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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1739_Библиотеки_им_академика_М_И_Перельмана.pdf
74
A Simple Introduction to Organ Transplant
Dr Gopi Ayyaswamy
hours. When supplemental IV insulin is necessary, administer the
prescribed IV insulin bolus from the sliding scale every hour after
checking the hourly FSG. Discontinue IV insulin when blood sugar
drops below 250 mg/dl.
c. The treatment approach for hyperglycemia involves rst eliminating
sources of exogenous glucose. Subsequently, administer subcutaneous
insulin according to the sliding scale provided above, with intervals
of four hours. Supplemental IV insulin should only be given every
hour if blood glucose levels remain above 225 mg/dl.
d. Subcutaneous insulin sliding scale (Fig. 11.1):
e. Supplemental intravenous insulin sliding scale. Give the q 4 hour
subcutaneous insulin as prescribed above plus the hourly IV bolus
prescribed below when the blood glucose or nger-stick glucose is
> 225 mg/dl (Fig. 11.2).
f. If glucose remains > 250 mg/dl four hours after the initial
subcutaneous insulin and subsequent IV insulin therapy, consult
physician/intensivist to discuss an insulin infusion.
Temperature Management
Brain death often leads to the loss of thermal regulation in the donor,
commonly resulting in hypothermia. The target temperature range is
36°–37.5°C (97°–99.5°F).
Fig. 11.1
Medical Issues and Management
75
Dr Gopi Ayyaswamy
I. Hypothermia: Treating temperatures below 36°C (97°F):
a. Core temperature measurement is preferred, using a site such as a
pulmonary artery catheter or specialized catheter in the bladder.
Axillary temperatures should be avoided, and oral temperatures
are less accurate during hypothermia. Rectal temperatures can be
used if the hypothermia is not severe (above 35°C).
b. Utilize active surface warming techniques with a heated-liquid or
hot air warming blanket, along with insulating thermal blankets.
c. Adjust the temperature of the inspired gas from the ventilator to
38.5°C (101.3°F).
d. Minimize exposure of the body surface to environmental tempera-
tures and limit the duration of exposure.
e. If the temperature remains below 36°C after three hours of attempted
rewarming, consult a physician or intensivist.
II. Hyperthermia (uncommon after brain death): Treating temperatures
above 37.8°C (100.1°F):
a. Remove unnecessary blankets.
b. Do NOT cool the inspired gas.
c. Administer acetaminophen 650 mg per suppository or via a gastric
tube every three hours.
Fig. 11.2
76
A Simple Introduction to Organ Transplant
Dr Gopi Ayyaswamy
d. Implement the use of an automated uid-lled cooling blanket.
e. If the temperature remains above 101°F after three hours of cooling
measures, consult a physician or intensivist.
Correction of Anaemia
While anaemia can have various underlying causes, when caring for a
donor, the most probable reasons are ongoing blood loss or excessive blood
draws for laboratory tests. Haemolysis, although rare, may also occur. The
objective is to maintain the haematocrit (Hct) above 30%.
I. Assessment
a. Review the donor’s medical records for any evidence of bleeding
sites, prior blood transfusions, and their frequency, or any other
relevant information regarding blood loss or haemolysis.
b. Monitor for signs of ongoing bleeding, such as external wounds,
intravenous (IV) sites, etc.
c. Assess for signs of gastrointestinal (GI) bleeding by observing
gastric tube output or bowel movements. Pay attention to abdominal
distension, firmness, and changes during repeat abdominal
assessments.
d. Check for blood in the urine through observation or laboratory
testing.
e. Evaluate for coagulopathy by obtaining prothrombin time (PT),
partial thromboplastin time (PTT), brinogen levels, and platelet
count. Treat as necessary based on the results.
f. If the Hct is between 28% and 30% and there are no signs of bleeding,
start measuring Hct every four hours.
g. If the Hct is between 28% and 30% and there is no gastric tube in
place, insert an orogastric tube to assess for upper GI bleeding by
lavaging the stomach.
