VIỆn nghiên cứu khoa học y dưỢc lâm sàng 108 nguyễn văn tuyến nghiên cứU ĐẶC ĐIỂm lâm sàNG, CẬn lâm sàng và chỉ ĐỊnh thông khí CƠ HỌC

4.2. Subclinical features

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  Serum glucose at admission: the proportion of patients with hyperglycemia (≥ 11 mmol/l) was 11.74%, while the proportion of patients with history of diabetes was only 6.08%. In the group of mechanical ventilation, serum glucose ≥ 7 mmol/l and ≥ 11 mmol /l was quite high (64.17% and 17.04%). In the group without mechanical ventilation, it was lower (35.1% and 4.1%).
  
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  Evaluate blood electrolyte disorders at admission: in both groups, most patients suffered from hyponatremia and hypokalemia (31.30% and 49.56%), whereas the rate of hypernatremia and hyperkalemia is very low (2.60% and 1.73%). According to Nguyen Minh Hien, hypernatremia 1.6%, hyponatremia 37.1%, hyperkalemia 2%, hypokalemia 28.6%.
  
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  In mechanical ventilation group, hematoma volume > 60 cm3 (41.80%), grades III of midline shift (35.82%), blood in subarachnoid cavity (35.07%), whereas in the group non-mechanical ventilation, hematoma volume > 60 cm3 (15.62%), grades III of midline shift (2.08%), blood in subarachnoid cavity (2.08%). This result of our study was reasonable, because hematoma volume, midline shift, blood in subarachnoid cavity are worse prognostic factors in hemorrhagic patients.
  

4.3. The relative factors to indications for mechanical ventilation.

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  The rate of mechanical ventilation: among 230 patients studied, 134 patients underwent mechanical ventilation account for 58.26%. According to the other authors: Nguyen Van Thong at al, the rate of hemorrhagic patients requiring mechanical ventilation was 25.2%. Stephan A. Mayer at al studied 510 acute stroke patients, the percentage of mechanical ventilation was 10% (hemorrhagic stroke 26%). Our study show that the rate of patients requiring mechanical ventilation was higher than these studies because our objects are the moderate and large hemorrhagic stroke.
  
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  Indications for intubation: intubation due to coma was the highest percentage (67.16%), followed by inability protective airway reflexes, mucus congestion (18.65%) and acute failure respiratory was lowest (14.18%). According to some authors, there are two indications for intubation such as: neurological causes and respiratory causes. In our study, neurological causes was 85.8% (including indicated by coma and the inability of airway protection), respiratory causes was 14.2%. According to Vu Anh Nhi, Tran Thanh Hung, neurological causes was 76.9%, respiratory causes was 23.1%. According to Gujjar AR., neurological causes was 86%, respiratory causes was 14%.
  
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  Characteristics of arterial blood gas test: Compare arterial blood gas before mechanical ventilation and during mechanical ventilation: the arterial oxygen pressure (PaO₂) was significantly improved. It is suitable, because of most stroke patients have normal lung, so it is easy to ensure arterial oxygen saturation by mechanical ventilation. Arterial blood gas test results in patients with coma (Glasgow score ≤ 8): PaO2 ≥ 60mmHg (95.56%), PaCO2 ≤ 50 mmHg (96.67%), pH ≥ 7,35 (95.56%). Most authors agree that patients with Glasgow coma score ≤ 8 were indicated mechanical ventilation. On the other hand, blood gas standards for indicated mechanical ventilation including: PaO₂ ≤ 60mmHg, PaCO2 ≥ 50 mmHg.Thus, arterial blood gas tests to indicate mechanical ventilation in patients with intracerebral hemorrhage is not sufficient evidence.
  
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  Stopping and weaning mechanical ventilation: Among 134 patients underwent mechanical ventilation, 63 patiens died, 71 patients were stoped and weaned mechanical ventilation, successful rate was quite high (90.14%), unsuccessful rate was low (9.86%). Our study is compatible with other’s, according to Nguyen Phuong Đong the successful rate was 100% in patients with severe traumatic brain. Vanderdu et al showed that the unsuccessful rate was high in patients with chronic obstructive pulmonary disease (61%), respiratory failure (32%), while it was low in neurological patients (9%).
  
