Post on 04-Apr-2018
7/30/2019 electrolyte disorders in critically ill
1/69
Electrolytedisordersin
Criticallyillpatients
8EDLGXU5DKDPDQ
6HQLRU5HVLGHQW&&0
6*3*,06/XFNQRZ,QGLD
7/30/2019 electrolyte disorders in critically ill
2/69
It is the internal environment (not the external world) that
provides the physical need for life
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
3/69
BODY FLUID COMPARTMENTSArrow represents fluid movement
Review ofMedical Physiology, William F. Ganong
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
4/69
ElectrolyteCompositionofBodyFluidCompartments
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
5/69
Compositionofbodyfluidslosingcontinuously
Source Daily Loss Na+ K+ Cl- HCO3-
Saliva 1000 30-80 20 70 30
Gastric 1000-2000 60-80 15 100 0Pancreas 1000 140 5-10 60-90 40-100
Bile 1000 140 5-10 100 40
Small Bowel 2000-5000 140 20 100 25-50
Large Bowel 200-1500 75 30 30 0
Sweat 200-1000 20-70 5-10 40-60 0
urine 1500-2000
7/30/2019 electrolyte disorders in critically ill
6/69
CompositionofIVfluidsincomparisontoPlasma
Fluid Na K Ca Mg Cl Buffers Glucose pH Osm
Plasma141 4.5 5 2 103
HCO3-26
Prot-160.7-1.1 7.4 290
NS 154 154 6.0 308
1/2NS 77 77 5.0 154
130 4 3 109 Lac-28 6.5 274
5%D 50 4.5 252
Plasmalyte140 5 3 98
Acet-27
Gluc-237.4 294
Gel
3%Saline 513 513 4.5 1026
5%Alb
20%Alb
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
7/69
Sodium Water
disturbances
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
8/69
Na is the most abundant molecule in ECFNa is the most osmotically active molecule in ECF
S. Osm ( mOsm/kg of water)
(2*[Na] + [Glucose/18] + [BUN/2.8]
Contribution of Gluc and BUN is
5 mOsm/L
Na in meq/L, Glucose in mg/dL, BUN in mg/dL)
Osmotic pressure and osmolality determinesdistribution of fluid in body compartments
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
9/69
OSMOLALITY
280-295 mOsm/kg
Serum
Urine
24 hour urine sample-500-800 mOsm/kgExtreme range-50-1400mOsm/kg
Random urine sample- 300-900mOsm/kg
After overnight fluid restriction
Urine omolality > 3 times serum osmolality (>800)
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
10/69
Real story in critically ill patients
S. Osm = 2* (140) + 90/18 + 5/2.8
= 280 + 5 + 1.7
= 286.7
S. Osm = 2* (145) + 180/18 + 60/2.8= 290 + 10 + 21
= 321
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
11/69
Na WATER
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
12/69
Na / water regulation
Thirst ADH RAA Kidney
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
13/69
E idemiolo of electrol te disorder in ICU
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
14/69
Intensive Care Medicine 2010, 36(2):304-11
Incidence and prognosis of dysnatremias present on ICU admission
Funk GC, Lindner G, Druml W, Metnitz B, Schwarz C, Bauer P, Metnitz PG
retrospective study in 77 medical, surgical, and mixed ICUs in Austria,
151,486 adults patients admitted over a period of 10 years (1998-2007).
