Emergency anaesthetic management of extensive thoracic trauma

Emergency Anaesthetic Management of Extensive

Thoracic TraumaHOSAM M ATEF;MD

Non-cardiac: which includes 1. Chest wall. 2. Pleural space. 3. Lung parenchymal contusion. 4. Tracheobronchial. 5. Diaphragmatic.

. Cardiac – which includes 1. Tamponade. 2. Coronary arteries. 3. Cardiac chambers. 4. Great vessels.

1.Chest wall: Chest wall injury -- a single rib

fracture to multiple rib fractures ---flail chest.

Fractured ribs---severe pain-- limiting the

respiratory movements leading to

hypoventilation--deleterious in pre-existing

COPD.

X-ray chest is required to rule out atelectasis or

pneumothorax.

Treatment: Surgical fixation or even strapping is

rarely required-- lead to atelectasis.

Ventilation can be improved by pain relief with

Analgesics

Intercostal nerve blocks, interpleural catheters,

epidural narcotics and PCA.

In case of persistent hypoxemia 5 cm CPAP via

mask may be required.

Surgical repair may necessitate intubation ,G.A.

and mechanical ventilation.

Sternal fracture with “Steering Wheel

Syndrome” now has been replaced by “Seat Belt

Syndrome” in motor vehicle accidents.

Steering wheel impact on sternum causes rapid

deceleration leading to deeper thoracic structure

injuries

A blunt chest injury may cause acute myocardial infarct

ion-like signs and symptoms

contusion of the

anterior epicardium

myocardium, compression of the heart between

sternum and vertebral column

An abrupt increased in intrathoracic pressure

potentially rupturing cardiac structures—

e.g., ventricular septum, chordae tendinieae

Steering Wheel Syndrome

2.Pleural space: Athoracic injury can give

rise to

Pneumothorax (PNT )

Tension PNT (TNT)

Simple open PNT

Haemothorax

PNT:An opening in the chest wall allows

atmospheric air to enter the pleural space

permitting the interpleural pressure to equalize

atmosphere pressure producing PNT and

pressure collapse of the lung.

A sort of ‘sucking wound’ i.e. air entering

pleural space during inspiration and exiting

during expiration

Pneumothorax

The air may also enter pleural space from inside from

tracheobronchial or lung parenchymal injury.

TNT occurs--air enters the pleural space during

inspiration -- cannot escape during expiration.

TNT compresses ipsilateral lung directly and opposite

lung by mediastinal shift.

Increase in pleural pressure decreases venous return

and COP.

Cardinal signs of TNT are

Rapid deterioration of vital signs

Decreased pulmonary compliance

Decreased or no breath sounds on affected sides

Tracheal deviation towards normal side

Occasionally, the air leak may also cause

pneumomediastinum and pneumopericardium.

Diagnosis: PNT less than 20% is not detectable

Clinically; PNT more than 20% causes chest

pain that increases on breathing.

PNT more than 40% may cause cyanosis and

tracheal deviation.

Clinical findings with rib fracture are

suggestive and CXR in expiration confirms it.

Treatment:

A simple open PNT--- chest tube drainage (ICD)

Small wounds --sealed by dressing

TNT suspected ---- immediate decompression by insertion of a

14G needle in the second intercostal space (ICS) in

midclavicular line (MCL) followed by ICD.

If patient --transported by air even a minor PNT should be

drained . i.e. air volume increases with decreasing pressure at

heights.

GA is indicated --debridement and primary closure.

ICD tube is inserted under local anaesthesia.

Anaesthesiologist must be very cautious considering

the possibilities of converting a small, untreated

simple PNT into a large TNT during induction and

IPPV.

Avoid nitrous oxide.

Monitor chest tube for continued function.

Specific anaesthetic considerations

Only about 400ml or more blood in pleural space can be detected in

upright CXR.

One side pleural space can easily accommodate 30-40% (>1.5L) of

victims’ blood.

The consequences are-

Hypotension

Compression of ipsilateral lung

Mediastinal shift followed by

Compression of contralateral lung

Ventilatory impairment

Haemothorax

Tube thoracostomy in 6th intercostal space in midaxillary

line.

If the source of bleeding is pulmonary vessel (low

perfusion pressure) only tube drainage is enough

bleeding from systemic vessel if 300 ml.hr-1 or more after

initial drainage will require emergency thoracotomy.

Sometimes a chest tube may release a tamponade --

massive haemorrhage.

Treatment

A fast transfusion with the help of pump may be

required.

Acute respiratory failure prior to surgery ---intubation

and PPV.

Double lumen tube (DLT) may be considered if

there is : Large air leak from chest tube

(tracheobronchial injury)

Hemoptysis or a significant amount of blood in airways


Pulmonary contusion--both penetrating--rapid

deceleration conditions.

Rib fractures--50% of such cases.

Initial CXR is not helpful and CT Scan is required to

know the extent.

Progressive decrease of pulmonary compliance and

PaO2 and increase in alveolar edema.

PaO2/FiO2 < 250 is the best indicator of poor outcome.

