Critical Care of the Orthopedic Surgery Patient

1. Description of the problem

Introduction

The most common reason for patient admission to the intensive care unit (ICU) with orthopedic problems is usually multiple trauma. Other causes for admission include patients with significant comorbidities undergoing elective or emergency orthopedic procedures. The priorities of management are quite often different in these two cohorts of patients.

Trauma patients

The intensive care physician is often involved in the management of patients before admission to the ICU. In the emergency department the management of the patients is commonly team-oriented and guided by the Advanced Trauma Life Support (ATLS) protocol, whose main tenets are as follows:

The primary survey:

A quick, logical assessment and management sequence constituting the ABCDE approach.

A: Airway maintenance with cervical spine protection

B: Breathing and ventilation

C: Circulation with hemorrhage control

D: Disability; neurological status

E: Exposure / Environmental control

Airway maintenance with cervical spine protection

• If patient is talking – airway is patent.

• In an unconscious patient a jaw thrust may be useful. Chin lift may be dangerous unless cervical spine injury is ruled out.

• A Glasgow Coma Scale (GCS) score of 8 or less is usually an indication to secure a definitive airway.

• Great care should be taken to minimize excessive movement at the cervical spine. A semi-rigid cervical collar should be placed as soon as possible. If intubation is required then a manual in-line cervical spine stabilization technique should be used with minimal movement at the cervical spine. Capnography is useful to confirm tracheal intubation.

Breathing and ventilation

• Ventilation requires functioning lungs, chest wall and diaphragm – all three should be evaluated rapidly.

• Visual inspection followed by percussion and auscultation will inform us of any obvious chest wall injury, tension pneumothorax, flail chest, massive hemothorax or open pneumothorax.

• Beware of a patient whose condition deteriorates rapidly after institution of positive-pressure ventilation – there might be a tension pneumothorax present. If the diagnosis is confirmed or a high degree of suspicion is present then initial management is insertion of a large-bore cannula in the 2nd intercostal space in the mid-clavicular line on the affected side. This should be followed by a definitive chest drain.

Circulation with hemorrhage control

• Hypotension must be considered to be hypovolemic in origin until proved otherwise.

• Focus should first be directed towards stopping catastrophic bleeding. Measures include direct manual pressure, tourniquets, pneumatic splints and emergency vascular surgery or embolization.

• Adequate intravenous (IV) access is essential – usually 2 large-bore cannulae are inserted.

• Fluid resuscitation is done to appropriate endpoints. The aim should not be to attain normal blood pressure. Permissive hypotension (accepting a lower blood pressure as long as a peripheral pulse can be felt) may be more appropriate. The idea is not to dislodge the clots that have already formed at a micro / macrovascular level.

Disability / neurological status

• A GCS assessment is useful to determine the level of consciousness and is predictive of patient outcome.

• Analgesia may be needed frequently in conscious patients – splinting of fractures and intravenous titrated boluses of a strong opioid like morphine is commonly used.

• Decreased consciousness may result not only from direct brain injury but also from a ventilatory / perfusion deficit or the influence of alcohol, drugs or hypoglycemia.

Exposure / Environmental control

It is important to completely undress the patient but at the same time take measures to prevent hypothermia. Measures include warm blankets, external warming devices and warm IV fluids.

Adjuncts to primary survey and resuscitation

• Electrocardiography – Look for dysrhythmias or ST segment changes.

• Urinary catheter – Beware of urethral injury, especially in pelvic trauma.

• Gastric tube – The nasal route is contraindicated in suspected base of skull fractures.

• Respiratory rate and arterial blood gases – used to monitor initial status and effect of therapy

• Pulse oximetry

• Blood pressure – poor measure of tissue perfusion. Serum lactate, if easily available, is useful.

• Imaging – Minimum x-ray sets should include cervical spine lateral, chest and pelvis. Most trauma units now prefer to do a vertex to pelvis computed tomography (CT) scan as soon as the patient is stable enough to be transferred.

The secondary survey

Secondary survey does not start until the primary survey (ABCDE) is complete, the patient is adequately resuscitated and the vital organs have demonstrated adequate function. Aim is to do a complete head-to-toe evaluation – which includes a complete history and physical examination to make sure no injuries are missed.

The AMPLE history mnemonic as advocated by the ATLS is useful:

A: Allergies

M: Medications

P: Past illnesses / Pregnancy

L: Last meal

E: Event / Environment related to injury

A systematic examination of the head, chest, abdomen, back and perineum is then performed. A log roll to examine the back, cervical, thoracic and lumbar spine and a per-rectal examination is mandatory. A complete assessment of musculoskeletal and neurological injury should be done.

