The concept of 'Brain Death' is important for those involved in organ transplantation, however this condition was not invented for the benefit of organ donation. The head injury due to road traffic accident can account for almost 50% of Brain Deaths. Organ donation is perhaps the only positive outcome of this grave tragedy, provided the relatives agree to the process.
EVOLUTION OF THE CONCEPT OF BRAIN DEATH
History: Two French physicians in 1959 first recognized "Brain Death" on patients being ventilated in the intensive care units and called it coma depasse (a state beyond coma). In 1968, an Ad Hoc Committee of Harvard Medical School defined brain death as 'irreversible-coma' with the patient being totally unreceptive and unresponsive with absence of all cranial reflexes and no spontaneous respiratory efforts during a 3 minutes period of disconnection from the ventilator. How much of brain needs to be actually dead before death can be diagnosed has been debated over the years. Experiments have shown that a few cubic centimeters of tissue called "brainstem" which is located beneath "Aqueduct of
Sylvius" anteriorly and "floor of fourth ventricle" posteriorly is the vital section of the brain that determines consciousness and ability to breathe spontaneously. Destruction of this tissues is what determines brain death. However in certain countries, the whole brain including the brainstem needs to die to diagnose the state of 'irreversible death' and requires four vessels (carotid and vertebral) angiography and Isotope studies of the cranium. This can be a cumbersome exercise to undertake in an intrinsically unstable patient. In contrast, the tests that determine brainstem death are more clinical and over the last 30 years have proven to be simple, clinical, foolproof and capable of confirmation. In 1988, the Irish working committee on 'Brain Death' in its memorandum said, if the brainstem is irreversibly lost, what goes on elsewhere in the brain is immaterial and 'Life cannot return'.
In the last three decades this concept evolved and has had judicial approval in many parts of the world. India in 1994, accepted the concept of brainstem death and passed an act to this effect and called it the "Transplantation of Human Organ Act"
(THO). The act also proposed to stop commercial dealing of organs by making regulatory authorities in each state to look into the whole process of organ donation for both live related (or unrelated) and cadaver organ donation and transplantation.
Patho-physiology: This situation of 'physiological decapitation' can be caused by any pathology that increases in the pressure within the confines of the cranium. Usually this happens as a result of bleeding from rupture of a vessel or a tumor (Fig.1). Increase in the intracranial pressure usually results in coning of the brainstem and ischemia leading to brainstem death. In this situation the heart can continue to beat and keep the circulation of some of the essential organs going provided the patient is kept adequately ventilated and hemodynamic stable. However this state can be only maintained temporarily and cardiac asystole occurs in all the patients.
Legal Aspects in brain death certification: As per the 'Transplantation of Human Organ Act' two clinicians who are experts in the field (like neurologists or
neuro-surgeons) are required for brain death certification. Ethically these clinicians must not have interest in or benefit in any way from transplantation of cadaver donor organs. They are required to do two sets of tests six hours apart to certify brain death. One of these two clinicians should be a nominated member from the panel of doctors listed by the State Government for this purpose. The legal time of death in these circumstances is taken as the second set of brainstem death tests. The certification should be done on the laid out forms as per the THO act. In a medico-legal case a forensic expert is also required for the certification. The medical director or medical superintendent of the hospital should finally countercheck and sign the form (Table-I - Form 8. THO Act) . It is only after these formalities have been completed, should ventilatory support be discontinued or organs retrieved.
DIAGNOSIS OF BRAIN STEM DEATH
The aim is to establish that the patient has absent brainstem reflexes and is
apnoeic. The testing itself is straightforward. There are certain preconditions that should have been fulfilled to make sure that the tests are performed on the right patients and at the right time. These are as follows:
1. Patient should be comatose and on ventilatory support.
2. The cause of irreversible structural brain damage should be known
3. Functional reversible causes of a non-functioning brainstem should have been ruled out. These causes include.
a. Primary Hypothermia
b. Alcohol intoxication
c. Neuromuscular blockades (like use of muscle relaxants)
d. Use of central nervous system depressant drugs like use of sedatives
e. Severe metabolic or endocrine disturbances.
