12. MULTIPLE ORGAN FAILURE The objective of all treatment of shock is to resuscitate the patient, to restore haemodynamic stability, and to prevent organ failure.
However, due to reasons not clearly understood, and depending on the severity of shock, or persistance of the state of shock, some patients will pass into Multiple Organ failure*.
It begins with pulmonary dysfunction, followed by hepatic, intestinal, and renal failure.
As the number of organs failing increase mortality climbs to 100%.
* also called
MODS (Multiple organ dysfunction syndrome)
MOSF (Multiple organ system failure)
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Wednesday, October 27, 2010
Wednesday, October 20, 2010
MORE DRUGS FOR SHOCK
Therapeutic Aids 2
Nor-epinephrine
Norepinephrine is used mainly in patients with hypotension, persisting after volume resuscitation and other Inotrops have been tried.
The sympathetic neurotransmitter nor-epinephrine exerts both alpha and beta adrenergic effects.
The beta adrenergic effects are most prominent at lower infusion rates, leading to increases in heart rate and contractility.
With increasing doses, the alpha mediated effects become evident and are responsible for increases in systemic vascular resistance and blood pressure.
Epinephrine
Epinephrine has a broad spectrum of systemic actions.
At lower rates of infusion Beta-adrenergic responses predominate, leading to an increase in heart rate and contractility (beta 1 effect) in conjunction with peripheral vaso-dilation (beta 2 effect).
These effects result in an increase in stroke volume and cardiac output with a variable effect on blood pressure.
At a higher rate of infusion, alpha effects predominate, leading to an increase in systemic vascular resistance and blood pressure.
All questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review
Followers may contribute
Nor-epinephrine
Norepinephrine is used mainly in patients with hypotension, persisting after volume resuscitation and other Inotrops have been tried.
The sympathetic neurotransmitter nor-epinephrine exerts both alpha and beta adrenergic effects.
The beta adrenergic effects are most prominent at lower infusion rates, leading to increases in heart rate and contractility.
With increasing doses, the alpha mediated effects become evident and are responsible for increases in systemic vascular resistance and blood pressure.
Epinephrine
Epinephrine has a broad spectrum of systemic actions.
At lower rates of infusion Beta-adrenergic responses predominate, leading to an increase in heart rate and contractility (beta 1 effect) in conjunction with peripheral vaso-dilation (beta 2 effect).
These effects result in an increase in stroke volume and cardiac output with a variable effect on blood pressure.
At a higher rate of infusion, alpha effects predominate, leading to an increase in systemic vascular resistance and blood pressure.
All questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review
Followers may contribute
Wednesday, October 13, 2010
DRUGS FOR SHOCK
Therapeutic aids
Pulmonary Artery Catheter
The differential diagnosis of the shock state is usually relatively straightforward. The clinical setting in conjunction with physical examination is often sufficient to guide diagnosis and therapy.
However, occasionally the cause of the shock state is unclear, in which case homodynamic parameters derived form a pulmonary artery catheter may provide valuable insight into the principal mechanism underlying the shock state.
Inotropes
Volume resuscitation, should precede pharmacological aids.
Drugs should be considered, when tissue perfusion is inadequate, after fluid administration.
Dopamine
Dopamine is an endogenous sympathetic amine, and is a biosynthetic precursor of epinephrine, which also acts as central and peripheral neurotransmitter effect. At low dose (1-3 µg/kg/min) dopamine may increase renal blood flow and diuresis.
At moderate doses (5 µg/kg/min) stimulation of cardiac beta-receptors produces increases in contractility and cardiac output with little effect on heart rate or blood pressure.
With increasing doses (5-10 µg/kg/min), Beta-adrenergic effects predominate, further increases in cardiac output are accompanied by increases in heart rate and blood pressure.
At higher doses (more than 10 µg/kg/min), peripheral vasoconstriction, from increasing alpha-activity becomes more prominent, resulting in
elevation of systemic vascular resistance,
blood pressure,
and myocadial oxygen consumption.
Dobutamine
Dobutamine is a synthetic adrenegic agonist.
The predominant effect is an increase in cardiac contractility with little increase in heart rate.
Dobutamine also has a peripheral vasodilating effect resulting from Beta2-receptor activation that is independent of any increase in cardiac output.
The combination of increased contractility, and reduction in afterload, contribute to improved left ventricular emptying and a reduction in pulmonary capillary wedge pressure.
As a result of these properties, dobutamine is an ideal agent when the therapeutic goal is to improve cardiac output rather than to improve blood pressure.
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review
Pulmonary Artery Catheter
The differential diagnosis of the shock state is usually relatively straightforward. The clinical setting in conjunction with physical examination is often sufficient to guide diagnosis and therapy.
However, occasionally the cause of the shock state is unclear, in which case homodynamic parameters derived form a pulmonary artery catheter may provide valuable insight into the principal mechanism underlying the shock state.
Inotropes
Volume resuscitation, should precede pharmacological aids.
Drugs should be considered, when tissue perfusion is inadequate, after fluid administration.
Dopamine
Dopamine is an endogenous sympathetic amine, and is a biosynthetic precursor of epinephrine, which also acts as central and peripheral neurotransmitter effect. At low dose (1-3 µg/kg/min) dopamine may increase renal blood flow and diuresis.
At moderate doses (5 µg/kg/min) stimulation of cardiac beta-receptors produces increases in contractility and cardiac output with little effect on heart rate or blood pressure.
With increasing doses (5-10 µg/kg/min), Beta-adrenergic effects predominate, further increases in cardiac output are accompanied by increases in heart rate and blood pressure.
