Fluid, Electrolyte and Acid-base Disturbance

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Fluid, Electrolyte and

Acid-base Disturbance

Sirirat Reungjui, MD

Body Fluid

TBW

ECF

1/3

Extravascular

3/4

Intravascular

1/4

ICF

2/3

• Total body water

- Male (60%) > Female (50%)

- Higher in slim than fat

- Steadily decrease with age

Ionic composition

ICF

K,

PO4, Protein

ISF Plasma

Na, Cl,

HCO3

Input Output Ingested water: 1000 mL

Urine 1000 mL

Water in food: 800 mL

Skin 500 mL

Respiratory tract 400 mL

Water of oxidation: 300 mL

Stool 200 mL

Input - Output

Water Turnover in the Bowel (ml/day)

Water from diet 2000-3000

Saliva 1000-2000

Gastric juice 1000-2000

Bile 500-1000

Pancreatic juice 1000-2000

Intestinal secretions 1000-2000

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Composition of GI secretion

Fluid replacement

Fluid therapy = Maintenance + Fluid loss

Maintenance • Holiday & Segar’s Law 1st 10 kg = 100 cc/kg/day 2nd 10kg = 50 cc/kg/day > 20 kg = 20 cc/kg/day


Dehydration

Mild dehydration (3–5%) - Thirsty

- Dry lip and tongue

Moderate dehydration (6–9 %) - tachycardia - orthostatic hypotension - decreased skin turgor - dry mucous membranes - irritability - delayed capillary refill (2 -3 s) - reduced urine output

Severe dehydration (≥10 %) - hypotension - capillary refill > 3 s - cool and mottled extremities - lethargy - deep respirations with rate

Crystalloids Isotonic crystalloids

- Lactated Ringer’s, 0.9% NaCl

- only 25% remain intravascular

Hypotonic solutions

- D5W, 0.45% NaCl

- less than 10% remain intra-

vascular, inadequate for fluid

resuscitation

Hypertonic saline solutions

- 3% NaCl

0500

100015002000250030003500400045005000

Infused

Volume

PV IFV ICV

Fluid Therapy to Expand Plasma

Volume by 1 Liter : NSS, RLS

PV: plasma volume, IFV: interstitial fluid volume,

ICV: intracellular fluid volume

Fluid Therapy to Expand Plasma

Volume by 1 Liter : D5W

0

2000

4000

6000

8000

10000

12000

14000

Infused V. PV IFV ICV

PV: plasma volume, IFV: interstitial fluid volume,

ICV: intracellular fluid volume

Colloid Solutions

Contain high molecular weight

substances do not readily migrate across

capillary walls

Preparations

- Albumin: 5%, 25%

- Dextran

- Gelifundol

- Haes-steril 10%

Fluid diffusion after intravascular infusion: to

achieve 1 liter of plasma volume expansion

Fluid Infused Volume(ml) PV IFV(ml) ICV(ml) D5W 14,000 1,000 3,700 9,300

NSS 4,000 1,000 3,000 0

RLS 4,700 1,000 3,700 0

3%NaCl 650 1,000 (-)120 (-)230

7.5%NaCl 140 1,000 (-)285 (-)575

Fluid replacement Solutions Volumes Na+ K+ Ca2+ Mg2+ Cl- HCO3

- Dextrose mOsm/L

ECF 142 4 5 103 27 280-310

Lactated Ringer’s

130 4 3 109 28 273

0.9% NaCl 154 154 308

0.45% NaCl

77 77 154

D5W

D5/0.45% NaCl

77 77 50 406

3% NaCl 513 513 1026

6% Hetastarch

500 154 154 310

5% Albumin

250,500 130-160

<2.5 130-160

330

25% Albumin

20,50,100 130-160

<2.5 130-160

330

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Diuretics


Metabolic Emergencies

Alteration of concious hyponatremia , hypernatremia

hypocalcemia , hypercalcemia hypomagnesemia , hypermagnesemia ,

metabolic alkalosis Convulsion hyponatremia , hypernatremia

hypomagnesemia , hypocalcemia metabolic alkalosis

Metabolic Emergencies

Muscle weakness

hypokalemia , hyperkalemia hypermagnesemia , hypomagnesemia hypercalcemia , metabolic alkalosis