4. Patient should have no circulating therapeutic levels of any drug that could cause coma
Establishing Loss of 'Brainstem Reflexes' at the Bedside: - Absence of brain stem function is essential for establishing the diagnosis of Brain death (Fig -2). In the situation of brain stem death the patient's cranial nerve reflexes (Table-II) are tested to observe their motor response to a sensory input. The absence of brain stem function is documented by conducting the following five tests:
a. Absence of Pupillary Reflex Response to Light
b. Absence of Corneal Reflexes
c. Absence of Vestibulo-Ocular Reflex
d. Absence of Cranial Nerve response to Pain
e. Absence of Gag and Cough Reflexes
Pupillary Reflexes: To check for absent pupillary response to light, a bright pen torchlight should be used in a darkened room. It should be made sure that no eye drops to dilate the pupils have been used in the four hours previously. The pupils may not be necessarily fixed and dilated in the brainstem dead patients, however there should be no pupillary response to light.
Corneal Reflexes: A moist cotton tipped swab should be used and firm pressure should be applied to the cornea without damaging it.
Vestibulo-Ocular Reflexes: testing involves instilling 20ml of ice-cold water into the external auditory canal and looking at eyeball movements of either eye for about a minute. No eyeball movement indicates absence of reflex. Presence of ruptured eardrums or discharge from the ear prevents this test from being performed.
'Gag and Cough Reflexes' Test: requires temporary disconnection from the ventilator. A cotton tipped swab can be used to stimulate the posterior pharynx to look for a response. Experienced ICU staff usually notice a progressive loss of response during the evolution of brainstem death when performing the routine suction of airways and
oropharynx.
Grimacing of the face to a painful stimulation is a normal response and this is absent in brainstem death situation. A firm supra-orbital pressure( trigeminal nerve) should be used to check this cranial reflex. Pin pricks should not be used to test this response.
Doll's Head Eye Phenomenon: (testing for oculo-cephalic reflex) This is one test that can be done to know if the brainstem is still alive. If this test is positive than other tests to establish brain death can be postponed. One may need to disconnect the patient from the ventilator for 15 to 20 second to perform this test. To do this test the physician holds the patient's head between his hands and move the head from side to side through 1800. The clinician should hold the head to one side for 3 to 4 seconds and look at the simultaneous eye movement to that side. A similar movement is done to the opposite side and eye movement is noticed. In a normal fully alert individual and in a cadaver the eyes move with the head and there is only a very fractional delay. If the cerebral hemispheres are damaged but brainstem is still alive there will be a obvious deviation of the eyes to the opposite side for a second or two followed by a "release phenomenon" when the eyes will get realigned to the side of the head. This test should not be done if cervical fracture is suspected.
The plantar response may continue to be present in brain death patients along with spinal reflexes and should not be tested. The decorticate and decerebrate posturing is absent, however on occasions it may be difficult to differentiate these from complex spinal reflexes.
Apnoea Test: The aim of apnoea test is to establish death of the respiratory centre in the brainstem (Table III). This is the ultimate test to establish brainstem death. It demonstrates that the spontaneous respiratory response fails to occur even in the absence of stimulatory drive from CO2. For this test the patient is disconnected from the ventilator for 10 minutes. However, to avoid hypoxia to vital organs, 100% oxygen is given for 5 minutes before disconnection from the ventilator. Even during the test period, 100% oxygen is given through a tracheal catheter. In the patient who is brain dead the carbondioxide tension increase at a rate of 2mm/min (0.3
kPa/min) during apnoea testing. If the initial CO2 tension before testing is about 40mmHg (5.3
kPa) then arterial CO2 tension after 10 minutes is likely to be 60mmHg (8
kPa). However a rise to 50mmHg in CO2 tension is acceptable and should provide sufficient stimulatory drive for spontaneous respiration in an intact respiratory
centre. In patients with chronic airway disease or severe chest trauma, the apnoea test may be difficult to perform.
Role of Cerebral Angiography & EEG for brain death testing: Four-vessel angiography is used to show absence of cerebral blood flow and confirm death of whole brain. However this test is not done routinely as it is a cumbersome investigation to undertake in an unstable patient. Nor is it necessary to use EEG to diagnose the condition. If there is any doubt in the diagnosis of brain death one should not proceed for a request for organ donation and ventilatory support should be continued. In case of severe facial trauma or presence of paralyses or severe chest trauma, routine tests may not be possible and one may require to do special tests like isotope scanning or colour flow duplex scanning of the cranium to confirm brain death. All these tests can have limitations and can sometimes be inconclusive. In these inconclusive situations, if organ donation is being contemplated, the patient's relatives should be told about it and the ventilator should only be disconnected in the operation theatre and organ retrieval started only after cardiac standstill. The Transplantation of Human Organ act does not require investigations like cerebral angiography or EEG for brain death certification.
