MINISTRY OF EDUCATION AND TRAINING MINISTRY OF NATIONAL DEFENSE
108 INSTITUTE O F CLINICAL MEDICAL AND
PHARMACEUTICAL SCIENCES
TRAN THI OANH
STUDYING CLINICAL, SUBCLINICAL CHARACTERISTICS
AND SOME RELAVANT FACTORS OF PATI ENTS WITH ACUTE
CEREBRAL INFARCTIONABOVETHE CEREBELLUM TENT
REQUIRI NGMECHANICAL VENTILATION
Speciality: Neurology
Code: 62720147
SUMMARY OF MEDICAL DOCTORAL THESIS
HA NOI – 2019
THE THESIS WAS DONE AT 108 INSTITUTE OF CLINICAL
MEDICAL AND PHARMACEUTICAL SCIENCES
Scientific instructors:
1. Prof. PhD. Nguyen Van Thong
2. PhD. Nguyen Hong Quan
Reviewer 1:
Reviewer 2:
Reviewer 2:
This thesis will be presented at Institute Council at:
Day Month Year
The thesis can be found at:
1. National library
2. Library of 108 Institute of clinical medical pharmacological sciences
1
INTRODUCTION
Stroke is one of the leading causes of death and disability in adults, with
about 80-85% of cerebral infarction. Patients with severe cerebral
infarction often have consciousness disorders, loss of ability to protect the
airway, sputum congestion, causing respiratory failure. Intubation and
mechanical ventilation for these patients is needed to support breathing to
protect the airway and ensure adequate oxygen supply to brain cells.
Although the proportion of patients with right ventilated cerebral infarction
is not high (10-16%), the prognosis is very poor. All patients have severe
clinical circumstances, complex evolutions, need many pos itive treatments
but high mortality. The death rate in the hospital is 35-75%. The patients
who survived are mostly w ith severe neurological sequelae and dependent.
There have been many studies in the world and in the country about
patients with cerebral infarction in general but there have not been many
studies on patients with mechanical ventilation with cerebral infarction
about factors related to ventilation indications and prognostic factors in
these patients.
Therefore, we conducted the subject: "Studying clinical, subclinical
characteristicand some relevant factors of patients with acute cerebral
infarction above the cerebellum tent requiring mechanical ventilation"
with two objectives as follows:
1. Description of clinical, subclinical characteristics and some factors
related to mechanical ventilation of patients with acute cerebral
infarction above the cerebellar tent.
2. Identify some of prognostic factors of patients with acute cerebral
infarction above the cerebellum tent requiring mechanical ventilation.
2
THE NEWCONTRIBUTIONOF THE THESIS
1. The thesis topic has scientific, practical and topical significance to
contribute to show some clinical, subclinical and imagingcharacteristics of
patients with acute cerebral infarction above the cerebellum tent requiring
mechanical ventilation.
2. Determining a number of factors related to mechanicalventilation of
patients with acute cerebral infarction above thecerebellum tent, some
prognostic factors of mortality and prognosis ofgood functional state mRS
0-3 at the time of 1 year. This will helpclinicians predict and prescribe
timely treatment intervention.
THE S TRUCTURE OF THE THESIS
The thesisconsists of130pages: 2pagesof introduction, 36pages of
overview, 13pages of subjects and methods, 33pages ofresearchresults,
43pages of discussion, 2pages of conclusionsand 1 page of suggestion, 40
tables,13 charts, 9 images, 1 figures and 148 references.
Chapter 1 - OVERVIEW
1.1.
Physiology of cerebral infarction
A cerebral infarction occurs when the amount of brain blood falls below
18–20 ml / 100g brain / m inute, the centre of the infarction is the necrotic
area with a blood flow of 10-15ml/100g brain/minute, around this area
(Penumbra area) has a blood flow of 20-25ml/100g brain / minute,
although brain cells are still alive but inactive. The area cells die over a few
hours and are different for every patient. This is the window time for
reperfusion treatment interventions. Treatment measures to save this area.
1.2.
Edema in cerebral infarction
3
Cerebral edema in a large cerebral infarction causes increased
intracranial pressure, which can lead to a brain hernia, aggravate
neurological deficiencies and high mortality if left untreated. The clinical
development of cerebral edema in patients with massive cerebral infarction
can be divided into 3 levels: fu lminant (within 24-36 hours), slowly (over
several days), or initial acute course then descending (about a week).
Cytotoxic Edema: Once clogged, there is a stop of oxygen exchange in the
damaged area which leads to the cell losing energy, losing the function of
the transport membrane, the ion pump stops working, Na + from outside
spills into the cell, dragging water causes the cell to swell causing cytotoxic
edema. This type of edema does not respond to anti-edematous drugs
according to the osmotic mechanism.
