Hypovolemic shock
-acute circulatory failure with inadequate or inappropriately distributed tissue perfusion resulting in generalized cellular hypoxia due to loss of circulatory volume.
Complications
Inadequate tissue perfusion:
a) skin- cold, pale, blue, slow capillary refill, clammy (peripheral cyanosis)
b) kidneys- oliguria, anuria (Oliguria is defined as a urine output that is less than 1 mL/kg/h in infants, less than 0.5 mL/kg/h in children, and less than 400 mL/day in adults. Anuria is defined as absent production of urine)
c) brain- drowsiness, confusion and irritability
d) multi organ failure due to lack of perfusion to organs
Increased sympathetic tone:
a) tachycardia, narrowed pulse pressure, “weak” or “thready” pulse
b) cold and clammy
c) blood pressure- maybe maintained initially but later hypotension will occur
Metabolic acidosis- anaerobic glycolysis occur within tissues to lack of oxygen
Haemothorax
A haemothorax is a condition that results from blood accumulating in the pleural cavity. Its cause is usually traumatic, from a blunt or penetrating injury to the thorax, resulting in a rupture of either of the serous membrane lining the thorax and covering the lungs. This rupture allows blood to spill into the pleural space, equalizing the pressures between it and the lungs. Blood loss may be massive in people with these conditions, as each side of the thorax can hold 30%-40% of a person's blood volume. If left untreated, the condition can progress to a point where the blood accumulation begins to put pressure on the mediastinum and the trachea, effectively limiting the amount of diastolic filling of the ventricles and deviating the trachea to the unaffected side.
Same pressure between pleural cavity and atmosphere means that there is no pressure gradient. Thus air does not enter or leave the lungs. There is no ventilation of the alveoli hence blood flowing through the capillaries do not get adequately oxygenated. This will result in hypoxia and infarct of tissues.
abnormal fast breathing
Dyspnoea.
Cyanosis.
Decreased or absent breath sounds on affected side.
Tracheal deviation.
Dull resonance on percussion.
Unequal chest rise.
Tachycardia.
Hypotension.
Pale, cool, clammy skin.
Possibly subcutaneous air
Narrowing pulse pressure
Showing posts with label pcl 4. Show all posts
Showing posts with label pcl 4. Show all posts
Wednesday, 28 March 2007
Friday, 23 March 2007
Resuscitation Procedures
Arrhythmias associated with cardiac arrest are divided into two groups: shockable rhythms (VF/VT) and non-shockable rhythms (asystole and PEA). The principle difference in management is the need for attempted defibrillation in patients with VF/VT. Subsequent actions, including chest compression, airway management and ventilation, venous access, administration of adrenaline, and the identification and correction of reversible factors, are common to both groups.
Non-shockable rhythms (PEA and asystole)
Pulseless electrical activity (PEA) is defined as cardiac electrical activity in the absence of any palpable pulse. These patients often have some mechanical myocardial contractions but they are too weak to produce a detectable pulse or blood pressure. PEA may be caused by reversible conditions that can be treated if they are identified and corrected. Asystole refers to a state of no cardiac activity. Survival following cardiac arrest with asystole or PEA is unlikely unless reversible cause can be found and treated effectively.
In asystole, the heart will not respond to defibrillation because it is already depolarized while in PEA, the heart is very unlikely to be shocked successfully into a perfusing rhythm and delivering repeated shocks will increase myocardial injury, both directly from the electric current and indirectly from the interruptions in coronary blood flow.
Sequence of actions for PEA
• Start CPR.
• Give adrenaline as soon as intravascular access is achieved.
• Continue CPR until the airway is secured, then continue chest compressions without pausing during ventilation.
• Recheck the rhythm after 2 min.
o If there is no change in the ECG appearance:
• Continue CPR.
• Recheck the rhythm after 2 min and proceed accordingly.
• Give further adrenaline every 3-5 min.
o If the ECG changes and organized electrical activity is seen, check for a pulse.
• If a pulse is present, start post-resuscitation care.
• If no pulse is present:
O Continue CPR.
o Recheck the rhythm after 2 min and proceed accordingly.
o Give further adrenaline every 3-5 min
Shockable rhythms (VF/VT)
VF refers to ventricular fibrillation with the presence of a pulse and VT refers to ventricular tachycardia.
