CHAPTER 31 Anesthesia in Trauma Patients





Introduction


In the case of trauma, an anesthesiologist not only plays a role in operation theaters but also participates in the primary survey and resuscitation, airway protection, intubation, and other procedures in the emergency room.


Anesthesia care in cases of trauma requires complete knowledge of the advanced trauma life support (ATLS) guidelines. This chapter aims to deliver the most important information required for an undergraduate under the following headings:




  • Evaluation of trauma patient by ATLS guidelines.



  • Resuscitation goals.



  • The blood component therapy.



  • Special monitors and pharmacology in the treatment of trauma patients.



  • Traumatic brain injury (TBI).



  • Burns.



Evaluation of Patient


Clinicians rapidly assess injuries of injured patients and institute life-saving therapy. The initial assessment includes:




  • Preparation including triage.



  • Primary survey (airway, breathing, circu­lation, disability, exposure [ABCDE]).



  • Consideration of the need for patient transfer.



  • Secondary survey (head-to-toe evaluation and patient history).



  • Adjuncts to the secondary survey.



  • Continued postresuscitation monitoring and reevaluation.



  • Definitive care.


The assessment of patients is not longitudinal, as mentioned above, in a clinical scenario, and primary as well as secondary survey should be done frequently to achieve optimal patient care.



Preparation


It has two phases, prehospital and the hospital phase.



Prehospital Phase

The prehospital system notifies the receiving hospital, which enables trauma members to do the required preparations, in order to receive patients. The trained members manage airway, control bleeding, immobilize the patient, and make necessary arrangements to transfer the patient to the nearest appropriate treatment facility (preferably a trauma center).



Hospital Phase

The hand over between prehospital providers and those at the receiving hospital should be a smooth process, which is directed by the trauma team leader. All health care workers should practice standard precautions during patient transfer due to the risk of transmitting infectious diseases through body fluids.



Primary Survey with Simultaneous Resuscitation


The primary survey encompasses the ABCDE of trauma care. It includes:




  • A: Airway maintenance with restriction of cervical spine motion.



  • B: Breathing and ventilation.



  • C: Circulation with hemorrhage control.



  • D: Disability (assessment of neurologic status).



  • E: Exposure/environmental control.


Clinicians can quickly assess A, B, C, D, and E in a trauma patient by asking the patient for his or her name and asking what happened (10-s assessment). An appropriate response, that is, ability to speak clearly, ability to generate air movement to permit speech, and alertness to describe what happened, suggests that there is no significant airway compromise and breathing is not severely compromised.



Airway Maintenance with Restriction of Cervical Spine Motion

Securing a compromised airway, delivering oxygen, and supporting ventilation remain the cornerstone of care of trauma patients, and man­agement of other conditions can be done later.


Supplemental oxygen with a tight-fitting mask (flow—10 L/min) should be administered to all trauma patients. Other vital steps are:




  • Observe the patient for the sign of hypoxia (agitation) and hypercarbia (obtundation).



  • Use of accessory muscles and retractions suggest respiratory distress.



  • The presence of noisy breathing, snoring, gurgling, hoarseness, and stridor may indicate upper airway/vocal cord edema or narrowing.



  • Pulse oximetry can detect inadequate oxygenation before cyanosis develops.



  • Remove the foreign body from the oral cavity to clear the airway and identify any facial fracture as a culprit of airway obstruction.



  • Neck trauma with compromised airway mandates early institution of definitive airway.



  • Triad of hoarseness, subcutaneous emphy­sema, and a palpable fracture identifies a possible laryngeal trauma.


Trauma with life-endangering injuries compels trauma members to acquire skills to assess the airway rapidly in trauma patients. The mnemonic “LEMON” helps identify difficult airway in emergencies.


L—Look externally




  • Presence of small mouth or jaw, large overbite, or facial trauma predicts difficult bag and mask ventilation.


E—Evaluate the 3-3-2 rule




  • At least 3-finger breadths gap between patient’s incisors (3).



  • At least 3-finger breadths between hyoid bone and chin (3).



  • A gap of at least 2-finger breadths between thyroid notch and floor of mouth (2).


M—Mallampati class




  • Poor mallampati class (MPC) makes intubation difficult.


O—Obstruction




  • Rule out culprits of airway obstruction (e.g., foreign body, facial trauma, etc.).


N—Neck mobility




  • Restricted neck mobility is associated with difficult laryngoscopy.


