Anesthesia and Perioperative Safety

Chapter 12 Anesthesia and Perioperative Safety



Deborah Dlugose, RN, CCRN, CRNA


Safety is the most important consideration in anesthesia care. The risk for death associated with anesthesia care has diminished greatly during the past 50 years. In To Err Is Human, the landmark publication that ignited the twenty-first century health care safety revolution, the authors specifically recognize the pioneering role of anesthesiology in advancing patient safety by a dedicated and consistent professional action program (Kohn et al, 2000).


Although each team member in perioperative care has specific profession-related goals, everyone is also invested in the anesthesia provider’s patient commitments: maintenance of airway, breathing, circulation, and other physiologic parameters; provision of analgesia, sleep, and amnesia; and optimizing anatomic and physiologic conditions for the surgeon’s work. Safety issues become more complicated by factors such as individual patient variability, complex medical and surgical conditions, defined institutional processes, and anesthesia-unique complications. Orkin and Longnecker (2008) relate about 75% of risk to patient-specific characteristics, including age, gender, and comorbidities; surgical issues account for 20% of risk; and 5% of risk is assigned directly to anesthesia-related factors.


With shared commitment to safety, everyone in the operating room (OR) is a member of the anesthesia care team. Complete safe care of the surgical patient cannot be separated from the anesthesia care. Anesthesia providers rely on other team members to help prevent certain complications and to assist with treatment of others. Knowledge about selected anesthesia complications and ongoing communication with anesthesia providers are essential components of perioperative safety. The different vantage point of perioperative nurses in the surgical environment, as well as sharply honed nursing skills and professional intuition (Benner and Tanner, 1987; Rovithis and Parissopoulos, 2005), also link them to the anesthesia team as communicators, patient advocates, resource providers, and hands-on colleagues.


Anesthesia providers, perioperative nurses, surgeons, and other team members share responsibility for many safety protocols and issues. Some of these include positioning, infection control, fire safety, latex allergy, electrosurgery safety, thermal support, and the Universal Protocol/Time Out for Patient Safety. These topics are addressed in other chapters of this book; their importance binds everyone together on the perioperative continuum.


Anesthesia care always has potential for disaster. Anesthesia providers deliver potent medications, interfere with breathing, alter physiology, and perform invasive procedures, often on patients with serious underlying medical and surgical problems, using sophisticated equipment and supplies. There is little or no margin of error. Quick intervention may be necessary, sometimes to the point of full resuscitative efforts. Vital sign changes, airway problems, major bleeding, or other serious intraoperative events sometimes require skilled assistance from other perioperative team members. Although the most serious anesthesia complications are very rare, it is important for the entire team to be prepared for them, just as airline, submarine, and space crews prepare for disasters. The goal of anesthesia care must be to ensure that no patient is harmed (Cooper and Longnecker, 2008). We must constantly remind ourselves that as anesthesia safety has improved during past decades, complacency and overconfidence are frequently our companions. Consider the analogy of Captain “Sully” Sullenberger’s safe landing of a large airliner on the Hudson River on January 16, 2009, with no loss of life to 155 passengers, after a bird strike caused complete engine failure (McFadden, 2009). Only a truly well-prepared team with disaster training and a strong leader could manage such a dramatic event. Like Captain Sullenberger and his crew, the perioperative team must be fully prepared for disasters we hope not to experience.


This chapter provides an overview of anesthesia care with an emphasis on selected complications and safety issues that may require perioperative team action. This knowledge will increase the ability of perioperative nurses to assist in minimizing anesthesia-related complications and to maximize team action when unforeseen complications occur. All team members may be required to participate when anesthesia providers must handle complications with rapid assessment, quick prioritization, and immediate intervention. This teamwork challenge may be magnified by the multiple responsibilities carried by perioperative nurses.