In children there remains uncertainty about the reliability of clinical brainstem testing. In neonates especially, organs for transplantation should not be removed in the first seven days of life with beating hearts. Radioisotope brain scanning has been recommended under the age of one year when brainstem death certification is required.
REQUEST FOR ORGAN DONATION
Brain death is relatively a new concept and making request for organ donation in these circumstances can be an extremely difficult task for a doctor or a nurse to undertake. If the decreased carries a 'Donor Card' (a card the size of a credit card expressing their desire about organ donation) the task of asking for organ donation becomes easier.
Usually the organ donation request is made in the time interval between the diagnosis of brain death and discontinuation of the ventilator. If the relatives are agreeable the process of organ donation is undertaken and vital organ like heart, lunge, liver, pancreas and kidneys are removed for transplantation. Corneas should be kept moist and eyelids should be closed and retrieval surgery can be done for up to 12 hours after cardiac standstill. Other tissues like heart valves, skin, bone and cartilages can be removed for up to 48 hrs after death. The process of organ donation and transplantation requires co-ordination (Table-IV) between different teams operating almost simultaneously and sometimes in different locations. It may require getting surgeons from different specialties together for both donor and recipient surgery.
Generally there is no bar to organ donation and one or the other organ or tissues can be donated at any age
(Table.V). However, it is important to do some essential virology screening prior to accepting the donor. All potential donors will require a virology screen to prevent possible transmission of disease from donor to the recipient
(Table.VI). The next of kin should be made aware that this is necessary, if there are any objections these should be respected. However, it does mean that donation cannot then take place.
Support of the Brain Dead Organ Donor
Once there is confirmation of brainstem death the clinicians should switch the focus of the management of the cadaver from therapy for elevated intracranial pressure and brain protection, to preservation of organ function and optimization of tissue oxygen delivery.
This will keep the organs in optimum condition so that the recipient has the best chance of recovery after transplant. Supportive treatment should start early as soon as brain death has been recognized irrespective of the consent; otherwise there can be rapid deterioration of initially suitable donors. In a poorly managed cadaver, the exercise of organ donation would yield organs that will result in poor graft outcomes.
Contraindications to organ donation :
The absolute contraindications to organ donation are:
1) Malignancy (except primary brain tumors, low grade skin malignancies and carcinoma in situ of the cervix),
2) Uncontrolled sepsis,
3) Active viral infections-hepatitis A and B, cytomegalovirus, herpes simplex virus and AIDS.
Specific criteria and contraindications exist for individual organs. There have been instances where kidneys from positive hepatitis status donors have been transplanted into positive hepatitis status recipient. Given the severe shortage of donor organs, the criteria for donor acceptance have been expanded. This has led to the concept of marginal donors as against ideal donors. Marginal donors may be elderly patients, patients with hypertension or poisoned victims
(organophosphrous poisoning) with significant complications of brain stem death. When there is concern about the suitability of organs, this may have to be resolved during the organ procurement procedure, by direct inspection and in some cases by open biopsy and frozen section histopathology examination.
Hemodynamic instability occurring during 'coning' or brain herniation is the result of an
"autonomic storm". This is the result of massive increase in systemic catecholamine
levels and increase in sympathetic activity. This phase occurs unheralded and is of
variable duration. During brain herniation major metabolic stress and impairment of
organ perfusion occur which affects post transplant organ function. This is of critical
significance in chemo-sensitive organs like the heart and liver where immediate graft function is essential. Following the autonomic storm there is a profound reduction in sympathetic outflow and catecholamine levels decreases to below baseline values. The resting vagal tone is abolished because of destruction of the nucleus
ambiguus. The subsequent chronic maintenance phase of brain stem dead donors is frequently characterized by
hypotension.
There is evidence that brainstem death eventually leads to cardiac arrest, even when cardio-respiratory support is maintained. Complications related to the profound physiological disturbances consequent on brain stem death include hypotension arrhythmias, pulmonary edema, hypoxia, diabetes
insipidus, metabolic acidosis, Disseminated intravascular coagulation and infections. The incidence of complications increases progressively after brainstem death and may affect organ function. The common and uncommon problems usually encountered in these patients are enlisted in Table VII. While optimizing the function of different organs, it is necessary to pay attention to the details. For instance large volume fluid resuscitation is important for maintaining kidney function, but may result in pulmonary edema rendering the lungs unsuitable for transplantation.