Vasogenic Edema: Occurs 4 to 12 hours after embolization, due to a
profound change in the endothelial lining of the capillaries, stagnation of
glycogen in stellar cells, causing bulging star cells, breaking the tight bonds
between intracellular cells tissue and between endothelial cells and stellar
cells leads to blood barrier brain ( BBB), the fluid from the lumen of the
artery is released causing brain edema. Brain edema b ecomes the strongest
on the third to fifth day and is reduced after one to two weeks. This type of
edema responds to anti-edematous drugs according to the osmotic
mechanism.
As recommended by the American Heart Association/American Stroke
Association in 2014, the signs predict malignant cerebral edema and poor
prognosis on cranial CT include increased mid-cerebral artery photon, dot
sign on film within 6 hours, infarction of one-third or more of the mid-
cerebral artery blood supply region, or midline shift push of 5 mm or more
on the cranial CT scan in the f irst 2 days is also associated with increased
nerve damage and death early in the acute phase. The American Heart
Association/American Stroke Association (2014) recommends serial CT
scans during the first 48 hours of stroke to assess the risk of malignant
brain edema.
4
1.3.
Indications and role of mechanical ventilation in patients with
cerebral stroke
The most common causes of hypoxemia in brain stroke patients may be
due to partial obstruction of the airways due to sputum stagnation,
respiratory depression and hypoventilation, choking pneumonia and
collapse. In these cases, mechanical ventilation helps improve blood
oxygenation, maintain oxygenation to the brain and reduce intracranial
pressure, but excessive ventilation should be avoided. SpO2 target> 94%
and pCO2 35 - 40 mmHg. In patients stroke with impaired consciousness,
or signs of brain stem dysfunction, decreased oropharyngeal motion and
airway reflex loss are at high risk of choking pneumonia. Intubation for this
patient is necessary to protect the airway and prevent choke complications.
Some patients have coma, disorders of breathing, have apnea, intubation
and mechanical ventilation to ensure respiration, ensure oxygen to the brain
and body to prevent brain edema progression.
The American Heart Association/Stroke Association 2014recommends
for mechanical ventilation in the treatment of acute cerebral infarction:
Intubation may be considered for patients with decreased levels of
consciousness resulting in poor oxygenation or impaired control of
secretions.
1.4.
Hyperventilation and role of pCO
2
in treatment intracranial pressure
Reducing pCO
2
is known as a cerebral artery contraction that reduces
cerebral blood flow leading to a reduction in intracranial pressure, mainly
due to changes in pH around the blood vessels. The effect of reducing
cerebral blood flow is temporary, after 4 hours brain blood flow has been
restored 90%. In addition, a rapid increase in pCO
2
causes a decrease in the
pH around the blood vessels, causing vasodilation to increase brain blood
volume and increase intracranial pressure ("rebound hyperemia"). Use
hyperventilation should only be used short in cases of life-threatening
increase in intracranial pressure, pending surgical intervention. pCO
2
should be normalized as soon as possible.
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Chapter 2 - SUBJECTS AND METHODS
2.1. Studying subjects
Severe cerebral infarction patients above the cerebellum tent were
treated at Strokecenter-Central MilitaryHospital108from 9/2013 – 6/2017.
2.1.1. Criteria for selecting a patient
The patients was diagnosed as stroke according to the World Health
Organization (1989) stroke definition, arriving at the hospital 72 hours
prior to the onset of c erebral infarction. Images of hemispherical infarction
on CT/MRI/ Severe nerve damage with NIHSS≥15 score (if the patient was
hospitalized prematurely, the damage on the first CT was unknown, the
patient would be diagnosed for a second time on CT. Patients were divided
into 2 groups: mechanical ventilation group and non mechanical ventilation
group.
2.1.2. Exclusion criteria
History of stroke with mRS score> 2 points, patients with severe
medical conditions such as liver failure, severe kidney failure, cancer,
COPD,…
2.2. Research methods:
2.2.1. Study design:Progressive, description, follow-up study
2.2.2.Sample size:
Sample size is determined by formula:
p (1-p) n = Sample size to study
n = Z
2
(1-α/2)
-------- Z
2
(1-α/2)
: At the probability level 95% (Z =1,96)
d
2
d: The desired accuracy (d = 0,05)
p: Estimated ratio, the rate ofcerebral
infarctionpatients requiring mechanical
ventilationin previous studies, p= 0,11.
→ Based on the above formula, the estimated patient sample sizeis 150.
In the period of taking data from 9/2013 – 6/2017, we collected 166
patients including 84 ventilated severe cerebral infarction patients and 82
severe cerebral infarction patients without mechanical ventilation.
