1 / 34

Antidiuretic Hormone ADH

H 2 O. ADH. Antidiuretic Hormone ADH. Collecting Duct. Hypertonic Interstitial Fluid. Urine. Calcitonin. Calcium. Estrogen. Calcium. Parathormone. Calcium. Blood pH = 7.4 (7.35-7.45). Blood pH regulated by 1. Kidneys 2. Lungs 3. Buffers in blood.

benjamin
Download Presentation

Antidiuretic Hormone ADH

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. H2O ADH Antidiuretic HormoneADH Collecting Duct Hypertonic Interstitial Fluid Urine

  2. Calcitonin Calcium

  3. Estrogen Calcium

  4. Parathormone Calcium

  5. Blood pH = 7.4(7.35-7.45) Blood pH regulated by 1. Kidneys 2. Lungs 3. Buffers in blood

  6. H+ Secreted HCO3- Resorbed Blood H+ Kidney Nephron Urine HCO3-

  7. Kidneys Regulate pH • Excreting excess hydrogen ions, retain bicarbonate • if pH is too low • Retaining hydrogen ions, excrete bicarbonate • if pH is too high

  8. Lungs Regulate pH • Breathe faster to get rid of excess carbon dioxide if pH is too low • Carbon dioxide forms carbonic acid in the blood • Breathe slower to retain carbon dioxide if pH is too high

  9. Carbonic Acid Carbon Dioxide and Acid CO2 + H2O H2CO3H++ HCO3-

  10. More Carbon Dioxide = More Acid = Lower pH • Breathing slower will retain CO2 , pH will • decrease (more acid) • Breathing faster will eliminate more CO2 pH will • increase (less acid)

  11. Blood pH Drops to 7.3How does the body compensate? • Breathe faster to get rid of carbon dioxide • eliminates acid

  12. Blood pH Increases to 7.45How does the body compensate? • Breathe slower to retain more carbon dioxide • retains more acid

  13. PG The role of ADH: • ADH = urinary concentration • ADH = secreted in response to ⇑ osmolality; = secreted in response to ⇓ vol; • ADH acts on DCT / CD to reabsorb water • Acts via V2 receptors & aquaporin 2 • Acts only on WATER

  14. PG Calculation of osmolality • Difficult: measure & add all active osmoles • Easy = [ sodium x 2 ] + urea + glucose • Normal = 280 - 290 mosm / kg

  15. PG Fluid shifts in disease • Fluid loss: • GI: diarrhoea, vomiting, etc. • Renal: diuresis • Vascular: haemorrhage • Skin: burns,sweat • Fluid gain: • Iatrogenic: • Heart / liver / kidney failure:

  16. PG Prescribing fluids: • Crystalloids: • 0.9% saline - not “normal” ! • 5% dextrose • 0.18% saline + 0.45% dextrose • Others • Colloids: • Blood • Plasma / albumin • Synthetics eg gelofusion

  17. PG The rules of fluid replacement: • Replace blood with blood • Replace plasma with colloid • Resuscitate with crystalloid or colloid • Replace ECF depletion with saline • Rehydrate with dextrose

  18. PG How much fluid to give ? • What is your starting point ? • Euvolaemia ? ( normal ) • Hypovolaemia ? ( dry ) • Hypervolaemia ? ( wet ) • What are the expected losses ? • What are the expected gains ?

  19. PG Signs of hypo / hypervolaemia: Signs of … Volume depletionVolume overload Postural hypotension Hypertension Tachycardia Tachycardia Absence of JVP @ 45o Raised JVP / gallop rhythm Decreased skin turgor Oedema Dry mucosae Pleural effusions Supine hypotension Pulmonary oedema Oliguria Ascites Organ failure Organ failure

  20. PG What are the expected losses ? • Measurable: • urine ( measure hourly if necessary ) • GI ( stool, stoma, drains, tubes ) • Insensible: • sweat • exhaled

  21. Electrolyte (Na+, K+, Ca++) Steady State • Amount Ingested = Amount Excreted. • Normal entry: Mainly ingestion in food. • Clinical entry: Can include parenteral administration.

  22. PG Case 1: • A 62 year old man is 2 days post-colectomy. He is euvolaemic, and is allowed to drink 500ml. His urine output is 63 ml/hour: 1. How much IV fluid does he need today ? 2. What type of IV fluid does he need ?

  23. PG Case 2: • 3 days after her admission, a 43 year old woman with diabetic ketoacidosis has a blood pressure of 88/46 mmHg & pulse of 110 bpm. Her charts show that her urine output over the last 3 days was 26.5 litres, whilst her total intake was 18 litres: 1. How much fluid does she need to regain a normal BP ? 2. What fluids would you use ?

  24. PG Case 3: • An 85 year old man receives IV fluids for 3 days following a stroke; he is not allowed to eat. He has ankle oedema and a JVP of +5 cms; his charts reveal a total input of 9 l and a urine output of 6 litres over these 3 days. 1. How much excess fluid does he carry ? 2. What would you do with his IV fluids ?

  25. PG Case 4: • 5 days after a liver transplant, a 48 year old man has a pyrexia of 40.8oC. His charts for the last 24 hours reveal: • urine output: 2.7 litres • drain output: 525 ml • nasogastric output: 1.475 litres • blood transfusion: 2 units (350 ml each) • IV crystalloid: 2.5 litres • oral fluids: 500 ml

  26. PG Case 4 cont: • On examination he is tachycardic; his supine BP is OK, but you can’t sit him up to check his erect BP. His serum [ Na+ ] is 140 mmol/l. • How much IV fluid does he need ? • What fluid would you use ?

  27. Case 5 • 30yo girl • SOB, moist cough, chest pain • ESKD • Very little urine output • Has missed dialysis last 3 sessions

  28. Case 5 • What next? • Current weight 78kg • IBW 68kg • JVP twitching her ear • No peripheral oedema • Coarse crackles to mid zones • BP 240/110 • P 100 • Gallop rhythm • 4cm of liver in RUQ

  29. Case 5 • Assessment • Acute significant overload • Probably about 10kg

  30. Case 6 • 55yo lady • Presents to dialysis for her routine session • BP 78/30 • History of dizziness for the last 6 hours • Current weight 58kg • IBW 59kg

  31. Case 6 • P 120 • Chest clear • HS dual • No oedema • Admits to 24hours of diarrhoea • Thirsty • No JVP visible

  32. Case 6 • Dehydrated • Volume constricted • Hypotensive due to decreased circulating fluid volume • Resuscitation?

  33. The End

  34. Acknowledgements • Paddy Gibson – 4th year teaching ppt 2009 • Robert Harris – Fluid Balance ppt 2009 • Heather Laird-Fick – Fluid and electrolyte disorders ppt 2009 • JXZhang Lecture 14 – ppt 2009 • Dennis Wormington – fundamentals of fluid assessment ppt 2009

More Related