Cardio-respiratory support
As indicated earlier the overall management goal is to ensure adequate tissue oxygen
delivery. Parameters that suggest this, in the absence of lactic acidosis are indicated in the
Table.VIII.. The usual problems encountered in a brain death patient are related to
1. Hypotension
2. Arrhythmias and cardiac arrest
3. Hypoxemia
4. Ventilatory support.
Hypotension
This is most common problem seen in brainstem dead organ donors. This is commonly
multifactorial, mainly due to volume depletion and to a lesser extent impaired myocardial contractility. The volume depletion is both 1) absolute, related to therapy for raised intracranial pressure; and 2) relative, related to the loss of sympathetic tone. The latter is due to complete vasomotor collapse with significant peripheral venous pooling.
The differential diagnosis includes, hypovolemia, cardiac dysfunction, electrolyte abnormalities, and hypothermia and drug effect.
Invasive monitoring of arterial and central venous pressure should be instituted. In the management of
hypotension, it is important to remember that proper fluid management is the cornerstone of therapy. If possible the use of vaso-pressors should be minimized because of their splanchic vaso constrictive effects. All inotropes and vasopressors have been used. The first choice is usually Dopamine, preferably at a dose below 10mcg/kg/min. Dobutamine should be used for impaired myocardial contractility; and Norepinephrine or Epinephrine for severe systemic
vasodilation. If the patient has tachycardia, dopamine will cause further tachycardia and in these situations dobutamine is useful as this will not increase the heart rate. Norepinephrine can be used in short bursts to maintain the blood pressure. Sometimes all the three drugs are used simulataneously to maintain an adequate pressure. If heart retrieval is contemplated for transplant these ionotropes should be controlled carefully and monitored.
Fluid resuscitation may require several litres of fluid. A combination of crystalloids and colloids is used. Relying on urine output alone to determine adequacy of fluid resuscitation is misleading because of polyuria due to diabetes
insipidus. In donors who remain unstable despite routine management, pulmonary artery catheterization may help in determining the problem.
Arrhythmias
Hemodynamic instability can be pronounced after brainstem death with a spectrum of bradyarrhythmias and tachyarrhythmias Bradyarrhythmias occurring as part of the Cushing reflex, during coning, do not require treatment . Correctable factors like acidosis, electrolyte abnormalities and
inotrope- related arrhythmias should be treated. Thereafter, medications that possess rapid reversibility and a short half-life should be used. Atropine is ineffective for bradyarrhythmias after brain death has occurred.
Hypoxia
This may be related to infections, collapse or pulmonary edema. The etiology of pulmonary edema may be
cardiogenic, fluid overload, neurogenic or Adult Respiratory Distress Reproduction. .This is treated by titrating the fractional inspired oxygen concentrations (FiO2) and positive and expiratory pressure (PEEP). While high FiO2, greater than 0.6, increases the risk of oxygen toxicity; high PEEP>15cmH2O reduces cardiac output.
Ventilatory support
This is an essential part of the support of brainstem dead organ donors as they are
apneic. Discontinue hyperventilation which is likely to have been employed for control of raised intracranial pressure. The partial pressure of CO2 should be maintained in the normal range. This may require a considerable reduction in minute volume. Routine use of PEEP at 5 cm H2O in brainstem dead organ donors is recommended to prevent
microatelectosis. Airway pressures, i.e. the plateau pressures should be below 35cmH2O to reduce the risk
barotrauma.
Renal support
If the urine output is less than 1ml/kg/hr, despite adequate filling pressures and blood pressure, loop diuretics or osmotic diuretics should be used to initiate
diuresis. Polyuria, a frequent finding in brainstem dead organ donors, is due to diabetes
insipidus. Other causes include osmotic diuersis due to mannitol or hyperglycemia and physiologic diuersis due to massive fluid resuscitation. Electrolyte abnormalities observed during diabetes insipidus include
hypernatremia, hypokalemia, hypocalcemia and hypomagnesemia.