The foundation for anesthesia patient safety begins with preanesthetic assessment and planning for each patient, with anesthetic strategy tailored to individual patient needs as well as surgeons’ and institutional requirements. That discussion is beyond the scope of this chapter, yet it lies behind every patient’s safe care: anticipation of potential problems, planning how to avoid them, and intervening appropriately if problems arise despite best efforts. Some of this preplanning must be closely coordinated between anesthesia providers and perioperative nurses (e.g., latex allergy, unusual blood type). Ideally, potential anesthesia issues should be shared at the time-out before the procedure’s beginning; unfortunately, some anesthesia complications arise in an unforeseen manner after procedures are underway.



TYPES OF ANESTHESIA


Although general anesthesia comes first to mind, anesthesia providers deliver a wide spectrum of other techniques, ranging from local anesthesia (with or without sedation and analgesia) to peripheral nerve blocks to central neural blocks (spinal or epidural). Combination techniques may be used for some procedures. Perioperative nurses and team members may assist with any of these techniques at selected points. Significant complications may arise with any anesthetic technique.



General Anesthesia


General anesthesia uses a variety of techniques in which unconsciousness is induced to provide hypnosis (sleep), amnesia (memory loss), and immobility. General anesthesia agents also have significant side effects (and potential complications) on all major body systems. Thus anesthesia providers delicately balance beneficial dosages against side effects and complications, in the dynamic scenario of surgical actions and physiologic responses.


Most commonly, general anesthesia is delivered by an inhalational agent such as desflurane, sevoflurane, or isoflurane, which are liquid agents vaporized in the anesthesia machine. The vaporized agent molecules are delivered to the patient’s lungs on carrier gases (oxygen, nitrous oxide, medical air, or some combination) via face mask, endotracheal tube, or laryngeal mask airway (LMA). Although various inhalational agents have been used for about 160 years, the exact mechanism by which they cause general anesthesia when they reach the brain is unknown.


Intravenous narcotics, neuromuscular blocker drugs, and other adjuncts such as antiemetics, antibiotics, and steroids may also be provided. General anesthesia may also be delivered completely as total intravenous anesthesia (TIVA) in selected situations, such as known or suspected malignant hyperthermia, when inhalational agents must be avoided.


Anesthesia providers carefully titrate all medications and agents throughout the anesthetic course, based on information from the patient’s vital sign monitors and the surgical field, as well as knowledge of physiology and pharmacology. The anesthesia provider is the most important monitor; all of the machines are simply extensions of the individual’s ability to gather information about the patient’s physiologic status. As technology has advanced, sophisticated monitoring devices have increased our assessment ability. However, safe anesthesia care requires vigilant prepared human providers with engaged brains. In the event of serious complications or crises, support from other anesthesia providers and perioperative team members is necessary.



Induction and Emergence


Induction of anesthesia may be one of the most taxing times for anesthesia providers, with multiple crisis opportunities in this brief period, much like the takeoff of an airliner. Although this challenging period coincides with the perioperative nurse’s own demanding responsibilities at the beginning of the case, true commitment to patient safety requires that anesthesia providers have hands-on colleagues available to assist in case of difficulty. If another anesthesia provider is available, the perioperative nurse should still maintain vigilance on the induction situation, in case even more help is needed.


As surgery starts, the anesthesia provider’s goal is to match the anesthetic level to the surgical situation, delivering appropriate amounts of medications as surgical stimuli wax and wane, as well as handling physiologic reactions that may result from underlying disease or from drug interactions. All doses are titrated exactly to the individual patient and the surgical moment; there are no standard “cookbook” anesthesia recipes. Although it may appear that identical anesthetic courses are delivered to various patients, decisions are actually matched to individuals and circumstances. Although perioperative team members may assume that “nothing is happening” during a quiet anesthesia period as uncomplicated surgery progresses, the anesthesia provider is gently adjusting medications, fluids, and techniques for smooth maintenance as well as a timely emergence at the end of surgery. Although smooth anesthesia maintenance (like a smooth airline flight) is everyone’s goal, development of any of the complications reviewed in this chapter (and others) will rapidly shift the anesthesia provider into a high-activity mode. The whole team may be called into assistance, including surgeons, perioperative nurses, and ancillary personnel.