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  Tracheal extubation: among the 71 patients was stoped and weaned mechanical ventilation, the successful tracheal extubation was only 42.25% at the first time, resetting or tracheostomy was 57,75%. The results of our study is higher than Vallverdu’s: Tracheal extubation failure in patients with severe traumatic brain was 35%.
  
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  The common complication is respiratory alkalosis (27.61%), pneumonia (6.71%), hypotension immediately after mechanical ventilation (8.20%), no cases of pneumothorax or atelectasis. This result is similar to Nguyen Phuong Đong, studied 129 severe traumatic brain patients with mechanical ventilation, respiratory alkalosis was 22.5%, pneumonia was 5.9%. The pneumonia rates were rarely in stroke patients, because of short-term mechanical ventilation and the majority of patients have no history of chronic lung disease.
  

4.4. Some features relating to indications for mechanical ventilation

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  In univariate analysis, there are 12 variables relating to requiring mechanical ventilation. In logistic regression analysis, there are only 4 variables that are statistical significant: Head-eye deviation (OR= 5,11; CI: 1,64 - 15,96), absence of pupillary light reflex in one or two sides (OR = 3,61; CI: 1,13 – 11,41), hematoma volume > 60cm3, (OR = 3,14 ; CI: 1,28 – 7,68), midline shift ≥ 1cm (OR= 4,80; CI: 1,32 – 17,35).
  
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  In patients with head-eye deviation contralateral paralysis. According to Nguyen Minh Hien, it is very valuable in worse prognosis in patients with acute stroke. According to Hoang Khanh, the bigger lesion volume, the lower Glasgow coma score and related to head-eye deviation contralateral paralysis closely.
  
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  Patients with supratentorial hemorrhage have Absence of pupillary light reflex in one or two sides as a result of severe brain hypoxia or brain herniation caused compression of the nerves  III in the brainstem. According to authors, there is an association between the Absence of pupillary light reflex with a worse prognosis and mortality in stroke patients requiring mechanical ventilation. Gujjar A.R at al studied 230 patients underwent mechanical ventilation (156 patients with hemorrhage), Absence of pupillary light reflex was a bad prognostic factor. Thorsten Steiner at al, studied 124 stroke patients were intubated, absence pupillary reflex to light was a two – months mortality prognosis.
  
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  Hematoma volume above 60 cm3 related to indication for mechanical ventilation. The Vietnamese authors as well as the authors of the world have confirmed that hematoma volume is a prognostic factor in hemorrhagic patients. As we known , brain edema occur 2-3 hours after onset of hemorrhage, to be maximum after 24 hours and last 5-10 days. brain edema causes increased intracranial pressure, decreased cerebral perfusion pressure. In fact, there are many patients with hematoma volume above 60 cm3, still conscious, normal breathing at the first hours, but after 12-24 hours, increased cerebral edema, brain injury will also increase rapidly. Nowadays, many authors agreed that Intubation and mechanical ventilation of severe stroke patients should be performed in a timely manner, before irreversible damage occurs.
  
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  The midline shift ≥ 1cm is considered as predictor for the application of mechanical ventilation. Large hematoma volume, severe brain edema can cause mass effect and the midline shift. Cerebral herniation can also occur in these patients. Therefore, it is necessary to keep patients quiet, avoid irritating flap, analgesic, tranquillizer well , ensure adequate brain oxygen. Therefore, patients should be quiet, to avoid struggling, analgesic, sedative and ensure adequate brain oxygen.
  
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  The area under the curve (AUC) of the midline shift (0.82) was higher than AUC of hematoma volume (0,68). Thus, the midline shift related to indications for mechanical ventilation more closer than hematoma volume. This problem is also reasonable, the level of the midline shift is not only depend on hematoma volume but also brain edema, location of hematoma.
  

