26. Clinical approach to patients with icterus (jaundice) Flashcards

1
Q

What is jaundice?

A

Jaundice is the yellow staining of serum or tissues by an excessive amount of bile pigment or bilirubin

Jaundice in general

Origins: Pre-hepatic; Hepatic; Post-hepatic

Because the liver is able to excrete bilirubin, for jaundice to occur,

there needs to be a large, persistent increase in bile pigment

production or a major impairment of its excretion

↑ Br → Detectable by lab tests

↑↑ Br → Plasma appears yellow

↑↑↑↑ Br → Jaundice

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2
Q

Prehepatic Jaundice ?

A

PREHEPATIC JAUNDICE (HAEMOLYTIC CRISIS)

Haemolysis → ↑ Hb degradation → ↑ Br

Haemolysis → ↓ RBCs → Hypoxia → Necrosis → Cholestasis

Causes:

§ Babesia

§ IMHA

§ Toxicosis: Snake bite; Onion/garlic; Paracetamol; Zn

§ Bacteria: Mycoplasma haemofelis

CSx: Hypercholic faeces (due to stercobilin)

Lab. D

§ ↓ PCV

§ ↑ Hb (due to haemolysis)

§ ↑ Reticulocytes (immature RBCs)

§ ↑ Bilirubin I in serum → Icteric serum

§ ↑ Bilirubin II & UBG in urine

Tests: PCV; TP; Icteric serum; Spherocytes; Agglutination

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3
Q

Hepatic/ Hepatocellular jaundice?

A

HEPATIC/HEPATOCELLULAR JAUNDICE

↓ Uptake & conjugation due to hepatic disease;↓ Hepatic excretion

Hepatocyte damage/structural damage → Leakage between

sinusoids & biliary vessel

Causes:

§ Severe/acute hepatitis § Plants

§ Abnormal conjugation § Neoplasia

§ Abnormal excretion § Bacteria

§ Intrahepatic cholestasis § Parasites

§ Extrahepatic infection § Sepsis

§ Cholangiohepatitis § Mycotoxins

CSx: Hypercholic faeces

Lab. D: ↑ Br; ↑ ALT; ↑ ALP; ↑GGT; ↑ AST

Imaging: Ultrasound

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4
Q

Posthepatic Jaundice?

A

POSTHEPATIC JAUNDICE

Obstruction of the biliary duct

Cause

Biliary tract obstruction: Stones/mucocele

§ Duodenal foreign body: Blocking of papillae

§ Pancreatitis

CSx: Grey faeces

Lab. D

§ ↑ Br; ↑ ALP; ↑ GGT; ↑/- AST

§ Ø Urinary UBG

§ Ø Faecal stercobilin

Imaging: Ultrasound (stones; biliary tract congestion; pancreatitis)

Note: Cholestasis → ↑ BBA (blood bile acid) → RBC destruction →

Haemolysis

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5
Q

Clinical approach to jaundice?

A

Clinical Approach To Jaundice

Normal serum total bilirubin

§ Dogs: <0.6mg/dl

§ Cats: <0.3mg/dl

Canine renal tubules have a low resorptive threshold for bilirubin &

and process Br to a limited extent ∴ bilirubinuria may be normal for

dogs

As for cats, they do not have this ability.

Bilirubinuria = Hyperbilirubinaemia = Pathologic!

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6
Q

Lab D in general?

A
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7
Q

Treatment?

A

TREATMENT

Treat the cause!

§ Supportive therapy: IVFT; Electrolytes; Antiemetics;

§ Antibiotics (cause dependent): Metronidazole; Ampicillin

§ Coagulopathy: Plasma; Vit. K injection

§ Adjunctive therapy

Antioxidants: Vit. E; Vit. C; SAMe

Choleretic: UDCA

N-acetylcysteine in paracetamol toxicosis cases

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