Lecture 7: Fluid loss and management

Lecture-7
LOSS OF BODY FLUID AND ITS
CONSEQUENCES
Dr Shamshad
Majamaah University

• Describe the various causes of loss of body fluids
• Discuss the consequences of hemorrhage
• Define vomiting and diarrhea
• Discuss the management of fluid loss from the body
Objectives
Suggested reading :
:Guyton and Hall “Textbook of Medical Physiology”13thed (pg. 294-296, 803-804)
-:Current Medical Diagnosis and treatment 2021.

• Pleural fluid
• Pericardial fluid
• Peritoneal fluid
• Synovial fluid
• Cerebrospinal fluid
• Intraocular
• Urinary lumen
• GIT lumen

1: Renal
Tubular disorder:
 Genetic
 Acute renal injury, salt losing nephropathy
 renal tubular acidosis (recovery phase)
 Chronic renal disease
Diuresis:
diuretics use, osmotic or postobstructvie.
Pathological causes of Body fluid loss

2: Non-renal
• Hormonal : Adrenal insufficiency, Diabetes Insipidus & D mellitus
• GIT losses
 Upper : Nasogastric suction , vomiting
 Lower: diarrhea, enteric or pancreatic fistula , Ileostomy or
colostomy,tube drainage…
• Dermal losses: Sweat ,burns…
• Transcellular fluid loss:
 Pleural & Pericardial effusion, Ascites, Intestinal obstruction…
• Hemorrhage: Internal or external
• Rhabdomylosis

Mild Moderate Severe
Water loss (ml) <50 ml/kg
body wt
50-100
ml/kg body wt
>100ml/kg
body wt
body weight ( %) <5% 5-10 % >10 %
Skin & mucous Slightly dry Dry and pale Grey and mottled
parched
Eye balls sunken Slightly moderate Deeply
Oliguria slightly moderately Anuria
Peripheral
circulation
Heart rate
Normal
Normal
Cool
Increased
Cool, weak and thread
pulse ,shock with
decreased BP
Alertness mental
condition
Normal to slightly
irritable
Irritable Unconscious to
comatose state
Anterior fontanelle Normal depressed depressed

Most common cause of hypovolemia: Hemorrhage
Decreases filling pressure of circulation
Leads to Decrease cardiac output
Ensues shock

Relationship of Bleeding Volume to Cardiac Output and
Arterial Pressure:
• About 10 % of the total blood volume can be removed with
almost no effect …
• But > 10 % loss diminishes the cardiac output first and later
the arterial pressure,
• >35-45 % blood loss    FATAL

The decrease in Arterial Pressure after hemorrhage causes powerful
sympathetic reflexes by the arterial baroreceptors and other vascular
stretch receptors).   resulting in three important effects:
(1) The arterioles constrict in most parts of the systemic
circulation, thus increasing the total peripheral resistance.

2) The veins and venous reservoirs constrict, to maintain
adequate venous return.
3) Heart activity increases leading  Increase Cardiac Output
 Importance of the Sympathetic Nervous Reflexes 
 Protect the cerebral and coronary circulation
 The reflexes extend the amount of blood loss that can occur
without causing death to about twice that which is possible in
their absence.

Shock stages :
1. Non-progressive stage (compensated stage):-
The normal circulatory compensatory mechanisms eventually
cause full recovery without help from outside therapy.

Mechanism
1. Baroreceptor reflexes,
 Powerful sympathetic stimulation of the circulation.
2. Central nervous system ischemic response,
 More powerful sympathetic stimulation throughout the body.
But not activated significantly until the BP falls < 50 mm Hg.
3. Reverse stress-relaxation of the circulatory system,
 Causes the blood vessels to contract provides more adequately
fills the circulation.

4. Formation of angiotensin by the kidneys,
 Constricts the peripheral arteries
 Thus decrease output of water & salt by the kidneys.
5. Formation of vasopressin (antidiuretic hormone)
 Constricts the peripheral vessels
 Thus increases water retention by the kidneys.

6. Compensatory mechanisms :Absorption of fluid
 From the intestinal tract,
 Into the blood capillaries from the interstitial spaces of the
body,
 Conservation of water & salt by the kidneys,
 Increased thirst & increased appetite for salt makes the person
drink water and eat salty foods if able.

Duration of action:
 Angiotensin, vasopressin & reverse stress-relaxation :
 Requires 10 minutes - 1 hour to respond completely,
 Readjustment of blood volume
 by absorption of fluid from the interstitial spaces and intestinal
tract, oral ingestion and absorption of additional quantities of
water and salt,
 Requires 1 – 48 hours.

2. Progressive stage:-
 Without therapy, the shock becomes steadily worse until
death.
3. Irreversible stage:-
 The shock has progressed to such an extent that all forms of
known therapy are inadequate to save the person’s life, even
though, for the moment, the person is still alive.

The forceful expulsion of gastric contents through oral route
The sensory signals that initiate vomiting originate mainly
from the pharynx, esophagus, stomach, and upper portions of
the small intestines.
Once the vomiting center sufficiently stimulated  act of
vomiting is instituted.
Vomiting centers triggered by other modality with sensory
signals originated from GIT:
Ex: Drugs / motion & vestibular stimulation….
Vomiting

Results from rapid movement of fecal matter through the large
intestine.
Clinical Causes: eg:
o Enteritis: Causes ..? Site ..?
Mechanism of action ..? (motility / toxin / secretion)
The amount can be 10 to 12 liters per day,
although the colon can usually reabsorb a maximum of only 6
to 8 liters per day.
o Psychogenic
Excessive stimulation of the parasympathetic nervous system,
An examples : … ?
o Allergic / immunomediated / others :
Diarrhea:

I: Investigation:
II: Treatment:
1- General Measures
Basic life support with an assessment of the patient’s airway, breathing, and
circulation.
Vital signs monitoring
Oxygen therapy
Establish I.V line (central / peripheral).
What's your DDx ? React accordingly 
2- Volume replacement
Fluids / blood / electrolyte replacement
3- Medications
a. Vasoactive therapy
b. Corticosteroids
c. Antibiotic ??
4- others:
Management

Lecture 7: Fluid loss and management

More Related Content

What's hot

What's hot (20)

Similar to Lecture 7: Fluid loss and management

Similar to Lecture 7: Fluid loss and management (20)

More from Dr Shamshad Begum loni

More from Dr Shamshad Begum loni (20)

Recently uploaded

Recently uploaded (20)

Lecture 7: Fluid loss and management

Editor's Notes