INTEGRATED USE OF BEDSIDE LUNG ULTRASOUND AND ECHOCARDIOGRAPHY AS AIDING PREDICTORS IN SUCCESSFUL WEANING PROCESS

Document Type : Original Article

Authors

1 Departments of Chest disease, Faculty of Medicine, Al-Azhar University

2 Departments of Cardiology, Faculty of Medicine, Al-Azhar University

Abstract

Background: We hypothesized that bedside lung ultrasound (LUS) and echocardiography could be a predictor of postextubation distress by detecting a high lung aeration defect immediately before weaning by evidencing significant lung derecruitment during the spontaneous breathing trial (SBT).
Objective: To evaluate the effectiveness of Lung Ultrasound (LUS) and Transthoracic Echocardiography (TTE) in predicting successful weaning of mechanically ventilated patients.
Patients and Methods: This study was performed on 50 mechanically ventilated patients in general and respiratory ICU during the period from August 2019 to January 2021, at Bab-Al-Sha'reia University Hospital. Lung ultrasound and echocardiography were determined before and at the end of a 60-min spontaneous breathing trial (SBT) and 4 hrs. after extubation. To quantify lung aeration, a lung ultrasound score was calculated.
Results: Forty-five patients had SBT success (90%) and 5 patients experienced SBT failure (10%), From those patients with SBT success, there were 16 patients (35.56%) had post extubation distress, and 29 patients (64.44%) had post extubation success. In patients who successfully passed the SBT, a lung ultrasound score ≤10 at the end of the SBT was highly predictive of postextubation success with a statistically significant difference (p value < 0.001). On the other hand, lung ultrasound score ≥18 at the end of the SBT was highly predictive of postextubation distress with a statistically significant difference (p value < 0.001). We found significant differences in E/A ratio 1.08 ± 0.2 in patients with spontaneous breathing trial success, and 1.6 ± 0.1 in patients with SBT failure with a statistical significant (p-value < 0.001).
Conclusion: LUS and TTE during spontaneous breathing trial may accurately predict postextubation distress.

Keywords

Main Subjects


INTEGRATED USE OF BEDSIDE LUNG ULTRASOUND AND ECHOCARDIOGRAPHY AS AIDING PREDICTORS IN SUCCESSFUL WEANING PROCESS

By

Ahmed Mohamed Abdalla Beshir, Ismael Abd El-Menem Attia, Mahmoud El-Saeed Ahmed, Ebrahim Faragallah Saeed*

Departments of Chest disease and Cardiology*, Faculty of Medicine, Al-Azhar University

Corresponding authors: Ahmed Mohamed Abdalla Beshir,

Mobile: +201288845932, E-mail: ahmedbeshir.6@azhar.edu.eg

ABSTRACT

Background: We hypothesized that bedside lung ultrasound (LUS) and echocardiography could be a predictor of postextubation distress by detecting a high lung aeration defect immediately before weaning by evidencing significant lung derecruitment during the spontaneous breathing trial (SBT).

Objective: To evaluate the effectiveness of Lung Ultrasound (LUS) and Transthoracic Echocardiography (TTE) in predicting successful weaning of mechanically ventilated patients.

Patients and Methods: This study was performed on 50 mechanically ventilated patients in general and respiratory ICU during the period from August 2019 to January 2021, at Bab-Al-Sha'reia University Hospital. Lung ultrasound and echocardiography were determined before and at the end of a 60-min spontaneous breathing trial (SBT) and 4 hrs. after extubation. To quantify lung aeration, a lung ultrasound score was calculated.

Results: Forty-five patients had SBT success (90%) and 5 patients experienced SBT failure (10%), From those patients with SBT success, there were 16 patients (35.56%) had post extubation distress, and 29 patients (64.44%) had post extubation success. In patients who successfully passed the SBT, a lung ultrasound score ≤10 at the end of the SBT was highly predictive of postextubation success with a statistically significant difference (p value < 0.001). On the other hand, lung ultrasound score ≥18 at the end of the SBT was highly predictive of postextubation distress with a statistically significant difference (p value < 0.001). We found significant differences in E/A ratio 1.08 ± 0.2 in patients with spontaneous breathing trial success, and 1.6 ± 0.1 in patients with SBT failure with a statistical significant (p-value < 0.001).