Arrythmia or EKG changes

hypokalemia , hyperkalemia hypomagnesemia , hypermagnesemia, hypocalcemia , hypercalcemia

metabolic acidosis

Water & sodium metabolism

1.03 x(Nae+Ke) TBW

[Na +]p = total Na in plasma Plasma volume

- 23.8

Serum osmolality = 2Na + BS/18 + BUN/2.8

Sodium = ECF volume

Water = Hypo-Hypernatremia ICF volume


Content of Na+ in ECF….

ECF volume

Concentration of Na+ (PNa)

ICF volume

Na+ +

H2O

Na

H2O

Na+ gain

Na+

Na+

Loss

Water deficit

H2O

Na+

H2O +

Na

H2O

Water gain

Na+

Loss

Na+ deficit

H2O

Na+

H2O


•Serum sodium < 135 mEq/l

•Severity…. rapidity and level

Acute vs Chronic hyponatremia

( 48 hr)

Mild : Plasma Na 125 – 134 mEq/l : N/V, malaise, hiccup Moderate : Plasma Na 115 – 124 mEq/l : headache, lethargy, confuse, obtundation Severe : Plasma Na < 115 mEq/l : stupor, seizure, apnea, coma

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Osmotic demyelination syndrome

serum

osmolarity

Normal

(280-295 mOsm)

Isotonic hyponatremia

Hyperlipidemia Hyperproteinemia

Low

(< 280 mOsm)

Uosm > 100

Uosm < 100

Psychogenic polydipsia

Elevate

(>295 mOsm)

Hypertonic hyponatremia

-hyperglycemia

-hypertonic infusion e.g.

glucose mannitol,ethanol

Uosm > 100

hypovolemia

UNa < 10

(extrarenal loss)

Vomiting

Diarrhea

Third space

loss

UNa > 20

Diuretics

Mineralocorticoid def.

Salt losing nephritis

Bicarbonaturia

Ketonuria

Osmotic diuresis

Euvolemia

UNa > 20

SIADH

Hypothyroidism

Glucocorticoid def.

Renal failure

Physical or emotional

stress

Post Op.

Hypervolemia

UNa < 10

Nephrotic syndrome

Cirrhosis

CHF

UNa >20

Acute or

chronic renal failure

Lab test

Blood sugar, serum osmole?

BUN/cr, uric acid

Causes of SIADH, TFT, Cortisol level

urine osmole less than 100 mosm/kg..shut down of ADH

more than 100 impaired free water excretion

(ADH still effect)

urine sodium


Criteria for SIADH

Hypotonic hyponatremia

Urine osmolality >100 mOsm/kg

Urine Na > 40 mEq/L (usually)

Absence of ECV depletion

Normal thyroid and adrenal function

Normal cardiac, hepatic, renal function


Causes of SIADH


Drugs That Can Cause SIADH

Carbamazepine (Tegretol)

Chlorpropamide (Diabinese)

Clofibrate (Atromid-S)

Cyclophosphamide (Cytoxan)

Opiates

Oxytocin (Pitocin)

Phenothiazines

Tricyclic antidepressants

Vincristine


1 Improve underlying condition

2 Increase PNa concentration - Acute vs chronic, symptom - Rate and type of fluid

ระดบ serum osmolarity

Normal (280-295 mOsm)

Elevated (>295 mOsm)

Low (<280 mOsm)

Isotonic Hyponatremia

(Pseudohyponatremia) Hyperlipidemia Hyperproteinemia

Hypotonic Hyponatremia

Hypertonic Hyponatremia

Hyperglycemia Hypertonic infusion e.g.