3.Pulmonary contusions

edema phase-- treated with application of PEEP,

diuretics and controlled fluid administration.

Colloid versus crystalloid infusion is not an important

issue as the area has to become edematous due to

deranged pulmonary characteristics.

Pulmonary laceration is infrequent with blunt chest

trauma but blunt shearing or the ends of the broken ribs

can cause it.

TBD should be suspected with penetrating

or blunt injury to the neck or chest.

Subcutaneous or mediastinal emphysema

Hemoptysis, PNT, bronchopleural fistulas

(BPF)

Persistent air leak after tube insertion are

the definite signs of TBD.

4.Tracheobronchial disruption (TBD)

A knife laceration to lung may transect

many bronchioles behaving like BPFs.

Flexible bronchoscopy should be performed

to assess the level of disruption

distal tears with minimal air leak or major bronchus

tear involving less than one third of circumference

_______ treated nonsurgically.

Small to moderate high tracheal tear --ETT with cuff

reaching distal to tear.

Tracheostomy is indicated in high tracheolaryngeal

disruptions.

Majority of TBD require surgery.

Treatment

Intubation is done depending upon

in awake or anaesthetized, relaxed or spontaneously ventilated

patient

using a single lumen tube (SLT) or double lumen tube (DLT)

over a fiberscope to reach distal to tear and avoiding further

tear by blind advancement of ETT.

DLT should be used when separation of lung is life saving and

PPV of the affected lung may convert a simple mucosal tear to

a major BPF , injuries at or below carina.


In case of SLT:

Maintain spontaneous ventilation during induction, intubation and

maintenance of anaesthesia.

If required, a gentle PPV can be given when chest is opened.

As an alternative to ETT, a small catheter can be passed beyond the

injury for High Frequency Ventilation and High Flow Apnoeic

Ventilation.

Sterile ETTs of different sizes should be kept ready for intraoperative

bronchial placement from within during airway repair.

Blunt forces--a sudden rise in intraluminal pressure or

esophagus may be crushed between trachea and vertebral

bodies but more common cause is penetrating trauma.

Injury to esophagus from outside or within is not immediately

life threatening

Untreated and unrecognized esophageal injury has an

extremely high mortality due to mediastinitis, empyema and

sepsis.

Repair within 24 hrs remarkably reduces mortality.

5.Esophageal injury

Diagnosis:

Clinically chest pain, dysphagia, hematemesis, emphysema

and fever.

Oesophagography ; Oesophagoscopy is not always necessary.

Treatment:

Surgery--a minor primary repair to resection of oesophagus .

Tears of upper and middle thirds are repaired from right and

lower one third from left thoracotomies.

Respiratory hemodynamic and GI

considerations.

Use of DLT and one lung ventilation

facilitate surgery.

No esophageal instrumentation -- gently

guiding a nasogastric tube beyond repair at

the end of operation by surgeon.

Special anesthetic considerations

Blunt forces or gunshots from chest or

abdomen can disrupt diaphragm.

Abdominal viscera may be pushed up to the

chest causing respiratory embarrassment.

If the injury is to be approached by

thoracotomy, the surgical exposure -- DLT

6.Diaphragmatic injury

Blunt trauma may cause cardiac contusion or aortic

disruption at isthmus with fractured sternum.

Cardiac arrhythmias and ST changes on ECG may

indicate cardiac contusions but rise in troponin I is

more specific.

Penetrating cardiac injuries –gunshots or stab

wounds to neck, precordium or upper left abdomen.

7.Cardiovascular injuries

Gunshot wounds are more devastating, can

injure one or more cardiac chambers .

Right ventricle with its anterior placement is

more prone to injury.

Several serious effects may result from

penetrating cardiac injury but the commonest

one is cardiac tamponade

Pericardial space normally contains 60 ml of serous Fluid

A relatively non-stretchable structure if filled with 100 –

200ml of blood may limit diastolic expansion of the heart.

Gradually if allowed it can accommodate up to 2 L of blood

severely affecting the cardiac output.

Diagnosis: It can be diagnosed by

Site of wound

Beck’s triad of – distended neck veins, hypotension Muffled

heart sounds

Cardiac tamponade

Kussmaul’s sign (paradoxic filling of neck veins on

inspiration).

Pulses paradoxus.

ECG – Pulsus alternans.

Shock and raised CVP.

Treatment: The definitive treatment is surgery but

pericardiocentesis may be done first to relieve

rapidly increasing tapenade.

Cardiac tamponade

In a moribund and unconscious patient

pericardiocentesis is done only under local

anaesthesia

Oxygen and/or PPV.

Administration of GA with a significant

tamponade is potentially lethal.

Special anaesthetic considerations

In a conscious, restless, non-cooperative patient

GA is required even for pericardiocentesis

followed by surgical correction.

Maintain CVP > 15cm H2O, avoid peripheral

vasodilatation, myocardial depression and

arrhythmias.


Ketamine, vecuronium, high FiO2 are the

choices.

If patient deteriorates before tamponade is

relieved, isoproterenol infusion is started

Conservative anaesthetic management must

be followed even after tamponade is relieved

but narcotics e.g. fentanyl can be added.