Conclusion: LUS and TTE during spontaneous breathing trial may accurately predict postextubation distress.

Key Words: Lung ultrasound, diastolic dysfunction, mechanical ventilation, postextubation distress, reintubation, weaning.

 

 

INTRODUCTION

     Unnecessary extubation delays can increase the morbidity and mortality associated with prolonged ventilation. Nevertheless, trying to decide when to extubate patients from mechanical ventilation can be challenging for the clinician and has been reported by some to be more art than science (Peouelas et al., 2011).

     Most proposed predictors of postextubation distress either require special equip-ment are too complex for bedside use, or have a limited predictive value (Nemer et al., 2011).

     There are no simple clinical indices known to be powerful predictors of postextubation distress. Many mechanisms whose relative weights vary from one patient to another may have an impact on the ability to wean from me‌chanical ventilation (Heunks and van der Hoeven, 2010).

     Lung ultrasound (LUS) could be a predictor of postextubation distress by detecting a high lung aeration defect im‌mediately before weaning and/or by evidencing significant lung derecruitment during the SBT (Boles et al., 2011).

     Cardiac dysfunction is another leading cause of weaning failure. The abrupt cessation of positive pressure ventilation increases venous return and left ventricular (LV) afterload, decreases LV compliance, and may even induce cardiac ischemia. All these factors tend to increase LV filling pressure, and may subsequently result in cardiogenic pulmonary edema (Girard et al., 2017).

     The aim of this work was to evaluate the effectiveness of LUS and TTE in predicting successful weaning of mechanically ventilated patients.

PATIENTS AND METHODS

Study design: This was a prospective study for evaluation the use of (LUS) and (TTE) in predicting successful weaning of mechanically ventilated patients. It was performed on 50 mechanically ventilated patients in general and respiratory ICU during the period from August 2019 to January 2021, at Bab-Al-Sha'reia University Hospital.

Data collection:

1.  Data were collected from these patients: Demographic data, clinical diagnosis, days of admission, cause of mechanical ventilation, days of mechanical ventilation, underlying cardiac and pulmonary diseases, and Simplified Acute Physiology Score (SAPS II).

2.  LUS scoring to detect lung aeration defect before and at the end of a 60-min spontaneous breathing trial and 4 hrs. after extubation (Table 1).

 

Table (1):  Lung US score for detection of the degree of lung aeration

Points for each lung zone (12 zones)

Degree of lung aeration

Pattern

0 point

Normal aeration

Horizontal A-line (no more than two B-line)

1 point

Moderate loss of aeration

Multiple B-line either regularly spaced or irregularly spaced

2 points

Severe loss of aeration

Multiple coalescent B-lines

3 points

Complete loss of aeration

Lung consolidation

Total score

From 0 to 3

 

 

 

3.  TTE at the end of a 60-min spontaneous breathing trial for assessment of fractional area changes, peak velocity of early and late mitral flow, ratio between early and late mitral flow, and deceleration time of velocity of early mitral flow.

Inclusion criteria: Patients mechanically ventilated for more than 48 hrs. when the underlying respiratory disease that has required intubation was considered by the attending physician as reversed, rendering the patient eligible to1-hr SBT.

Exclusion criteria: Patients aged <18 yrs., patients with tracheostomy, Paraplegia with medullar level above T8, significant cardiac arrhythmias and severe ICU-acquired neuromyopathy.

Statistical analysis: Data were analyzed using Statistical package for the Social Sciences (SPSS) version 15.0. Quantitative data were expressed as mean ± standard deviation (SD) and were compared by independent t-test. Qualitative data were expressed as frequency and percentage and were compared by Chi square test.


 

RESULTS

 

 

     As regard spontaneous breathing trial, there were success in 45 patients (90%) and failure in 5 patients (10%). As regard post extubation distress/success, there were distress in 16 patients (35.5%) and success in 29 patients (64.4%) (Table 2).


 

Table (2):  Description of spontaneous breathing trial and post extubation distress/success in all studied patients

 

Studied patients

(N = 50)

Spontaneous breathing trial

Success

45

90%

Failure

5

10%

Post extubation

Distress

16

35.56%

Success

29

64.44%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

     No statistical significant difference of diagnosis, MV causes and associated diseases as regard spontaneous breathing trial. Statistically significant difference of simplified acute physiologic score II, duration of MV, ICU stay and ICU mortality were as regard spontaneous breathing trial (Table 3).

