|Year : 2007 | Volume
| Issue : 5 | Page : 394
Emergency Anaesthetic Management of Extensive Thoracic Trauma
MD, Professor, Dept of Anaesthesiology, M.L.N. University Medical College, AU, Allahabad., India
|Date of Acceptance||11-Aug-2007|
|Date of Web Publication||20-Mar-2010|
H C Chandola
Dept of Anaesthesiology, M.L.N. University Medical College, AU, Allahabad.
High speed vehicles, drug abuse, alcohol and easy availability of handguns are the main reasons of increasing number of trauma especially thoracic trauma. Anaesthesiologist plays an important role in the management of extensive thoracic trauma. Thoracic trauma, penetrating or blunt, may cause damage to organs suspended in thorax viz. pleura, lungs, heart, great vessels, trachea and oesophagus. It may lead to pneumothorax, cardiac tamponade or life threatening haemorrhage. With aggressive care and management of these factors, majority of patients can survive and return to normal life.
Keywords: Thoracic trauma, Penetrating, Non-penetrating, Haemorrhage, Injury severity score, Pneu-mothorax, Haemothorax, Tamponade, Double lumen endobronchial tube.
|How to cite this article:|
Chandola H C. Emergency Anaesthetic Management of Extensive Thoracic Trauma. Indian J Anaesth 2007;51:394
| Introduction|| |
Extensive thoracic injuries are always life threatening and they should be managed aggressively as an emergency.
Thoracic traumas are classified as:
- Non-penetrating usually caused by blunt trauma, deceleration or blast forces.
- Penetrating injuries caused by gunshots, stabs, arrows and high velocity splinters. The majority of chest wounds result from blunt trauma, secondary to a motor vehicle or road traffic accident. Most of the deaths in these cases are due to asphyxia and haemorrhage and are avoidable.
The extent of injuries following blunt trauma generally depends on the-
- Mass of the offending object 
- Physical characteristics of the resulting shockwave and,
- Ability of target tissues to dissipate the shockwave.
The deceleration injuries are either due to impact or momentum. The impact injury causes fracture of the ribs or sternum with little damage to underlying tissues whereas Momentum injury affects the organs suspended in the thoracic cage viz. lungs, heart, aorta. The amount of destruction of the organ is proportional to the shearing forces.
Tissue destruction following a gunshot depends upon the kinetic energy (KE) transmitted to the tissues on impact; which is the product of bullet weight (W) and velocity (V) as
KE = WV 2 /2G (W=weight, V=velocity, G=acceleration due to gravity) i.e. soft bullets that fragment after striking cause more local destruction than hard bullets whereas rifles generally cause wider area tissue destruction  .
Stab injuries on the other hand cause damage to the tissues only directly underlying the point of contact.
The management of the thoracic trauma victim should be started right from the site of occurrence and the victim should be quickly brought to a trauma center.
| Principles of management|| |
The principles of management of thoracic trauma are simultaneous i.e.
- assessment and resuscitation: patient should be scaled on injury severity score(ISS). Any ISS more than 25 is severe [Table 1] .
- physical examination (involving one side of chest or transmediastinal gunshot wound)
- diagnostic studies
- life-saving surgery
ISS is based on the abbreviated injury score (AIS) on a numerical scale from 1-6 (minor to severe injury). AIS is assigned to six body regions as shown in table to calculate ISS three top AIS numbers are squared and their sum is taken as ISS, eg:
Resuscitation has two components - the primary survey with initial resuscitation followed by secondary survey if patient improves.
1. Primary survey: The aim of primary survey is to:
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.
A. Airway: Intubate an unconscious, shocked and hypoxic patient immediately. If there is neck injury or bleeding, do cricothyroidotomy or tracheotomy.
B. Patient with collapsed neck veins is assumed to be in hypovolemic shock.
Patient with distended neck veins but hypotensive may have the possibilities of:
Any patient especially with 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.
- myocardial contusion or MI
- tension pneumothorax (TNT)
- air embolism
- pericardial tamponade
Intubated patient on IPPV who develops sudden cardiovascular collapse should be presumed to have either TNT or coronary air embolism. The definitive treatment is emergency thoracotomy in 'steep head down' position.
Pericardial tamponade is a frequently met condition. A pericardiocentesis can be done as life saving measure but immediate thoracotomy is the definitive treatment.
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. Blunt thoracic trauma is usually associated with other injuries viz. head, abdomen, limb  etc.
The mechanism of PTI can be understood from [Figure 1].
2. Secondary Survey
If patient becomes haemodynamically stable after initial resuscitation then a secondary survey for diagnostic studies and surgical priorities should be followed.
| General anaesthetic management considerations|| |
A brief account of general anaesthetic considerations is given below for extensive chest trauma before discussing the specific injury anaesthetic management.
1. Pre-operative assessment:
Inclusion of anaesthesiologist in trauma team saves valuable time from resuscitation to pre-operative evaluation. In conscious patient the following brief history should be taken.