2.2.3. Research variables
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Clinical variables: gender, age, medical history, time of admission, pulse,
blood pressure, temperature, level of consciousness at admission on
Glasgow scale, NIHSS score, degree of paralysis, language disorder,
sensory disorders, urinaryincontinence, pupil abnormalities, light reflexes,
head-eye deviation, progression of symptoms, related mechanical
ventilation complications.
Subclinical variables: hematology, biochemistry, coagulation, arterial blood
gases.
Imaging variables: CT, CTA, DSA: parenchymal, artery damage, midline shift.
Variables of treatment outcome: death, live, mRS at discharge, 1 year.
2.2.4. Research contents
Patients were divided into 2 groups: MVgroup and non MVgroup. The
patients were divided into two groups, the MVgroup and the non MV group.
MVis indicated when at least one of the following criteria: Glasgow ≤ 8, loss
of reflexes protects airway causing mucus congestion, patients with
consciousness disorders, stimulation must use safety drugs strong spirit causes
respiratory depression, patients with respiratory failure, circulatory failure.
Describe the clinical and paraclinical features with analysis and comparison
between two groups of MV and non MV group to highlight c linical and
subclinical characteristics of patients requiring MV.
Identify factors related to MV, factors related to prognosis of death at
hospital discharge and mRS 0-3 at 1 year. The supposedly relevant
variables are included in univariate analysis and logistic multivariate
regressions to find meaningful prognostic factors.
2.3. Data analysis
Data processing using SPSS 16.0 software.
Description of clinical, subclinical, imaging features: neurological signs
on onset, on admission and during hospitalization, intubation designation,
subclinical characteristics, imaging, complications during MV, treatments
and outcome.
7
Analysis of related factors: Chi-square test of qualitative or quantitative
variables with clustering. Statistically significant variables in Chi-square
test were included in univariate regression analys is. Variables related to
MVand mortality in univariate analysis with significance level p <0,05
were included in multivariate regression analysis to identify independent
prognostic variables.
2.4. Diagramresearch
Chapter 3 – RESULTS
3.1. Clinical, subclinical characteristics and some factors related to MV in
patients with acute cerebral infarction above the cerebellar tent.
3.1.1. Clinical symptoms
Neurological symptoms onset
ISCHEMIC
STROKE
without MV
(n = 82patients)
ACUTE ISCHEMIC STRO KE
- Images of HI on CT/MRI
- NIHSS≥15if the damage on the first CT is
unknown, will be diagnosed for 2nd on CT
(n = 166 patients)
ISCHEMIC
STROKE
with MV
(n = 84patients)
1. Descripti on of clinical,
subclini cal characteristics and
some facto r rela ted to MV
2. Identif y some of prog nostic
factors in patients ischem ic
stroke with MV
Prognostic factors
of mortality
Clinicalcharac
teristics
Related factors of
mRS 0-3 at 1 year
Subclinical
characteristics
of MV
8
Table 3.4. Neurological symptoms onset
Symptoms MV(n=84)
Non -
MV(n=82) p
n
%
n
%
Conscious disorders onset 67 79,8 31 37,8 <0,001
Lips/ coma does not say 53 63,1 41 50 >0,05
Hemiplegia in the face 83 98,8 82 100 >0,05
Hemiplegia 84 100 82 100 >0,05
Headache 9 9,5 5 8,0 >0,05
Dizzy 8 9,5 7 9,1 >0,05
Vomiting /nausea 14 16,7 3 3,7 <0,05
Ur inary incontinence 56 66,7 16 19,5 <0,001
Comment: Disturbances of consciousness, vomiting/nausea, and urinary
incontinence were statistically different with p <0,05.
Neurologic symptoms at hospital arrival
Table 3.5. Neurologic symptoms at hospital arrival
Symptoms MV(n=84) Non - MV(n=82)
p
n % n %
Average Glasgow score 10,31 ± 2,02 11,84 ± 1,95
<0,001
Average NI HSS score 22,82 ± 5,39 19,90 ± 3,73
<0,001
Glasgow point at
admission≤10 51 60,7 27 32,9 <0,001
NIHSS point at admission>20 52 61,9 34 41,5
< 0,01
Head-eye deviation 36 42,9 16 19,5
<0,001
Dilated pupils admission 10 11,9 1 1,2
< 0,01
Language d isorders 83 98,8 82 100 > 0,05
Ur inary incontinence
admission 62 73,8 4 4,9 <0,001
Severe paralysis
(Muscle strength 0/5-1/5) 78 92,9 64 78 < 0,01
Average strength of arm 0,32 ± 0,64 0,62 ± 0,94
< 0,05
Average strength of leg 0,45 ± 0,67 0,87 ± 1,05
< 0,01