 

 

Table (3):  Comparison of clinical data as regard spontaneous breathing trial

Spontaneous

breathing trial

Parameters

Success

(n = 45)

Failure

(n = 5)

P-value

Diagnosis

Medical

32

71.1%

3

60%

0.607

Surgical

13

28.9%

2

40%

MV causes

Respiratory failure

14

31.1%

1

20%

0.946

Multiple trauma

8

17.8%

1

20%

Non-traumatic coma

2

4.4%

0

0%

Severe hemodynamic instability

16

35.6%

2

40%

Post-operative complication of abdominal surgery

5

11.1%

1

20%

Associated diseases

None

6

13.3%

0

0%

0.665

Pulmonary disease

21

46.7%

3

60%

Cardiovascular disease

14

31.1%

1

20%

Cardiovascular disease and pulmonary disease

4

8.9%

1

20%

Simplified Acute Physiologic Score II

Mean ±SD

49.9 ± 12.5

66.8 ± 14.7

0.013*

Duration of MV (days)

Mean ±SD

5.2 ± 1.4

7.4 ± 0.9

0.002*

ICU stay (days)

Mean ±SD

11.6 ± 5.5

19.8 ± 3.03

0.004*

ICU mortality

No

41

91.1%

3

60%

0.042

Yes

4

8.9%

2

40%

*: Mann Whitney U test.

 

 

 

 

 

 

 

 

 

 

 

 

 

     There was a statistical significant difference of LUS (before SBT, End of SBT & H4 post-extubation) as regard post-extubation success/distress (Table 4).

 

 

Table (4):  Comparison of LUS as regard post-extubation success/distress.

Post-extubation

Parameters

Distress

(n = 16)

Success

(n = 29)

P-value

LUS before SBT

Mean ±SD

15.3 ± 1.4

9.8 ± 2.5

< 0.001*

LUS end of SBT

Mean ±SD

18.3 ± 1.1

9.8 ± 2.5

< 0.001*

LUS H4 post-extubation

Mean ±SD

20.3 ± 5.4

10.4 ± 2.8

< 0.001*

*: Mann Whitney U test.

 

 

     No statistical significant difference of fractional area change (%), peak velocity of late mitral flow, and deceleration time of velocity of early mitral flow as regard spontaneous breathing trial. Statistical significant difference of peak velocity was of early mitral flow and ratio between early and late mitral flow as regard spontaneous breathing trial (Table 5).

 

 

Table (5):  Comparison of ECHO as regard spontaneous breathing trial

Spontaneous

breathing trial

Parameters

Success

(n = 45)

Failure

(n = 5)

P-value

Fractional area change (%)

Mean ±SD

45.5 ± 4.3

48.6 ± 4.5

0.141

Peak velocity of early mitral flow (m/sec)

Mean ±SD

0.79 ± 0.08

1.06 ± 0.08

< 0.001

Peak velocity of late mitral flow (m/sec)

Mean ±SD

0.73 ± 0.11

0.68 ± 0.08

0.309

Ratio between early and late mitral flow

Mean ±SD

1.08 ± 0.2

1.6 ± 0.1

< 0.001

Deceleration time of velocity of early mitral flow (msec)

Mean ±SD

169.7 ± 21.3

181.2 ± 39

 

 

 

DISCUSSION

     Unnecessary extubation delays can increase the morbidity and mortality associated with prolonged ventilation. Nevertheless, trying to decide when to extubate patients from mechanical ventilation can be challenging for the clinician and has been reported by some to be more art than science (Peouelas et al., 2011).

     As regard simplified acute physiologic score II (SAPSII) in our study the mean of SAPSII in patients with spontaneous breathing trial success and in patients with Spontaneous breathing trial failure showed a statistical significant difference. On the other hand the mean of SAPSII in patients with post extubation distress and in patients with post extubation success it showed a statistical significant difference. In contrary to our result, Soummer et al. (2012) and Sliva et al. (2017) found that SAPS II has no statistical significance in predicting weaning failure.