Glucose, mannitol, ethanol Sorbitol, glycerol, glycine

Uosm > 100 Uosm < 100

Psychogenic polydipsia Beer potomania

ประเมน extracellular fluid volume

Hypovolemia Euvolemia Hypervolemia

ไมตองรกษา รกษาตาม สาเหต

Hypovolemia

Extrarenal loss - Vomiting - Diarrhea - 3rd space loss Burn Pancreatitis

U[Na] > 20 U[Na] < 10

Renal loss - Diuretics - Addison’s Disease - Salt-losing nephritis - Bicarbonaturia - Ketonuria - Osmotic diuresis

การรกษา รกษาตามสาเหตและแกไข volume deficit ดวยการใหสารน าและเกลอทดแทน

Euvolemia

สงตรวจระดบ urine osmolality

< 100 mOsm/L > 100 mOsm/L

- Primary polydypsia - Water intoxication

Water loading test (ดมน า 15 cc/kg)

ขบน าออก > 80% ของน าทดมใน 4 ชม.

ขบน าออก < 80% ของน าทดมใน 4 ชม.

Reset osmostat

ตดตามอาการ ไมตองรกษา

SIADH มอาการ : ให 3%Nac ไมมอาการ : จ ากดน าดม 500-1000 ซซ/วน

ลดน ำดม รกษำทำงจตเวช

Treatment of chronic SIADHs

Restrict water intake (osmolol load/Uosm)

A high-sodium, high-protein diet

Loop diuretic

Urea

V2 receptor antagonists

Demeclocycline (rarely used)

Lithium is not used anymore


Hypervolemia

U[Na] > 20 U[Na] < 10

Edematous disorder - Nephrotic syndrome - Cirrhosis - CHF

Acute or Chronic renal failure

การรกษา รกษาโดยการจ ากดน าดมและจ ากดเกลอ หากผปวยมอาการเหนอยจากปอดบวมน า กควรใหยาขบปสสาวะ


Rate and degree of correction

Na for 1 L of IVF = [(infusate Na + infusate K) – SNa]

TBW + 1

Na requirement (mEq) = (Desired Na - Serum Na)

x TBW

24 L

Water … L

Na + K ……….

Na + K

………

Water … L

Na

H20

+ …… mEq

……..

PNa 120 mEq/L

PNa 130 mEq/L

Tonicity balance


Type of fluid replacement

• Hypovolemia : isotonic,0.9% saline • Euvolemia, Hypervolemia : hypertonic solution, 3% saline

- 2-6 days after Na treatment

- Dysarthria, dysphagia, paraparesis, quadriparesis, alteration of conscious, seizure, coma

• Risks..rapid correction (>20 mEq/first 24 hrs)

seizure, respiratory failure,

alcoholism, malnutrition,

chronic thiazide use, burn

Osmotic Demyelination Syndrome

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Hypernatremia Sirirat Reungjui, MD.

Content of Na+ in ECF….

ECF volume

Concentration of Na+ (PNa)

ICF volume

Na+ +

H2O

Na

H2O

Na+ gain

Na+

Na+

Loss

Water deficit

H2O

Plasma Na > 145 mEq/L Common in elderly, debilitated, esp. acute

(febrile) illness Risk factors Advanced age Mental or physical impairment Uncontrolled DM Underlying polyuria disorders Diuretic therapy Inadequate nursing care Hospitalization


Characteristics of hypernatremia

Symptoms

Cognitive dysfunction ( neuronal cell shrinkage)

Lethargy, obtundation, confusion, abn. speech, irritability, myoclonic jerks, nystagmus, seizures

Dehydration (volume depletion)

Orthostatic BP changes, tachycardia, oliguria, dry oral mucosa, skin turgor

Other clinical findings Weight loss, generalized weakness

ADH

Osmostat

Thirst center

Uvol

Uosm

ADH

Hypernatremia

Hypovolemic

( water ↓↓,Na ↓)

UNa > 20

Renal loss

Osmotic or loop diuretic

Intrinsic renal dz

UNa < 10

Extra Renal loss

Sweating

Burn

Diarrhea

fistula

Euvolemic

( water ↓,Na ↔)

