Weaning from postoperative mechanical ventilation is a common activity in surgical intensive care units. This presentation provides an example of key activities and measures used during the process for clinical decision making.

1. Clinical Decision Support System
(CDSS) Sample Scenario
© 2011 J. Zaleski

2. State of Acute Care
• American College of Physicians estimates 500,000 deaths
annually in ICUs (U.S.)
• Key Drivers
 Patient safety
 Longitudinal EMR deployment
 Increase efficiency
 Staffing shortages
 Increasing numbers of CC beds
• Larger amounts of hemodynamic, respiratory, I&O
information will be automated
 Motivates enterprise integration
 Reduces charting workload
 Improves completeness, accuracy

3. Types of Data Most Used in ICU Clinical
Decision Making
Data Type Value
Monitors and monitoring 13%
Observations 21%
Laboratory 33%
Drugs, I&O, IV 22%
Blood gas 9%
Other 2%
Source: E.H. Shortliffe and J.J. Cimino, Biomedical Informatics Computer Applications in Health Care and Biomedicine, page 605.

4. CDSS Sample Case:
When to discontinue post-operative mechanical ventilation
• Discontinuation from mechanical ventilation a key activity in
surgical intensive care unit (SICU), yet, no guarantees as to
outcomes:
– When to begin spontaneous breathing trials?
– When is patient viable to be extubated?
• Discontinue as quickly as possible
– Longer time on ventilator higher likelihood of adverse events
• Ventilator acquired pneumonia
• Respiratory distress
– Can exacerbate co-morbidities
– Cost
• Candidate patients: Coronary artery bypass grafting (CABG)
– Fairly common procedure
– Technologically-dependent patients

5. Devices Supporting Acute Care
Environment
Anesthesia
Intra-
Aortic
Balloon
Monitors
Mechanical Pumps
Ventilation
Highly Technologically-Dependent Patients
Bed
Infusion

6. Source: J. Zaleski
Case Study: CABG Patient
Restart Determine
Patient
On Heart / Transfer Monitoring & Viability
Arrives in Induction Extubate
Bypass Off to SICU Management for
OR
Bypass Weaning

7. Source: J. Zaleski
Case Study: CABG Patient
Restart Determine
Patient
On Heart / Transfer Monitoring & Viability
Arrives in Induction Extubate
Bypass Off to SICU Management for
OR
Bypass Weaning
Time In: 7:15 Induction: Isoflurane Pt Ht: 157 cm
CABG x 3 40 CCs fentanyl (15 g/kg) BSA: 1.7 m^2
15 mg
Pancuronium
pancuronium
Time HR (bpm) ABP (s/d) O2Sat CO (L/m) T Core T blad ETCO2 RR Vt fentanyl g lopressor Notes
mg
7:15 76 121/64 98 7 0.5
7:30
7:40
83
57
117/66
93/52
99
100
4.3
Meds & Drips
7:45 66 100/55 100 300 7
8:00 61 95/57 100 Swan in place
8:05 62 101/60 100 34.3
8:10
8:25
64
86
Continuous
97/58
132/78
100
100
34.4
34.3
34.9
34.7 29
8:30 116 Monitoring
116/76 99 34.3 35.2 27
8:35 98 116/75 99 34.2 35 29
8:40 92 112/74 100 34.1 34.9 29
8:45 100 113/70 99 34.1 34.8 29
8:50 96 112/71 99 34 34.7 29
9:00 91 97/62 99 34 34.7 31
9:05 97 109/70 100 33.9 34.5 30
9:20 93 114/68 100 33.8 34.4 31
9:30 103 95/61 100 33.7 34.2 32

8. Source: J. Zaleski
Case Study: CABG Patient
Restart Determine
Patient
On Heart / Transfer Monitoring & Viability
Arrives in Induction Extubate
Bypass Off to SICU Management for
OR
Bypass Weaning
pancuronium
Time HR (bpm) ABP (s/d) O2Sat CO (L/m) T Core T blad ETCO2 RR Vt fentanyl g lopressor Notes
mg
Canula placed-
9:35 94 93/60 100 33.6 34.2 30 rt. atria;
bypassing heart
9:40 94 103/65 100 33.6 34.1 36
Core temperature reduction
9:45 94 112/67 100 33.6 34.1 36 3 mg (up)
9:50 94 113/68 100 33.6 34 33
9:55 95 103/69 100 33.6 33.9 29
Fibrillation.
10:00 99 101/68 100 33.6 33.9 28 12 0.48
Cross-Clamp
K injection
10:07
Heart stoppage 20.8
commenced
10:08 16
10:09 12
K injection
10:11 10
complete
10:15 33 32.5
10:20 32.8 32.7
Myocard temp:
10:30 32.9 33
14
10:35 33.1 33
10:45 33 33
10:50 33.3 33.4 Begin re-warm