As surgery draws to an end, the anesthesia provider starts the process of emergence, much as an airline captain starts final descent. The anesthesia provider takes multiple steps that aim to awaken the patient very shortly after the dressing is placed, in stable condition, ready for transport to the postanesthesia care unit (PACU). Reduction of percentage of inhalational agent, reversal of neuromuscular blockade, and return to 100% oxygen (with agent finally turned off) bring the patient back to consciousness, with strong spontaneous breathing, strong protective airway reflexes (cough, gag, swallow), excellent muscle strength (indicated both by peripheral nerve stimulator and motor activity), as well as the ability to follow commands, which confirms return of higher brain function. At this point the trachea may be extubated or the LMA removed after oropharyngeal suction, with face mask oxygen immediately applied. Every step in this process has profound safety implications because significant crises can easily arise during emergence, just as problems may arise during airline landings. Some of these potential crises will be discussed later.


In this emergence period, perioperative nurses are also taxed with end-of-case responsibilities, yet first allegiance to patient safety requires presence and engagement during the emergence process. Besides increasing safety, participation with anesthesia providers during the most critical parts of anesthesia care increases the ability of perioperative nurses to provide meaningful reports to the next registered nurse (RN) in the PACU or the intensive care unit. A structured communication tool such as the SBAR (situation, background, assessment, recommendation) report developed by the Institute for Healthcare Improvement (2009) and adapted by others allows coherent organization of the information to be transmitted. Although anesthesia providers deliver the full anesthesia care report, the perioperative nurse’s responsibility for the whole patient should include a brief description of the anesthetic course, especially if there were untoward events or crises. Reports that focus only on surgical drains, dressings, and names of procedures diminish the role of the perioperative nurse as a professional participant in whole-patient care. Communication and interaction among the anesthesia provider, surgeon, and perioperative nurse during events of the procedure are then summarized at the end-of-procedure sign-out, as recommended by safety groups such as the World Health Organization (2008).


Transport from OR to the next unit requires supplemental oxygen and—for some patients—hemodynamic monitoring. Whether or not perioperative nurses accompany patients to the next unit, nursing care should be finalized with brief, clear communication and documentation of the anesthetic course, surgical procedure, and nursing-related concerns.



Safety and General Anesthesia


Safety issues for general anesthesia may be related to anesthesia techniques, patient variability, underlying medical conditions, and surgical situations. This section will review some of the most common acute perioperative safety concerns.



Airway Problems


Airway maintenance is paramount. Many airway issues are only mildly complicated. Anesthesia providers may cope with patient anatomy that creates difficult mask ventilation or difficult intubation, but both may be achieved without danger, often with the help of other team members and airway adjuncts, such as oral airways, nasal airways, LMAs, various laryngoscopes, and videolaryngoscopes.


However, despite best efforts, complete inability to oxygenate and ventilate a patient by any means may occur, creating a “lost airway.” This critical airway situation requires the full attention of everyone in the operating room because nothing else matters if the airway is lost. Failure to deliver oxygen and remove carbon dioxide from organs and tissues will quickly result in serious injury to tissues and organs, followed by death (Hagberg et al, 2005). As technology, training, and crisis anticipation have improved during recent decades, deaths associated with airway problems at induction have decreased. However, difficult airway problems during maintenance, emergence, and recovery have not decreased. (Peterson et al, 2005).


The American Society of Anesthesiologists (ASA) has developed Practice Guidelines for Management of the Difficult Airway (Figure 12-1). As part of the ASA Difficult Airway Algorithm, anesthesia providers aim to avoid problems with careful preanesthetic assessment to allow safe planning for potentially difficult airways identified in advance (ASA, 2003).


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Figure 12-1 The American Society of Anesthesiologists (ASA) Difficult Airway Algorithm.


(From ASA Task Force on Management of the Difficult Airway: Practice guidelines for management of the difficult airway: an updated report, Anesthesiology 98:1269–1277, 2003.)


The Mallampati classification of oral opening (Mallampati, 1983) has become well established as one of the simplest elements of airway evaluation, although it is not a stand-alone assessment. Perioperative nurses should be familiar with the Mallampati classification for their own planning at the beginning of a case when word arrives of a patient with a class III or class IV airway, or if they participate in preoperative evaluations themselves (Figure 12-2). Preliminary airway evaluation has moved into the realm of nursing practice (Odom-Forren and Watson, 2005).


