritis Features o MSSU: If >65 YO; Haematuria
o Urination: Cystitis symptoms - Symptomatic Pregnant Women
o Urine: White casts seen on microscopy o MSSU: Performed in all patients
o System: Costovertebral Pain; Fever; Rigors; N&V o 1L: Nitrofurantoin (Avoid in 3TM/BF – G6PD)
o Pain: Loin; Flank; Costovertebral pain o 2L: Amoxicillin; Cefalexin
o Cc: Septic shock o 3L: Trimethoprim (Avoid in 1TM-2TM)
- Prostatitis Features o NB: 7 d course even if Asx
o System: Fever; N&V; Malaise - Asymptomatic Pregnant Women
o Pain: Genital; Perineum; Rectum; Back pain o MSSU: Routinely done at first antenatal clinic
o PR Exam: Swollen and tender prostate o Abx: If ↑ CFU/mL treat as symptomatic
Causes o NB: ↓ Risk of acute pyelonephritis + Pre-term
- Infective Organisms - Male Patients
o Common: E. coli (80 %); S. aureus (5-10 %) o Abx: Trimethoprim; Nitrofurantoin 7 d course
o Other: Proteus mirabilis (males); Pseudomonas o Prostatitis: Ciprofloxacin for 14 d
o NB: Proteus ➔ ↑ Urea ➔ Urate stones in bladder - Catheterised Patients
- Risk Factors o Asx: Do not treat asymptomatic bacteriuria
o Inoculation: Sex; ↓ Hygiene; Faecal Incontinence o Sx: 7-day as opposed to 3d Abx course
o Urinary: Infrequent voiding; Hurried micturition o NB: Replacecatheter
o Obstruction: Constipation; Neuropathic bladder - Acute Pyelonephritis
o Vesioureteric Reflux: 35 % of kids with UTI o Local: Follow local guidelines
o NB: Avoiding urination/ stopping mid-flow o BSA: Cephalosporin; Quinolone for 10-14 d
, Acute Kidney Injury
Aetiology of AKI
Considerations of Medications in AKI
Location Pathology Example
↓ Vascular Volume Haemorrhage; D&V; Burns; Pancreatitis Safe to Continue Worsens AKI Risk of Toxicity
↓ Cardiac Output Cardiogenic shock; MI
Pre-Renal Paracetamol NSAIDs Metformin
Systemic vasodilation Sepsis; drugs
Renal vasoconstriction NSAIDs; ACEi; ARBs; Hepatorenal syndrome Warfarin Aminoglycosides Lithium
Glomerular Glomerulonephritis; ATN
Statins ACEi Digoxin
Renal Interstitial Drug reaction; Infection; Infiltration (sarcoid)
Vessels Vasculitis; HUS; TTP; DIC Aspirin ARBs -
Within Renal tract Stone; Renal tract malignancy; Stricture; Clot Clopidogrel Diuretics -
Post-Renal Pelvic malignancy; Prostatic hypertrophy;
Extrinsic compression β-Blockers - -
Retroperitoneal fibrosis
Description
Acute Kidney Injury (AKI) is a syndrome of decreased renal function, measured by serum creatinine or urine output,
occurring over hours-days. The Kidney Diseases: Improving Global Outcomes (KDIGO) define AKI as; A rise in creatinine
>26 μmol/L within 48 hrs; A rise in creatinine >1.5 x baseline (i.e. before the AKI) within 7 days; Urine output <0.5
mL/kg.hr for >6 consecutive hours. The severity of AKI is then staged according to the highest creatinine rise or longest
period/severity of oliguria. AKI occurs in up to 18 % of hospital patients and ~50 % of ICU patients. Risk factors include
CKD, age, male sex and comorbidity such as DM, CVD, malignancy, CLD (chronic liver disease), complex surgery.
