Author Credentials

Author: Julianna Jung, MD, Johns Hopkins Medical School

Editor: Robert Hyde, MD, Mayo Clinic

Section Editor: Matthew Tews, DO, Indiana University School of Medicine

Last Update: 2023

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Introduction

At long last, you’ve sat down to catch up on charts for the patients you’ve seen in the past few hours.  How many were there?  Seven?  Nine?  You rummage in the pockets of your white coat – there used to be a list in there somewhere.  Suddenly, the PA system blares, “MEDICAL PATIENT TO CRITICAL CARE!!  ETA FOUR MINUTES!”

You’re on your feet before you’ve fully realized what’s happening, bolting for the resuscitation area.  What will it be?  Myocardial infarction?  Sepsis?  Respiratory distress?  Status epilepticus?  You pass the charge nurse and give her an inquiring look, but he just shrugs.   Whatever it is, it will be a surprise.  It’s your first night as team leader for medical resuscitations – you hope you’re ready…

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Objectives

By the end of the session, you will be able to:

• Describe elements of the primary survey of a critically ill or injured patient
• List signs and symptoms of airway compromise, and indications for definitive airway management
• List signs and symptoms of respiratory distress and failure
• Describe stabilizing measures for patients with respiratory distress
• List signs and symptoms of shock
• Describe stabilizing measures for patients with shock
• Explain how shock treatment differs based on etiology

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Introduction

In the Emergency Department (ED), patients may arrive at any time, in any condition, with little or no warning.  It is essential for ED physicians to be ready for anything, including acutely unstable patients in need of immediate intervention.  This chapter will walk you through the primary survey for critically ill patients, covering both assessment and stabilization.

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Presentation

Critically ill patients have a wide variety of clinical presentations, but the common theme is that they all have a significant derangement of one of the “ABCDs”:  airway, breathing, circulation, or disability (neurologic status).  These patients typically have abnormal vital signs and/or physical exam findings suggestive of severe pathology.  

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Initial Actions and Primary Survey

Pre-Arrival

Before the patient arrives, do as much as you can to prepare your team and your resuscitation room so that you’re optimally situated to stabilize the patient:

• Personnel:  It is essential for every member of the resuscitation team to have a clearly defined role.  The team leader is responsible for oversight of the entire resuscitation, and ideally should never touch the patient.  When the leader gets focused on individual tasks, they lose track of the big picture, so should delegate tasks whenever possible. Tasks to delegate include:
  • Primary/secondary survey
  • Airway management
  • Vascular access
  • Medication administration
  • Scribe/timekeeper
  • For cardiac arrest, establish a rotation of CPR providers and designate a quality CPR monitor whenever possible
• Equipment:  When a patient is really sick, say “OMI!”  (Oh my! Get it?) OMI stands for oxygen, monitor, and IV – these interventions are appropriate for every critically ill patient regardless of the cause.
  • Oxygen:  Be sure you have an oxygen source and a means of oxygen delivery.  A cannula or face mask is appropriate if the patient is breathing, but also make sure you have a working bag-valve-mask device in case the patient is apneic.  If time permits, set up intubation equipment as well.
  • Monitor:  Set up a cardiac monitor and pulse oximeter, and make sure that you have a working defibrillator in case of serious dysrhythmia.
  • IV:  Set up equipment for establishing peripheral IV access.  If time permits, set up advanced vascular access equipment as well – intraosseous and/or central central line kits.

Sequence of Assessment

The Primary Survey

The goals of the primary survey for critically ill patients are twofold:

• Rapidly and systematically identify life threats
• Provide simultaneous treatment of all life threats identified

This means that the primary survey isn’t just about assessment.  It’s about synthesizing the information gained during the assessment in order to recognize imminent life threats, and providing immediate stabilization for life threats.  You should never proceed with assessment when you identify a life threat during the primary survey – you should stop and deal with each threat as you identify it.  For this reason, assessment and treatment topics will be interspersed throughout the discussion below.

Airway Assessment

The ability to speak is the single most important indicator of airway patency.  By definition, any patient who is able to phonate has an intact airway…for now.

When your patient is unable to speak, you must immediately determine why, and assume that they have the potential for serious airway compromise until proven otherwise.  Not every patient who is unable to speak will have a compromised airway – conditions that alter mental status or language function may prevent speech without affecting the airway.  However, the burden is on you to demonstrate that these patients have and are able to maintain patent airways. There are many physical examination findings that suggest a compromised airway.

