A study that has been conducted to assess incidence and risk factors of postintubation cardiovascular collapse and its impact on ICU length of stay and ICU mortality

1. SEVERE CARDIOVASCULAR COLLAPSE FOLLOWING ENDOTRACHEAL
INTUBATION AND ITS ASSOCIATION WITH PROLONGED ICU LENGTH
OF STAY AND ICU MORTALITY
Thesis submitted to Department of Critical Care Medicine
Faculty of Medicine - Alexandria University
In partial fulfillment of the requirements for the degree of Master In Critical Care Medicine
Presented by
Amr Mohamed Elsharkawy
Alexandria University
Faculty of Medicine
Department of Critical Care Medicine

2. SUPERVISORS
Prof. Dr. Tamer Abdullah Helmy
Professor of Critical Care Medicine
Department of Critical Care Medicine
Faculty of Medicine
Alexandria University
Prof. Dr. Samir Mohammed Al-Awady
Associate Professor of Critical Care Medicine
Department of critical care medicine
Faculty of medicine
Alexandria University

3. The items that will be discussed in this presentation will include
the following:
(1) Introduction
(2) Aim of the work
(3) Patients and inclusion criteria
(4) Methods
(5) Results
(6) Conclusion
(7) Recommendations

4. (1) Introduction:
- Endotracheal intubation (indications – Complications)
- Pathophysiology of postintubation hypotension

5. Endotracheal intubation
Endotracheal intubation (ETI) has been a recognized maneuver in anaesthesia and intensive care
for decades. Over the years, as the procedure and equipment were refined, ETI became a routine
intervention for adults and children in a variety of fields such as: anaesthesia, emergency,
pulmonology and critical care.

6. Indications for endotracheal
intubation intubation
(1) Established respiratory failure (Type l &
Type ll) or impending respiratory failure
(2) Disturbed level of consciousness (GCS <8)
(3) Aspiration due to incompetent or
obstruction of upper airway due to trauma,
oedema or immobile vocal cords
(4) Persistent shock state or persistent severe
metabolic acidosis under specific
circumstances
(4) Intraoperative during general anaesthesia

7. Complications of endotracheal intubation
(A) Acute traumatic complications
(B) Hypoxia
(C) Vomiting and aspiration
(D) oesophageal intubation
(E) Malposition of the tube (laryngeal or
endobronchial)

8. Complications of endotracheal intubation
(F) Tension pneumothorax
(G) Elevated intracranial pressure
(H) Hypertension, tachycardia and
arrhythmia
(I) Cardiac arrest
(J) Hypotension

9. Pathophysiology of postintubation hypotension
A composite of alterations in one or more factors affecting circulatory physiology:
(1) Impaired of Gas exchange:
Due to any of the previously mentioned complications that may be associated with intubation
which may cause hypoxia and haemodynamic instability
(2) Decreased Venous return and increased Intrathoracic pressure
due to intubation and positive pressure ventilation
(3) Decreased cardiac output due to abortion of the normal compensatory
tachycardia by sedative drugs
(4) Loss of catecholamine surge after intubation
(5) Decreased PaCO2 after intubation which also reduces catecholamines
(6)Vasovagal reaction in response to laryngoscopy or insertion of ETT

10. (2) Aim of the work
The target of this study was to evaluate the incidence of severe cardiovascular
collapse after endotracheal intubation, analyze the risk factors for it and evaluate
its impact on ICU length of stay and ICU mortality

11. (3) Patients and inclusion criteria
The study was carried on 300 critically ill patients in six ICUs in AMUH
Inclusion Criteria:
Adult patients aged above 18 years old, who were intubated in AMUH
and admitted to the selected ICUs
Exclusion Criteria:
- Patients below 18 years old
- Patients who were haemodynamically unstable before ETI or those
who were intubated during cardiac arrest
- Patients who developed cardiac arrest during the intubation procedure

12. (4) Methods
- This was a prospective cohort study
Patients were
classified into
two main groups
Haemodynamically
stable after intubation
Haemodynamically
unstable after
intubtion

13. Components of the recorded data
1) Demographic data: Age and gender
2) Cause of ICU admission
3) Reason for intubation
4) Simplified Acute Physiologic Score (SAPS) II at admission
5) Past medical history
6) Social history: alcoholism and smoking
7) Method of preoxygenation
8) Number of laryngoscopic attempts for intubation
9) Minimum heart rate before and during intubation
10) Maximum heart rate before and during intubation
11) Systolic blood pressure (SBP) before and during intubation
12) Drugs used for intubation
13) Incidents occurred during intubation such as: agitation, aspiration, arrhythmias, esophageal
intubation and desaturation
14) ICU length of stay
15) ICU mortality with 28 days

