Anesthesia

1. LEVY MWANAWASA MEDICAL
UNIVESITY
PRESENTER : RUTH MBEWE
TOPIC : ANAESTHESIA IN RENAL FAILURE PATIENT

2. THE RENAL SYSTEM
 The kidneys play a central role in implementing and
controlling a variety of homeostatic functions of the body.
This includes:
 EXCRETORY FUNCTION
• Waste excretion
• Drug excretion
• Toxin
• Metabolites
 HOMEOSTATIC FUNCTION
• Regulation of the bodies fluid balance.
• Regulation of the bodies acid-base.
• Regulation of electrolyte balance.

3.  ENDOCRINE FUNCTION
• Renin secretion - RAAS which in turn regulates blood pressure.
• Erythropoietin - stimulates the production of RBC in the bone
marrow.
• Prostaglandins – via systemic effects.

4. RENAL IMPAIREMENT - ACUTE KIDNEY
INJURY
 Acute renal failure is characterized by the sudden and
often reversible deterioration of renal functions over a
period of hours to few days or weeks, resulting failure of
the kidneys to excrete nitrogenous waste products and to
maintain fluid, electrolytes and acid-base homeostasis.
 AKI is defined as any of the following:
• Increase in serum creatinine by 0.3mg/dL or more within 48hrs or
• Increase in serum creatinine to 1.5 times baseline or more within
the last seven days or
• Urine output less than 0.5mL/kg/hour for 6hrs

5.  It can be categorized as;
 Pre-Renal AKI(55%)-Diseases that cause renal
hypoperfusion, resulting in decrease in renal
function without frank parechymal damage
 Renal or Intrinsic AKI(40%)-Diseases that directly
involve the renal parenchyma
 Post-Renal AKI(5%)-Diseases associated with
urinary tract obstruction

7.  Patients with AKI can be oliguric or non-oliguric on
the basis of their urine production. (Oliguria
<400ml/day, Non-oliguria >400ml/day).
 The prognosis of patients with AKI is related to the
cause, the presence or absence of pre-exiting renal
disease as well as the duration or renal dysfunction
prior to therapeutic intervention. The condition was
thought to be completely reversible, however some
patients may progress to chronic renal failure.

8. CHRONIC KIDNEY DISEASE
 Chronic Kidney Disease(CKD)- Refers to an irreversible
and progressive deterioration in renal function which
develops over months to years.
 It causes a multi-systemic dysfunction which can be
caused by the primary disease process, effects of uremia
or both.
 Stage 1; kidney damage with normal or decreased GFR
(greater than or equal to 90ml/min)
 Stage 2; Kidney damage with mild decreased GFR (60-
89 ml/min)
 Stage 3; Moderate decreased GFR(30-59 ml/min)
 Stage4; Severe decreased GFR (15-29 ml/min)
 Stage 5; Kidney failure with GFR <15 ml/min or need to
dialysis.

9. CAUSES OF CKD
 Hypertension(35%)
 Diabetes Mellitus(15%)
 Glomerulonephritis(6%)
 HIV(5%)
 Sickle Cell Disease(4%)
 Others

10. SOME FEATURES OF CKD
 Metabolic acidosis
 Altered haemostasis
• Platelet dysfunction
• Prothrombotic tendency and reduced fibrinolysis
 Autonomic neuropathy
• Delayed gastric emptying
• Parasympathetic dysfunction
 Uremia
 Hypertension

11.  Fluid and electrolytes abnormalities
• Volume overload
• Hyperkalemia-exacerbated by acidaemia
• Hypocalcemia
• Hyperphosphatemia
• Hyponatremia
 Hypoalbuminemia
 Increased cardiovascular mortality
 Increased risk for infections
 Bone diseases

12. PRE-OPERATIVE MANAGEMENT
PRE-OPERATIVE MANAGEMENT IN AKI
If the cause of AKI is unclear, further investigation is
warranted before all surgery except for emergencies
 The underlying cause should be addressed
 Pre-Anesthetic Optimization in these patients require
optimization in the form of;
• Early nephrology consultation
• The symptomatic and supportive treatment of
hypotension and hypovolemia
• Judicious fluid administration to maintain blood
pressure/ urine output
• Correction electrolyte derangements (hyperkalemia,
acidosis, etc
• Treatment of sepsis
• Removal of nephrotoxic agents where possible
• Transfusion if needed

13.  Use of certain medications as free radical scavengers to
decrease ischeamic injury.
• mannitol
• N-acetylcysteine
 Dialysis
• Criteria for dialysis
 Hyperkalemia refractory to medical
• Correction of severe acid-base disturbances
• Severe uremia and its effects (pericarditis, gastritis,
encephalopathy etc)
• Coagulopathy
• Drug toxicity etc.

14. PRE-OPERATIVE MANAGEMENT IN
CKD
 These patients should be optimized using a multi displinary approach
as CKD affects all organ systems. There should be a collective
collaboration between the nephrologists, surgeons and anesthetists.
 There pre-op management is similar to that of patients with AKI
 CKD is strongly associated with an accelerated form of ischeamic
heart disease and as such, all patients should have a baseline ECG.
 Vascular access should be chosen carefully, current and potential
fistula sites should be avoided
 Patients with chronic renal failure should receive dialysis treatment
12-24hrs before planned surgery to optimize their electrolyte;
metabolic and volume status.
 N.B: Potassium abnormalities must be corrected, these predispose
patients to cardiac arrythmias and ECG abnormalities can be
manifested.