II. Treatment
a. If the donor has previously required transfusions, submit a blood
bank order to ensure that 2–4 units of packed red blood cells (PRBC)
Medical Issues and Management
77
Dr Gopi Ayyaswamy
are available. Otherwise, write an order to type and cross-match and
maintain 2 units of PRBC.
b. If the Hct is below 30%, rapidly transfuse 2 units of PRBC.
c. Reassess the Hct one hour after the last unit of PRBC has been
infused. If the Hct remains below 30%, consider repeating the
transfusion.
d. Reassess the Hct one hour after the fourth unit of PRBC has been
transfused and reevaluate the assessment items mentioned earlier.
If the Hct is still below 30% after 4 units of PRBC, reconsider the
treatment approach.
Coagulopathy and Thrombocytopenia
Blood loss, regardless of the cause, can pose a threat to the perfusion
of donor organs. Severe trauma and resuscitation may lead to
disseminated intravascular coagulation or “dilutional” coagulopathy.
The treatment objective is to address clinically signicant coagulopathy
and thrombocytopenia. It is important to correct any identied disorders
since ongoing hemorrhage can exacerbate coagulation abnormalities and/
or thrombocytopenia. Refer to the anaemia guideline for guidance on
correcting such disorders.
It should be noted that commonly performed laboratory tests to assess
coagulation, such as partial thromboplastin time (PTT), prothrombin
time (PT), brinogen, and platelet count, may yield abnormal results.
However, treatment may not always be necessary. Treatment is reserved
for donors who demonstrate ongoing signicant blood loss based on
physical assessment, hemodynamic instability, and changes in coagulation
parameters.
I. Assessment
a. Review the donor’s medical record to identify any potential injuries
that could account for bleeding.
b. Ensure that the medical record indicates no recent administration of
drugs that may interfere with coagulation or platelet function, such
as warfarin, aspirin, heparin, clopidogrel, dipyridamole, etc.
78
A Simple Introduction to Organ Transplant
Dr Gopi Ayyaswamy
c. Conduct laboratory assessments, including PT, PTT, brinogen,
platelet count. Repeat coagulation tests should be performed
30 minutes after any administration of blood products.
Normal reference ranges are as follows:
• PT < 14.5 seconds
• Platelet count > 150,000/cc
3
• PTT < 35.6 seconds
• Fibrinogen: 150–350 mg/dl
• Measure ionized calcium levels in fluid/electrolytes and treat
hypocalcemia if < 2.3 mmol/L and ionised calcium (< 1.2 mmol/L).
II. Treatment for continued signs of signicant blood loss and abnormal
coagulation parameters or platelet count:
a. Examine for external bleeding or further assess possible
gastrointestinal or urinary injuries. Follow the anemia guideline
for treating anemia.
b. Overcome platelet dysfunction caused by prior aspirin intake by
infusing a platelet 5-pack dose, even if the platelet count is normal.
Treat platelet count < 65,000/cc
3
as follows:
1. Administer 1 intravenous pack of platelets (typically containing
5 or 6 individual units) as a rapid infusion.
2. Recheck the platelet count one hour after the rst platelet pack
and transfuse a second platelet pack if the count remains below
65,000/cc
3
. Obtain a follow-up platelet count exactly one hour
after completing the second platelet infusion.
a. Coagulopathy (PT, PTT): Treat PT > 15 seconds, PTT > 38 seconds
as follows:
1. If the donor has been receiving intravenous heparin and PTT is >
75 seconds, consider administering protamine.
2. Rapidly infuse 4 units of fresh frozen plasma (FFP).
3. Repeat PT and PTT measurements 30 minutes after the initial FFP
infusion. Repeat FFP infusion if PT and PTT remain above the
treatment ranges.
Medical Issues and Management
79
Dr Gopi Ayyaswamy
4. Repeat PT and PTT measurements 30 minutes after the second
FFP infusion. If PTT and PT continue to be elevated above the
treatment ranges, further intervention may be necessary.
b. Coagulopathy (Decreased brinogen)–Treat brinogen < 100 mg/
dL as follows:
1. Infuse 6 units of cryoprecipitate rapidly.
2. Repeat fibrinogen measurement one hour after the initial
cryoprecipitate infusion. Repeat cryoprecipitate infusion if
brinogen remains below 100 mg/dl.
3. Repeat fibrinogen measurement one hour after the second
cryoprecipitate infusion. If the concentration remains below
100 mg/dl, additional measures may be required.