Management in the ICU

The principles of management of these patients are a natural continuation of the therapy initiated in the emergency department. Frequently patients may be admitted to ICU with no secondary survey done or without clearance of cervical spine injury. Some patients may have deteriorated in the process of transfer and may need further resuscitation.

The priorities remain ABCDE. Once the patient’s physiology has stabilized a secondary survey should be performed (if not already done).

Cervical spine clearance: Either clinical or radiological clearance of the cervical spine injury should be attempted, and if not successful then spinal precautions should remain in place. At this point, it may be prudent to replace the semi-rigid collar with a collar designed to protect skin integrity during extended wear, for example Miami J^® collar.

Immunization with 250 units of human tetanus immune globulin should be considered for all trauma patients.

A complete list of all injuries in the patient should be made and specialist teams contacted to formulate specific treatment plans for various injuries. This may include the general, vascular, neurosurgery, cardiothoracic, orthopedic, urology and plastic surgeons.

Further specific investigations that may be needed should be done at this point. This may include further imaging to rule out vascular injury to major structures like the aorta, especially if thoracic trauma has taken place.

These patients are frequently in pain. Analgesia options include intravenous opioid infusions, opioid-sparing analgesics, nerve blocks and neuroaxial local anesthetic / opioid infusions. In awake patients, a patient-controlled analgesia system is recommended.

While the various treatment plans are carried out over days or even weeks, monitoring and continued or escalating organ support for these patients may be required.

Respiratory support using continuous positive pressure ventilation (CPAP), non-invasive ventilation (NIV) or invasive positive pressure ventilation (IPPV) may be required. An indwelling arterial catheter is valuable to repeat arterial blood gases, to do blood investigations and to measure invasive blood pressure. It is also useful for cardiac output monitoring using minimally invasive devices to guide fluid management.

Cardiovascular support with fluids and inotropes is frequent. If acute kidney injury occurs, then renal replacement therapy can be considered.

Crush injuries – Extensive crush injuries can result in traumatic rhabdomyolysis and acute kidney injury. Common features are dark urine, increased serum creatine kinase and hyperkalemia. Treatment includes generous intravenous fluid therapy, mannitol to flush the kidneys and correction of electrolytes. A bicarbonate infusion is commonly used to alkalinize the urine to promote myoglobin excretion.

A tracheostomy may be indicated to provide a definitive airway or to assist weaning or surgery.

It is important to consider thromboprophylaxis on a daily basis as these patients are at a high risk of deep vein thrombosis (DVT) and pulmonary embolism (PE). In some centers patients with pelvic trauma frequently have a temporary vena cava filter inserted and / or warfarin therapy initiated to prevent DVT / PE.

Physiotherapy, both respiratory and musculoskeletal, plays a key role in the subsequent rehabilitation of these patients.

Care of pressure areas can be a challenge in these patients, especially if they have spinal injuries or are placed in skeletal traction. Pressure-relieving mattresses, frequent turning of the patients, adequate analgesia and a constant lookout for skin damage is extremely important to prevent pressure sores.

Documentation of the primary / secondary survey, injuries, interventions, investigations and plan is crucial. Many hospitals that deal with trauma frequently find it easier to have a trauma booklet that has the relevant forms printed, in which the information can be filled in. A form for spinal assessment and precautions is also desirable for clear and effective communication.

Transfer of critically ill trauma patients

It may be necessary to initiate intra- and inter-hospital transfers for specific investigations, definitive therapy or non-clinical reasons (for instance, availability of ICU beds). These transfers have to be carefully planned at an early stage. If transferring to a specialist trauma center for definitive treatment then there is no point in delaying transfer to complete a full secondary survey. The patient should be transferred as soon as deemed stable. Accurate documentation (including imaging) and clear, systematic communication between the transferring and receiving teams is absolutely vital. Again a checklist is useful. All the precautions for a safe transfer should be employed.

Orthopedic surgery

The orthopedic surgery patients who present to the ICU can be classified according to the type of surgery they have had. The usual orthopedic procedures include:

• Joint replacements

• Spinal surgeries

• Extremity surgeries

Joint replacements

• Patients are usually elderly with significant comorbidities and may have severe osteoarthritis or rheumatoid arthritis (RA). The several challenges in patients with severe RA are shown in Table I.