SHOCK TREATMENT OPTIONS & CHOICES

11. TREATMENT OF SHOCK(Causative & General)
- Take into consideration the etiological classification discussed above, you will have diagnosed the underlying causative factor, and correction undertaken rapidly.
-The general treatment measures include.

11.1. Oxygen Inhalation Check Airway : This has special reference
to wounds of the chest. If oxygenation is deficient and
patients are cyanosed, it may need to be combined with
Intermittent positive pressure ventilation with 100% O2
After intubations.

11.2. Infusion + Transfusion
Two large bore infusion
lines are started in
Severe shock 1-2 liter
of Ringer's lactate are
infused, if blood is
Lost fully cross
Matched whole blood is
Of great importance in
cases. In the group of
cases which do not
respond to intravenous
blood transfusion O group packed cells can be given. The
recommended fluid requirements are given in table.

Disadvantages of Blood
-Grouping and cross matching takes time
-Stored blood has high potassium,fragments of platelets,and WBC
-Blood maybe infected with malaria,HIV,HBV
-Viscosity of blood in microcirculation may require fluids other than blood

Selection of Fluid
The most cost effective approach is with rapid infusion of isotonic (Normal) saline or a balanced salt solution.
-Infusion of 2 to 3L of crystalloid over 10 to 30 min should restore adequate intravascular volume in most cases as the result of fluid input and distribution.
-In patients with hemorrhagic shock, restoration of blood volume with crystalloid usually requires at least three times the estimated blood loss.
• If blood pressure does not improve after rapid administration of 21 of crystalloid, this suggests that blood loss is in excess of 1500ml, or there is ongoing active bleeding, or, alternatively, another cause of shock must be considered.
• Volume resuscitation in hemorrhage should include simultaneous blood transfusion, either as fully cross matched blood, type specific blood, or, in some circumstances, O-positive or O-negative packed cells.
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SHOCK TREATMENT CONCERNS

10. HEMORRHAGE
Treatment concerns
What concerns us most, in this section are the effects, of the
loss of whole blood, from torn blood vessels in the injured part.
This hemorrhage may be external, if the skin has been torn (visible loss), or it is internal into body cavities or tissue spaces, and cannot be estimated.

10.1 The clinical state of shock, that follows, also depends
on, the rate at which blood is lost and this is dependent upon :

-The extent of injured area(number of torn vessels)
-Vessels injured, whether these are arteries where the loss is
much greater, or veins when the loss is much less, over time.
Injury may also be to the capillaries, with the least amount
of blood loss.

-The size of the blood vessels-major arterial injury can
produce extreme blood loss, over a short time eg.
injuries to the aorta.

10.2 The hemorrhage may occur immediately on receiving
injuries, or later when the initial clot formed at that time is dislodged.

Intravenous fluid delivery
Resuscitation of hemorrhagic shock or severe hypovolemia, requires two large bore (16 gauge or larger) intravenous lines, for rapid volume expansion.
Access may be achieved by peripheral vein catheterization.
Cut downs on the basilic, greater saphenous, or cephalic veins
Or percutaneous central venous access via subclavian, internal jugular, or femoral venous puncture.
The most important consideration for vascular access, is the choice of catheter and tubing. The rate of flow is proportional to, the fourth power of the radius of the canulla, and is inversely related to its length.
Thus a short large bore catheter connected to the widest administration tubing or direct insertion of beveled tubing via a cut down venotomy provides the most efficient restoring of circulating volume.


Treatment of hypo-volemic shock aims at two primary goals at the same time, they are;
-To re-expand the circulating blood volume and
- A surgical interventions, to control any further blood volume loss.

Adequate replacement of the circulating volume,
-Expands vessels & restores venous return, -
-This reestablishes ventricular filling.
These results in, improved left ventricular end diastolic volume,-> contractile function, and stroke volume improved
The cardiac output responds positively,- as cardiac output improves, this leads to systemic vascular resistance returning to normal- and tissue perfusion improves
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review

SHOCK MONITORING MODERN TECHNIQUES 2

9.1.3 Transcutaneous O2 monitoring

This noninvasive technique for measuring skin PO2 is dependent on
cardiac output and skin perfusion in a stable patient but not in
patients in shock

Gastric Tonometry
Gut perfusion, can be indirectly assessed, using tonometric techniques, to measure the gastric intramucosal pH (pHi).
- Involves instilling saline into a semi permeable balloon, at the end of a modified nasogastric tube, after a period of equilibration, remove the saline and measure the carbon dioxide tension (Pco2), of the saline sample.
-Mucosal ischemia, leads to the production of increased CO2 within the stomach lumen, which is detected as an increased Pco2, in the saline sample.
-Gastric mucosal Pco2 is used with measured arterial bicarbonate to calculate the pHi. -Trauma patients with pHi less than 7.32 have a higher rate of MOF and death.
-Recent technical innovations, have lead to the development, of a semicontinuous gas tonometer, and a model of this device is now available for clinical use.
Gut perfusion using this technique is detected by an elevated mucosal-arterial CO2 gap.
Gas tonometry is automated, and less prone to sampling error.