Assume cervical spine injury in all trauma patients unless proven. The absence of neurological deficits does not rule out damage to the cervical spine. The cervical spine must be stabilized with a cervical collar in all patients, and extreme caution should be taken during transfer and airway handling. Head tilt and chin lift to keep the airway patent is contraindicated in trauma patients with a suspected cervical spine injury; however, jaw-thrust can be used to maintain patency of the airway, if required. In case of risk of aspiration and/or inability to keep airway patent, the airway should be secured with an endotracheal tube and with surgical techniques (tracheostomy or cricothyroidotomy) if endotracheal tube placement fails.



Breathing and Ventilation

A patent airway ensures the free movement of gases till alveoli. The presence of airway obstruction, central nervous system (CNS) depression, altered ventilatory mechanics, and chest trauma, along with paresis/paralysis of respiratory muscles, can compromise ventilation significantly. The entities like tension pneumothorax, open pneumothorax, massive hemothorax, and tracheal or bronchial injuries can cause mortality if not treated in time.



Circulation with Hemorrhage Control

Circulatory collapse due to excessive bleeding is a common cause of mortality. Death can also occur due to nonhemorrhagic reasons of circulatory collapse. All these need to be identified and should be treated in a timely fashion to save lives.


Identifying sources of bleeding, controlling it in a timely fashion, and adequate resuscitation can improve the patient’s morbidity and mortality significantly. Hypotension due to bleeding should be the first differential of circulatory collapse after the exclusion of tension pneumothorax in trauma victims.



Clinical Evaluation

Clinical evaluation that yields essential infor­mation within seconds is:




  • Deranged level of consciousness.



  • Pale extremities showing poor skin perfusion.



  • Rapid thread pulse.



Bleeding

The source of bleeding can be from either an external site or an internal organ.


External hemorrhage is addressed during the primary survey by direct manual pressure on the wound and application of tourniquets over bleeding sites at the extremities.


Internal hemorrhage: The physical examina­tion and imaging (e.g., chest X-ray, pelvic X-ray, focused assessment with sonography for trauma [FAST], or diagnostic peritoneal lavage [DPL]) can identify the internal source of bleeding (chest, abdomen, pelvis, etc.). Immediate chest decom­pression, stabilization of pelvis, and appli­cation of splint on extremities are initial measures to control bleeding, followed by definitive manage­ment with interventional radiology and surgery.



Classification of Hemorrhage

Aggressive and continued volume resuscitation cannot replace for definitive control of bleeding. The hemorrhage can be categorized into four classes, based on severity (Table 31.1):




Table 31.1 Signs and symptoms of hemorrhage by class






































































Table 31.1 Signs and symptoms of hemorrhage by class

Parameter


Class I


Class II


Class III


(moderate)


Class IV


(severe)


Approximate blood loss


<15%


15–30%


31–40%


>40%


Heart rate



No Image Available!


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Blood pressure



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No Image Available!


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Pulse pressure



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Respiratory rate



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Urine output



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GCS score



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Base deficit


0 to –2 mEq/L


–2 to –6 mEq/L


–6 to –10 mEq/L


–10 mEq/L or less


Need for blood products


Monitor


Possible


Yes


MTC


Abbreviations: GCS, Glasgow coma scale; MTC, massive transfusion protocol.




  • Class I hemorrhage: For example, an indi­vidual who has donated one unit of blood.



  • Class II hemorrhage: Uncomplicated hemor­rhage which requires resuscitation crystalloid fluids.



  • Class III hemorrhage: Complicated hemor­rhagic state, which may require blood transfusion along with resuscitation with crystalloids.



  • Class IV hemorrhage: The patient will die within minutes if not resuscitated in time; blood transfusion is required.



Management of Hemorrhagic Shock

Hemorrhagic shock is hypovolemic in nature, and resuscitation starts with crystalloid fluids along with simultaneous assessment of response to fluid therapy. Infused fluid should be warm, as massive volume resuscitation with cold fluids can cause dangerous hypothermia. Fluid administration in excess can cause dilutional thrombocytopenia and dilutional coagulopathy and add to further bleeding.


Early use of tranexamic acid has shown promising results in decreasing coagulopathy. Bolus should be administered within 3 hours and can be given by the paramedic team in the prehospital phase, followed by infusion in the hospital over 8 hours.



Causes and Management of Nonhemorrhagic Shock

The category of nonhemorrhagic shock includes tension pneumothorax, cardiogenic shock, cardiac tamponade, neurogenic shock, and septic shock.