14. (5) Results

15. Distribution of studied sample according to the
development of cardiovascular Collapse (CVC)

16. (1) Relation between cardiovascular collapse and
demographic data: Gender
Gender had no statistically significant relation with postintubation CVC (P = 0.883)

17. (1) Relation between cardiovascular collapse and
demographic data: Age
- The average age for all subjects was 54.69 ± 14.03 years.
- The mean value for age for those who experienced postintubation CVC was
65.85 ± 13.44 years which was significantly higher than those who did not 50.71 ±
11.96 years. (P < 0.001)
- 88.6% of collapsed patients were older than 50 years while only 55% of non-
collapsed subjects were older than 50 years. (P <0.001)

18. (2) Relation between cardiovascular collapse and
cause of ICU admission
- Sepsis was the most common cause for admission followed by trauma with percentage of
15.7% and 15.3% respectively.
- Endocrinological, toxicological and surgical causes were the least common causes of
admission.
- No statistically significant relation was identified between any cause ICU admission and the
development of CVC.

19. (3) Relation between cardiovascular
collapse and reason for intubation
There was no statistically significant relation between these causes and development of
postintubation cardiovascular collapse (P = 0.871)

20. (4) Relation between cardiovascular collapse and SAPS II score
Total
Collapse
Test of
sig.
p
No
(n=221)
Yes
(n=79)
SAPS II score at admission
Min – Max.
3.0 – 77.0 29.0 – 77.0 3.0 – 74.0
t=
5.086*
<0.001*
Mean ± SD
46.39 ± 12.95 43.87 ± 10.98 53.42 ± 15.33
Median
44.0 42.0 56.0
Postintubation cardiovascular collapse had statistically significant relation with SAPS II score

21. (5) Relation between cardiovascular collapse
and Past medical history
- The relation between six aspects of past medical history and postintubation cardiovascular collapse
has been investigated
- Neither diabetes nor liver cirrhosis had any statistically significant relation with postintubation CVC.
- Hypertension, heart failure, CKD and COPD had a statistically significant relation with postintubation
CVC as patients with these diseases were more liable to develop CVC.
Past medical history
Total
(n=300)
Collapse
χ2 p
No
(n=221)
Yes
(n=79)
No. % No. % No. %
Diabetes 112 37.3 80 36.2 32 40.5 0.461 0.497
Hypertension 144 48.0 98 44.3 46 58.2 4.494* 0.034*
COPD 45 15.0 15 6.8 30 38.0 44.396* <0.001*
Cirrhosis 30 10.0 19 8.6 11 13.9 1.835 0.176
CKD 85 28.3 52 23.5 33 41.8 9.538* 0.002*
Heart failure 74 24.7 38 17.2 36 45.6 25.216* <0.001*

22. (6) Relation between cardiovascular collapse
and Social history: alcoholism and smoking
Social history
Total
(n=300)
Collapse
χ2 p
No
(n=221)
Yes
(n=79)
No. % No. % No. %
Alcoholic
No 289 96.3 214 96.8 75 94.9
0.592
FEp=
0.488Yes 11 3.7 7 3.2 4 5.1
Smoker
No 146 48.7 106 48.0 40 50.6
0.166 0.684
Yes 154 51.3 115 52.0 39 49.4
It seems that no statistically significant relation was observed.

23. (7) Relation between cardiovascular collapse
and method of preoxygenation
The method of pre-oxygenation had a statistically significant relation with postintubation
cardiovascular collapse (CVC) as the usage of NIV for pre-oxygenation was associated with
lower incidence of CVC although BMV was associated with higher incidence (P = 0.002).

24. (8) Relation between cardiovascular collapse and
Number of laryngoscopic attempts for intubation
Characteristics of the intubation
Total
(n=300)
Collapse
χ2 P
No
(n=221)
Yes
(n=79)
No. % No. % No. %
Only one attempt
163 54.3 124 56.1 39 49.4 1.066 0.302
Two to three attempts
110 36.7 74 33.5 36 45.6 3.660 0.056
More than three (difficult)
27 9.0 23 10.4 4 5.1 2.029 0.154
The number of laryngoscopic attempts for intubation had no statistically
significant relation with CVC.