     Despite elevated SAPS II at admission, ICU-mortality rate was low (12%) in agreement with Soummer et al. (2012) with mortality (8%) and Sliva et al. (2017) with mortality (10%). The fact that the SAPS II score on admission was not associated with death may be explained by the significant proportion of patients that died before any weaning attempt was made. Thus, the power of the SAPS II score to predict death as associated with the weaning categories may have been weakened by the loss of the most severely ill patients.

     The mean length of stay in ICU was significantly prolonged in patient with post extubation distress. This coincided with a recent retrospective study of Chung et al. (2020) who established a model for predicting extubation based on the predictive factors of successful extubation. This result could be attributed to the more severity and more associated comorbidities of those patients with prolonged ICU stay.

     As regard the mean duration of MV, patients with post extubation distress and patients with post extubation success showed a statistically significant difference. This finding matches with those of Abdel Rahman et al. (2020) who showed that prolonged mechanical ventilation of critically ill patients is associated with higher rates of mortality and morbidity.

     These results show that the means of SAPS II, length of ICU stay and duration of MV have great effect on weaning process and considered critical causes of post extubation distress.

     Among patients who successfully pass SBT, the derecruitment was greater in patients who developed postextubation distress than in those who were definitively weaned. Ferré et al. (2019) concluded a similar observation in their study which included 42 patients and aimed at detecting weaning-induced pulmonary edema (WIPO) using lung ultrasound.

     In patients who successfully passed the SBT, a lung ultrasound score ≤10 at the end of the SBT was highly predictive of postextubation success with a statistically significant difference. On the other hand, lung ultrasound score ≥18 at the end of the SBT was highly predictive of postextubation distress with a statistically significant difference. Similarly, Soummer et al. (2012) reported that LUS score less than 13 was associated with extubation success, while LUS score more than 17 was associated with extubation failure (EF) in ventilated adults.

     On MV, before the SBT, we found significant differences in E/A ratio in patients with spontaneous breathing trial success and in patients with spontaneous breathing trial failure with a statistical significant. There was in agreement with Ait-Oufella et al. (2012) in the study of patients undergoing a spontaneous breathing trial on a T-tube to assess the cardiac consequences of successful respiratory weaning using the variations of circulating B-type and atrial natriuretic peptides (BNP, ANP) and Doppler mitral flow.

CONCLUSION

     The use of transthoracic ultrasound aimed at assessing lung aeration changes during SBT, a new, easy-to-perform, and noninvasive measurement, may contribute to reducing the occurrence rate of postextubation distress, a clinical condition associated with increased morbidity and mortality. Assessment of Lung aeration and LV diastolic function before attempting a weaning process could be useful in the detection of patients likely to fail weaning.

REFERENCES

  1. Abdel Rahman, Dalia A, Saber S, and El-Maghraby A (2020): Diaphragm and lung ultrasound indices in prediction of outcome of weaning from mechanical ventilation in pediatric intensive care unit. The Indian Journal of Pediatrics, 87: 413-420.
  2. Ait-Oufella H, Tharaux PL, Baudel JL, Vandermeersch S, Meyer P and Tonnellier M (2012): Variation in natriuretic peptides and mitral flow indexes during successful ventilatory weaning: a preliminary study. Intensive Care Med., 33:1183-1186.
  3. Boles JM, Bion J, Connors A, Herridge M, Marsh B, Melot C, Pearl R and Silverman H. (2011): Weaning from mechanical ventilation. Eur Respir J., 29:1033–56
  4. Chung, Chan W, Sheu CC, Hung JY, Hsu TJ, Yang SH, and Tsai JR (2020): Novel mechanical ventilator weaning predictive model. The Kaohsiung journal of medical sciences, 36: 841-849.
  5. Ferre, Alexis, Guillot M, Lichtenstein D, Meziere G, Richard C, Teboul JL, and Monnet. X (2019): Lung ultrasound allows the diagnosis of weaning-induced pulmonary oedema. Intensive care medicine, 45: 601-608.
  6. Girard TD, Alhazzani W and Kress JP (2017): Liberation from Mechanical Ventilation in Critically Ill Adults. Rehabilitation Protocols, Ventilator Liberation Protocols, and Cuff Leak Tests. Am J Respir Critical Care Medicine, 195:120-129.
  7. Heunks, L. M., and Van Der Hoeven, J. G. (2010): Clinical review: The ABC of weaning failure-a structured approach. Critical Care, 14(6): 1-9.
  8. Nemer SN, Barbas CS and Caldeira JB (2011): A new integrative weaning index of discontinuation from mechanical ventilation. Critical Care, 13: 152-157.
  9. Penuelas, Oscar, Frutos-Vivar F, Fernandez C, Anzueto A, Epstein SK, Apezteguia C, and Gonzalez M (2011): Characteristics and outcomes of ventilated patients according to time to liberation from mechanical ventilation. American journal of respiratory and critical care medicine, 184(4): 430-437.
  10. Schmidt, Gregory A, Timothy D, Girard, Kress JP, Morris PE, Ouellette DR, Alhazzani W, and Burns SM (2017): Official executive summary of an American Thoracic Society/American College of Chest Physicians clinical practice guideline: liberation from mechanical ventilation in critically ill adults. American journal of respiratory and critical care medicine, 195: 115-119.
  11. Silva S, Aissa D, Cocquet P, Hoarau L, Ruiz J, Ferre F, Rousset D, Mora M, Mari A, Fourcade O, Riu B, Jaber S, and Bataille B. (2017): Combined Thoracic Ultrasound Assessment during a Successful Weaning Trial Predicts Postextubation Distress. Anesthesiology, 127(4): 666–674.
  12. Soummer, Alexis, Perbet S, Brisson H, Arbelot C, Constantin JM, Lu Q, and Rouby JJ (2012): Ultrasound assessment of lung aeration loss during a successful weaning trial predicts postextubation distress. Critical care medicine, 40(7): 2064-2072.


