PERIOPERATIVE FLUID MANAGEMENT Anaesthesiology

Perioperative fluid management.
Special focus:Goal directed fluid therapy.

1. PERIOPERATIVE FLUID MANAGEMENT Dr. Satyajit Nihar Singh Junior Resident Guide: Dr. Neha Padhi Assistant Professor

2. WHY FLUID MANAGEMENT IS NECESSARY?

3. CRYSTALLOIDS VS COLLOIDS

4. MAINTENANCE FLUID VS REPLACEMENT FLUID Replacement Fluids: Treat existing deficits/compensate for ongoing losses during perioperative period. Commonly used :0.9% NaCl, Ringers’ Lactate, Synthetic Colloids Maintenance Fluids: required for optimization of ongoing losses due to physiological processes to maintain homeostasis. commonly used: Dextrose, Dextrose saline, Dextrose Hypotonic saline, Isolyte .

5. CRYSTALLOIDS VS COLLOIDS

6. PRE-OPERATIVE FLUID THERAPY There should be correction of :- • Hypovolemia • Anemia • Electrolyte disorders Which fluid to give? • It depends upon the nature of loss , hemodynamic status , concentration and composition of abnormality. • Mostly 0.9% saline , Ringer’s lactate , colloids , whole blood are used. How to monitor? • Improvement in tachycardia and BP • Absence of orthostatic hypotension • urine output > 0.5 ml/kg/ hr (in absence of diuretics)

7. INTRA-OP FLUID THERAPY Why intra-operatively volume derangement occurs? Blood loss Intraoperative fluid loss by 3rd space loss , evaporative loss from viscera and wound itself Vasodilatory effect of anaesthesia Which IV fluid to give? RL – as it is most physiological fluid , composition similar to body fluid Isotonic saline : - when RL is contraindicated . Colloids – to treat sudden hypotension due to major blood loss till blood is awaited

8. HOW MUCH FLUID TO GIVE? Maintenance fluid to be given as per Holiday-Segar Rule i.e : 4-2-1 formula: 4ml/kg/hr for the 1 st 10kg + 2ml/kg/hr for next 10kg+ 1ml/kg/hr for every body weight above 20kg. Deficit is calculated based on total duration of NPO hours . Replacement is done : 50% in the 1 st hour + 25% in the 2 nd hour + rest 25% in the 3 rd hour in addition to the maintenance fluid.

9. THIRD SPACE LOSS REPLACEMENT CALCULATION

10. POST-OP FLUID THERAPY The goal of this is to :- a) maintain reasonable MAP >65mmHg b) pulse rate < 120 BPM c) urine output >0.5ml/kg/hr with normal temp. , warm skin , normal resp. , sensorium Causes of post-op hypovolemia a) NPO b) inadequate correction of pre-op and intra-op losses c) 3rd space loss , fluid loss from NG aspiration , drains , fistulas

11. GDFT: PO>>>>>IV

12. MEASUREMENT OF VOLUME STATUS: VARIOUS METHODS

13. COMMONLY USED TECHNIQUES IN GDFT TRANSOESOPHAGEAL ECHOCARDIOGRAPHY:Measures SV,CO,CVP. PULMONARY ARTERY CATHETERIZATION:Measures CVP,SvO2,LVEDP,LVEDV,SV,CO,CI and SVR ARTERIAL WAVE FORM ANALYSIS BASED TECHNIQUES:Continuous monitoring of BP,CO,SV,PPV,SVR

14. Passive Leg Raising Test : Independent of Heart Lung interaction. Helps to access preload Induces gravitational blood transfer from Legs to Thorax. 10 -15% increase in CO/SV  Fluid responsiveness Limitations: Cannot be used where patient mobilisation is not possible ( Head Trauma).

15. Inferior Vena Cava Collapsibility Index ( cIVC ): IN SPONTANEOUS RESPIRATION : Inspiration  Negative Intra thoracic pressure Increased Venus return to Heart IVC Collapse. Expiration  IVC diameter increases Return to baseline again. IN MECHANICALLY VENTILATED PATIENT: Effect or respiration is completely reverse. This is called “ Distensibility Index ”. cIVC = ( IVCdmax – IVCdmin )/ IVCdmax X 100 cIVC value 40-48%  Fluid responsiveness

16. OESOPHAGEAL DOPPLER: Measures thoracic aortic blood velocity to calculate SV,CO. Relatively easier to perform than TEE.