25. (9) Relation between cardiovascular collapse and
minimum heart rate before and during intubation
- A statistically significant relation has been identified between the heart rate (minimum or maximum)
before and during intubation, and postintubation cardiovascular collapse.
- The mean value for minimum heart rate before intubation was 99.08 ± 5.62 in those who experienced
postintubation CVC whereas it was 92.71 ± 11.72 for those who did not develop CVC (P < 0.001).
- The average of minimum heart rate during intubation was 93.57 ± 5.56 for collapsed patients
compared to 84.97 ± 10.04 for non-collapsed patients (P < 0.001)

26. (10) Relation between cardiovascular collapse and
maximum heart rate before and during intubation
- The mean value for maximum heart rate recorded before intubation was 121.5 ± 6.96 for
those who collapsed and 119.2 ± 10.47 for those who did not (P < 0.028).
- The average of maximum heart rate during intubation was 115.2 ± 6.33 for collapsed patients
compared to 100.9 ± 10.94 for non-collapsed patients (p < 0.001).

27. (11) Relation between cardiovascular collapse and
Systolic blood pressure before and during intubation
Systolic blood pressure
mmHg
Total
(n=300)
Collapse
t pNo
(n=221)
Yes
(n=79)
Before intubation
Min – Max. 90.0 – 200.0 90.0 – 200.0 90.0 – 130.0
14.036* <0.001*Mean ± SD 127.0 ± 24.06 134.3 ± 23.22 106.5 ± 10.89
Median 125.0 130.0 105.0
During intubation
Min – Max. 70.0 – 180.0 90.0 – 180.0 70.0 – 120.0
15.705* <0.001*Mean ± SD
118.0 ± 23.31 126.18 ± 20.69 95.13 ± 12.48
Median 115.0 125.0 90.0
A statistically significant relation has been identified between systolic blood pressure before
and during intubation, and postintubation cardiovascular collapse.

28. (12) Relation between cardiovascular collapse
and drugs used for intubation
- Propofol was the only drug that have shown a statistically significant relation with the
development of postintubation hypotension.
- 35.4% of collapsed patients have received propofol compared to 20.4% of non-collapsed
patients (P = 0.007)

29. (13) Relation between cardiovascular collapse and
incidents during intubation
Incidents during
intubation
Total
(n=300)
Collapse
χ2 p
No
(n=221)
Yes
(n=79)
No. % No. % No. %
Agitation 19 6.3 9 4.1 3 3.8 0.011 0.915
Aspiration 52 17.3 43 19.5 9 11.4 2.642 0.104
Arrhythmias 26 8.7 16 7.2 10 12.7 2.159 0.142
Esophageal
intubation
51 17.0 36 16.3 15 19.0 0.300 0.584
Desaturation 65 21.7 53 24.0 12 15.2 2.651 0.104
No statistically significant relation was detected between any of these events and
postintubation cardiovascular collapse.

30. - Finally, Both ICU length of stay and ICU
mortality within 28 days as two endpoints
were recorded.
- Both have shown a statistically
significant relation with postintubation
cardiovascular collapse.

31. (14) Relation between cardiovascular collapse and
ICU length of stay
The mean value for ICU length of stay for collapsed patients
was 15.08 ± 8.51 days whereas it was 10.97 ± 9.60 days for non-
collapsed patients (P < 0.001).

32. (15) Relation between cardiovascular collapse and
ICU mortality with 28 days
67.2% of collapsed patients have died within 28 days of intubation
while only 27.1% of non-collapsed patients have died within the same
period (P < 0.001).

33. (6) Conclusion

34. - Postintubation cardiovascular collapse is a frequent
but life-threatening complication of endotracheal
intubation and mechanical ventilation.
- A variety of risk factors have been incriminated in its
occurrence although further investigation is needed.
- Postintubation CVC is associated with poor outcome
as regards ICU morbidity and mortality.

35. (7) Recommendations

36. (1) All healthcare providers who are involved in the practice
of intubation and mechanical ventilation should be aware of
and prepared for postintubation cardiovascular collapse.
(2) Further studies need to be conducted to verify the
causal relationship between suggested risk factors and the
development of postintubation collapse.
(3) Preventative ICU bundles could be set to predict
postintubation CVC and manage the potential modifiable
risk factors that may lead to its occurrence.