Description Investigations
- Incidence: ~15 % of inpatients will develop an AKI - U&E: ↑ K+; ↑ Urea; ↑ Creatinine
Presentation - Urinalysis: Perform on all patients
- Urinary: ↓ Urine output; Fluid overload - Imaging: Renal USS within 24 hrs if unknown cx
- Uraemia: Pericarditis; Encephalopathy Management
Classifications - General Management
- Prerenal AKI o Basic: Stop nephrotoxics; Fluid before contrast
o Path: ↓ Perfusion to the kidney due to ischaemia o Support: Fluid balance; Review meds (below)
o Cx: Hypovolaemia; D&V; Renal Artery stenosis o Furosemide: Cautious use in fluid overload
- Intrarenal AKI o Arrythmias: See table below
o Path: Damage to glomeruli, tubules or interstitium o Haemodialysis: If pulmonary oedema
o NB: Proteinuria and haematuria may be observed - Prerenal Management
o Cx: GN; ATN; AIN; Rhabdomyolysis; Tumor lysis syn. o Fluids: Correct volume depletion
- Postrenal AKI o Perfusion: ↑ Renal perfusion
o Path: Obstruction to urine flow o Support: Circulatory and Cardiac support
o Cx: Renal stone; BPH; Ext. compression of ureter - Intrarenal
Risk Factors o Biopsy: Refer for biopsy to determine cause
- Age: ≥65 YO o Specialist: Requires specialist intervention
- Renal: CKD; Hx of AKI - Postrenal Management
- Systems: HF; Liver disease; DM o Relieve: Urinary catheter
- DAMN: Diuretics; AGCs/ACEi/ARBs; Metformin; NSAID o Surgical: Nephrostomy
KDIGO Criteria
- Creatinine ↑ ≥26 mmol/L in 24 hrs - Stage 1: ↑ 1x Baseline Creatinine
- Creatinine ↑ 1.5xin past 7 days - Stage 2: ↑ 2x Baseline Creatinine
- Urine output <0.5 mL/kg/hr for ≥6 hrs - Stage 3: ↑ 3x Baseline Creatinine
Treatment of Hyperkalaemic Arrythmias
Stabiolisation of Cardiac Short-term shift in Removal of Potassium from
Membrane Potassium from ECC to ICC the body
IV Calcium Gluconate Infused Insulin/Dextrose Calcium Resonium
- Nebulised Salbutamol Loop diuretics
- - Dialysis
Seán Keenan
2022
,Urinary Tract Infection
Description
Bacteriuria may be symptomatic or asymptomatic and is not in itself a disease. A UTI is diagnosed on the basis of signs
and symptoms with tests such as urinalysis and culturing providing more information. It should be noted that there is
no standardised bacterial count for urine as it is highly variable per person. A lower UTI involves the bladder (cystitis)
or prostate (prostatitis) whereas an upper UTI involves the kidney / renal pelvis (pyelonephritis). Annual incidence of
UTI in women is 10-20 %. 10 % of men and 20 % of women >65 YO have asymptomatic bacteriuria. Pyelonephritis
occurs 3 per 1000 patient years.
Presentation Investigations
- Lower UTI Features - Urinalysis: CI in Asx pregnancy + catheterised Pt
o Urination: Dysuria; Frequency; Urgency - NB: -ve dipstick ↓ probability of UTI to <20 %
o Urine: Dysuria; Pyuria; Malodorous - MSSU: Cut off >105 CFU/m
o System: Low Grade Fever; Malaise - Systemic: FBC; U&E; CRP; Blood culture
o Pain: Lower Abdominal Pain - NB: BCx only +ve in 15 % of pyelonephritis
o Elderly: Acute confusion is common - Imaging: Cystoscopy; Urodynamics; CT
- Cystitis Features - NB: If Male UUTI; Pyelonephritis; Haematuria
o Urination: Dysuria; Frequency; Urgency Management
o Urine: Dysuria; Haematuria; Polyuria - Non-Pregnant Women
o System: Suprapubic pain o Abx: Trimethoprim or Nitrofurantoin for 3 d
- Acute Pyelonephritis Features o MSSU: If >65 YO; Haematuria
o Urination: Cystitis symptoms - Symptomatic Pregnant Women
o Urine: White casts seen on microscopy o MSSU: Performed in all patients
o System: Costovertebral Pain; Fever; Rigors; N&V o 1L: Nitrofurantoin (Avoid in 3TM/BF – G6PD)
o Pain: Loin; Flank; Costovertebral pain o 2L: Amoxicillin; Cefalexin
o Cc: Septic shock o 3L: Trimethoprim (Avoid in 1TM-2TM)
- Prostatitis Features o NB: 7 d course even if Asx
o System: Fever; N&V; Malaise - Asymptomatic Pregnant Women
o Pain: Genital; Perineum; Rectum; Back pain o MSSU: Routinely done at first antenatal clinic
o PR Exam: Swollen and tender prostate o Abx: If ↑ CFU/mL treat as symptomatic
Causes o NB: ↓ Risk of acute pyelonephritis + Pre-term
- Infective Organisms - Male Patients