75% patients had normal sodium levels (Na:135-145) on ICU admission
Incidence
hyponatremia-17.7%, Hypernatremia-6.9%
All types and grades of dysnatremia were associated with increased hospital mortality
independent mortality risk rising with increasing severity of both
hyponatremia and hypernatremia
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
15/69
Critical Care 2008, 12:R162
The epidemiology of intensive care unit-acquired hyponatraemia
and hypernatraemia in medical-surgical intensive care unitsHenry Thomas Stelfox, Sofia B Ahmed, Farah Khandwala, David Zygun, Reza Shahpori, Kevin Laupland
8142 adults admitted in 3 medical-surgical ICUs Over 6 years
documented to have normal S. sodium levels (133 to 145 mmol/L) on
the first day of ICU admission
Incidence Hyponatremia- 11%, hypernatremia-26%
Median time to develop dysnatremia- 2 days
Median duration of dysnatremia-2 days
More than 1 distinct epi of dysnatremia- 25%
(Hyponatremia-16%, hypernatremia-19%)
hospital mortality increased significantly
Independent of SOI
( hypoNa-28%, hyperNa-34%, normoNa-16%)
Continued..Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
16/69
Critical Care 2008, 12:R162
The epidemiology of intensive care unit-acquired hyponatraemia
and hypernatraemia in medical-surgical intensive care unitsHenry Thomas Stelfox, Sofia B Ahmed, Farah Khandwala, David Zygun, Reza Shahpori, Kevin Laupland
Continued..Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
17/69
Increased risk of hypernatremia
Raised S.creatinine
Mechanical ventilation
Increased risk of both hyper and hyponatremia
Critical Care 2008, 12:R162
The epidemiology of intensive care unit-acquired hyponatraemia
and hypernatraemia in medical-surgical intensive care units
Henry Thomas Stelfox, Sofia B Ahmed, Farah Khandwala, David Zygun, Reza Shahpori, Kevin Laupland
Length of stay in ICU
Increased APACHE II score
Dysnatremias develop insidiously over 2 days
Difficult to identify as clinicians preoccupied with
more acute medical issues and other lab investigations
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
18/69
Critically ill patients
prone toelectrolyte disturbances
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
19/69
Disturbance in fluid and electrolyte homeostasissepsis, shock, cardiac failure, acute kidney injury, burn, surgery, C.N.S. disorders
Activation of neuro hormonal system- SNS, RAAS, Vasopressin
Non osmotic release of Vasopressin
pain, nausea, medication, hypovolemia Diuresisiotrogenic- renal and osmotic diuretics
Vasopressin deficiency in sepsis
Insensitivity to insensible losses
Impaired thirst mechanism
Inappropriate administration of fluid and electrolytes
Urea, glucose inducedHypokalemia, hypercalcemia
Drug induced- aminoglycoside, ampho B
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
20/69
AmJKidneyDis2009Oct,54:674-679
tonicity balance in patients with Hypernatremia Acquired in the
Intensive Care UnitGregorL,NikolausK,UlrikeHolzinger,WilfredDruml,christiphschwartz
Solute balance= [Na+K]input [Na+K]outputContinued
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
21/69
c
Urea/ glucose
AmJKidneyDis2009Oct,54:674-679
tonicity balance in patients with Hypernatremia Acquired in the
Intensive Care UnitGregorL,NikolausK,UlrikeHolzinger,WilfredDruml,christiphschwartz
Causes of ICU acquired hypernatremia
osmoti
DI
Nonoliguri
Addition of KCl to 0.9%saline led to positive solute balance in 27% patients
Hypertonic
Osm>150
Continued
7/30/2019 electrolyte disorders in critically ill
22/69
Positive solute balance contributed 56% cases
Primary reason was inadequate substitution of hypotonic losses
with isotonic or hypertonic fluids
AmJKidneyDis2009Oct,54:674-679
tonicity balance in patients with Hypernatremia Acquired in the
Intensive Care UnitGregorL,NikolausK,UlrikeHolzinger,WilfredDruml,christiphschwartz
m n um n n y x ng
inadequate intake of free water
Community acquired hypernatremia- hypovolemic hypernatria
ICU- euvolemic or hypervolemic hypernatremia
ContinuedUbaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
23/69
AmJKidneyDis2009Oct,54:674-679
tonicity balance in patients with Hypernatremia Acquired in the
Intensive Care UnitGregorL,NikolausK,UlrikeHolzinger,WilfredDruml,christiphschwartz
Characteristics of patientsContinued
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
24/69
AmJKidneyDis2009Oct,54:674-679
tonicity balance in patients with Hypernatremia Acquired in the
Intensive Care UnitGregorL,NikolausK,UlrikeHolzinger,WilfredDruml,christiphschwartz
Characteristics of patients
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
25/69
Patients admitted over 1 year
medical, surgical or neurological ICU
Renal dysfunction, Hypokalaemia, hypercalcemia, mannitol, sodium bicarbonate
hypernatremia 150 mmol/l in the ICU
Nephrol Dial Transplant 2008,23:1562-1568
Hypernatremia in critically ill patients: too little water and too much saltEwout J. Hoorn, Mecheil G.H.Betjes, Joachim Weigel, Robert Zietse
more common in cases
independently associated with hypernatraemia.