15. OTHER CONCERNS

16.  Anemia is frequent in patients with chronic renal failure along with
this, they are at increased risk for bleeding as a result of altered
platelet function and decreased levels of some clotting factors.
 Generally, these patients should be optimized with the use of
erythropoiesis-stimulating agents(ESA) and other agents, pending an
investigation of their anemia,
 Transfusions are best avoided but if their clinical situation warrants
one, pre-operatively, fresh units are recommended.
 Generally if the Hb >7g/dL transfusion is recommended, usually 2
units then the patient’s clinical status should be reassessed.
 High risk patients (age 65 and/or cardiovascular or respiratory
disease) may tolerate anemia poorly and may be transfused when
Hb concentration is <8g/dL

17. OTHER PREOPERATIVE CONCERNS
 Drugs that are excreted solely via the kidney should
be switched.
 Medications may need to be stopped or used with
caution during the perioperative period, especially
with regards to certain analgesics and antibiotics
used cautiously and with appropriate dose
adjustment.

18. OPERATIVE MANAGEMENT
PRE MEDICATION
 Reduced doses of opioids or BZD.
 H2 blocker- Aspiration prophylaxis
 Metoclopramide- 10mg for accelerating gastric,
prevent vomiting, reduce risk of aspiration,
antihypertensive agents should be continued until
the time of surgery.

19. MONITORING
 All routine monitoring- ECG, NIBP, SpO2, EtCO2
 Monitoring urine output and intravascular volume
(desirable urinary output: o.5ml/kg/hour)
 Intra-arterial’ central venous, pulmonary artery
monitoring are often indicated.
 Intra-arterial blood pressure monitoring in poorly
controlled hypertensive patients.

20. LOCAL ANAESTHESIA
 LA infiltration of the surgical field is the most
physiologically stable of the anesthetic techniques
and is therefore used in patients with severe co-
morbidity.
 It’s main disadvantage is that it is the least well
toralated by patients of the anesthetic options.

21. REGIONAL ANAESTHESIA
 This offers many advantages over other
techniques, including intraoperative hemodynamic
stability and good postoperative analgesia
 Adequacy of coagulation should be considered and
the presence of uremic neuropathies excluded
before regional anesthesia is performed in these
patients
 Co-exiting metabolic acidosis may decrease the
seizure threshold for local anesthetics.

22. REGIONAL + SEDATION
 An alternative is a combined approach using RA
and sedation. This improves patients tolerability of
RA whilst maintaining its advantages over LA
infiltration and GA(minimal physiological
disturbance, improvement in regional vascular flow
and good postoperative analgesia.
 Patients with CRD have multiple GA risk factors, as
described previously in this article. However there
is no evidence that GA presents a higher risk than
techniques.

23. ANESTHESIA TECHNIQUES

24. INDUCTION
 The dose of induction agent should be carefully
considered. Many patients will need a reduced dose.
 In hypovolemia there is a diversion of blood to essential
organs and across the blood brain barrier, therefore
effects of induction agents may be exacerbated.
 Patients are at increased risk of aspiration: rapid-
sequence induction with cricoid pressure should be done.

28. MUCLE RELAXANTS

30. REVERSAL
 Neuro-muscular blockage is reversed with neostigmine or
pyridostigmine in combination with anticholenergic.
 Neostigmine and pyridostigmine has 50% & 70% renal
elimination respectively.
 Glycopyrolate has 80% renal excretion so should be
used cautiously.
 Atropine undergoes 25% renal elimination and rest
hepatic metabolism to form metabolite noratropine which
has renal excretion.
 Extubation should be done after complete reversal of NM
blockage.

31. POST OPERATIVE
 Monitoring of fluid overload or hypovolemia titrated fluids.
 Residual neuromuscular blockade.
 Monitoring of urea and electrolytes.
 ECG monitoring for detecting cardiac dysrhythmias.
 Continue oxygen supplementation post operative period.

32. POST OPERATIVE CONTD.
 Analgesia with regional
 Carefully titrated opioids, increased CNS depression,
respiratory depression – naloxone.
 Post operative cardiac assessment should be performed
and continued for 3-5 days with daily ECFs and
screening of cardiac enzyme levels to detect and treat
possible perioperative MI.
 Admission to high dependency or intensive care facilities
may be suitable for patients with significant co-morbidity
and after major surgical procedures.

33. POST OPERATIVE CARE
HIGH DEPENDENCY CARE UNITY CARE
 Post operative patients who need detailed monitoring for longer than
can be accommodated in a recovery unit.
 Unstable patients requiring greater observation than can be provided
on a general ward.
 Patients requiring single organ support, excluding advanced
respiratory support.
 Patients no longer needing intensive care but who are nit yet well
enough to be returned to a general ward.
INTENSIVE CARE UNIT
 Patients with respiratory failure requiring advanced respiratory
support.
 Patients requiring support of two or more organ systems.
 Patients with chronic co-morbidity of one or more organ systems that
require support fir an acute reversible failure or another system.

34. SUMMARY
 Patients presenting for surgery with renal insufficiency or
failure present a significant challenge for the
anesthesiologist.
 The perioperative care of these patients should be
arranged and carried out by senior staff from surgery,
anesthesia and renal medicine
 failure to care for these patients well will impact the
perioperative morbidity and mortality.
END.