Performing physical examination, send blood sample especially for ABG analysis& hematocrit.
- past medical and surgical history
- previous anaesthesia difficulties
- malignant hyperthermia
- current medication
- NPO status
- review of systems.
All life saving drugs, equipments and monitoring systems should be labeled and calibrated in advance.
Monitoring: ECG, oximetry, automated BP, precordial stethescope, IBP (arterial& CVP) and urine output are essential but no time should be wasted in arranging all the monitors at a time.
- Unconscious moribund patient should be intubated and surgery is performed without anaesthesia.
- When vital signs and consciousness improve, anaesthetics 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 hence 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.
- O 2 /air mixtures, muscle relaxants, narcotics, amnestics and minimal inhalational agents can be used.
- Avoid N 2 O.
- Intraoperatively watch for the development of any other unwanted new sign e.g. TNT or tamponade.
- Non-responding fluid replacement therapy from upper veins may indicate towards possibility of tear in SVC. In such condition cannulate lower extremity veins and vice versa.
- Muscle relaxant:
- Avoid succinylcholine in massive trauma fearing hyperkalemia
- Vecuronium or rocuronium are cardiovascularly stable and relaxants of choice.
- Avoid atracurium due to rapidly changing acid base 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  .
4. Post operative care:
Take particular care for
Other than thoracic vertebral and spinal cord injuries, though devastating but not immediately life threatening, the specific thoracic injuries, penetrating or blunt, can be grouped as following :
- Respiratory support
- Fluid replacement
A. Non-cardiac: which includes
- Pleural space.
- Lung parenchymal contusion.
B. Cardiac - which includes
1. Chestwall: Chestwall injury may range from a single rib fracture to multiple rib fractures leading to flail chest. Fractured ribs cause severe pain limiting the respiratory movements leading to hypoventilation which may be deleterious in pre-existing COPD. X-ray chest is required to rule out atelectasis or pneumothorax.
- Coronary artery.
- Cardiac chambers.
- Great vessels.
Treatment: Surgical fixation or even strapping is rarely required. Strapping itself may lead to atelectasis. Ventilation can be improved by pain relief with
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 which is not so prominent if seat belt is used.
- 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.
2. Pleural space: A thoracic injury can give rise to -
- Pneumothorax (PNT )
- Tension PNT (TNT)
- Simple open PNT
I. Pneumothorax (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 is formed.
The air may also enter pleural space from inside. Air may leak into it from tracheobronchial or lung parenchymal injury.
TNT occurs when air enters the pleural space during inspiration but cannot escape during expiration. TNT compresses ipsilateral lung directly and opposite lung by mediastinal shift. Increase in pleural pressure decreases venous return and thus a fall in cardiac output.
Cardinal signs of TNT are
Occassionally, the air leak may also cause pneumomediastinum and pneumopericardium.
- rapid deterioration of vital signs
- decreased pulmonary compliance
- decreased or no breath sounds on affected sides
- tracheal deviation towards normal side
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.
- A simple open PNT requires only a chest tube drainage (ICD)
- Small wounds can be sealed by dressing
- TNT suspected even clinically requires immediate decompression by insertion of a 14G needle in the second intercostal space (ICS) in midclavicular line (MCL) followed by ICD.
- If patient is to be transported by air even a minor PNT should be drained as Pá 1/V (Boyle's law) i.e. air volume increases with decreasing pressure at heights.
Specific anaesthetic considerations (SAC):
II. Haemothorax: 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-
- GA is indicated only for 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.
- Compression of ipsilateral lung
- Mediastinal shift followed by
- Compression of contralateral lung
- Ventilatory impairment
Sometimes a chest tube may release a tamponade around a major vessel leading to massive haemorrhage.
- Tube thoracostomy in 6 th intercostal space in midaxillary line.
- Volume replacement is essential. Blood collected from pleural space is free of clotting factors and can be readily reinfused ,.
- If the source of bleeding is pulmonary vessel (low perfusion pressure) only tube drainage is enough but bleeding from systemic vessel if 300 ml.hr -1 or more after initial drainage will require emergency thoracotomy.
Specific anaesthetic considerations:
A fast transfusion with the help of pump may be required.
- Acute respiratory failure prior to surgery may require intubation and PPV.
- Double lumen tube (DLT) may be considered if there is :
- Large air leak from chest tube (tracheobronchial injury)
- Haemoptysis or a significant amount of blood in airways
3. Pulmonary contusions:
Pulmonary contusion can occur in both penetrating and rapid deceleration conditions. Rib fractures are found in 50% of such cases. Initial CXR is not helpful and CT Scan is required to know the extent. There may be a progressive decrease of pulmonary compliance and PaO 2 and increase in alveolar oedema. PaO 2 /FiO 2 < 250 is the best indicator of poor outcome.
The oedema phase should be 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 oedematous 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.