Sequence of actions
• Attempt defibrillation
• Immediately resume chest compressions without reassessing the rhythm or feeling for a pulse.
• Continue CPR for 2 min, then pause briefly to check the monitor:
o If VF/VT persists:
• Give a further (2nd) shock
• Resume CPR immediately and continue for 2 min.
• Pause briefly to check the monitor.
• If VF/VT persists give adrenaline IV followed immediately by a (3rd) shock
• Resume CPR immediately and continue for 2 min.
• Pause briefly to check the monitor.
• If VF/VT persists give amiodarone (anti-arrhythmic drug) IV followed immediately by a (4th) shock
• Resume CPR immediately and continue for 2 min.
• Give adrenaline IV immediately before alternate shocks (i.e. approximately every 3-5 min).
• Give a further shock after each 2 min period of CPR and after confirming that VF/VT persists.
o If organised electrical activity is seen during this brief pause in compressions, check for a pulse.
• If a pulse is present, start post-resuscitation care.
• If no pulse is present, continue CPR and switch to the nonshockable algorithm.
o If asystole is seen, continue CPR and switch to the nonshockable algorithm.
Potentially reversible causes
Potential causes or aggravating factors for which specific treatment exists must be sought during any cardiac arrest. For ease of memory, these are divided into two groups of four, based upon their initial letter, either H or T:
• Hypoxia
• Hypovolaemia
• Hyperkalaemia, hypokalaemia, hypocalcaemia, acidaemia, and other
metabolic disorders
• Hypothermia
• Tension pneumothorax
• Tamponade (fluid in the pericardial sac)
• Toxic substances
• Thromboembolism (pulmonary embolus/coronary thrombosis)
Signs of life
If signs of life (such as regular respiratory effort or movement) reappear during CPR, or readings from the patient’s monitors (e.g. exhaled carbon dioxide or arterial blood pressure) are compatible with a return of spontaneous circulation, stop CPR and check the monitors briefly. If an organized cardiac rhythm is present, check for a pulse. If a pulse is palpable, continue post-resuscitation care. If no pulse is present, continue CPR.
Contributed by John Lee
Non-shockable rhythms (PEA and asystole)
Pulseless electrical activity (PEA) is defined as cardiac electrical activity in the absence of any palpable pulse. These patients often have some mechanical myocardial contractions but they are too weak to produce a detectable pulse or blood pressure. PEA may be caused by reversible conditions that can be treated if they are identified and corrected. Asystole refers to a state of no cardiac activity. Survival following cardiac arrest with asystole or PEA is unlikely unless reversible cause can be found and treated effectively.
In asystole, the heart will not respond to defibrillation because it is already depolarized while in PEA, the heart is very unlikely to be shocked successfully into a perfusing rhythm and delivering repeated shocks will increase myocardial injury, both directly from the electric current and indirectly from the interruptions in coronary blood flow.
Sequence of actions for PEA
• Start CPR.
• Give adrenaline as soon as intravascular access is achieved.
• Continue CPR until the airway is secured, then continue chest compressions without pausing during ventilation.
• Recheck the rhythm after 2 min.
o If there is no change in the ECG appearance:
• Continue CPR.
• Recheck the rhythm after 2 min and proceed accordingly.
• Give further adrenaline every 3-5 min.
o If the ECG changes and organized electrical activity is seen, check for a pulse.
• If a pulse is present, start post-resuscitation care.
• If no pulse is present:
O Continue CPR.
o Recheck the rhythm after 2 min and proceed accordingly.
o Give further adrenaline every 3-5 min
Shockable rhythms (VF/VT)
VF refers to ventricular fibrillation with the presence of a pulse and VT refers to ventricular tachycardia.
Sequence of actions
• Attempt defibrillation
• Immediately resume chest compressions without reassessing the rhythm or feeling for a pulse.
• Continue CPR for 2 min, then pause briefly to check the monitor:
o If VF/VT persists:
• Give a further (2nd) shock
• Resume CPR immediately and continue for 2 min.
• Pause briefly to check the monitor.
• If VF/VT persists give adrenaline IV followed immediately by a (3rd) shock
• Resume CPR immediately and continue for 2 min.