At higher doses (more than 10 µg/kg/min), peripheral vasoconstriction, from increasing alpha-activity becomes more prominent, resulting in
elevation of systemic vascular resistance,
blood pressure,
and myocadial oxygen consumption.
Dobutamine
Dobutamine is a synthetic adrenegic agonist.
The predominant effect is an increase in cardiac contractility with little increase in heart rate.
Dobutamine also has a peripheral vasodilating effect resulting from Beta2-receptor activation that is independent of any increase in cardiac output.
The combination of increased contractility, and reduction in afterload, contribute to improved left ventricular emptying and a reduction in pulmonary capillary wedge pressure.
As a result of these properties, dobutamine is an ideal agent when the therapeutic goal is to improve cardiac output rather than to improve blood pressure.
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review
Wednesday, October 6, 2010
SHOCK TREATMENT CHOICES 2
Hypertonic Saline
The logic behind the use of hyperosmotic soultions in patients with hypovolemic shock is
-The hypertonic component of these solutions draws water out of the intracellular space and expands the volume of the extracellular space.
-To increase the intravascular osmotic pressure 6% dextran has been added to the hypertonic saline solution.
-The colloid component holds the newly arrived readmitted fluid in the intravascular space and thus, should prolong the beneficial effects of the hypertonic solutions. Based on published data, hypertonic saline with or without dextran offers a little benefit than standard resuscitation regimes.
• In-patients with shock and traumatic brain injury the brain edema hypertonic saline may offer some benefit in the form reducing edema.
• Hypertonic saline as method of small volume resuscitation may also offer some advantages in prolonged transport or longer evacuation periods times require of resuscitation with limited supplies.
• Additionally, the small weights and volumes of hypertonic saline required for resuscitation may prove of advantage in stored supplies for the war and disasters.
Use of Colloids
It is uncertain whether the use of colloid solutions has any benefit over the use of crystalloid solutions.
Analysis of randomized, controlled trials, comparing albulmin to crystalloid, have suggested that use of colloid solutions, in resuscitation may in fact increase mortality.
It is thought that albumin, for instance may increase edema , impair sodium and water exeretion, and worsen renal failure.
There are two forms of synthetic colloid in use.
-Hetastarch, a 6% hydroxyethyul starch solution, has a significant volume expanding effect that lasts as long as 24 hours.
-Potential disadvantages with the use of hetastarch, include rare anaphylaetic reactions, and the development of a coagulopathy, when given in excess of 100ml/day.
Clinical trials, with this agent have shown improvements in tissue perfusion, without any difference, in clinical outcomes.
-Pentastarch is a synthetic colloid, with several advantages over hetastarch.
Its structure allows for a more concentrated solution, and therefore higher osmotic pressures, for plasma expansion, and faster plasma clearance, and renal excretion
This new solution, has been proved to cause less allergy, and is associated with fewer renal, or anaphylactic complications.
Pentastarch has a volume expanding effect that lasts approximately 12 hours in comparison to herastarch (24 hours). Approximately 90% of the pentastarch given is eliminated form the intravascular space within 24 hours.
Pentastarch induces plasma volume expansion of about 1.5 times the volume introduced, whereas hetastarch produces expansion approximately equal to the volume administered.
Thus pentastarch may be a more potent volume expander with a shorter duration of action than either hetastarch or albumin
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review
The logic behind the use of hyperosmotic soultions in patients with hypovolemic shock is
-The hypertonic component of these solutions draws water out of the intracellular space and expands the volume of the extracellular space.
-To increase the intravascular osmotic pressure 6% dextran has been added to the hypertonic saline solution.
-The colloid component holds the newly arrived readmitted fluid in the intravascular space and thus, should prolong the beneficial effects of the hypertonic solutions. Based on published data, hypertonic saline with or without dextran offers a little benefit than standard resuscitation regimes.
• In-patients with shock and traumatic brain injury the brain edema hypertonic saline may offer some benefit in the form reducing edema.
• Hypertonic saline as method of small volume resuscitation may also offer some advantages in prolonged transport or longer evacuation periods times require of resuscitation with limited supplies.
• Additionally, the small weights and volumes of hypertonic saline required for resuscitation may prove of advantage in stored supplies for the war and disasters.
Use of Colloids
It is uncertain whether the use of colloid solutions has any benefit over the use of crystalloid solutions.
Analysis of randomized, controlled trials, comparing albulmin to crystalloid, have suggested that use of colloid solutions, in resuscitation may in fact increase mortality.
It is thought that albumin, for instance may increase edema , impair sodium and water exeretion, and worsen renal failure.
There are two forms of synthetic colloid in use.
-Hetastarch, a 6% hydroxyethyul starch solution, has a significant volume expanding effect that lasts as long as 24 hours.
-Potential disadvantages with the use of hetastarch, include rare anaphylaetic reactions, and the development of a coagulopathy, when given in excess of 100ml/day.
Clinical trials, with this agent have shown improvements in tissue perfusion, without any difference, in clinical outcomes.
-Pentastarch is a synthetic colloid, with several advantages over hetastarch.
Its structure allows for a more concentrated solution, and therefore higher osmotic pressures, for plasma expansion, and faster plasma clearance, and renal excretion
This new solution, has been proved to cause less allergy, and is associated with fewer renal, or anaphylactic complications.
Pentastarch has a volume expanding effect that lasts approximately 12 hours in comparison to herastarch (24 hours). Approximately 90% of the pentastarch given is eliminated form the intravascular space within 24 hours.
Pentastarch induces plasma volume expansion of about 1.5 times the volume introduced, whereas hetastarch produces expansion approximately equal to the volume administered.
Thus pentastarch may be a more potent volume expander with a shorter duration of action than either hetastarch or albumin
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review
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