mortality was higher in case
Hypernatremia was independent predictor
Continued
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
26/69
Approximately half of cases were polyuric, even when fluid balance was negative
+
Impaired thirst mechanism
Inappropriate iv fluid administration with isotonic fluids
Nephrol Dial Transplant 2008,23:1562-1568
Hypernatremia in critically ill patients: too little water and too much saltEwout J. Hoorn, Mecheil G.H.Betjes, Joachim Weigel, Robert Zietse
Aim of treatment- negative solute balance
Hypotonic fluid may aggravate fluid overload
Diuretic may be considered:combination of loop diuretic and water or thiazide diuretic alone
Continued
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
27/69
Potential factors contributing to hypernatremia
Page 1566
Nephrol Dial Transplant 2008,23:1562-1568
Hypernatremia in critically ill patients: too little water and too much saltEwout J. Hoorn, Mecheil G.H.Betjes, Joachim Weigel, Robert Zietse
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
28/69
Use of hypotonic fluid is avoided in ICU
Ca illar leakiness in se sis atients
Fear of hyponatremia as many patient show non osmotic release of
Vasopressin
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
29/69
JUST ANANALYSIS
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
30/69
NephrolDialTransplant2008,23:1562-1568
Hypernatremiaincriticallyillpatients:toolittlewaterandtoomuchsaltEwoutJ.Hoorn,MecheilG.H.Betjes,JoachimWeigel,RobertZietse
47-year-old male
(body weight 95 kg)
cystectomy complicated by
faecal peritonitis.
Tonicity balance illustrating mechanism of hypernatremia
large isotonic volume resuscitation,
+ hypertonic fluids (NaHCO3)
Water loss
Renal: renal insufficiency and
hyperglycaemianon-renal: wound drains and
colostomy
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
31/69
IntensiveCareMed2001;27:921-924
Tonicitybalance,andnotelectrolytefreewatercalculations,moreaccuratelyguidetherapyforacutechangeinnatremia
A.P.C.P.Carlotti,D.Bohn,J.P.Mallie,M.L.Halperin
14 year old male
( weight 40 kg, total body water 24 L)
Operated for craniopharyngioma
During surgery
TBW* ( [S.Na] /140 ) - 1
excreted 4L in 9 hours
Over this period
P.[Na] rose from 140 to 157 meq/L
received 3 L of isotonic saline
His urine [Na+K] was 50 meq/L.
Free Water deficit: 24* [ (157/140) 1 ] = 2.9 L
2.9L
2.9L
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
32/69
Intensive Care Med 2001;27:921-924
Tonicity balance, and not electrolyte free water calculations, more accurately
guide therapy for acute change in natremia
A.P.C.P. Carlotti, D. Bohn, J.P. Mallie, M.L. Halperin
4 L urine with 200meq Na= 1.3 L isotonic saline + 2.7 L of EFW
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
33/69
IntensiveCareMed2001;27:921-924
Tonicitybalance,andnotelectrolytefreewatercalculations,moreaccuratelyguidetherapyforacutechangeinnatremia
A.P.C.P.Carlotti,D.Bohn,J.P.Mallie,M.L.Halperin
Na
200 mmol
Tonicity balance
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
34/69
IntensiveCareMed2001;27:921-924
Tonicitybalance,andnotelectrolytefreewatercalculations,moreaccuratelyguidetherapyforacutechangeinnatremia
A.P.C.P.Carlotti,D.Bohn,J.P.Mallie,M.L.Halperin
1
3 situations with hypernatremia and negative balance of 2.7 L of EFW
2
3
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
35/69
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
36/69
HYPERNATREMIA
True/ Relative water deficit
S. Na > 145 meq/L
Clinical manifestation
Lethargy, irritability, restlessness