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Figure 12-2 Modified Mallampati classification of pharyngeal structures. Class I, Soft palate, tonsillar fauces, tonsillar pillars, and uvula visualized. Class II, Soft palate, tonsillar fauces, and uvula visualized. Class III, Soft palate and base of uvula visualized. Class IV, Soft palate not visualized.


(From Samsoon GL, Young JR: Difficult tracheal intubation: a retrospective study, Anaesthesia 42:487–490, 1987.)


Some other conditions that may be associated with difficult intubation and airway management include obesity; obstructive sleep apnea (OSA); inadequate neck extension related to arthritis, ankylosing spondylitis, or fusion; tumors; epiglottitis; neck abscesses; postoperative hematomas; airway trauma; and foreign body. The classic difficult airway, often associated with obesity and obstructive sleep apnea, includes a short thick neck, large tongue, and generous submandibular tissue, which reflects redundant tissue in the oropharyngeal and laryngeal areas. Prominent upper incisors (“buck teeth”) and receding mandible also make laryngoscopy difficult. Men with full beards may be difficult for mask ventilation, although not necessarily for intubation, unless it is discovered that the beard was grown to disguise an anomaly such as an extremely receding mandible.


The results of preanesthetic airway evaluation are not completely reliable. Occasionally an airway that has been deemed easy by examination parameters results in unanticipated difficulty; conversely, a planned difficult airway may turn out to be surprisingly easy to manage. However, most anesthesia providers experience that classic predictors of difficult airway management are usually true, and conservative action is the standard of care. Knowledge of a difficult airway allows planning for safe management to secure the airway, often with techniques such as awake, sedated fiberoptic-assisted intubation after topical local anesthetic (LA) has been applied to the mucosa of the airway to reduce gag and cough reflexes. Recent introduction of videolaryngoscopes to clinical practice has improved ability to visualize airway structures in many patients whose intubation pathways in the past may have included fiberoptic-assisted technique. However, the videolaryngoscope is only a major step forward in safety, not a guarantee for every patient airway.


Unanticipated difficult airway management may arise from several situations, such as difficult tracheal intubation despite preoperative evaluation deemed adequate; oversedation during a planned “awake” intubation; unrecognized esophageal intubation; airway obstruction by laryngospasm or edema; postoperative bleeding in neck surgery; tumor; vomitus or foreign body; or failure to establish a surgical airway quickly when conventional airway maneuvers fail. It is important to note that patients with OSA have a high incidence of difficult intubation and that patients with difficult intubations have a high incidence of sleep apnea (F. Chung et al, 2008). OSA patients require extra care and planning both for airway management and for their increased postoperative risk for easy oversedation with analgesics (ASA, 2006b). Many cases have been reported of postoperative hypoventilation or respiratory arrest in OSA patients with emergency treatment ending up with a difficult-to-impossible airway by providers unfamiliar with appropriate airway rescue techniques. Although the serious nature of obstructive sleep apnea is recognized by anesthesia providers (S.A. Chung et al, 2008), it is important for all team members to understand its acute and chronic implications.


Any difficult airway situation quickly requires help from other team members. Everyone in the operating suite should know the exact location of the difficult airway cart, what to unplug to transport it to the bedside, and what its various components include. Perioperative nurses provide valuable leadership in this process as well as hands-on skill for assistance with mask-ventilation, airway suction, cricoid pressure, opening and testing of airway devices, and documentation of events, medications, vital signs, and times during an airway crisis.


Familiarity with airway techniques such as LMA, intubating laryngeal mask airway (ILMA) (Liu et al, 2008), lightwands (Massó et al, 2006), and videolaryngoscopes allow perioperative nurses to assist anesthesia providers with airway rescue attempts and to document these techniques appropriately. Although such documentation may not be part of formal perioperative nursing notes, they may be considered analogous to Code Blue records; even informal notes and times can be helpful to the anesthesia provider who must later create a detailed report of the crisis.