• Look – Externally examine for swelling of tongue, lips, or neck.  Look inside the mouth for foreign bodies, loose teeth, vomitus or secretions.  A word of caution – look but don’t touch!  Blind finger sweeps are more likely to worsen than alleviate airway obstruction.
• Listen – Noisy breathing is obstructed breathing, so listen with the naked ear to the sound of respiration.  Snoring or gurgling are signs of mild-moderate upper airway obstruction, usually with soft tissue or secretions.  Stridor, a high-pitched inspiratory sound, suggests high-grade upper airway obstruction – this is always an emergency.
• Feel – Palpate the neck and upper chest for crepitus, which suggests pneumothorax or tracheolaryngeal injury.  Feel for swelling or masses in the neck as well, as these may lead to airway compromise in the future, even if the airway is patent now.

Even if there is no sign of immediate airway compromise, consider the likelihood that the airway will become obstructed in the near future.  A patient with angioedema, for example, may have no significant airway compromise on presentation, but 30 minutes later can develop complete obstruction.  The time to intubate is before the patient loses their airway!

You approach the bedside, place your hand on the patient’s shoulder, and introduce yourself.  “Get off me!” your patient growls.  You smile and announce, “Airway’s intact!” You’re relieved that this patient’s airway is okay, but what would you do if it wasn’t?  What if he was stridorous, or unable to speak?  The short answer is that you need to rapidly establish a patent airway - more on that in the section on Treatment!

Breathing Assessment

First, make sure your patient IS breathing!  If your patient is apneic, this is an emergency and requires immediate assisted ventilation. Assuming your patient is breathing, the next step is to determine whether their breathing is adequate and likely to remain that way.  Assessment steps include:

• Look:  Assess the patient’s respiratory effort – are they breathing slowly or quickly?  Deeply or shallowly?  Using accessory muscles?  Sitting up in the “tripod” position?  More importantly, develop your gestalt sense of the patient’s work of breathing – does it look easy or effortful?  Remember that normal respiration is almost imperceptible, so anytime you can really see a patient breathing, their work of breathing is increased.
• Listen:  Don’t worry about the subtleties of auscultation – first make sure that there are breath sounds –a lot of respiratory effort that produces minimal air exchange is a sign of imminent respiratory failure.  Then make sure you hear breath sounds on both sides – unilaterally absent breath sounds may suggest a tension pneumothorax, which requires immediate treatment.  Finally the quality of the breath sounds may provide a clue as to the underlying diagnosis (e.g., wheezing for asthma/COPD, or crackles for pulmonary edema).
• Count:  There is no substitute for a respiratory rate that you count yourself.  Documented respiratory rates are commonly inaccurate, and this is a critical vital sign for a patient in respiratory distress.
• Monitor:  The oxygen saturation is really the “bottom line” on respiration, at least in the short term.  The whole mission of the lungs is to deliver oxygen to hemoglobin, which will in turn deliver it to organs and tissues.  If the oxygen saturation is low, some significant pathology is present which is causing the lungs to fail in that mission.  Anything less than 96% is abnormal, though some patients are chronically hypoxic and may have a low baseline saturation.  Anything less than 90% is potentially life-threatening.

The goal of your respiratory assessment is to determine whether your patient has respiratory distress or failure.  Patients with respiratory distress are compensating for some type of underlying pathology.  Patients may compensate well in the short term, maintaining adequate oxygenation and ventilation.  The problem is that this compensation requires a lot of energy, and patients can’t maintain it indefinitely.  This means that patients with severe distress that is not alleviated will progress to respiratory failure.  These patients are exhausted, and no longer able to compensate for their underlying pathology, leading to worsening oxygenation and ventilation.

Table 1. Progression of respiratory failure

Your patient has a respiratory rate of 40, and you can see that he’s using accessory muscles to breathe.  His oxygen saturation is only 92%. You realize that this is pretty bad respiratory distress with mild hypoxia, and he’s at high risk of progressing to failure.  You know you’d better do something quickly - but what?  The short answer is to give him some oxygen to start with - more on that in the section on Treatment! 

Circulation Assessment

The goal of circulation assessment is to figure out if your patient is in shock.  Shock is a physiologic state characterized by inadequate delivery of oxygen to meet metabolic demands at the tissue level.  Shock can’t be seen or measured directly, but there are signs and symptoms that can provide clues about whether shock is present.