Spasticity, hyperreflexia, seizure, coma
Death
Cerebral Hemorrhage/ ischemia
Insulin resistance, impaired gluconeogenesisCardiac dysfunction
Severity of symptoms correlate with rate and magnitude of change in [Na]
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
37/69
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
38/69
Hypernatremia
Hypertonic saline load
NaHCO3, 3% saline
Hyperaldosteronism
Cushings syndrome
Primary
Na gain
HYPERVOLEMIA
Hypotonic
fluid loss
HYPOVOLEMIA
ISOVOLEMIA
Extra renal lossRenal loss
Diuresis
Osmotic
glucose, urea, mannitol, high osmolar feeds
Diuretics- frusemide, thiazide
Insensible loss
Fever, burn
Diabetes insipidusCDI
NDI
renal disease
Drugs- amphoterecin, aminoglycosides, lithium
Electrolyte disorders- hypokalemia, hypercalcemia
Azotemia out of proportion
to decrease in GFR
Catabolic patients with
Moderate renal
insuficiency on high
protein diet and stress
dose steroid
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
39/69
Excretion ofsmall volume 800 mOsm/L)
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
40/69
Hypernatremia
Urine volume
Hypotonic
fluid loss
>1000 ml
7/30/2019 electrolyte disorders in critically ill
41/69
7/30/2019 electrolyte disorders in critically ill
42/69
HYPERNATREMIA
Correction
Risk : development of brain odema
Chronic hypernatramia- brain cells fully adapted
Risk is more
Acute hypernatremia: 1-2 meq/L/h ( 10-12 meq/L/day)
Chronic hypernatremia: 0.5 meq/L/h ( 8-10 meq/L/day)
GOAL
Na
7/30/2019 electrolyte disorders in critically ill
43/69
HYPERNATREMIA
Correction
TBW* ( [S.Na] /140 ) - 1
EFW deficit calculation (L)
Madias and Adrogue equation
Scan Page 74 JW LEE
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
44/69
Mind it
Ongoing lossMust be considered
along with calculated water deficit
Formulas assume a closed system
Require separate account of ongoing losses
as
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
45/69
70 kg women
Diarrhoea of volume 2 L/ day
S.[Na]= 160meq/L , S.[K]= 3.0meq/L
75 160 / (70*50) + 1 = - 2.3 meq/ L
Estimated change in S.[Na] with 1 L of N/2 saline
change of 10 meq/L = 4.3L of N/2 saline has to be given in 24 hours
But ongoing loss = 0.7 L + 2.0 L = 2.7 L / 24 hours
Total volume to be given
4.3 L + 2.7 L = 7.0 L / 24 hours
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
46/69
Hypernatremia
Hypotonic fluid diuretic
Urine output < water replacement
HYPERVOLEMIAHypotonic
fluid loss
HYPOVOLEMIA
ISOVOLEMIA
Osmotic diuresis
Diabetes insipidus
Hemodynamically unstable
Correct volume with isotonic saline
Switch over to hypotonic fluid to
to correct Na
Remove / treat cause of DI
Replace losses with hypotonic fluid
CDI
Ddavp
NDI
low Na diet + thiazide low protein diet NSAID
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
47/69
HYPERNATREMIA
summary of management
Hemodynamic unstable: resuscitate with isotonic fluid (0.9% saline or RL)
Switch over to hypotonic fluid once resuscitated
Hypovolemic hypernatremia:AIM- positive EFW and solute balance
isovolemic hypernatremia:AIM- positive EFW balance
Replace losses with Hypotonic fluid
Treatment of cause: DI
Hypervolemic hypernatremia:AIM- negative EFW and solute balance
Na restriction + Hypotonic fluid + frusemide
CDI: ADH analogue
dDAVP: 10-20 ug intranasal bd
or 1-2ug sc bd
NDI
remove/ correct causative agent
Thiazide/ indomethacin
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
48/69
hypernatremia
Duration of h ernatremia
Absent/ mild neurologic signs
Na 155 me /L
Severe neurologic compromise
