Sharven Taghavi MD, MPH, Lucas Ferrer MD, Senthil Jayarajan
MD, Halley Vora BS, Conor McKee BS, Rich Milner BS, John
Gaughan PhD, Jay Dujon MD, Lars Sjoholm MD, Abhijit Pathak
MD, Joseph Rappold MD, Thomas Santora MD, Steven Houser
PhD, Amy Goldberg MD
Temple University Hospital
Department of Surgery
October 24, 2013


Most penetrating trauma patients in severe hemorrhagic shock receive positive pressure ventilation (PPV) upon transport to definitive care

Intubation and manual ventilation

Bag-valve mask (BVM) ventilation

Intubation clearly shown to have detrimental effects for penetrating trauma patients in urban locations


Whether BVM ventilation improves outcomes in severe shock-state has not been studied

Previous study showing detrimental effects of BVM 1

New ACLS guidelines prioritizing uninterrupted chest compressions over advanced airway

Backed by animal and clinical studies

Consideration should be given to immediate transportation without airway intervention
1 - Taghavi et al. Examining Prehospital Intubation for Penetrating Trauma in a Swine Hemorrhagic Shock Model.
Journal of Trauma. 2012. 74 (5): 1246-51.


Test the idea of “permissive hypoventilation” – where manual breaths are not given and 100% oxygen is administered passively via facemask

In severe low-flow states, PPV would have harmful physiological effects and that “permissive hypoventilation” would result in better outcomes


Yorkshire swine weighing 30.0 kg

Started on a propofol drip

Three groups of animals
1)
2)
3)
Intubation and manual ventilation (n=6)
BVM ventilation with ambu-bag (n=7)
Permissive hypoventilation with face mask (n=6)


Placement of Swan-Ganz catheter through central venous introducer

Femoral arterial line placed

14-gauge catheter with stopcock in carotid artery for exsanguination

Baseline arterial blood gas (ABG), laboratory values, and hemodynamic parameters


Stopcock opened and animal was exsanguinated

Hemodynamic and laboratory values measured at 10 minute intervals

Primary outcome was time until death

Secondary Outcomes

Hemodynamic Parameters – cardiac index, CVP


Metabolic values – pH, lactic acid, O
2
End-organ damage – creatinine

150
100
50
0
0 20 40
Minutes
60 80
Intubated
Bag-Valve Mask
Facemask
Mean Survival:
Intubated: 51.1 mins
Bag-Valve Mask: 48.5 mins
Facemask: 50.0 mins p = 0.84

Body Temperature
38.5
38.0
37.5
37.0
36.5
36.0
35.5
35.0
34.5
34.0
33.5
0 10 20 30
Time (minutes)
40
✖ p<0.001 when compared to intubated and BVM group at all time points
50
Intubated
Bag-valve
Facemask

Systolic Blood Pressure
160
140
120
100
80
60
40
20
0
0 10 20 30
Time (minutes)
40
✖ p<0.001 when compared to intubated group at all time points
50
Intubated
Bag-valve
Facemask

Central Venous Pressure
12
10
8
6
4
2
0
0 10 20 30
Time (minutes)
40
✖ p<0.001 when compared to intubated group at 10 minutes
50
Intubated
Bag-valve
Facemask

Cardiac Output
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0 10 20 30
Time (minutes)
40
✖ p<0.001 when compared to intubated and BVM group at all time points
50
Intubated
Bag-valve
Facemask

pH
7.80
7.60
7.40
7.20
7.00
6.80
6.60
0 10 20 30
Time (minutes)
40
✖ p<0.001 when compared to intubated and BVM group at all time points
50
Intubated
Bag-valve
Facemask

Carbon Dioxide
160
140
120
100
80
60
40
20
0
0 10 20 30
Time (minutes)
40
✖ p<0.001 when compared to intubated and BVM at all time points
50
Intubated
Bag-valve
Facemask

PaO
2
Level
600
500
400
300
200
100
0
0 10 20 30
Time (minutes)
40 50
Intubated
Bag-valve
Facemask

Bicarbonate Levels
40
35
30
25
20
15
10
5
0
0 10 20 30
Time (minutes)
40 50
✖ p<0.001 when compared to intubated and BVM group at all time points
Intubated
Bag-valve
Facemask

Base Deficit
-8
-10
-12
-14
-2
-4
-6
6
4
2
0
0 10 20 30
Time (minutes)
40 50
Intubated
Bag-valve
Facemask

Lactic Acid
14
12
10
8
6
4
2
0
0 10 20
Time (minutes)
30
✖ p<0.001 when compared to intubated at all time points
★ p<0.05 when compared to BVM at 30 and 50 minutes
40 50
Intubated
Bag-valve
Facemask

Creatinine Levels
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
0 10 20
Time (minutes)
30
✖ p<0.05 when compared to BVM at all time points
★ p<0.05 when compared to intubated at 40 minutes
40 50
Intubated
Bag-valve
Facemask

Creatinine Levels by Weight
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
0 10 20 30
Time (minutes)
40
✖ p<0.05 when compared to intubated and BVM at all time points
50
Intubated
Bag-valve
Facemask


Positive pressure ventilation, whether by endotracheal tube or BVM, does not result in a survival advantage

Worse thermoregulation

Hemodynamic compromise

Worse perfusion vital organs

Higher lactic acid levels

Worse increase in creatinine



“Permissive Hypoventilation” leads to decreased
CO
2 elimination
More profound respiratory acidosis

Evidence of protective effects of hypercapnia

Profound alkalosis with positive pressure ventilation


Consideration should be given to immediate transportation without airway intervention

Similar to change with ACLS guidelines, prospective, randomized trials are needed to determine best mode of ventilation for penetrating trauma patients in urban locations


Small sample size

Use of propofol – hemodynamic depression

Ideal for large animal studies

Examined only physiological changes

Inflammatory markers