9. Source: J. Zaleski
Case Study: CABG Patient
Restart Determine
Patient
On Heart / Transfer Monitoring & Viability
Arrives in Induction Extubate
Bypass Off to SICU Management for
OR
Bypass Weaning
pancuronium
Time HR (bpm) ABP (s/d) O2Sat CO (L/m) T Core T blad ETCO2 RR Vt fentanyl g lopressor Notes
mg
10:55 33.8 33.7 5 mg (up)
250 mics
11:00 34.9 34.9 2 mg (up)
(up)
11:05 35.4 35.3
11:10 35.9 35.4
11:15 Heart restart 36 35.5 Restart / Defib
11:16 36.2 35.9
11:17 90 79/65 36.3 36
11:20 77 107/58 100 4.18 36.2 36 24 Off Bypass
11:25 79 103/56 100 35.9 35.9 25
11:30 88 103/52 100 35.5 35.9
11:35 89 106/55 100 35.4 35.7 26
11:40 96 108/61 100 35.2 35.6 24
11:45 93 115/64 100 35.1 35.5 25
11:50 93 96/53 100 34.9 35.3 23
11:55 96 112/65 100 34.8 35.1 25
12:00 108 104/62 100 34.7 35 24
12:05 105 107/66 100 34.7 34.8 24
12:10 88 103/63 100 34.6 34.4 23 2.5 mg
12:15 87 99/60 100 34.6 34.9
12:20 88 121/73 100 34.8 24 Move to SICU

10. Source: J. Zaleski
Case Study: CABG Patient
Restart Determine
Patient
On Heart / Transfer Monitoring & Viability
Arrives in Induction Extubate
Bypass Off to SICU Management for
OR
Bypass Weaning
Time HR (bpm) ABP (s/d) O2Sat CO (L/m) T Core CVP PAP
12:40 100 99/62 99 5.4 34.8 6 23/10
13:15 99 99/59 100 4.48 35.3 7 24/14
13:45 104 115/63 100 5.18 35.7 10 26/15
14:15 101 102/54 98 5.18 36.3 9 25/12
14:40 98 108/53 100 5.2 36.6 18 31/14
14:50 105 128/62 99 5.2 36.6 20 39/16
14:55 104 128/62 100 5.2 36.7 19 35/18
15:00 101 128/63 100 5.2 36.7 16 35/17
15:25 102 110/58 100 5.2 36.7 18 28/13
15:50 103 107/57 100 5.2 37 32 28/15
16:45 100 107/59 100 5.2 37.1 13 30/15
17:00 104 98/56 98 5.2 37.2 13 40/21
17:20 103 97/56 97 5.2 37.3 13 32/18
17:40 100 98/57 98 5.2 37.3 12 29/16
17:45 102 94/54 98 5.2 37.3 12 31/18
19:05 104 97/58 97 5.2 37.3 13 30/18
20:15 106 99/59 97 5.2 37.5 11 31/16
21:15 101 101/60 98 4.8 37.6 15 33/19
22:35 Extubated: Vc 1.2 liters
NIF -25 cmH2O

11. Respiratory Rate (br/min)
10
15
20
25
30
35
40
45
0
5
OR
12:44:18
Patient
Arrives in
12:57:33
13:35:52
13:47:42
13:59:32
14:11:23
RRsp
(/min)
14:23:13
Induction
14:35:03
RRm (/min)
14:46:53
14:58:43
15:10:34
15:22:24
15:34:15
On
15:46:05
Bypass
15:57:55
16:09:45
• pH = 7.44
16:21:35
•Time: 12:45
16:33:25
16:45:16
16:57:07
Off
17:08:57
Bypass
Heart /
Restart
• PO2 = 100 mmHg
• PCO2 = 31 mmHg
17:20:47
17:32:37
17:44:27
17:56:17
18:08:07
18:19:57
18:31:48
to SICU
18:43:38
Transfer
18:55:28
19:07:18
19:19:08
19:30:59
19:42:49
19:54:39
20:06:29
• Initial blood gas obtained upon patient arrival
20:18:20
20:30:11
Monitoring &
Management
20:42:01
20:53:51
21:05:41
21:17:31
21:29:22
21:41:12
for
21:53:02
Viability
Weaning
Determine
Case Study: CABG Patient
Extubate
Source: J. Zaleski