• Heart rate:  Tachycardia is one of the first compensatory responses to shock.  Hypoperfusion elicits a sympathetic nervous system response, increasing heart rate and contractility in order to raise cardiac output.  Remember that tachycardia may not always be present, especially in patients with underlying cardiac disease or medications that lower the heart rate.
• Pulse pressure:  The sympathetic response to hypoperfusion also leads to vasoconstriction, raising the diastolic pulse pressure.  In compensated shock, the systolic pressure will remain normal, while the diastolic increases, leading to a decrease in pulse pressure.  Again, this phenomenon may not be observed in patients with vascular disease or those using vasodilating medications.
• Respiratory rate:  Remember, shock is a disease of tissue-level hypoxemia, so the body will raise the respiratory rate in an effort to provide additional oxygen to the tissues.  Tachypnea is common in shock, and does not necessarily imply a pulmonary disease state.
• Blood pressure:  Hypotension occurs when compensatory mechanisms are no longer adequate to support perfusion.  It is important to remember that hypotension is a late sign of shock, and shock may be present in the absence of hypotension.  It is also important to consider the patient’s baseline blood pressure – a patient who normally lives at 170 may be in shock at 120, which is “normal” for many people.
• Mental status:  Patients with compensated shock are generally alert, though may be anxious and apprehensive.  In uncompensated shock, cerebral hypoperfusion leads to confusion or decreased level of consciousness.
• Other physical exam findings:  there are a variety of physical exam findings which have been suggested to correlate with volume status, though evidence for the accuracy of these in adults is quite limited.  Signs to consider include:
  • Skin color:  pink indicates good perfusion, whereas pallor or cyanosis suggest the opposite.  Look at mucous membranes (mouth, conjunctiva) in dark skinned patients.
  • Capillary refill:  under 2 seconds is normal, longer refill times may indicate hypoperfusion.
  • Skin turgor:  when pinched, the skin should return to its normal configuration in less than 2 seconds – longer suggests hypoperfusion
  • Pulse strength: bounding pulses suggest good perfusion, weak/thready pulses suggest the opposite
  • Extremity temperature:  cold extremities suggest shock, as the body shunts blood centrally to maintain vital organ perfusion
  • Mucous membranes:  dry membranes suggest dehydration

• Hypovolemic:  occurs when circulating blood volume is significantly reduced.  Can be caused by hemorrhage (internal or external), or by GI or urinary losses of water.
• Cardiogenic:  occurs when the cardiac “pump” fails.  Caused by disease processes that impair myocardial contraction, like cardiomyopathies and dysrhythmias.
• Distributive:  occurs when the vasculature is abnormally dilated and/or leaky.  Caused by disease processes that impair vascular tone and increase permeability, like sepsis and anaphylaxis.
• Obstructive:  occurs when there is an extra-cardiac obstruction to blood flow.  Caused by disease processes that impair cardiac filling, like tension pneumothorax and cardiac tamponade.

History and physical exam findings can provide helpful clues about the cause of your patient’s shock, and can allow you to select the right treatment.  Bedside ultrasound is also a very helpful adjunct in evaluating the patient.

Your patient has a heart rate of 136 and a blood pressure of 78/40.  You know that he’s in shock but you need some more information to figure out why.  You want to stabilize him while you work him up - but how?  The short answer is to establish IV access and consider some fluids - but more on that in the Treatment section! 

 

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Diagnostic Testing

As this chapter covers the acutely unstable patient, we focus on patients who are newly arrived to the ED in a critically ill condition, and for whom little or no diagnostic testing is immediately available.  Some common initial diagnostic tests are reviewed in the section on Treatment, but much more extensive coverage is offered in the individual chapters devoted to each major disease entity mentioned here.

Treatment

Airway Management

The main question to be answered in airway management is whether your patient needs to be intubated.  Not every patient with compromised airway or breathing requires intubation.  Many patients with snoring or gurgling respirations can be managed conservatively, with positioning or nasopharyngeal airway placement.  Many patients with hypoxia can be stabilized with supplemental oxygen or respiratory therapies.  The following are indications for intubation:

• High-grade airway obstruction of any etiology
• Suspected imminent airway obstruction of any etiology
• Inability to maintain or protect the airway over time
• Severe hypoxia refractory to less invasive treatment
• Severe hypercarbia refractory to less invasive treatment

The next critical aspect of airway management is deciding when and by whom intubation should be performed.  The key to making this decision safely is recognizing a potentially difficult airway and planning management strategies accordingly. Any condition that distorts the normal anatomy of the face and neck will make intubation difficult.  “LEMON” is a helpful mnemonic for remembering signs of a potentially difficult airway:

• Look:  visual inspection of the face and neck can reveal anatomic factors that make intubation difficult:  facial dysmorphism (particularly micrognathia), obesity, dental abnormalities, short or thick neck, facial/neck trauma or swelling
• Evaluate 3/3/2:  this rule refers to the normal facial and neck anatomy in terms of finger breadths – if any of these measurements are less than the amount specified, expect trouble:
  • 3 finger breadths between the incisors when the mouth is opened
  • 3 finger breadths from the mental vertex to the hyoid bone
  • 2 finger breadths from the hyoid bone to the thyroid notch
• Mallampati score:  this is a great tool for cooperative patients in the preoperative setting, but is less useful for critically ill patients in the ED.  It requires that the patient sit upright and voluntarily open the mouth as widely as possible.  The score is based on how much of the posterior pharynx can be visualized.
• Obstruction:  check for foreign body, listen for stridor as above
• Neck mobility:  assess range of motion of the neck, as limitations can make positioning for intubation difficult.  Note that trauma patients have limited neck mobility by definition, as they generally require cervical spine immobilization, though this does not usually present a significant obstacle to airway management.

When a difficult airway is anticipated, you should prepare for standard intubation to fail.  You must have backup equipment available, including a surgical cricothyrotomy setup.  Don’t give sedative or paralytic agents until backup equipment is available and ready for use.  Call for assistance if time and circumstances permit - some hospitals have difficult airway management teams that can be very helpful if the patient doesn’t require immediate intubation.

Breathing Management

Apnea and Agonal Respirations: The first priority is to make sure your patient is breathing, and to provide assisted ventilations if not.  Assisted ventilations are given using a bag-valve-mask (BVM) device, attached to 10-15 L/min of oxygen.  BVM ventilation is ONLY performed on patients with agonal or absent respirations.  Do not attempt to perform BVM ventilation on a spontaneously breathing patient – this is poorly tolerated and tends to worsen hypoxia.

If ventilation is ineffective (e.g., no chest rise is observed or oxygenation does not improve), then troubleshoot your technique:

• Optimize patient position:  Is the patient lying flat, with no pillows or clothing in the way?  Is the patient in the “sniffing position,” with the neck slightly flexed and the head slightly extended?  Sometimes a shoulder roll is needed to achieve this position, as the occiput tends to force the head into flexion.
• Optimize your position:  Are you standing squarely at the head of the bed?  It is not possible to correctly perform BVM ventilation from the side.  Are you holding the mask to the face using the “C/E” technique?
• Use two-person technique:  Sometimes even with perfect positioning, it isn’t possible to perform effective BVM ventilation.  When this occurs, the person managing the airway can use two hands to hold the mask to the patient’s face, while an assistant squeezes the bag to provide breaths.  This is much easier and more effective than single-person technique, particularly for large patients and/or small providers.
• Use an oropharyngeal airway:  This device hooks over the root of the tongue, pulling it forward out of the hypopharynx.  It is so helpful for maintaining airway patency during BVM ventilation that it should feel wrong to use a BVM device without one!

The vast majority of patients can be effectively ventilated with proper BVM technique.  Patients don’t die from not being intubated, they die from not being oxygenated – meaning that if you are able to effectively oxygenate the patient using a BVM device, there is no immediate need for intubation.   You may ultimately intubate the patient if indicated, but in the initial phase of resuscitation, BVM is perfectly acceptable provided it produces adequate oxygenation.

Oxygen therapy is initially appropriate for every patient with respiratory distress.  However, prolonged use of oxygen can be detrimental, particularly at high concentrations, so be sure to titrate oxygen to the lowest flow rate appropriate for your patient.

Noninvasive positive pressure ventilation (NIPPV) is a helpful treatment for some common causes of respiratory distress, including pulmonary edema, asthma, and chronic obstructive pulmonary disease (COPD).  Modes of NIPPV include continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP).  Physiologic benefits of NIPPV include improved oxygenation, reduction in work of breathing, recruitment of collapsed alveoli, and redistribution of fluid from alveoli back into the vasculature.  NIPPV has been shown to reduce need for intubation for patients with COPD and pulmonary edema, and is considered the standard of care for moderate-severe cases of these conditions.  NIPPV requires use of a tight-fitting mask, which is poorly tolerated by some patients, and it is absolutely contraindicated in patients who are unable to maintain or protect their airways.

High flow nasal cannula (HFNC) is a method of oxygen delivery that has become popular in recent years, particularly during the early pandemic when pulmonary COVID-19 was common.  HFNC delivers warmed, humidified oxygen at flow rates up to 60 L/min, and is very effective for improving refractory hypoxia in patients who don’t respond to conventional oxygen therapy.  HFNC is not available in all settings, and it is important to note that it is not just a regular nasal cannula turned up all the way - it requires specialized equipment to implement. 