• Pause briefly to check the monitor.
• If VF/VT persists give amiodarone (anti-arrhythmic drug) IV followed immediately by a (4th) shock
• Resume CPR immediately and continue for 2 min.
• Give adrenaline IV immediately before alternate shocks (i.e. approximately every 3-5 min).
• Give a further shock after each 2 min period of CPR and after confirming that VF/VT persists.
o If organised electrical activity is seen during this brief pause in compressions, check for a pulse.
• If a pulse is present, start post-resuscitation care.
• If no pulse is present, continue CPR and switch to the nonshockable algorithm.
o If asystole is seen, continue CPR and switch to the nonshockable algorithm.
Potentially reversible causes
Potential causes or aggravating factors for which specific treatment exists must be sought during any cardiac arrest. For ease of memory, these are divided into two groups of four, based upon their initial letter, either H or T:
• Hypoxia
• Hypovolaemia
• Hyperkalaemia, hypokalaemia, hypocalcaemia, acidaemia, and other
metabolic disorders
• Hypothermia
• Tension pneumothorax
• Tamponade (fluid in the pericardial sac)
• Toxic substances
• Thromboembolism (pulmonary embolus/coronary thrombosis)
Signs of life
If signs of life (such as regular respiratory effort or movement) reappear during CPR, or readings from the patient’s monitors (e.g. exhaled carbon dioxide or arterial blood pressure) are compatible with a return of spontaneous circulation, stop CPR and check the monitors briefly. If an organized cardiac rhythm is present, check for a pulse. If a pulse is palpable, continue post-resuscitation care. If no pulse is present, continue CPR.
Contributed by John Lee
Stabilising a Trauma Patient
Trauma patient usually refer to someone who has suffered serious and life-threatening physical injury which has the potential to result in secondary complications such as shock, respiratory failure and death. Trauma patients require specialized care within the so-called golden hour of emergency medicine, the first sixty minutes after trauma occurs.
When a trauma patient is brought to the hospital, a primary survey should have already been conducted by the ambulance officers. Any problems related to the ABCs (Airway, Breathing, and Circulation) that are highlighted by the officers should be dealt with immediately.
Any obstruction in the airway would probably have been removed by the ambulance officers. However, if the trauma patient still has an obstructed airway, the cause of the obstruction should be removed immediately.
In the case of breathing difficulties, the trauma patient may have to be intubated and undergo positive pressure ventilation.
In a trauma patient with falling blood pressure, for example, in someone who is suffering from hypovolaemic shock caused by bleeding, it is necessary to immediately control the bleeding and restore the victim's blood volume by giving infusions of balanced salt solutions. Blood transfusions are necessary for loss of large amounts of blood (e.g. greater than 20% of blood volume). Sodium is essential to keep the fluid infused in the extracellular and intravascular space whilst preventing water intoxication and brain swelling. Metabolic acidosis (mainly due to lactic acid) accumulates as a result of poor delivery of oxygen to the tissues, and mirrors the severity of the shock. It is best treated by rapidly restoring intravascular volume and perfusion. Inotropic and vasoconstrictive drugs should be avoided, as they may prevent us from accurately assessing the blood volume.
Regardless of the cause, the restoration of the circulating volume is priority. As soon as the airway is maintained and oxygen administered the next step is to commence replacement of fluids via the intravenous route.
Once the ABCs have been stabilized, a secondary survey consists of a systematic assessment of the abdominal, pelvic and thoracic viscera, complete inspection of the body surface to find all injuries, and neurological exam. Priority should be given to regions of the body that are suspected to be damaged after considering the history given by the ambulance officers. The purpose of the secondary survey is to identify all injuries so that they may be treated
In this PCL case, a haemothorax was identified and an attempt was made to remove the blood by the insertion of a chest tube.
Contributed by John Lee
When a trauma patient is brought to the hospital, a primary survey should have already been conducted by the ambulance officers. Any problems related to the ABCs (Airway, Breathing, and Circulation) that are highlighted by the officers should be dealt with immediately.
Any obstruction in the airway would probably have been removed by the ambulance officers. However, if the trauma patient still has an obstructed airway, the cause of the obstruction should be removed immediately.