Endocrine changes
Diabetes insipidus
This should be suspected when urine volumes exceed 300ml/hr (or 7ml/kg/hr) in association with hypernatremia (serum sodium greater than 150mEq/l), elevated serum osmolality (>310mOsm/L) and a low urinary sodium concentration. Desmopressin
(dDAVP) should be used in preference to Vasopressin. The latter has undesirable splanchnic and renal vasoconstrictive effects. The dose is titrated to maintain urine outputs of 1-2ml/kg/hr. usual dosages are Desmopressin 1-4 mcg every 8 to 12 hours or Vasopressin 1-4 units/hr. Ocne there is hyernatremia the replacement intravenous fluids should contain free water, i.e. Dextrose and / or half strength (0.45) Normal saline.
Hyperglycemia
This is due to the administration of glucose containing fluids, reduced insulin secretion and increased levels of
catecholamines. Hyperglycemia results in an osmotic diuresis and electrolyte disturbances. Blood glucose levels should be controlled with intravenous insulin infusion.
Other hormones
The use of hormonal therapy, Thyroxine, tri-iodothyronine(T3), corticosteriods and insulin, has been advocated to improve cardiovascular stability. At present, such therapy are regarded as experimental.
MISCELLANEOUS PROBLEMS
Infection
Systemic infection is a relative contraindication to organ donation. All unnecessary indwelling devices should be removed. All lines and catheters must be inserted aseptically and meticulous care of dressings and wounds is vital. Tracheal suction should be done with sterile precautions. Appropriate samples from suspected sources of infection should be sent for culture and sensitivity. Treatment should be initiated based on culture reports. Prophylactic antibiotics are indicated only immediately prior to organ retrieval.
Coagulopathy
Disseminated intravascular coagulation is common in patients with traumatic head injuries. This is due to the release of thromboplastin from the injured brain. If it results in clinically significant mucocutaneous bleeding, treatment with appropriate blood components is required.
Hypothermia
Core temperature should be monitored using rectal thermometers. The core temperature should be maintained above 350C. After brain death, the body becomes poikilothermic because of the loss of central temperature control mechanisms. Treatment includes use of humidified and warmed ventilator gases ; warmed intravenous fluids and blood products ; and heating blankets. Sometimes a "hot blower" next to the patient is the best solution to maintain the body temperature.
CONCLUSION:
A severe shortage of organs the world over has led to increased pressure on the intensive
care staff for early identification of the brain dead donor and optimum management of
this condition. The diagnosis of brain death as per the Transplantation Human Organ Act
is based as simple clinical bedside tests. The passing of this Act in 1994 and its
subsequent adaptation by many Indian States has made it possible in India to use this
pool of patients for organ retrieval and transplantation.
FORM - 8
We the following members of the Board of medical experts after
careful personal examination hereby certify that Shri/Smt/Km-----------------------------------------------------
aged about ------------------------son of/wife of/ daughter
of-----------------------------------
resident of
---------------------------------------------------------is dead on account of permanent and irreversible cessation of all
function of the brain stem. The tests carried out by us and the
findings therein are recorded in the brain stem death Certificates
annexed hereto.
Dated-----------------------
Signature------------------------
1. R.M.P. Incharge of the Hospital which brain - stem death has occurred.
2. R.M.P. nominated from the panel of Names approved by the Appropriate Authority.
3. Neurologist / Neuro Surgeon nominated from the panel of names approved by Appropriate by Appropriate Authority.
4. R.M.P. treating the aforesaid deceased person.
BRAIN STEM DEATH CERTIFICATE
(A) PATIENT DETAILS :
1. Name of the Patient - Mr/Ms.------------------------------
S/O,D/O,W/O -Mr.-----------------------------------------------------
Sex --------------------Age-----------------------
2. Home Address -----------------------------------------------------
--------------------------------------------
------------------------
3. Hospital Number ------------------------------------------------------
4. Name and Address of next of kin or ------------------------------------------------------
person responsible for the patient (if none
--------------------------------------------exists, this must be specified) ------------------------------------------------------
------------------------------------------------------
------------------------------------------------------
5. Has the patient or next of kin agreed ------------------------------------------------------
to any transplan? ------------------------------------------------------
6. In this a police Case? ------------------------------------------------------
Yes----------------------No-----------------------(C) PRE-CONDITIONS:
1. Diagnosis : Did the patient suffer from any illness or accident that led to irreversible brain damage? Specify details
------------------------------------------------------------------------------------Date and time of accident/onset of illness----------------------------------------------------------
Date and onset on non-responsive coma------------------------------------------------------------
2. Findings of Board of Medical Experts:
(i) The following reversible causes of coma have been excluded:
Intoxication (Alcohol)
Depressant Drugs
Relaxants (Neuromuscular blocking agents)
Primary hypothermia
Hypovalaemic shock
Metabolic or endocrine disorders
Tests for absent of brain stem functions2) Coma
First Medical Examination Second Medical Examination
________________________________________________
1st 2nd 1st 2nd
3) Cessation of spontaneous breathing.