12. Source: J. Zaleski
Case Study: CABG Patient
Restart Determine
Patient
On Heart / Transfer Monitoring & Viability
Arrives in Induction Extubate
Bypass Off to SICU Management for
OR
Bypass Weaning
• Patient initially supported by
45 mechanical ventilator on synchronous
40
RRm (/min)
intermittent mandatory ventilation
35 RRsp (SIMV) mode of 12 breaths per
Respiratory Rate (br/min)
(/min)
30 minute, tidal volume of 0.85
25 liters, PEEP of 5 cmH2O
20
• Patient spontaneous breathing is absent upon
15
arrival due to the anesthesia and paralytic drugs
10 administered during surgery
5
0
12:44:18
12:57:33
13:35:52
13:47:42
13:59:32
14:11:23
14:23:13
14:35:03
14:46:53
14:58:43
15:10:34
15:22:24
15:34:15
15:46:05
15:57:55
16:09:45
16:21:35
16:33:25
16:45:16
16:57:07
17:08:57
17:20:47
17:32:37
17:44:27
17:56:17
18:08:07
18:19:57
18:31:48
18:43:38
18:55:28
19:07:18
19:19:08
19:30:59
19:42:49
19:54:39
20:06:29
20:18:20
20:30:11
20:42:01
20:53:51
21:05:41
21:17:31
21:29:22
21:41:12
21:53:02

13. Respiratory Rate (br/min)
10
15
20
25
30
35
40
45
0
5
OR
12:44:18
Patient
Arrives in
12:57:33
13:35:52
13:47:42
13:59:32
14:11:23
RRsp
(/min)
14:23:13
Induction
14:35:03
RRm (/min)
14:46:53
14:58:43
15:10:34
15:22:24
15:34:15
On
15:46:05
Bypass
15:57:55
16:09:45
16:21:35
16:33:25
16:45:16
16:57:07
Off
17:08:57
Bypass
Heart /
Restart
17:20:47
17:32:37
17:44:27
17:56:17
18:08:07
18:19:57
18:31:48
• pH = 7.41
to SICU
•Time: 14:00
18:43:38
Transfer
18:55:28
19:07:18
19:19:08
• PO2 = 202 mmHg
• PCO2 = 29 mmHg
19:30:59
19:42:49
19:54:39
20:06:29
• Second blood gas obtained
20:18:20
20:30:11
Monitoring &
Management
20:42:01
20:53:51
21:05:41
21:17:31
21:29:22
21:41:12
for
21:53:02
Viability
Weaning
Determine
Case Study: CABG Patient
• Decision made to reduce ventilatory support
Extubate
Source: J. Zaleski

14. Respiratory Rate (br/min)
10
15
20
25
30
35
40
45
0
5
OR
12:44:18
Patient
Arrives in
12:57:33
13:35:52
13:47:42
13:59:32
14:11:23
RRsp
(/min)
14:23:13
Induction
14:35:03
RRm (/min)
14:46:53
14:58:43
15:10:34
15:22:24
15:34:15
On
15:46:05
Bypass
15:57:55
16:09:45
16:21:35
16:33:25
16:45:16
16:57:07
Off
17:08:57
Bypass
Heart /
Restart
17:20:47
17:32:37
17:44:27
17:56:17
18:08:07
18:19:57
18:31:48
to SICU
18:43:38
Transfer
18:55:28
19:07:18
19:19:08
19:30:59
19:42:49
breathing trial
19:54:39
20:06:29
20:18:20
20:30:11
Monitoring &
Management
20:42:01
20:53:51
21:05:41
21:17:31
21:29:22
• Support reduced to 8 br/min
21:41:12
• Some spontaneous breathing.
for
21:53:02
before attempting spontaneous
Viability
Weaning
Determine
Case Study: CABG Patient
Clinicians choose to evaluate and
await re-warming and third blood gas
Extubate
Source: J. Zaleski