In the case of breathing difficulties, the trauma patient may have to be intubated and undergo positive pressure ventilation.
In a trauma patient with falling blood pressure, for example, in someone who is suffering from hypovolaemic shock caused by bleeding, it is necessary to immediately control the bleeding and restore the victim's blood volume by giving infusions of balanced salt solutions. Blood transfusions are necessary for loss of large amounts of blood (e.g. greater than 20% of blood volume). Sodium is essential to keep the fluid infused in the extracellular and intravascular space whilst preventing water intoxication and brain swelling. Metabolic acidosis (mainly due to lactic acid) accumulates as a result of poor delivery of oxygen to the tissues, and mirrors the severity of the shock. It is best treated by rapidly restoring intravascular volume and perfusion. Inotropic and vasoconstrictive drugs should be avoided, as they may prevent us from accurately assessing the blood volume.
Regardless of the cause, the restoration of the circulating volume is priority. As soon as the airway is maintained and oxygen administered the next step is to commence replacement of fluids via the intravenous route.
Once the ABCs have been stabilized, a secondary survey consists of a systematic assessment of the abdominal, pelvic and thoracic viscera, complete inspection of the body surface to find all injuries, and neurological exam. Priority should be given to regions of the body that are suspected to be damaged after considering the history given by the ambulance officers. The purpose of the secondary survey is to identify all injuries so that they may be treated
In this PCL case, a haemothorax was identified and an attempt was made to remove the blood by the insertion of a chest tube.
Contributed by John Lee
Physiology of Pneumothorax and Haemothorax
Pressure Relationships In The Thoracic Cavity
Atmospheric pressure = 760 mmHg = 1 atm
Intrapulmonary pressure – the pressure in the alveoli
– rises and falls with the phases of breathing
Intrapleural pressure – the pressure in the pleural cavity
– always about 4 mmHg less than intrapulmonary pressure
due to the strong adhesive force between the parietal and visceral
pleura
– the amount of pleural fluid in the pleural cavity must remain minimal in
order for the negative intrapleural pressure to be maintained
(active pumping of the pleural fluid into the lymphatics)
Transpulmonary pressure – the difference between the intrapulmonary and intrapleural
pressures
– keeps the air spaces of the lung open and prevent the lungs from
Atmospheric pressure = 760 mmHg = 1 atm
Intrapulmonary pressure – the pressure in the alveoli
– rises and falls with the phases of breathing
Intrapleural pressure – the pressure in the pleural cavity
– always about 4 mmHg less than intrapulmonary pressure
due to the strong adhesive force between the parietal and visceral
pleura
– the amount of pleural fluid in the pleural cavity must remain minimal in
order for the negative intrapleural pressure to be maintained
(active pumping of the pleural fluid into the lymphatics)
Transpulmonary pressure – the difference between the intrapulmonary and intrapleural
pressures
– keeps the air spaces of the lung open and prevent the lungs from
collapsing
Pneumothorax and Haemothorax
1. Pneumothorax
- presence of air in the pleural cavity
- spontaneous pneumothorax
caused by rupture of a small bleb
often occur in tall, thin men who smoke where mechanical stresses at the apex weaken the lung tissue
chronic obstructive pulmonary disease, cystic fibrosis, necrotizing pneumonia and AIDS patients with pneumocytis carinii infection
- traumatic pneumothorax
internal trauma such as rib fracture
external trauma such as stab wound or bullet wound
invasive or therapeutic procedures (iatrogenic pneumothorax)
- tension pneumothorax
air accumulates in the pleural cavity more rapidly than it can be evacuated
lung collapses
can also shift the mediastinum and severely impede venous return and cardiac ouput
2. Haemothorax
- presence of blood in the pleural cavity
- chest trauma where virtually every blood vessel in the chest can bleed into the pleural space
When air or fluid enters the pleural cavity:
visceral and parietal pleura are separated, disrupting the negative pressure that prevents the lungs from collapsing
compresses the lungs
Thus, lungs collapse.