Tension Pneumothorax

Tension pneumothorax is a reversible and life-threatening injury that should be treated by needle decompression in the second intercostal space in the midclavicular line, followed by chest tube insertion in the fifth intercostal space (anterior axillary line).



Cardiogenic Shock

Blunt cardiac injury, cardiac tamponade, an air embolus, or, rarely, myocardial infarction can cause fatal cardiac dysfunction. ECG is the most common investigation ordered in patients with blunt trauma to the chest in order to detect dysrhythmias.



Cardiac Tamponade

Cardiac tamponade can be caused due to blunt as well as penetrating injuries to the chest. The presence of tachycardia, muffled heart sounds, and dilated, engorged neck veins with hypotension and insufficient response to fluid therapy suggest cardiac tamponade. It can be diagnosed with FAST in emergency department (ED) and should be managed with the definitive operative intervention (pericardiocentesis is a temporary measure only). Transthoracic echocardiography can help in diagnosing cardiac tamponade but is often not available due to limited resources.



Neurogenic Shock

Neurogenic shock is uncommon in isolated intracranial injuries without injury to the brainstem. The classic presentation of neuro­genic shock is hypotension without tachycardia or cutaneous vasoconstriction.



Septic Shock

It is a rare cause of hemodynamic instability in trauma patients. However, it can occur when the patient arrives at the ED after several hours of injury. Penetrating abdominal injuries and the contamination of peritoneal cavity by intestinal content are common culprits of septic shock in trauma patients. Normal circulating volume, modest tachycardia, warm skin, near-normal systolic blood pressure (BP), and wide pulse pressure characterizes the early phase of sepsis.



Measuring Patient Response to Fluid Therapy

The rise in pulse rate, pulse pressure, and BP suggests improving perfusion during the resusci­tation phase. Urinary output of 0.5 and 1.0 mL/kg/h in children and adults, respectively, is an adequate and sensitive indicator of renal perfusion.



Patterns of Patient Response

The patient’s response to initial fluid resuscitation is the key to determining subsequent therapy.




  • Rapid response: “Rapid responders” qui­ckly respond to the initial fluid bolus and become hemodynamically stable with no evidence of inadequate tissue perfusion. Usually, these patients come under class I hemorrhage and require no further fluid bolus or immediate blood administration.



  • Transient response: “Transient responders” initially respond to resuscitative measures but later on deteriorate because of ongoing blood loss. Transient responders belong to class II/III hemorrhage and require blood transfusion. Also, identifying such a group of patients for the possible operative or angiographic intervention to control bleeding is very important.



  • Minimal or no response: The trauma victims with class IV hemorrhage rarely respond to fluid and blood product administration. They require activation of massive blood transfusion protocol and immediate defini­tive operative intervention at the earliest.



Massive Blood Transfusion

In cases of blood loss, most deaths happen in the first 6 hours, and thus early blood transfusion initiation efforts are needed. The goal of massive transfusion is not just the replacement of intra­vascular volume, but the correction of trauma-induced coagulopathy, in an attempt to curb further blood loss. Massive transfusion definitions include:




  • Replacement of whole blood volume in
    24 hours (7% of ideal body weight in adults).



  • Replacement of 50% of blood volume in
    3 hours.



  • Blood loss > 1,500 mL in 10 minutes.


Blood products in the ratio of 1:1:1 are widely followed. A fibrinogen level lower than 100 mg/dL substantially increases in-hospital mortality. With ongoing resuscitation, one should target to achieve the below-mentioned goals:




  • Hematocrit > 30%.



  • Platelets > 50,000/µL.



  • Prothrombin time (PT) < 18 seconds (inter­national normalized ratio [INR] < 1.5).



  • Activated partial thromboplastin time (APTT) < 45 seconds.



  • Fibrinogen > 150 mg/dL.


The massive transfusion of blood is not without complications and can lead to lung injury (in the form of transfusion-related acute lung injury [TRALI], transfusion-associated circulatory over­load [TACO], infectious complications, hypo­thermia, and hypocalcemia).


Point of care is coagulation studies or thrombo­elastogram (TEG), which is now considered the gold standard for all massive transfusion protocol (MTP) monitoring. It is beyond the scope of this chapter to discuss TEG, but readers are encouraged to understand the use and functionality of TEG in a clinical scenario.

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Dec 11, 2022 | Posted by in ANESTHESIA | Comments Off on CHAPTER 31 Anesthesia in Trauma Patients

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