Keseimbangan Asam-Basa (2) : Sudarno, DR M.Kes
Keseimbangan Asam-Basa (2) : Sudarno, DR M.Kes
Keseimbangan Asam-Basa (2) : Sudarno, DR M.Kes
ASAM-BASA (2)
Sudarno, dr M.Kes.
Gangguan Keseimbangan asam-basa
Umumnya disertai perubahan kadar elektrolit
dalam plasma
H+ tak dapat menumpuk tanpa anion yang
menyertainya (misalnya Cl-, SO42- , laktat-)
atau tanpa pertukaran dengan kation
(misalnya Na+, K+)
Jadi pengukuran keadaan keseimbangan asam
basa perlu pemeriksaan:
pH darah
pCO2 darah
Kadar elektrolit darah : Na+, K+, Cl-
dll
Acid-Base Imbalances
pH< 7.35 acidosis
pH > 7.45 alkalosis
The body response to acid-base imbalance is
called compensation
May be complete if brought back within
normal limits
Partial compensation if range is still outside
norms.
Primary Acid-Base Disorders
As dictated by the Henderson-Hasselbalch equation,
disturbances in either the respiratory component (pCO2) or
metabolic component (HCO3-) can lead to alterations in pH.
coma
death
Alkalosis
Alkalosis causes over excitability of the central and
peripheral nervous systems.
Numbness
Lightheadedness
It can cause :
Nervousness
Convulsions
Loss of consciousness
Death
Compensation (continued)
Primary Disorder Compensatory Mechanism
Metabolic acidosis Increased ventilation
* Check the pH
Clinicians use the anion gap to identify the cause of metabolic acidosis.
Anion Gap
Normal = 12 + 2
Na+ Cl-
K+
= Albumin
HCO3-
Other Cations Other Anions
Phosphate, sulphate, organic anions
Bicarbonate loss
– GI loss
– Renal failure
Ketoacidosis
– Diabetes
Lactic acidosis
– Tissue hypoxia (Type A)
– Drugs eg phenformin, ethanol, methanol
(Type B)
Practical Approach
Mekanisme kompensasi:
Bufer kimia: terutama oleh bufer
bikarbonat/asam karbonat
Bufer fisiologis(pernafasan): pH yang
turun merangsang Hiperventilasi agar
ekskresi CO2 meningkat [H2CO3]
agar ratio [HCO3-]/[H2CO3] kembali
20/1
Bufer fisiologis (renal)
Ginjal berusaha mengembalikan
komposisi elektrolit semula dan PH
dengan cara ekskresi asam dan
menahan basa
pertukaran Na+-H+
pembentukan ammonia
reabsorpsi HCO3-
IV lactate solution
Treatment of Metabolic Acidosi
Metabolic acidosis
Compensation by
Blowing off CO2
Asidosis Respiratorik
Primary event =
retention of CO2
Renal retention of
Bicarbonate
minigates level of acidosis
Primary event =
retention of CO2
SELAMAT BELAJAR
Alkalosis Respiratorik
Primer kekurangan [H2CO3] pCO2
pH
Sebab:
Semua keadaan yang menyebabkan meningkatnya
laju (rate) atau kedalaman (depth) pernapasan,
atau keduanya
Misalnya demam , suhu luar yang tinggi, histeria
yang menyebabkan hiperventilasi, hipoksia, dan
keracunan salisilat