Sources:
mcb.berkeley.edu/courses/mcb136/topic/Respiration/SlideSet1/Resp1.pdf
www.teleflexmedical.com/ucd/normal_anatomy_physiology.pdf
(Posted by: Vivian)
Thursday, 22 March 2007
Chest Drainage
Chest Drain/Tube Thoracotomy/Intercostal Chest Drain/Chest Tube Insertion/Chest Catheter Insertion
- An unobstructed chest drain
- A collecting container below chest level
- A one-way mechanism such as water seal or Heimlich valve
Indications for Chest Drain
(should wait for confirmation via X-Ray/ultrasound before proceeding)
Haemothorax (pleural space filled with blood)
Empyema (pleural space filled with pus) and other Pleural effusion (pleural space filled with fluid)
Post-operative- thoracotomy, oesophagectomy and cardiac surgery
Traumatic Arrest (with no cardiac output)
Patients in shock, or hypoxic due to penetrating trauma
Traumatic haemopneumothorax
Diagnostic:
Feel the texture of lung surface (for contusions)
Feel surface of diaphragm (for lacerations)
Feel heart (for presence of tamponade)
Bright red/arterial blood – patient requires a thoracotomy
Intestinal contents – oesophageal injury or stomach/bowel injury
Persistent air leak – lung laceration
Large leaks – bronchial disruption
Bleeding
Inform the patient of the possibility of major complications and their treatment
Explain the major steps of the procedure, and necessity for repeated chest radiographs
- Get materials ready, determine size of chest tube
- Confirm site of insertion
- Maintain sterile environment
- Position patient
- Anesthesia/Analgesia
- Insertion
Materials
Chest tube
Chest tube suction unit
Chest tube tray to include scalpel blade and handle, large clamps of choice, needle driver, scissors
Packet of 0 or 1.0 silk suture on a curved needle
Tape, gauze
Anaesthesia of choice, 20cc syringe, 23-gauge needle for infiltration
Sterile prep solution; mask, gown and gloves
Selection of Chest Tube (measurement is Frenches: Fr/F)
Small, medium, large Chest Tube
Depends on what is being drained (larger for blood)
Depends on age (larger for older people)
Confirm Site of Insertion
Mid- or anterior- axillary line
Behind Pectoralis Major (to avoid having to dissect through this thick muscle)
Line lateral to the nipple (On expiration, the diaphragm rises to the 5th rib at the level of the nipple, and thus chest drains should be placed above this level)
Between 4th or 5th rib (highest rib space that can be easily felt in the axilla)
Sterile Environment/Position Patient
Don mask, gown, gloves.
Prep and drape area of insertion.
Position the patient. Have patient place arm over head to “open up” ribs.
Anesthesia/Analgesia
Chest tube insertion is a painful procedure, especially in muscular individuals; usually a combination of anaesthesia and analgesia is used.
Intravenous analgesia:
Opiods e.g. Morphine
Ketamine (alternative to opiods) (20mg)
Widely anesthetize area of insertion with local anaesthesia. Infiltrate skin, muscle tissues, and right down to pleura.
Local anaesthesia:
2% lidocaine (10-20ml)
Insertion
1. Make a 3-4 cm incision through skin and subcutaneous tissues between the 4th and 5th ribs, parallel to the rib margins.
2. Continue incision through the intercostal muscles, and right down to the pleura.
3. Insert Kelly clamp (or other curved clamp) through the pleura and open the jaws widely again parallel to the direction of the ribs (blunt dissection).
4. Insert finger through your incision and into the thoracic cavity. Make sure you are feeling lung (or empty space) and not liver or spleen.
5. Grasp end of chest tube with the Kelly forceps (convex angle towards ribs), and insert chest tube through the hole you have made in the pleura. Direct the tube over the top of the lower rib to avoid the intercostal vessels lying below each rib.
6. After tube has entered thoracic cavity, remove Kelly, and manually advance the tube in.
7. Suture/secure the tube in place. Certain closure sutures can be used in anticipation of removal.
8. Connect the tube to the drainage unit.
9. The chest is re-examined to confirm effect.
10. A chest X-ray is taken to confirm placement & position.
Drainage Unit
All chest tubes should be connected to a single flow (one direction of flow) drainage system e.g. underwater seal bottle or flutter valve.
A closed underwater seal bottle is one in which the tube is placed underwater (distilled water) at a depth of approximately 3 cm with a side vent which allows escape of air.