Initial acute management of
Na 2 days
Change in [Na] should not exceed
10 meq/L in first 24 hours
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
49/69
DIABETES INSIPIDUS
Hypotonic urine in face of hyperosmolar plasma
CDI- Osm U
7/30/2019 electrolyte disorders in critically ill
50/69
7/30/2019 electrolyte disorders in critically ill
51/69
HYP0NATREMIA
True/ Relative water excess
S. Na < 135 meq/L
Clinical manifestation
headache, nausea
lethargy, disorientation, restlessness
Muscle cramp, weakness, depressed reflexes, seizures, coma
Death
Chronic hyponatremia: developing over >48 hours
Adaptative mechanism minimize symptoms
Severity of symptoms correlate with rate and magnitude of fall in [Na]
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
52/69
APP A H
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
53/69
hyponatremia
Hypertonic HypoNaHyperglycemia
Hypertonic sodium free sol
(mannitol)
Hypotonic HypoNa
Isotonic HypoNaPseudohyponatremia
Hyperlipidemia
hyperproteinemia
Normal serum osmolality
low serum osmolality
high serum osmolality
Assess serum osmolality
hypotonic Hypovolemic
hyponatremia
Assess volume status
isovolemichypovolemic hypervolemic
hypotonic isovolemichyponatremia
hypotonic Hypervolemic
HyponatremiaCirrhosis
Congestive heart failure
Nephrotic syndrome
Renal falire
Discussed in next pages
7/30/2019 electrolyte disorders in critically ill
54/69
DiuresisOsmotic- glucose, urea, mannitol
Diuretics- thiazide, frusemide
Electrolytes-Hypokalemia, hypercalcemia
Drugs- aminoglycoside, ampho B
hypotonic Hypovolemic Hyponatremia
Adrenal deficiency
Mineralocorticoid deficiency
Renal
loss
LOSS
(both water and Na) = Negative water and Na balance
Salt wasting nephropathy
Cerebral salt wasting
GI lossnaso gastric aspirate,
abdominal Drains/ fistula
third space loss
(pancreatitis, ileus, obstruction)
Vomiting, diarrhea
Non renal
loss
Skin lossfever
open wounds,
burns
hemorrhage
7/30/2019 electrolyte disorders in critically ill
55/69
Acute psychosis
CNS disorders
Hypotonic Isovolemic Hyponatremia
Drug inducedOpiods
NSAIDS
Antipsychotics- haloperidolSSRI- fluoxetine, sertraline
Pain, nausea, stress
SIADH
Impaired free water loss in urine
Normal Na loss in urine
hypothyroidism
TCA
Carbamezapine
antineoplasticsPulmonary disease
Infections
malignancy
Cortisol deficiency
7/30/2019 electrolyte disorders in critically ill
56/69
CORRECTION
7/30/2019 electrolyte disorders in critically ill
57/69
PRECAUTION IN CORRECTION
Absolute magnitude of correction in 24 hoursmore important than rate
central pontine myelinosis
Initial rapid rate of correction tapering off after several hours
incurs less risk
than
slow steady correction that exceeds 12 meq/L in 24 hours
Increased risk
Hypoxemia, hypokalemia, malnutrition, alcoholism
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
58/69
HYPONATREMIA
1-2 meq/L/h ( 10-12 meq/L/day)
Rate of correction
Symptomatic
or
Acute hyponatremia(change >0.5 meq/L/h or onset in < 48 hours)
0.5 meq/L/h ( 8-10 meq/L/day)Chronic hyponatremia
(Change over > 48 hours or unknown duration)
Increased risk of CPM
as adaptive mechanism has occured
120-130 meq/L
Lower iin patients with s.Na
7/30/2019 electrolyte disorders in critically ill
59/69
Any saline solution that is hyperosmolar to urine can increase [Na]
when
oral water intake is restricted
Mind it
RULE FOR CORRECTION
A crystalloid with an osmolarity less than urine osmolarity
may actually worsen hyponatremia,
even if the fluid [Na] is greater than serum [Na]
CONTINUED.