الاستخدام التکاملى للموجات فوق الصوتية السريرية على الرئة و تخطيط صدى القلب کمتنبئات مساعدة لعملية الفطام الناجحة

أحمد محمد عبدالله محمد بشير، إسماعيل عبدالمنعم عطية، محمود السعيد أحمد، ابراهيم فرج الله سعيد

قسم الأمراض الصدرية و قسم القلب والأوعية الدموية، کلية الطب، جامعة الأزهر، القاهرة

E-mail: ahmedbeshir.6@azhar.edu.eg

خلفية البحث: يمکن أن تکون الموجات فوق الصوتية للرئة السريرية وتخطيط صدى القلب مؤشرا على ضائقة ما بعد ازالة الانبوبة الحنجرية عن طريق الکشف عن عيب شديد في تهوية الرئة على الفور قبل الفطام عن طريق إثبات عدم تجنيد الرئة بشکل کبير أثناء تجربة التنفس التلقائي.

الهدف من البحث: تقييم فعالية الموجات فوق الصوتية للرئة وتخطيط صدى القلب عبر الصدر في التنبؤ بالفطام الناجح للمرضى الذين يخضعون للتهوية الميکانيکية.

المرضى و طرق البحث: أجريت هذه الدراسة على 50 مريضاً خضعوا للتهوية الميکانيکية بوحدة الرعاية العامة و وحدة العناية المرکزة التنفسية خلال الفترة من أغسطس 2019 إلى يناير 2021 في مستشفى باب الشعرية الجامعى. وقد تم عمل الموجات فوق الصوتية للرئة وتخطيط صدى القلب قبل وفي نهاية تجربة التنفس التلقائي لمدة 60 دقيقة و 4 ساعات بعد نزع الأنبوبة الحنجرية لقياس تهوية الرئة، و تم حساب درجة الموجات فوق الصوتية للرئة.

نتائج البحث: حقق 45 مريضًا نجاحًا في تجربة التنفس التلقائي (90٪) فيما عانى 5 مرضى من فشل تجربة التنفس التلقائي (10٪)، ومن هؤلاء المرضى الذين نجحوا في تجربة التنفس التلقائي کان هناک 16 مريضًا (35.56٪) يعانون من ضائقة ما بعد نزع الأنبوب، بينما حقق 29 مريضًا (64.44٪) نجاحًا بعد نزع الأنبوب. وفي المرضى الذين اجتازوا اختبار تجربة التنفس التلقائي بنجاح، کانت نتيجة الموجات فوق الصوتية للرئة ≤10 في نهاية اختبار تجربة التنفس التلقائي متنبئًا بدرجة عالية بنجاح العملية مع وجود فرق إحصائى (p <0.001). من ناحية أخرى، کانت درجة الموجات فوق الصوتية للرئة ≥18 في نهاية تجربة التنفس التلقائي تنبؤية للغاية لضائقة ما بعد الأنبوب مع وجود فرق إحصائيًا (p<0.001). وقد وجدنا فروقًا ذات دلالة إحصائية في نسبة E/A 1.08±0.2 في المرضى الذين نجحوا في تجربة التنفس التلقائي و 1.6 ±0.1 في المرضى الذين يعانون من فشل تجربة التنفس التلقائي مع قيمة ذات دلالة إحصائية (P<0.001).