The drainage bottle should always be kept below the level of the patient, otherwise its contents will siphon back into the chest cavity.
The bottle may also be connected to a suction pump (when suction is turned on, air and fluid are pulled out of the pleural space and into the drainage collection bottle).
In basic terms:
Drainage occurs during expiration when pleural pressure is positive
Fluid within pleural cavity drains into water seal
Air bubbles through water seal to outside world
Complications
Tube placed subcutaneously: tube goes along chest wall instead of into chest cavity
Tube inserted too deep (lung laceration), or not deep enough (holes in tube sticking out)
Tube inserted too low: diaphragm and abdominal cavity penetration; puncture liver or spleen
Bleeding (usually ceases)
Pneumothorax after removal
Removal
Remove drain as soon as it has served it purpose
To remove drain ask patient to perform a Valsalva manoeuvre
Remove drain at the height of expiration
Tie pre-inserted closure suture.
Perform a post-procedure chest x-ray.
Documentation
1. Consent if obtained
2. Indications and contraindications for the procedure on this patient
3. Procedure used (trocar vs. non-trocar)
4. Any complications, or “none”
5. Who was notified of any complication (family, attending physician)
6. Patient education materials on chest drainage
Sources:
http://apps.med.buffalo.edu/procedures/chesttube.asp?p=7
http://www.cssolutions.biz/cts.html
http://thorax.bmjjournals.com/cgi/reprint/58/suppl_2/ii53.pdf (fantastic article for everything one needs to know about chest drains)
http://www.surgical-tutor.org.uk/default-home.htm?specialities/cardiothoracic/chest_drains.htm~right
http://www.trauma.org/index.php/main/article/400/
Compensatory Mechanism for Hemorrhage
The most obvious situation faced a patient with penetrating chest wall is hemorrhage. So here I will focus on the physiological response of the body or the compensatory mechanism to hemorrhage.
Course of Arterial Blood Pressure Changes
Cardiac output decreases as a result of blood loss. If sufficient blood is lost rapidly to bring mean arterial pressure to 50 mmHg, the pressure tends to return spontaneously back toward control over the next 20 or 30 minutes. In some cases (Curve A) this trend continues, and normal pressures are regained within a few hours, especially if the hemorrhage is quickly arrested. In other cases (Curve B), after an initial pressure rise, the pressure may subsequently decline and continue to fall at an accelerating rate until death ensues. The progressive deterioration of cardiovascular function is termed shock. At some point, if hemorrhage is not stopped and blood volume restored in time, the deterioration will become irreversible.
Compensatory Mechanisms:
A. Baroreceptor Reflexes.
The reduction in mean arterial pressure and pulse pressure during hemorrhage decreases the stimulation of the baroreceptors in the carotid sinuses and aortic arch. Several cardiovascular responses are thus evoked, all of which tend to return the arterial pressure toward normal. Reduction of vagal tone and enhancement of sympathetic tone increase heart rate and enhance myocardial contractility. The increased sympathetic discharge also produces generalized venoconstriction. Sympathetic activation constricts certain blood reservoirs such as the cutaneous, pulmonary, and hepatic vasculatures which provide an autotransfusion of blood into the circulating blood stream.
Generalized arteriolar vasoconstriction is a prominent response to the diminished baroreceptor stimulation during hemorrhage. The reflex increase in peripheral resistance minimizes the fall in arterial pressure resulting from the reduction of cardiac output.
Vasoconstriction is most severe in the cutaneous, skeletal muscle, and splanchnic vascular beds and is slight or absent in the cerebral and coronary circulations. In many instances the cerebral and coronary vascular resistances are diminished and the reduced cardiac output is redistributed to favor flow through the brain and the heart. Flow through the kidneys may also be sustained because of the strong local autoregulatory response within this organ system.
Thus, patient with hemorrhage appears pale and has cold skin due to the cutaneous vasoconstriction.