4) Pupillary Size
5) Pupillary light reflexes
6) Doll's head eye movement
7) Corneal reflexes (Both Sides)
8) Motor response in any cranial nerve
distribution, any responses to stimulation
of face, limb or trunk
9) Gag reflex,
10) Cough (Tracheal)
11) Eye movements on caloric testing bilaterally
12) Apnoea tests as specified
13) Were any respiratory movements seen?
Date and Time of first testing ------------------------------------------------------
Date and Time of second testing
---------------------------------------
This to certify that the patient has been carefully examined twice after an interval of about six hours and on the basis of findings recorded above,
Mr/Ms----------------------------------------------------is declared brain-stem dead.
1. Medical Administrator Incharge of the hospital
2. Authorised Specialist
3. Neurologist/Neuro Surgeon
4. Medical officer treating patient.
NB.I. The minimum time interval between the first testing and second testing will be six hours.
II. No.2 and No.3 will co-opted by the administrator in charge of the hospital from the panel of experts approved by the Appropriate Authority.
|
|
Brainstem
Reflexes |
Sensory
cranial nerve |
Motor cranial
nerve |
|
1. |
Absence of pupillary response
to light |
II |
III
(parasympathetic Nerve fibres) |
|
2. |
Absence of
corneal reflexes
|
V |
VII |
|
4. |
Absence of
cranial nerve response to pain |
V |
VII (and limb
motor responses) |
|
5. |
Absence of
Vestibulo-ocular
|
VIII |
III, VI
|
|
6. |
Absence of
gag and cough reflexes |
X |
IX |
Table II. Clinical Testing For
Cranial Nerves to diagnose absence of Brainstem Reflexes
The PaCo2 should be 5.33 kPa
(.40mmHg) prior to testing and should rise to at least 6.66kPa
(50mmHg) during the test.
The patient should be
pre-oxygenated with 100% oxygen for 10 minutes prior to testing
& baseline arterial blood gases should be taken.
Disconnect patient from ventilator
but oxygen should be administered at 6 litres/min via a fine bore
catheter down the endo-tracheal tube.
Observe patient for 5 to10 minutes
for any respiratory effort and ensure PaCo2 has risen above
6.66kPa (50mmHg) by repeating arterial blood gases.
Reconnect patient to the
ventilator.
Discontinue testing if any
hypotension, cardiac arrhythmia’s or hypoxia occurs
Table V. Different
Age criteria for organ donation
- Testing for HIV, Hepatitis B
& C on all organ donors
- Additional tests for syphilis,
cytomegalovirus and toxoplasmosis may be necessary
- Virology testing is performed
after the completion of brain stem death tests but before the
ventilator is discontinued.
- Virology screening should be
done after consent from next to kin
Table VI -
Virology Screen For Brain Dead Patient When Organ Donation is
Being Considered
- Hypotension
- Hypothermia
- Endocrine Disturbances
- Electrolyte Imbalance
- Arrhythmias
- Hypoxia
Uncommon Clinical Problems
- Coagulopathy
- Neurogenic Pulmonary Oedema
Table VII. Common
& Uncommon Clinical Problems in Brain dead patients
|
CARDIOPULMONARY |
|
|
Systolic
blood pressure |
100-120mmHg |
|
Mean arterial
pressure |
>60mmHg |
|
Central
venous pressure |
8-10 mmHg |
|
Hemoglobin |
10gm/dl |
|
Hematocrit |
30 |
|
(Arterial
blood gas) pH
|
7.37-7.45 |
|
PaO2 |
>75mmHg |
|
PaCO2 |
40mmHg |
|
SpO2 |
95 |
|
RENAL |
|
|
Urine output |
1-2ml/kg/hr |
|
Core
temperature (rectal) |
>350
C |
|
METABOLIC |
|
|
Correct glucose and
electrolyte abnormalities |
Na+, K+,
Ca++,PO4-, Mg++ |