15. Source: J. Zaleski
Case Study: CABG Patient
Restart Determine
Patient
On Heart / Transfer Monitoring & Viability
Arrives in Induction Extubate
Bypass Off to SICU Management for
OR
Bypass Weaning
45 • Third blood gas obtained
40
RRm (/min)
•Time: 16:35
35 RRsp • pH = 7.40
Respiratory Rate (br/min)
(/min)
30
• PCO2 = 37 mmHg
• PO2 = 183 mmHg
25
20
• Re-warming complete
15
• Decision made to reduce to CPAP in
10
preparation for spontaneous breathing
5
trials
0
12:44:18
12:57:33
13:35:52
13:47:42
13:59:32
14:11:23
14:23:13
14:35:03
14:46:53
14:58:43
15:10:34
15:22:24
15:34:15
15:46:05
15:57:55
16:09:45
16:21:35
16:33:25
16:45:16
16:57:07
17:08:57
17:20:47
17:32:37
17:44:27
17:56:17
18:08:07
18:19:57
18:31:48
18:43:38
18:55:28
19:07:18
19:19:08
19:30:59
19:42:49
19:54:39
20:06:29
20:18:20
20:30:11
20:42:01
20:53:51
21:05:41
21:17:31
21:29:22
21:41:12
21:53:02

16. Respiratory Rate (br/min)
10
15
20
25
30
35
40
45
0
5
OR
12:44:18
Patient
Arrives in
12:57:33
13:35:52
13:47:42
13:59:32
14:11:23
RRsp
(/min)
14:23:13
Induction
14:35:03
RRm (/min)
14:46:53
14:58:43
15:10:34
15:22:24
15:34:15
On
15:46:05
Bypass
15:57:55
16:09:45
16:21:35
16:33:25 Breathing Index normal
16:45:16
16:57:07
• Respirations, Rapid-Shallow
Off
17:08:57
Bypass
Heart /
Restart
17:20:47
17:32:37
17:44:27
17:56:17
18:08:07
18:19:57
18:31:48
to SICU
18:43:38
Transfer
18:55:28
19:07:18
19:19:08
19:30:59
19:42:49
19:54:39
20:06:29
20:18:20
20:30:11
Monitoring &
Management
20:42:01
20:53:51
21:05:41
21:17:31
21:29:22
21:41:12
for
21:53:02
Viability
Weaning
Determine
Case Study: CABG Patient
Extubate
Source: J. Zaleski

17. Key Parameters Used to Determine
Viability for Extubation
Parameter Threshold Value/Range Our Patient
Vital Capacity, Vc > 10mL/kg
Positive End-Expiratory 5 cm H2O
Pressure, PEEP
Negative Inspiratory Force, NIF -20 cm H2O
Inspired Oxygen Fraction,FiO2 < 0.6
Spontaneous Tidal Volume, Vt > 5 mL/kg
Parameters,
Spontaneous Respirations Value Thresholds,
8<Rresp< 30 Patient Values,
Pi Vpth Vpti
Blood Alkalinity/Acidity 7.32 < pH <i 7.48
Partial Pressure of Oxygen, PO2 > 80 mmHg
Partial Pressure of Carbon Dioxide, 30 mmHg < PCO2 < 50 mmHg
PCO2
Normal Body Temperature,Tcore ~37 C
Ventilation Mode CPAP

18. Key Parameters Used to Determine
Viability for Extubation
Parameter Threshold Value/Range Our Patient
Vital Capacity, Vc > 10mL/kg
Positive End-Expiratory 5 cm H2O
Pressure, PEEP
Negative Inspiratory Force, NIF -20 cm H2O
Inspired Oxygen Fraction,FiO2
P1 < 0.6
Spontaneous Tidal Volume, Vt > 5 mL/kg
P2
Spontaneous Respirations Parameters Used to 30
Key 8<Rresp< Determine Extubation Viability
P3
Blood Alkalinity/Acidity 7.32 < pH < 7.48
…
Partial Pressure of Oxygen, PO2 Clinical Decision Support Systems
> 80 mmHg
Partial Pressure of Carbon Dioxide, 30 mmHg < PCO2 < 50 mmHg
PCO2
Normal Body Temperature,Tcore <Vpt1 Vpt2 < C
~37 …
Vpti <
Action
Vpth1 Vpth2 Vpthi
Ventilation Mode CPAP

