Download non-invasive ventilation in the prophylaxis of shunt hypoxemia in

Rusu Gabriel- General Medicine
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Major interventions significantly affects the functions of more
systems such as respiratory one, increasing the risk of pulmonary
postoperative complications.
Atelectasis, pneumonia, respiratory failure are frequently.
Personal pathological status plays an important role in developing
those, such as: COPD, chronic smoking, cardiovascular or renal
disease.
Surgical positions on the operative room and the duration of
intervention influence the morbidity through pulmonary
complications.
General anaesthesia reduces functional residual capacity, that will
lead to atelectasis.
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Non-invasive ventilation is increasingly used in the treatment of
acute respiratory failure
It is addressed to hypoxemia, preventing atelectasis, improving
gas exchange and decreasing the respiratory labor.
More indications: acute COPD, pulmonary edema (cardiogenic or
non-cardiogenic), acute respiratory failure.
The patient is breathing spontaneous through a pressurized
system against a resistance that maintain a default positive
pressure.
Although many studies have shown the ability of CPAP to reduce
atelectasis, none of them have shown that the rate of intubation it
is actually reduced.
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The connection between respiratory physiotherapy and
improvement of acid-base parameters and oxygenation of the
critic surgical patient in the first 24 hours postoperative.
Parameters: PH, PO2, PCO2, Alveolar-arterial gradient, SO2
Right after physiotherapy there are no changes in the PH and
neither after 15 minutes.
PCO2 decreases after the procedure, but after 15 minutes the
average value rises again, without reaching statistical significance.
It is noticed an improvement of PO2 after the CPAP, but no
significant statistical difference occurred.
A-a gradient has a stationary evolution.
SO2 rises immediately after procedure, but also after 15 minutes
the average value decreases.
Twenty consenting patients of which: 55% men and 45% women,
hemodynamic stable, spontaneous respirations.
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Respiratory therapy with nebulizer
1. Saline solution (0,9% or 5,85% in 1:1 dilution)
2. The patient had to breath deeply and rare, in order to
maximize the effects.
3. Followed by the clearing of mucus and relief of the cough.
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Non-invasive ventilation(CPAP)
1. Parameters: PEEP: 5, FiO2: 0,35, ASB: 12. Duration: 15
minutes.
2. Three blood gas analysis(ASTRUP): before, after and also 15
minutes after.
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Thoracic tapotement
1. Purpose: clearing of mucus from lower respiratory tract to
the superior one.
2. Each lung was massaged from the base to the apex. The
patient had to cough in order to eliminate the mucus.
E v o lu tia p H
PH evolution
7 .6
7 .4
)
(2
(1
)
7 .2
)
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(0
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After the procedures, 15 of the 20 patients had improvements,
and 5 of them didn’t, because of postoperative pain and lack of
compliance.
Average value of PH before was: 7.38. After the procedures was
7.39 and 15 minutes from them was 7.37.
Between these values there is no statistical difference (U-Mann
Whitney Test, p=0.72 for (1) moment and p=0.1 for (2) towards (0))
pH
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v o lu tia P a C O 2
PCO2Eevolution
50
45
40
2
35
30
25
)
(2
)
(1
)
20
(0
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Average value of PCO2 before the procedures was 38.3 mmHg.
Right after them turns 37.7 mmHg and 15 minutes after
39.7mmHg.
It has been observed the decrease of the average value of PCO2,
right after the CPAP, but 15 minutes after, the value rises again
also with no significantly statistical difference between the
moments( p=0.17, and p=0.6)
PaC O
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E v o lu tia P a O
PO2 evoluton
2
150
100
)
(2
)
(1
)
50
(0
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Before: 80.7mmHg, after: 84.9 mmHg and 15 minutes after the
procedures: 84 mmHg
It was observed an improvement of the values right after the
CPAP and nebulization, however there is no significantly
statistical difference(p=0.1 and p=0.51)
PaO 2
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o lu tia s a tu ra tie i a rte ria le
SO2E vevolution
100
98
96
94
)
(2
)
(1
)
92
(0
2
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Before the CPAP average value was: 96%, after: 96.6% and 15
minutes after 96.1%.
There has been an increase of the SO2 value after the CPAP, but
the moment (2) shows us that the value of SO2 is decreasing, also
with no significantly statistical difference(p=0.4 and p=0.9)
SaO
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E v o lu tia g raA-a
d ie n tuevolution
lu i a lv e o lo -a rte r ia l
Gradient
200
150
100
50
)
(2
)
(1
)
0
(0
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Average value of the gradient before CPAP was 94.9 mmHg, it has
increased immediately after at 103.8 mmHg and after 15 minutes
reached 93mmHg
It is a stationary evolution of the values between the moments
(0),(1) and (3).
A -a
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Analyzing the whole group of patients, I concluded that there were
no significantly changes in the values of: PH, PCO2, PO2, SO2 and Aa gradient.
Five of the patients actually show worsening of the parameters,
because of postoperative pain that decreases the compliance of the
patients to the procedures.
To the fifteen compliant patients, to which have been observed
improvements, the only significantly change was of the PCO2, the
lung collapsing quickly after the PEEP ended.
Patient monitoring was short, so that we cannot reach a definite
conclusion among the impact of prophylactic respiratory
physiotherapy in those patients where the characteristic changes of
pulmonary shunt are not present.
Postoperative pulmonary complications are often seen in ICU after
major surgery and are needed more prospective studies to show the
prophylactic benefits of the procedures.