o Common: E. coli (80 %); S. aureus (5-10 %) o Abx: Trimethoprim; Nitrofurantoin 7 d course
o Other: Proteus mirabilis (males); Pseudomonas o Prostatitis: Ciprofloxacin for 14 d
o NB: Proteus ➔ ↑ Urea ➔ Urate stones in bladder - Catheterised Patients
- Risk Factors o Asx: Do not treat asymptomatic bacteriuria
o Inoculation: Sex; ↓ Hygiene; Faecal Incontinence o Sx: 7-day as opposed to 3d Abx course
o Urinary: Infrequent voiding; Hurried micturition o NB: Replacecatheter
o Obstruction: Constipation; Neuropathic bladder - Acute Pyelonephritis
o Vesioureteric Reflux: 35 % of kids with UTI o Local: Follow local guidelines
o NB: Avoiding urination/ stopping mid-flow o BSA: Cephalosporin; Quinolone for 10-14 d
, Acute Kidney Injury
Aetiology of AKI
Considerations of Medications in AKI
Location Pathology Example
↓ Vascular Volume Haemorrhage; D&V; Burns; Pancreatitis Safe to Continue Worsens AKI Risk of Toxicity
↓ Cardiac Output Cardiogenic shock; MI
Pre-Renal Paracetamol NSAIDs Metformin
Systemic vasodilation Sepsis; drugs
Renal vasoconstriction NSAIDs; ACEi; ARBs; Hepatorenal syndrome Warfarin Aminoglycosides Lithium
Glomerular Glomerulonephritis; ATN
Statins ACEi Digoxin
Renal Interstitial Drug reaction; Infection; Infiltration (sarcoid)
Vessels Vasculitis; HUS; TTP; DIC Aspirin ARBs -
Within Renal tract Stone; Renal tract malignancy; Stricture; Clot Clopidogrel Diuretics -
Post-Renal Pelvic malignancy; Prostatic hypertrophy;
Extrinsic compression β-Blockers - -
Retroperitoneal fibrosis
Description
Acute Kidney Injury (AKI) is a syndrome of decreased renal function, measured by serum creatinine or urine output,
occurring over hours-days. The Kidney Diseases: Improving Global Outcomes (KDIGO) define AKI as; A rise in creatinine
>26 μmol/L within 48 hrs; A rise in creatinine >1.5 x baseline (i.e. before the AKI) within 7 days; Urine output <0.5
mL/kg.hr for >6 consecutive hours. The severity of AKI is then staged according to the highest creatinine rise or longest
period/severity of oliguria. AKI occurs in up to 18 % of hospital patients and ~50 % of ICU patients. Risk factors include
CKD, age, male sex and comorbidity such as DM, CVD, malignancy, CLD (chronic liver disease), complex surgery.
Description Investigations
- Incidence: ~15 % of inpatients will develop an AKI - U&E: ↑ K+; ↑ Urea; ↑ Creatinine
Presentation - Urinalysis: Perform on all patients
- Urinary: ↓ Urine output; Fluid overload - Imaging: Renal USS within 24 hrs if unknown cx
- Uraemia: Pericarditis; Encephalopathy Management
Classifications - General Management
- Prerenal AKI o Basic: Stop nephrotoxics; Fluid before contrast
o Path: ↓ Perfusion to the kidney due to ischaemia o Support: Fluid balance; Review meds (below)
o Cx: Hypovolaemia; D&V; Renal Artery stenosis o Furosemide: Cautious use in fluid overload
- Intrarenal AKI o Arrythmias: See table below
o Path: Damage to glomeruli, tubules or interstitium o Haemodialysis: If pulmonary oedema
o NB: Proteinuria and haematuria may be observed - Prerenal Management
o Cx: GN; ATN; AIN; Rhabdomyolysis; Tumor lysis syn. o Fluids: Correct volume depletion
- Postrenal AKI o Perfusion: ↑ Renal perfusion
o Path: Obstruction to urine flow o Support: Circulatory and Cardiac support
o Cx: Renal stone; BPH; Ext. compression of ureter - Intrarenal
Risk Factors o Biopsy: Refer for biopsy to determine cause
- Age: ≥65 YO o Specialist: Requires specialist intervention
- Renal: CKD; Hx of AKI - Postrenal Management
- Systems: HF; Liver disease; DM o Relieve: Urinary catheter
- DAMN: Diuretics; AGCs/ACEi/ARBs; Metformin; NSAID o Surgical: Nephrostomy
KDIGO Criteria
- Creatinine ↑ ≥26 mmol/L in 24 hrs - Stage 1: ↑ 1x Baseline Creatinine
- Creatinine ↑ 1.5xin past 7 days - Stage 2: ↑ 2x Baseline Creatinine
- Urine output <0.5 mL/kg/hr for ≥6 hrs - Stage 3: ↑ 3x Baseline Creatinine
Treatment of Hyperkalaemic Arrythmias
Stabiolisation of Cardiac Short-term shift in Removal of Potassium from
Membrane Potassium from ECC to ICC the body
IV Calcium Gluconate Infused Insulin/Dextrose Calcium Resonium
- Nebulised Salbutamol Loop diuretics
- - Dialysis