Coronary artery injury: Being anterior usually left coronary

artery is involved. It may lead to hemorrhage, infarction or

tamponade. From an-aesthetic view point these patients should

be managed similarly to the patients with acute MI.

Cardiac chamber injury: Immediate surgery for

repair of hole is required.

General anesthetic considerations as discussed earlier with

special management of hemorrhagic shock --Great vessels’

injury:

Aort ic injury – It leads to devastating haemorrhage and only

15% reaches hospital alive.

The signs are:-

Mediastinal widening

Haemothorax

Tracheal deviation

Caval injuries -

Most difficult to deal surgically

Extremely high mortality

Depending upon the condition , the general

anaesthetic management plan is employed.

Goal is to maintain a rapid fluid replacement.

Cardiopulmonary bypass is rarely required but

always better to keep the facility available.


Extensive chest trauma is always life threatening

due to respiratory and hemorrhage problems.

The anesthesiologist must be able to initiate

primary resuscitation, diagnose life threatening

chest injuries and plan the anesthetic

management of any surgical intervention if

required.

Non-penetrating usually caused by blunt

trauma, deceleration or blast forces.

Penetrating injuries caused by gunshots,

stabs, arrows

Most of the deaths in these cases are due to

asphyxia and hemorrhage and are

avoidable.

Extensive thoracic injuries are always life

threatening and they should be managed

aggressively

The amount of destruction of the organ is

proportional to the shearing forces

Tissue destruction following a gun shot depends

upon the kinetic energy (KE) transmitted to the

tissues

Assessment and resuscitation: patient

should be scaled on injury severity score

(ISS). Any ISS more than 25 is severe .

physical examination (involving one side of

chest or transmediastinal gun shot wound)

Diagnostic studies

Life-saving surgery

Principles of management

A. Establish airway and ventilation.

B. Maintain circulation in terms of cardiac

function and intravascular volume.

C. Check neurological status (GCS)

D. Determine the mechanism of injury.

Primary survey

Airway: Intubate an unconscious, shocked

and hypoxic patient immediately.

If there is neck injury or bleeding, do

cricothyroidotomy or tracheotomy.

Patient with collapsed neck veins is

assumed to be in hypovolemic shock.

C. Neurologic status: Glasgow Coma Scale is

only important when there are associated

head and neck injuries or air in cerebral

circulation.

D. Mechanism: It may be penetrating, blunt

with high velocity, low velocity or crushing

factor.

Patient with distended neck veins but

hypotensive may

have the possibilities of:

Myocardial contusion or MI

Tension pneumothorax (TNT)

Air embolism

Pericardial tamponade

penetrating thoracic injury (PTI) who has no

obvious head injury but has focal neurological

signs may have air bubbles occluding the

cerebral circulation.

Fundoscopy showing air bubbles in retinal

vessels may confirm it.

Intubated patient on IPPV who develops sudden

cardiovascular collapse ----- either TNT or

coronary air embolism.

The definitive treatment is emergency

thoracotomy in ‘steep head down ’position.

Pericardial tamponade is a frequent---

pericardiocentesis can be done as life saving

measure but immediate thoracotomy is the

definitive treatment.

If patient becomes haemodynamically

stable after initial resuscitation then a

secondary survey for diagnostic studies and

surgical priorities should be followed

Secondary Survey

Pre-operative assessment: Monitoring

Induction:

Unconscious moribund patient should be intubated

and surgery is performed without anesthesia.

When vital signs and consciousness improve,

anesthetics can be added to start with lower doses.

Ketamine is the drug of choice.

Avoid thiopentone and like drugs including

inhalational agents in shocked patients.

They should be used only after correction of

BP with adequate fluid replacement.

Excessive crystalloids may lead to

hypoproteinemia and further

pharmacokinetic disturbances

after adequate hydration colloids should be added

as plasma expanders.

Consider full stomach and delayed gastric

emptying.

Pre-curarization and rapid sequence induction and

intubation is a must with succinylcholine

Apply cricoid pressure from intubation to cuff

inflation

In a stable patient it is left to the discretion of the

anaesthesiologist.

O2/air mixtures, muscle relaxants, narcotics,

amnestics and minimal inhalational agents can be

used.

Avoid N2O .

Intraoperatively watch for the development of any

other unwanted new sign e.g. TNT or tamponade.

Maintenance

Non-responding fluid replacement therapy

from upper veins may indicate towards

possibility of tear in SVC

Muscle relaxant :

Avoid succinylcholine in massive trauma

____hyperkalemia

Vecuronium or rocuronium are cardiovascularly

stable and relaxants of choice.

Avoid atracurium due to rapidly changing

acidbase status and due to its hypotensive

effect.

Observe for drug interactions e.g. antibiotic

vs relaxants.

Hypothermia is hazardous.

Awareness is a major but almost

unavoidable hazard .

Respiratory support Fluid replacement Hypothermia

Post operative care

Emergency anaesthetic management of extensive thoracic trauma

Health & Medicine

Transcript of Emergency anaesthetic management of extensive thoracic trauma