Mechanical Ventilation
Under most circumstances volume limited controlled mechanical
ventilation will be used during donor care. Pressure limited controlled
mechanical ventilation is indicated when peak and plateau airway
pressures are elevated, indicating high airway resistance or poor lung
compliance (see below). The goals during mechanical ventilation are:
1. Peak airway pressure (Peak AWP) < 40 cm H
2
O
2. Plateau airway pressure (Plat AWP) < 35 cm H
2
O
3. FIO
2
—lowest possible to maintain SpO
2
> 92% and PaO
2
> 80 mm Hg
4. PEEP—minimum 5 cm H
2
O, adjust to maintain PaO
2
> 80 mm Hg
5. Auto PEEP-<5 cm H
2
O
6. Arterial blood gas (ABG) values: pH 7.35–7.45; PaCO
2
36–44 mm
Hg to maintain pH within goal range; PaO
2
> 80 mmHg; HCO
3
not
independently adjusted.
I. Assessment
1. Evaluate the medical record for cardio-pulmonary diseases prior
to or during this admission. Assess related issues such as chronic
oxygen use at home, ongoing pneumonia, chest radiograph results,
culture results, antibiotics ordered, respiratory treatments given, etc.
80
A Simple Introduction to Organ Transplant
Dr Gopi Ayyaswamy
2. Assure recent ABG results available or obtain sample for testing.
Compare results to the above treatment goals.
3. Perform a physical examination with attention to abnormalities such
as wheezing, rhonchi, sputum appearance/thickness/tenacity, etc.
4. Repeat ABGs at least every 4 hours or more frequently to assess
changes in respiratory status or after adjustments in ventilator
settings.
5. Consult with a respiratory care practitioner to identify if above
mechanical ventilation goals are being met, i.e. auto-PEEP, airway
pressures, etc.
II. General ventilator settings
A. Volume-limited controlled ventilation
1. Tidal Volume (VT)—10 ml/kg ideal body weight (kg). If high
peak airway pressures are present, reduce VT to 6–8 ml/kg ideal
body weight (kg).
Ideal body weight:
a. Male: 50 kg + 2.3 kg per inch > 60 inches
b. Female: 45 kg + 2.3 kg per inch > 60 inches
2. Rate (f)—adjusted to maintain minute ventilation (VT x f) (VE)
of approximately 8–10 L/min or to maintain PaCO
2
> 16 mmHg
< 60 mm Hg, so as to maintain arterial pH at 7.35–7.45.
Downward adjustment in rate may be needed to minimize auto-
PEEP.
3. Flow rate—usually about 60 L/min; adjust to minimize peak AWP;
beware of auto-PEEP as ow rate is slowed; higher ow rate may
be needed to minimize auto-PEEP.
4. PEEP—minimum 5 cm H
2
O—adjusted to assist in maintaining
PaO
2
> 70 mm Hg.
5. FIO
2
—adjust to maintain PaO
2
> 80 mm Hg.
6. Use decelerating (ramp) pattern for ow delivery, when available.
Medical Issues and Management
81
Dr Gopi Ayyaswamy
B. Pressure-limited controlled ventilation
1. Inspiratory pressure setting—to limit peak airway pressure at
35–40 cm H
2
O, consult with respiratory care practitioner for nal
pressure limit setting to various ventilator types.
2. Rate—same as A (2) above.
3. PEEP—same as A (4) above. However, recall PEEP adjustments.
May change delivered VT and VE during pressure-limited
ventilation, i.e. increased PEEP will generally decrease VT and
VE causing PaCO
2
to rise (reverse with decreased PEEP).
4. FIO
2
—same as A (5) above.
III. General respiratory treatment
a. Assure adequate suctioning of excessive sputum.
b. Assure bronchodilators are ordered as indicated by wheezing or a
peak airway pressure—plateau airway pressure gradient of > 10 cm
H
2
O.
c. Other forms of chest physiotherapy or related devices are optional
but should be considered.
IV. Ventilator adjustments: Volume-limited controlled ventilation
Note: Repeat ABGs 30 minutes after any change of ventilator settings to assess effects
Note: Combinations of adjustments listed below may be necessary as guided by arterial blood gas
results and airway pressures.
A. Acidemic pH—arterial pH < 7.35 and PaCO
2
>45 mmHg
1. Increase VT to maximum 12 ml/kg ideal wt as long as Plat AWP
remains < 35 cm H
2
O, or
2. Increase rate to maximum 22 breaths/min as long as auto-PEEP
remains < 5 cm H
2
O.