Other treatments for respiratory distress are chosen based on the underlying etiology.  There is a broad differential diagnosis for respiratory distress, including pulmonary, cardiac, neurologic, and metabolic conditions.  Clues to the underlying cause of respiratory distress can be obtained through history, physical examination, and ancillary tests like chest imaging and laboratory studies.  All patients with significant respiratory distress should be auscultated to ensure that bilateral breath sounds are present, as tension pneumothorax must be identified and immediately treated if present.  All patients should also undergo chest radiography to screen for common causes of respiratory distress.  Further workup should be guided by clinical suspicion.

Respiratory Failure

The goal of treating respiratory distress is to prevent progression to respiratory failure.  Despite treatment, some patients will progress to respiratory failure, and it is important to recognize and promptly manage these patients.  Patients in respiratory failure are no longer able to compensate for their underlying disease process, and require respiratory support.  In some cases this can be accomplished with NIPPV, but usually intubation and mechanical ventilation will be required.  Treatment directed at the underlying cause of respiratory failure should always be provided along with respiratory support.

Some important causes of respiratory distress and failure:

Table 3. Important causes of respiratory and failure, with their diagnosis and management

Management of Shock

Monitoring:  Every critically ill patient should be monitored.  In shock, monitoring of heart rate and blood pressure will help you determine your patient’s degree of physiologic compromise, and keep track of their response to interventions.

Vascular access:  Every patient with shock must have adequate vascular access.  For an adult, this means two “large-bore” peripheral IVs (18g or bigger), or an intraosseous line, or a central line.  Remember that intraosseous lines are safe and simple, and are preferred over central lines for patients who need rapid access.  Also remember that central lines are long and thin, and therefore poorly suited for large-volume resuscitation – if your patient needs a lot of fluid or blood, use peripheral or intraosseous access, or place a large-caliber “trauma line.”

• Hypovolemic/hemorrhagic shock – do not use vasopressors!  The treatment is volume - either IV fluid or blood - rather than medication.
• Cardiogenic shock – use vasopressors to support inotropy and vascular tone.  Norepinephrine is the first-line agent.
• Septic shock – start with fluids, but if inadequate response to 30cc/kg of crystalloid, then begin vasopressors.  Norepinephrine is the first-line agent.
• Anaphylactic shock – epinephrine is the drug of choice in all cases, and it is not necessary to begin a fluid challenge before administering it.
• Obstructive shock – do not use vasopressors!  The focus of treatment is on alleviating the underlying obstruction.

The chart below summarizes diagnosis and treatment of the various causes of shock:

Table 4:  Causes of shock with their diagnosis and management

Pearls and Pitfalls

• Reassess, reassess, reassess! The primary survey isn’t a one-time evaluation - it must be repeated frequently to determine the patient’s response to interventions and to ensure that no new problems have arisen.
• Do a thorough physical exam.  Your patient needs to be fully exposed and examined head to toe so that you don’t miss potentially important clues about their diagnosis
• In cases of airway obstruction, prepare for the worst. NEVER begin an intubation without having all the equipment, personnel, and medications needed for success.  Have a plan, a backup plan, and a secondary backup plan - particularly if your patient has signs of a potentially difficult airway.  When you anticipate trouble, get help if time and circumstances permit.
• In the acute phase of resuscitation, there is no such thing as too much oxygen.  If your patient has acute respiratory distress or hypoxia, don’t hesitate to give them as much oxygen as they need to maintain appropriate saturations.  Just remember to reduce it to the minimum needed once they’re stable.
• Always make sure you have adequate IV access, which means two large-bore peripherals for adults!  That ensures that you’ll always have a backup if one falls out or becomes infiltrated.

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Case Study Resolution

Once you get your patient undressed, you find a chronic wound on his leg that is obviously infected.  He has a temperature of 101.9.  You suspect sepsis as the cause of his shock, and start 30cc/kg of lactated ringers, along with oxygen via nasal cannula.  His respirations and oxygen saturation normalize, and his blood pressure comes up to 102/60.  You start broad spectrum antibiotics, and begin the workup to look for an abscess or necrotizing fasciitis.  Leaving the critical care bay, you encounter the patient’s wife, who is standing in the hallway obviously distraught.  When she asks how he is, you take her hand.  “He’s stable now,” you say with a smile.  And you realize in that moment that you saved his life!