17. SPECIAL CONSIDERATIONS NEUROSURGERY: Receive diuretics to decrease ICP  urine output is not reliable. Avoid hypoosmolar fluids(0.45% saline/5%glucose)reduce plasma osmolality movement of fluid across BBB into brain tissue from plasma increase cerebral oedma  increase ICP. Glucose administration local/global ischemia. AVOID SALT FREE GLUCOSE CONTAINING SOLUTIONS. Hypertonic saline solutions help to decrease ICP and maintain CPP.

18. OPEN HEART SURGERY: Use of CPB makes volume replacement complicated. Review patient’s underlying electrolyte status before choosing the fluid. Avoid potassium containing fluids in presence of hyperkalemia . Low ejection fraction  excessive use of crystalloidsvolume overload pulmonary oedema Colloids(except Albumin Coagulation abnormalities/Anaphylactic reactions Infants & Children blood volume replacements>>>non blood volume replacements

19. KIDNEY TRANSPLANT SURGERY: Determination of volume status is challenging conventional monitors are misleading. GDFT with dynamic indices is useful. CO used as measure of effectiveness of therapy. 500 ml crystalloid givenCO increased by 15%/CVP by 2 mmHg positive response. Lack of positive response consider INOTROPES/VASOPRESSORS

20. LIVER TRANSPLANT SURGERY: Patient with End Stage Liver Disease Low SVRsodium and water retentionIncrease in total body fluid. Portal Hypertensionexpands splanchnic circulationfall in relative amount of fluid in systemic circulation. Movement of protein rich fluids into body cavitiesASCITES/PLUERAL EFFUSION. Cross clamping of IVC during surgeryHypotensionrenal dysfunction. Preoperative Coagulopathy commonIncreased chances of Haemorrhage. Avoid excessive fluid administrationmaintain low CVP. Use FFP,platelets,cryoppt prevent coagulopathy & reduces risk of volume overload.

21. OBSTETRIC SURGERY: LSCS Rapid volume fluctuations. Mostly Spinal anaesthesia usedPreloading was advocated. Later studiesPreloadingrelease of ANPdamage endothelial glycocalyx extravasation of fluid from Intravascular compartments . Co-loadingmore appropriatefluid administration coincides with maximal vasodilatory effect of spinal anaesthesia.

22. PAEDIATRIC SURGERY: Children are very sensitive to even minor fluctuations in volume status  clinical assessment is of great significance. Losses can range from 1ml/kg/hr for minor cases to 50 ml/kg/hr for necrotising enterocolitis in premature infants.\ Younger the child,greater is the relative proportion of losses(Larger ECF fluid)

23. Avoid hypo/hyperglycaemia Administer dextrose selectively only in high risk cases(neonates, endocrinopathies) Start glucose infusion @ 120-300 mg/kg/hr: monitor blood glucose levels to maintain acceptable levels  titrate as per need  prevent lipid mobilisation in hypoglycemia prone infants. Children are susceptible to hospital acquired hyponatremia due to use of hypotonic solutions Current guidelines  ISOTNONIC SOLUTIONS[Sodium concentration similar to PlasmaLyte /0.9% Saline]

24. DAYCARE SURGERY: Choice of fluid is highly variable depending on type of surgery. Minor procedures minimal fluid loss. Liposuctionsignificant fluid shifts Adequate fluid administered to avoid PONV, dizziness. Early feeding to minimise risk of unwarranted hypovolemia.

25. TAKE HOME MESSAGE Perioperative Fluid Management is both an ART and a SCIENCE. Appropriate fluid management leads to enhanced patient outcomes, decreased complications and hospital length of stay. Individualised plans following GDFT helps to optimise patient outcome. NPO duration should be minimised, PO hydration is superior to IV hydration . Special precaution must be taken in high risk cases ( Elderly , Children, Kidney Disease)