9.1.4 Serum Lactate

The more important information comes from demonstrating rising or
falling serum lactate levels in response to treatment of shock.
The lactate/pyruvate ratio is also of help in this regard.

Recent developments have led to the availability of bedside testing of serum lactate levels, and an effective clinical method of determining perfusion status through serial measurement of lactate at the bedside in critically ill patients.

In summary it is observed that in shock resulting from
decreased blood volume (oligaemia) there would be on INVESTIGATION:
i)A decreased cardiac output
ii)An increased peripheral resistance and
iii)Decreased central venous pressure


Metabolic effects of untreated shock include:
* A decreased, oxygen consumption
* Hyperglycaemia followed by hypoglycaemia in late stages
where glycogen stores have been depleted
* A rise in blood lactate and pyruvate
* Metabolic acidosis
* Increase in ACTH secretion
* Decreased urine output (<0.5 ml.kg body wt.)
Modern techniques can help give you information, if you look for it
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review

SHOCK MONITORING MODERN METHODS

9.1 MODERN TECHNIQUES

Pulmonary artery catheterization usng Swan-Ganz catheters can
supplement the parameters discussed above.
It is required in
-Major trauma,
-High risk surgical patients,
-Cardiac surgery or
-Diagnosis is uncertain.
It is passed per-cutaneous through internal Jugular or Subclavian veins into the right atrium, right ventricle, and into the pulmonary artery.
Proper placement shows the dichrotic pulmonary/artery wave.
The balloon is inflated and the wave form shows the pulmonary capillary wedge pressure (PCWP) this represents, left ventricular preload pressure.
Cardiac output can be measured using thermo-dilution techniques.
Some of the parameter used in monitoring a shock patient are given in table 4.2.

The volumetric oximetery PAC measures right ventricular volumes, has proven to be very useful in the care of critically ill patients.
This modified PAC measures beat to beat temperature changes with sampling, from which the right ventricular ejection fraction (RVEF) is calculated.
This technology improves the clinician’s ability to estimate preload, contractility, and afterload.
Continuous mixed venous oxygen saturation (Svo2) monitoring using fiber optics incorporated into the PAC has been available and monitoring Svo2.
The ability to continuously monitor cardiac output represents a recent advance in PAC technology. Monitoring systems that measure cardiac output as often as every 15 seconds are now available.

9.1.1 Continuous Cardiac Output

The most widely used method is noninvasive skin electrodes that
measure small amplitude alternating current.

Invasive and non-invasive Doppler methods have been used to
provide continuous cardiac output measurement.

9.1.2 Mixed Venous Oxygen

This is possible with a modified pulmonary artery catheter with a
Fiber-optic bundle, and use of reflectance spectrometer.
This technique can give us mixed venous oxygen saturation
SV(overbar)O2.

The arterial base deficit (BD) represents a rapid, widely available measure of post-traumatic metabolic acidosis.
-This variable is calculated from directly measured values of arterial pH and arterial carbon dioxide tension (Paco2) from an arterial blood gas sample
-Persistently elevated values of BD throughout the resuscitation period have been correlated with impaired oxygen utilization, and may provide insight into the adequacy of ongoing resuscitation and therapy.
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review

SHOCK SPOT AND TREAT

8. PRESENTATION OF SHOCK

A patient with a history of having had any one of the causative
events listed under Shock syndrome presents with:

* Pallor best seen on the face
* Cold moist skin of the extremities(vasoconstriction of skin
vessels)
* Rapid weak pulse (>90/min) and a collapse of superficial veins
because of compensatory peripheral vasconstriction
* Cyanosis and rapid shallow breathing (air hunger)
* Patient may have tendency to vomit and is restless,
later there may be diminishing sensibility, drowsiness and
coma
** On examination there is a declining pulse pressure
followed latter by a drop in blood pressure (systolic < 90 mm
of Hg)

9. MONITORING

In an average hospital or Nursing home, the patient with any of the shock syndromes, is observed, and progress assessed, recording the following
parameters:

* Blood pressure
* Central Venous pressure
* Haematocrit
* Arterial blood gases
* Urine output

All these values, if altered, are the late manifestations of shock.
Thus it is difficult to assess the treatment of shock.
Normal values may not reflect reversal of shock and give no indication of tissue perfusion or O2 debt. Thus silent hypoxia remains undetected.
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review