Studied 230 patients with acute moderate and large supratentorial itracerebral hemorrhage (first 72 hours from onset), divided into two groups, 134 patients with mechanical ventilation and 96 patients without mechanical ventilation. The studying Patients were inpatients of the Stroke center - Central Military Hospital 108 from August 2008 to March 2012. some conclusions were drawn as follows:

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  Mean age 61.01 ± 14.2, including ages from 50 to 59 accounted for the highest percentage (31.34%). Men was more than women, male / female 2.52.
  
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  Main clinical symptoms: The admission Glasgow score ≤ 8 accounted for 55.22%, 9-12 points 42.53%, 13-15 points 2.23%. Severe hemiplegia (0 point of Henry scale of arm muscle strength (77.61%), 0 point of Henry scale of leg muscle strength (76.11%). Patients requiring mechanical ventilation account for 58.26%, mechanical ventilation causes included: coma (67.16%), inability to protect the airway, mucus congestion (18.65%), acute failure respiratory (14.18%). Intubated within 24 hours after admission account for 67.16%. Withdrawing and weaning from mechanical ventilation success 90.14%; withdraw the endotracheal tube before discharge (42.25%); reset intubation or tracheostomy (57.75%). Complications: respiratory alkalosis up (23.13%), pneumonia (6.71%), hypotension (8.20%), no cases of atelectasis, pneumothorax.
  
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  Main subclinical symptoms: mean hematoma volume was 67.7 ± 46 cm3 (30-60 cm3 58.20%, above the 60 cm3 (41.80%), midline shift including: grade I (20.89%), grade II (38.06%), grade III (35.07%). Blood in the ventricles (62.68%), blood in subarachnoid cavity (35.07%). Admission serum glucose ≥ 7 mmol/l (64.17%), ≥ 11 mmol/L (17.04%), hyponatremia (31.30%), hypokalemia (49.56%). Arterial blood gas test before mechanical ventilation in patients with Glasgow coma score ≤ 8 points: PaO₂ ≥ 60mmHg (95.56%), PaCO₂ ≤ 50mmHg (96.67%), pH ≥ 7.35 (95.56%).
  

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  Relative features to indications for mechanical ventilation including: head - eye deviation (OR= 5,11; CI: 1,64 - 15,96), absence of pupillary light reflex in one or two sides (OR = 3,61; CI: 1,13 – 11,41), hematoma volume > 60cm³, (OR = 3,14 ; CI: 1,28 – 7,68), midline shift ≥ 1cm (OR= 4,80; CI: 1,32 – 17,35). Clinically, it can be based on these factors to indicate mechanical ventilation for patients with moderate and large supratentorial itracerebral hemorrhage although patients with Glasgow coma score above 8 points.
  

4. 
   Mechanical ventilation in patients with hemorrhagic patients is a useful measure of treatment brain edema, increased intracranial pressure. Mechanical ventilation must be done properly and timely. Mechanical ventilation strategy must be appropriate to increase the effectiveness of treatment.
   
5. 
   Some features relating to indications for mechanical ventilation from the results of this thesis is one of the factors that should be considered to indicate mechanical ventilation for patients with intracerebral hemorrhage.
   
6. 
   Indications for mechanical ventilation in patients with intracerebral hemorrhage is not necessary to base on the results of arterial blood gas test.
   

5. 
   Nguyen Van Tuyen, Nguyen Van Thong (2011), “The screening and assessments of dysphagia in acute stroke patients”, Journal of 108 – clinical medicine and pharmacy, vol 6, Special issue, pp. 54-61.
   
6. 
   Nguyen Van Tuyen, Nguyen Van Thong (2012), “The risk factors for the application of mechanical ventilation in patients with sponteneous supratentorial hemorrhage”, Journal of 108 – clinical medicine and pharmacy, vol 7, Special issue, pp. 156-162.
   
7. 
   Nguyen Van Tuyen, Nguyen Van Thong (2012), “Early fatal predictor in moderate and large supratentorial hemorrhagic patients requiring mechanical ventilation”, Practical medical journal, vol 844, pp. 196-201.
   
8. 
   Nguyen Van Tuyen, Nguyen Van Thong (2012), “Studying clinical and subclinical characteristics in young patients with intracerebral hemorrhage”, Journal of 108 – clinical medicine and pharmacy, vol 7, Special issue, pp. 55-60.