4. Tracheobronchial disruption (TBD):
TBD should be suspected with penetrating or blunt injury to the neck or chest. Subcutaneous or mediastinal emphysema, haemoptysis, PNT, bronchopleural fistulas (BPF) or persistent air leak after tube insertion are the definite signs of TBD. A knife laceration to lung may transect many bronchioles behaving like BPFs. Flexible bronchoscopy should be performed to assess the level of disruption.
Only few distal tears with minimal air leak or major bronchus tear involving less than one third of circumference and in apposition can be treated non-surgically.
- Small to moderate high tracheal tear may be overcome by ETT with cuff reaching distal to tear.
- Tracheostomy is indicated in high tracheolaryngeal disruptions.
- Majority of TBD require surgery.
Specific anaesthetic considerations:
Sterile ETTs of different sizes should be kept ready for intraoperative bronchial placement from within during airway repair.
- 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. It is also indicated in 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.
5. Oesophageal injury:
Blunt forces may cause a sudden rise in intraluminal pressure or oesophagus may be crushed between trachea and vertebral bodies but more common cause is penetrating trauma. Injury to oesophagus from outside or within is not immediately life threatening but untreated and unrecognized oesophageal injury has an extremely high mortality due to mediastinitis, empyema and sepsis. Repair within 24 hrs remarkably reduces mortality.
- Clinically chest pain, dysphagia, hematemesis, emphysema and fever.
- Oesophagoscopy is not always necessary.
Special anaesthetic considerations:
- Surgery ranging from a minor primary repair to resection of oesophagus may be required.
- Tears of upper and middle thirds are repaired from right and lower one third from left thoracotomies.
- Respiratory haemodynamic and GI considerations.
- Use of DLT and one lung ventilation facilitate surgery.
- No oesophageal instrumentation other than gently guiding a nasogastric tube beyond repair at the end of operation by surgeon.
Blunt forces or gunshots from chest or abdomen can disrupt diaphragm.
Extreme forces are required to disrupt diaphragm with blunt trauma which also has a high incidence of injury to other organs with a very high ISS hence mortality. Abdominal viscera may be pushed up to the chest causing respiratory embarrassment.
A 'Cork Screw' position allows exploration of abdomen and thorax, if required simultaneously.
If the injury is to be approached by thoracotomy, the surgical exposure can be greatly facilitated by DLT.
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 occur as a result of gunshots or stab wounds to neck, precordium or upper left abdomen. Gunshot wounds are more devastating, can injure one or more cardiac chambers whereas knife injury is usually single and less destructive. 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.
1. 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 upto 2 L of blood severely affecting the cardiac output.
Diagnosis: It can be diagnosed by
Treatment: The definitive treatment is surgery but pericardiocentesis may be done first to relieve rapidly increasing tamponade.
- Site of wound
- Beck's triad of - distended neck veins, hypotension and muffled heart sounds
- Kussmaul's sign (paradoxic filling of neck veins on inspiration).
- Pulsus paradoxus.
- ECG - Pulsus alternans.
- Shock and raised CVP.
Special anaesthetic considerations:
- 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.
- In a conscious, restless, non-cooperative patient GA is required even for pericardiocentesis followed by surgical correction.
- Prepare and drape the patient conscious.
- Rapid supine horizontal incision in left 4 th /5 th ICS is given after anaesthesia.
- Maintain CVP > 15cm H 2 O, avoid peripheral vasodilatation, myocardial depression and arrhythmias.
- Ketamine, vecuronium, high FiO 2 are the choices.
- If patient deteriorates before tamponade is relieved, isoproterenol 0.1-1ìg.kg -1 .min -1 infusion is started (preparation 4mg.ml) i.e. 1-2ml.min -1.
- Conservative anaesthetic management must be followed even after tamponade is relieved but narcotics e.g. fentanyl can be added.
2. Coronary artery injury: Being anterior usually left coronary artery is involved. It may lead to haemorrhage, infarction or tamponade. From anaesthetic view point these patients should be managed similarly to the patients with acute MI.
3. Cardiac chamber injury: Immediate surgery for repair of hole is required. Management is planned under general anaesthetic considerations as discussed earlier with special management of haemorrhagic shock.
4. Great vessels' injury:
i. Aortic injury - It leads to devastating haemorrhage and only 15% reaches hospital alive. The signs are:
- Mediastinal widening
- Tracheal deviation
ii. Caval injuries -
- Most difficult to deal surgically
- Extremely high mortality
Special anaesthetic considerations:
Cardiopulmonary bypass is rarely required but always better to keep the facility available.
- Depending upon the condition of the victim, the general anaesthetic management plan is employed.
- Foremost goal is to maintain a rapid fluid replacement.
Extensive chest trauma is always life threatening due to respiratory and haemorrhage problems. The anesthesiologist must be able to initiate primary resuscitation, diagnose life threatening chest injuries and plan the anaesthetic management of any surgical intervention if required.
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