B. Chemoreceptor Reflexes.
Reductions in arterial pressure below about 60 mmHg do not evoke any additional responses through the baroreceptor reflexes, because this pressure level constitutes the threshold for stimulation. However, low arterial pressure may stimulate peripheral chemoreceptors because of hypoxia in the chemoreceptor tissue consequent to inadequate local blood flow. Chemoreceptor excitation enhances the already extant peripheral vasoconstriction evoked by the baroreceptor reflexes. Also, respiratory stimulation assists venous return by the auxiliary pumping mechanism--the abdomino-thoracic pump
C. Cerebral Ischemia.
When the arterial pressure is below about 40 mmHg, the resulting cerebral ischemia activates the sympathoadrenal system. The sympathetic nervous discharge is several times greater than the maximum activity that occurs when the baroreceptors cease to be stimulated. Therefore, the vasoconstriction and facilitation of myocardial contractility may be pronounced. With more severe degrees of cerebral ischemia, however, the vagal centers also become activated. The resulting bradycardia may aggravate the hypotension that initiated the cerebral ischemia.
D. Reabsorption of Tissue Fluids.
The arterial hypotension, arteriolar constriction, and reduced blood volume during hemorrhagic hypotension lower the hydrostatic capillary pressure. The balance of these forces promotes the net reabsorption of interstitial fluid into the vascular compartment. The reabsorption of fluid can occur rather quickly
E. Endogenous Vasoconstrictors.
The catecholamines, epinephrine and norepinephrine, are released from the adrenal medulla in response to the same stimuli that evoke widespread sympathetic nervous discharge. These humoral substances reinforce the effects of sympathetic nervous.
F. Renal Conservation of Fluids and Electrolytes.
Fluid and electrolytes are conserved by the kidneys during hemorrhage in response to various stimuli, including the increased secretion of vasopressin (antidiuretic hormone). The lower arterial pressure decreases the glomerular filtration rate, and thus curtails the excretion of water and electrolytes.
Contributed by Lawrence Oh
Wednesday, 21 March 2007
TRIAGE SYSTEM
TRIAGE SYSTEM
Simple triage - used at the scene of a mass casualty incident to select patients into those who need immediate transport to the hospital in order to save their lives and those who can wait for help later. This skill is required by first responders performing field triage on the battlefield or at a disaster site to assess the patients' need for transport prior to transportation becoming available. The categorization of patients based on their severity of injury can be aided with the use of printed triage tags or colored flagging.
Advanced triage -doctors may decide that some seriously injured people should not receive certain care because they are unlikely to survive. This does not mean that these patients will not receive any care; it only means that more advanced care will be used on less seriously wounded patients. The available care is then concentrated on those with some hope of survival. (ethical implications??)
Triage in Malaysia – emergency department:
This is done by allocation of triage cards according to the patient’s severity or condition.
1.Red / Immediate
They require immediate surgery or other life-saving intervention, first priority for surgical teams or transport to advanced facilities, "cannot wait" but are likely to survive with immediate treatment.
2.Yellow / Observation
Their condition is stable for the moment but requires watching by trained persons and frequent re-triage, will need hospital care
3.Green / Wait (walking wounded)
They will require a doctor's care in several hours or days but not immediately, may wait for a number of hours or be told to go home and come back the next day (broken bones without compound fractures, many soft tissue injuries).
Simple triage - used at the scene of a mass casualty incident to select patients into those who need immediate transport to the hospital in order to save their lives and those who can wait for help later. This skill is required by first responders performing field triage on the battlefield or at a disaster site to assess the patients' need for transport prior to transportation becoming available. The categorization of patients based on their severity of injury can be aided with the use of printed triage tags or colored flagging.
Advanced triage -doctors may decide that some seriously injured people should not receive certain care because they are unlikely to survive. This does not mean that these patients will not receive any care; it only means that more advanced care will be used on less seriously wounded patients. The available care is then concentrated on those with some hope of survival. (ethical implications??)
Triage in Malaysia – emergency department:
This is done by allocation of triage cards according to the patient’s severity or condition.
1.Red / Immediate
They require immediate surgery or other life-saving intervention, first priority for surgical teams or transport to advanced facilities, "cannot wait" but are likely to survive with immediate treatment.
2.Yellow / Observation
Their condition is stable for the moment but requires watching by trained persons and frequent re-triage, will need hospital care
3.Green / Wait (walking wounded)
They will require a doctor's care in several hours or days but not immediately, may wait for a number of hours or be told to go home and come back the next day (broken bones without compound fractures, many soft tissue injuries).
Subscribe to:
Posts (Atom)