Renal loss

DI

Hypodipsia

Extra Renal loss

Insensible loss

Hypervolemic

( water ↑ ,Na ↑↑ )

UNa > 20

Sodium gains

Primary hyperaldosteronism

Cushing’s syndrome

Hypertonic dialysis

• Correct underlying diseases

• Correct water deficit =

TBW x ( PNa - 1 )

140

• 50 % in 12-24 hr and 50% later in 48-

72 hr ( < 0.5 mEq/L/hr )


Water deficit

water deficit = TBW [(PNacurrent/PNadesire)-1)

(TBW=x*BW : x=0.6 in male , 0.5 in woman)

Ongoing water losses

= V*[1-(Una+UK/140)]

(V=urine output per day , UNa=urine Na ,

UK=Urine K)

Insensible loss ~ 10 ml/kg/day

HYPERNATREMIA TYPE OF FLUID

Hypovolumic hypernatremia

Initial: Restore extracellular fluid volume

- Administer 0.9% NSS Next: Correct Serum Na - Administer 0.45% NSS or

5% dextrose

Euvolumic hypernatremia

Correction of water deficit • 5% dextrose or oral water

Hypervolemic hypernatremia

Removal of excess Na • Furosemide with 5% DW • Hemodialysis for RF


Potassium


Transcellular shift Insulin, 2 agonist,

antagonist, alkalosis

Acidosis, hyperglycemia, 2 antagonist ,

agonist, exercise


• plasma K< 3.5 mEq/l • Mild hypokalemia ………… 3-3.5 mEq/L Moderate hypokalemia ….. 2.5-3 mEq/L Severe hypokalemia ……… < 2.5 mEq/L.


Moderate

Severe

Mild

Cardiac arrhythmia (digitalis)

•Atrial & Ventricular arrythmia •Flat T wave,PR prolong, U wave,PVC •constipation •Muscle weakness, Fatique,muscle cramp

•Flaccid paralysis •Hyporeflexia •Hypercapnia •Tetany •Rhabdomyolysis •Bowel ileus •Respiratory mucle weakness→arrest

< 3.5 2.5 - 3.5

< 2.5


ECG OF HYPOKALEMIA


Approach hypoK

Transcellular shift

Renal or extrarenal loss

..urine K (>20 mEq/day)

..TTKG

Acid-base..acidosis,alkalosis

Blood pressure

Hypokalemia

Extrarenal loss

TTKG < 3

Metabolic acidosis

Diarrhea

GI fistula

Laxative abuse

Normal acid-base

GI loss

Laxative abuse

Metabolic alkalosis

chloride losing diarrhea

Renal loss

High

BP

Cushing’s syndrome

- Licorice

- Carbenoxolone

- Congenital adrenal

hyperplasia

- Aldosteronism

- Glucocorticoid remediable

-Apparent mineralocorticiod

excess

Malignant HT

Renovascular HT

Renin-secreting tumor

High renin

Low renin High Aldo

Primary aldosteronism

Low renin Hi cortisol

Lo renin Lo cortisol

Renal K loss


Normal

BP

- Vomiting

- Nonreabsorbable

anion

- Diuretics

- Bartter’s syndrome

- Gitleman’s syndrome

- Normetensive

hyperaldosteroism

- Hypomagnesemia

RTA

Met Acid Met Alk

Urine Cl Ucl < 20 mEq/L

Ucl > 20 mEq/L

Renal K loss

1. Treat cause 2. K supplement Mild to moderate hypokalemia ↓ K 1 mEq/L = K deficit 200-400 mEq/L Oral : elixir KCl (40-120 mEq/day) E.KCl 30 ml = K 20 mEq Follow K+ level Severe hypokalemia Intravenous : KCl in 0.9% NaCl (< 40-60 mEq/L) monitor EKG if replace > 10 mEq/hr