الاستنتاج: قد تتنبئ الموجات فوق الصوتية للرئة وتخطيط صدى القلب عبر الصدر أثناء تجربة التنفس التلقائي لحدوث ضائقة ما بعد ازالة الأنبوبة الحنجرية.

الکلمات الدالة: الموجات فوق الصوتية للرئة، قصور القلب الإنبساطى، التهوية الميکانيکية، الفطام.

  1. REFERENCES

    1. Abdel Rahman, Dalia A, Saber S, and El-Maghraby A (2020): Diaphragm and lung ultrasound indices in prediction of outcome of weaning from mechanical ventilation in pediatric intensive care unit. The Indian Journal of Pediatrics, 87: 413-420.
    2. Ait-Oufella H, Tharaux PL, Baudel JL, Vandermeersch S, Meyer P and Tonnellier M (2012): Variation in natriuretic peptides and mitral flow indexes during successful ventilatory weaning: a preliminary study. Intensive Care Med., 33:1183-1186.
    3. Boles JM, Bion J, Connors A, Herridge M, Marsh B, Melot C, Pearl R and Silverman H. (2011): Weaning from mechanical ventilation. Eur Respir J., 29:1033–56
    4. Chung, Chan W, Sheu CC, Hung JY, Hsu TJ, Yang SH, and Tsai JR (2020): Novel mechanical ventilator weaning predictive model. The Kaohsiung journal of medical sciences, 36: 841-849.
    5. Ferre, Alexis, Guillot M, Lichtenstein D, Meziere G, Richard C, Teboul JL, and Monnet. X (2019): Lung ultrasound allows the diagnosis of weaning-induced pulmonary oedema. Intensive care medicine, 45: 601-608.
    6. Girard TD, Alhazzani W and Kress JP (2017): Liberation from Mechanical Ventilation in Critically Ill Adults. Rehabilitation Protocols, Ventilator Liberation Protocols, and Cuff Leak Tests. Am J Respir Critical Care Medicine, 195:120-129.
    7. Heunks, L. M., and Van Der Hoeven, J. G. (2010): Clinical review: The ABC of weaning failure-a structured approach. Critical Care, 14(6): 1-9.
    8. Nemer SN, Barbas CS and Caldeira JB (2011): A new integrative weaning index of discontinuation from mechanical ventilation. Critical Care, 13: 152-157.
    9. Penuelas, Oscar, Frutos-Vivar F, Fernandez C, Anzueto A, Epstein SK, Apezteguia C, and Gonzalez M (2011): Characteristics and outcomes of ventilated patients according to time to liberation from mechanical ventilation. American journal of respiratory and critical care medicine, 184(4): 430-437.
    10. Schmidt, Gregory A, Timothy D, Girard, Kress JP, Morris PE, Ouellette DR, Alhazzani W, and Burns SM (2017): Official executive summary of an American Thoracic Society/American College of Chest Physicians clinical practice guideline: liberation from mechanical ventilation in critically ill adults. American journal of respiratory and critical care medicine, 195: 115-119.
    11. Silva S, Aissa D, Cocquet P, Hoarau L, Ruiz J, Ferre F, Rousset D, Mora M, Mari A, Fourcade O, Riu B, Jaber S, and Bataille B. (2017): Combined Thoracic Ultrasound Assessment during a Successful Weaning Trial Predicts Postextubation Distress. Anesthesiology, 127(4): 666–674.
    12. Soummer, Alexis, Perbet S, Brisson H, Arbelot C, Constantin JM, Lu Q, and Rouby JJ (2012): Ultrasound assessment of lung aeration loss during a successful weaning trial predicts postextubation distress. Critical care medicine, 40(7): 2064-2072.