19. Respiratory Rate (br/min)
10
15
20
25
30
35
40
45
0
5
OR
12:44:18
Patient
Arrives in
12:57:33
13:35:52
13:47:42
13:59:32
14:11:23
RRsp
(/min)
14:23:13
Induction
14:35:03
RRm (/min)
14:46:53
14:58:43
15:10:34
15:22:24
15:34:15
On
15:46:05
Bypass
15:57:55
16:09:45
16:21:35
16:33:25 Breathing Index normal
16:45:16
16:57:07
• Respirations, Rapid Shallow
Off
17:08:57
Bypass
Heart /
Restart
17:20:47
17:32:37
17:44:27
17:56:17
18:08:07
18:19:57
18:31:48
to SICU
18:43:38
Transfer
18:55:28
19:07:18
19:19:08
19:30:59
19:42:49
19:54:39
20:06:29
20:18:20
20:30:11
Monitoring &
Management
20:42:01
20:53:51
21:05:41
• Vc = 1.2 liters
21:17:31
21:29:22
and in normal range
21:41:12
• NIF = -24 cmH2O
for
21:53:02
Viability
Weaning
Determine
Case Study: CABG Patient
• Vital capacity & NIF test performed
Extubate
Source: J. Zaleski

20. Respiratory Rate (br/min)
10
15
20
25
30
35
40
45
0
5
OR
12:44:18
Patient
Arrives in
12:57:33
13:35:52
13:47:42
13:59:32
14:11:23
RRsp
(/min)
14:23:13
Induction
14:35:03
RRm (/min)
14:46:53
14:58:43
15:10:34
15:22:24
15:34:15
On
15:46:05
Bypass
15:57:55
16:09:45
16:21:35
16:33:25
16:45:16
16:57:07
Off
17:08:57
Bypass
Heart /
Restart
17:20:47
17:32:37
17:44:27
17:56:17
18:08:07
18:19:57
18:31:48
to SICU
18:43:38
Transfer
18:55:28
19:07:18
19:19:08
19:30:59
19:42:49
19:54:39
20:06:29
20:18:20
20:30:11
Monitoring &
Management
20:42:01
20:53:51
21:05:41
21:17:31
could have led to earlier extubation
21:29:22
21:41:12
for
21:53:02
Updated real-time knowledge of patient data
Viability
Weaning
Determine
Case Study: CABG Patient
Extubate
Source: J. Zaleski

21. Key Parameters Used to Determine
Viability for Extubation
Data suggest attempts at Threshold Value/Range trials could begin much
Parameter spontaneous breathing Our Patient
Vital Capacity, Vc sooner than 10mL/kg occurred
> actually 1.2L (70 kg)
Positive End-Expiratory 5 cm H2O 5 cm H2O
Pressure, PEEP
Negative Inspiratory Force, NIF -20 cm H2O -24 cm H2O
Inspired Oxygen Fraction,FiO2 < 0.6 0.35
Spontaneous Tidal Volume, Vt > 5 mL/kg 0.55L (70 kg)
Spontaneous Respirations 8<Rresp< 30 ~20
Blood Alkalinity/Acidity 7.32 < pH < 7.48 7.4
Partial Pressure of Oxygen, PO2 > 80 mmHg 183 mmHg
Partial Pressure of Carbon Dioxide, 30 mmHg < PCO2 < 50 mmHg 37 mmHg
PCO2
Normal Body Temperature,Tcore ~37 C ~37 C
Ventilation Mode CPAP CPAP

22. Workflow Considerations
• Data show patient meets extubation criteria many hours
before actual extubation
– Indicates clear benefit of utilizing these data for patient care
– Simple reminders to staff can achieve great benefits for patient
• Notification of readiness to wean important for clinical
workflow, patient care management
– Is patient viable or is it too early?
– Any co-morbidities that can influence the outcome?
– All necessary staff so informed and aligned on plans?
• Notification as to life-threatening events requires up-to-
date and accurate information
– Hemodynamic instabilities/Shock
– Respiratory distress

23. THANK YOU!