3. If pH remains < 7.32 after above changes, refer to Rx Guideline:
Acid–base treatment.
B. Alkalemic pH—arterial pH > 7.45 and PaCO
2
< 35 mmHg
1. Decrease ventilator rate sequentially to minimum of 6 breaths/
min to achieve pH
82
A Simple Introduction to Organ Transplant
Dr Gopi Ayyaswamy
2. Decrease VT to minimum of 6 ml/kg ideal body wt.
3. If pH remains > 7.45, consult physician/intensivist.
C. High Plat AWP > 35 cm H
2
O
1. Reduce ow rate to minimum 50 L/min—as long as auto-PEEP
remains < 5 cm H
2
O.
2. Reduce VT to minimum of 6 ml/kg ideal body wt—assess effect
on arterial pH.
3. Reduce PEEP to minimum 5 cm H
2
O—assess effect on PaO
2
.
4. If Plat AWP remains > 35 cm H
2
O, consult physician/intensivist.
D. Auto-PEEP > 5 cm H
2
O
1. Increase ow rate to maximum of 90 L/min—as long as Plat AWP
remains < 35 cm H
2
O.
2. Decrease VT to minimum 6 ml/kg ideal body wt—assess effect
on arterial pH.
3. Decrease ventilator rate sequentially to minimum of 8 breaths/
min to minimize. Auto-PEEP—assess effect on arterial pH.
4. If auto-PEEP remains > 5 cm H
2
O, consult physician/intensivist.
E. Low PaO
2
: PaO
2
< 70 mm Hg
1. Increase FIO
2
to maximum 1.0 (100%).
2. Increase PEEP to maximum 15 cmH
2
O—as long as Plat AWP
remains < 35 cm H
2
O.
3. Add inspiratory pause (hold) to maximum 1.0 second as long as
auto-PEEP remains < 5 cm H
2
O.
4. If PaO
2
remains < 70 mm Hg, consult physician/intensivist.
F. Ventilator adjustments: Pressure-limited controlled mechanical
ventilation
Acidemic pH–arterial pH < 7.35
1. Increase ventilator rate to maximum 22 breaths/min as long as auto-
PEEP < 5 cm H
2
O
Note: Auto-PEEP will decrease VT delivered and may worsen acidemia.
Medical Issues and Management
83
Dr Gopi Ayyaswamy
2. Increase inspiratory pressure setting to maximum Peak AWP of 45 cm
H
2
O.
3. If arterial pH remains < 7.32, consult physician/intensivist.
Alkalemic pH–arterial pH > 7.45
1. Decrease ventilator rate sequentially to minimum of 6 breaths/min to
achieve pH goals.
2. Decrease inspiratory pressure setting but maintain V
T
above 6 ml/kg
ideal body wt.
3. If arterial pH remains > 7.45, consult physician/intensivist.
A. Auto-PEEP–auto PEEP > 5 cm H
2
O
i. Decrease ventilator rate sequentially to minimum 8 breaths/
min—assess effect on arterial pH.
ii. If > 5 cm H
2
O auto-PEEP persists, consult physician/intensivist.
B. Low PaO
2
–PaO
2
< 70 mm Hg
i. Increase FIO
2
to maximum 1.0 (100%).
ii. Increase ventilator PEEP to maximum of 15 cm H
2
O as long as pH
iii. Remains > 7.35 (increased PEEP will decrease tidal volume
delivered in pressure-limited ventilation)
4. If PaO
2
remains < 70 mmHg, consult physician/intensivist.
Fluid and Electrolyte Treatment
The objective of treatment is to maintain electrolyte levels within the normal
range determined by the clinical laboratory at each specic hospital. To
achieve this goal, regular laboratory testing of sodium (Na), potassium (K),
chloride (Cl), bicarbonate (HCO
3
), magnesium (Mg), phosphorous (P), and
ionized calcium (Ca
++
) should be conducted every 4 hours. In cases where
critical levels are present, more frequent monitoring and treatment may be
necessary. It is important to allow a 30-minute interval after administering
the last dose of any electrolyte before conducting laboratory testing. All
electrolyte replacements should be administered intravenously.