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
60/69
Gain of 154 mOsm will be lost in 300 ml urine
Gain of 700 ml of EFW
(154* 1000/500= 300 ml, OsmU > 500)
60 years male, febrile encephalopathyBody weight: 60 kg, TBW: 36 L
Develops SIADH
S.[Na]= 118, urine Osm > 500 mOsm/L
Given 1 L of 0.9% saline
ONE RULE FOR CORRECTION
Na=154
Water=1000
Na=0
water= 700 Water= 300
Na=154
Na=115
Na=118
Simultaneous IV loop diuretic can counteract this phenomenonBy promoting free water excretion
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
61/69
HYPONATREMIACALCULATION OF [Na] deficit
TBW* ( 140 s.Na)
Na deficit (meq)
Anticipated change in s.Na with 1L of fluid(Madias and Adrogue equation)
Scan Page 74 JW LEE
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
62/69
HYPONATREMIA
Remove or treat cause
of hypertonicity
Hypertonic HypoNaHyperglycemia
Hypertonic sodium free sol
(mannitol)
Repeat lab
Use newer method of lab
Isotonic HypoNaPseudohyponatremia
Hyperlipidemia
hyperproteinemia
Fluid shift to ICF compartment does not take placeNeuronal cell swelling does not occur
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
63/69
hypotonic hyponatremia
Primary polydypsia
Beer potomania
Post TURP
urine osmolality 100 mOsm/L
Urine [Na]
20meq/L
Renal loss Non renal loss
TreatmentcIsotonic saline to correct hypovolemia
Correct hypokalemia if present
hypervolemic
IsovolemicContinued
on next page
Continued.
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
64/69
hypotonic hyponatremia
Assess volume status
Urine [Na]Urine [Na]
hypervolemic
urine osmolality > 100 mOsm/L
Urine [Na]
Isovolemic
20meq/L
Renal failure
Cirrhosis
Congestive heart failure
Nephrotic syndrome
EFW restriction
(restriction less than urine output)
>20meq/L
SIADH
Hypothyroidism
Cortisol deficiency,
Administer
saline with osmolality more than urine osmolality
Loop diuretic
ADH antagonist
Treat underlying disease
Stop drug causing increased ADHsecretionCorrect hypokalemia if present
TREATMENT
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
65/69
HYPONATREMIA
summary of management
Replace calculated Na deficit with isotonic saline or RL
hypotonic Hypovolemic hyponatremiaAIM- positive water and Na balance
hypotonic isovolemic hyponatremia
AIM- negative EFW and positive Na balance
Symptomatic
frusemide ivi + 3% saline
Asymptomatic
Water restriction Intermittent frusemide enteral salt
hypotonic Hypervolemic hyponatremia
AIM- negative EFW and Na balance
Na and EFW restriction + frusemide
ADH antagonist( for chronic SIADH as delayed onset of action)
demeclocycline HCL: 600-1200mg PO daily
Phenytoin sod: 200-300mg PO daily
Lithium: 600-1200mg PO daily
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
66/69
hyponatremia
Duration of h onatremia
Absent/ mild neurologic signs
Na < 125 me /L
Severe neurologic compromise
Initial acute management of
Na >125 me /L
Search for alternative cause
of neurologic compromize
3% saline ivi
Initial goalincrease [Na] by 1.5-2.0 meq/L/h
for 3-4 hours or until symptoms resolve Change in [Na] can occur rapildlyImmediate attainment to normalIs not goal
< 2 days
> 2 days
Change in [Na] should not exceed
10 meq/L in first 24 hours and
18 meq/L in first 48 hours
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
67/69
SOLUTION=SOLUTE+SOLVENT
Molality: number of moles of a solute perkilogram of solvent
Molarity: number of moles of solute per litre of solution
Osmolality: number of osmoles of solute per kilogram of solvent
Tonicity = effective osmolality
sum of the concentrations of the solutes which have the capacity to exert anosmotic force across the membrane.
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
68/69
Free water (FW)Calculated base on osmolality
(Na, Glucose, BUN)
As urea is freely permeable across all cell membraneDoes not contribute to effective osmolality ie tonicity
Electrolyte free water (EFW)Calculation based on S.[Na}
Modified Electrolyte free water (MEFW)Calculation takes into consideration Glucose along with s.[Na]
Ubaidur Rahaman, Senior Resident, CCM, SGPGIMS, Lucknow, India
7/30/2019 electrolyte disorders in critically ill
69/69
hank You