100-400 (>200) mEq

> 500 mEq

• Plasma K > 5 mEq/l • Mild hyperkalemia….. 5 - 6 mEq/L

Moderate hyperkalemia …6 - 6.5 mEq/L Severe hyperkalemia …. > 6.5-7 mEq/L

1. Cardiovascular system ; arrhythmia, EKG change - Pk 5-6.5 mEq/l → tall peak T - Pk 6.5-8 mEq/l → P wave flattening, PR prolong, widening of QRS complex - Pk >8 mEq/l → biphasic sine wave, ventricular fibrillation, cardiac arrest

2. Numbness, muscle weakness, flaccid paralysis 3. Nausea, vomiting, abdominal pain, bowel ileus



Approach hyperK

Transcellular shift

Renal causes

..renal failure

..aldosterone deficiency

or resistance

..inhibit ENAC

..decrease distal flow

Hyperkalemia

Cause of hyperkalemia

Extra renal cause

Spurious

Increase intake or

tissue release

Redistribution

hemolysis

thrombocytosis

leukocytosis

mononucleosis

i.v. ,oral

hemolysis rhabdomyolysis

Tumor lysis

acidosis Insulin def

DKA B – Adrenergic blockage

Periodic paralysis

digitalis Tissue damage

Hyperkalemia

Renal cause

GFR <20 ml/min GFR >20 ml/min

- Acute renal failure Aldosterone def. Tubular hyperkalemia

- addison’s dz. - Hereditary adrenal

enz. defect

-hyporeniemic

hypoaldosteronism

-drug: heparin, NSAIDs,ACEI, CSA

- obstructive uropathy

- Post renal transplant

- SLE

- amyloidosis

- interstitial nephritis

- K sparing diuretics

- pseudohypoaldosteron

type I,type II

- Chronic renal

failure

EKG change

present

1. Ca gluconate 2. Glucose and insulin or albuterol 3.Consider Na polystyrene sulfonate depending on the timing for dialysis 4.Arrange for dialysis if ARF present 5.Use NaHCO3 if pH < 7.25

absent

Plasma K>6.5-7 Treat as pt with

EKG change

Plasma K < 6.5 1.Corrected cause 2.diuretic, Na polystyrene sulfonate, mineralocorticoid may

be used

Drug Dose Onset (Duration)

10% calcium gluconate Glucose and insulin Albuterol (nebulizer) NaHCO3 Kayexalate Furosemide

10-30 ml Glucose 25-50 g + Insulin 5-10 unit iv 20 mg in NSS 4 ml 44 – 132 mEq PO (15-30 g.) Per rectal (50-100 g,) 20-40 mg iv

1-3 min (30-60 min) 10 -20 min (4-6 hr) 20-30min (2-4 hr) 30-60 min (2-4 hr. 1-2 hr (4-6 hr) 1 hr (4-6 hr)

Hypocalcemia

Severe

10 % Calcium gluconate ( 93 mg /amp )

10 % Calcium chloride ( 273 mg /amp )

93 - 186 mg over 10 -15 min then

10-15 mg / kg over 4-6 hrs

Hypercalcemia

Acute: symptomatic

0.9%NSS..initial 200-300mL/h..adjusted

to maintain urine 100-150 mL/h.

Furosemide

Hemodialysis

Others : glucocorticoid , bisphosphonate,

calcitonin, gallium nitrate

Hypomagnesemia

Mild - moderate deficiency (1.2 -1.7 mg/dL)…diet or oral Mg supplement

Symptomatic pts… 3 - 4 g (24 mEq to 32 mEq) of iv MgSO4 over 12-24 hrs

Repeated dose..maintain Smg > 1.2 mg/dL

Renal insufficiency.. reduce dose (25-50%)

Treatment of RTA

Underlying disease

Proximal RTA…alkali Rx, K replacement, thiazide, vit D , phosphate

Distal RTA…alkali Rx, K

Aldosterone deficiency.. mineralocorticoid

Calculated Bicarbonate Dose = 0.3 x Wt x BE BE = base excess Bicarbonate deficit = (0.5 x LBW) x (24 – HCO3) LBW = lean body weight

Alkali Treatment

Replace 50 % of the deficit over the first 24 hours

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Fluid, Electrolyte and Acid-base Disturbance

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