Difficult Airway Classification


If intubation cannot be achieved, but oxygenation and ventilation can be maintained by face mask or LMA, the airway is classified as difficult. However, if the situation deteriorates to the situation of “cannot ventilate (by mask/LMA) and cannot intubate,” the airway is declared lost. The clock is ticking as oxygenation falls, CO2 rises, and tissue and organ damage become imminent.


The steps for handling such a crisis are outlined in the ASA Difficult Airway Algorithm (ASA, 2003). Although perioperative nurses do not perform airway rescue, they must be familiar with basic knowledge of the algorithm’s steps. With the possibility that movement through the algorithm’s steps may fail to secure the airway by various endotracheal intubation techniques, perioperative nurses must anticipate and prepare for a rapid surgical airway.


The decision for an immediate surgical airway (cricothyroidotomy or tracheostomy) cannot be delayed; worsening hypoxemia and hypercarbia that occur with a lost airway may lead to cardiopulmonary arrest. Full advanced life support should be anticipated before it is needed. Concurrent airway rescue and advanced cardiac life support may be required.


Any airway difficulty at the beginning of a procedure sets the stage for extra caution at the end of the procedure, when extubation is considered (and may possibly be delayed for safety reasons). Premature extubation in a difficult airway patient may result in a repeat difficult airway situation, with chance of rescue reduced the second time around, because of airway edema, trauma related to prior attempts, or intrinsic pathologic conditions such as obstructive sleep apnea (Isono, 2009). The airway danger during this period cannot be minimized. Fully awake extubation in the sitting position is mandatory; some suggest extubating over an airway exchange catheter, which is left in the trachea as a conduit to allow rapid blind reintubation if deterioration occurs (Mort, 2007). Transfer planning, documentation, and nursing report must emphasize the critical airway status, which may overshadow an uncomplicated surgical course.


Patients who have had a difficult airway experience should be notified in writing, including a description of what technique finally worked to secure the airway. There is also a Medic-Alert Registry for Difficult Airway.



Dental Injury


Dental injury is one of the most common anesthesia complications (Hagberg et al, 2005). All patients should be advised of this risk before anesthesia care, personalized to their own dental status (Anderson and Abbey, 2008). Perioperative nurses should be aware of dental status, as well as dental prostheses. However, every anesthesia provider has anecdotes about dental prostheses discovered after induction of general anesthesia, related to patient’s denial of appliances, staff overlook of prostheses, or some combination of circumstances.


Teeth are easily damaged during airway manipulation and laryngoscopy, particularly when loose or in poor condition as a result of periodontal disease or caries. Although most patients with poor dentition seem to show minimal concern with tooth loss during airway manipulation, a dislodged tooth that tumbles into the airway creates danger by airway obstruction. To prevent this problem, the anesthesia provider may deliberately remove a very loose tooth just before laryngoscopy; it must be properly labeled in a specimen cup for the patient. A tooth that is unintentionally loosened and falls down the airway must be retrieved by bronchoscopy or esophagoscopy. Young children with loose teeth should have any removed teeth saved both to protect their airways and to provide to parents or guardian.


Even smooth endotracheal intubation technique may elicit physiologic complications related to patient comorbidities. Hypertension, dysrhythmias, or myocardial ischemia may be provoked by the sympathetic stimulation of laryngoscopy and intubation. Patients with poor respiratory status may develop hypoxemia and/or hypercarbia, as well as laryngospasm and bronchospasm. Increased intracranial pressure and increased intraocular pressure from the stimulus of laryngoscopy are serious concerns for neurosurgical and ophthalmology patients. Tissue damage to lips, tongue, uvula, vocal cords, esophagus, or other laryngeal structures is always possible. Cervical spine or temporomandibular joint injuries may also occur during airway manipulation. Some of these complications may be readily evident and serious enough to cause cancellation of surgery (e.g., myocardial ischemia); some may be noted later with minor effect (e.g., postintubation sore throat); and some may be noted later with potentially critical results (e.g., esophageal tear).



Breathing Problems


The patient with a clear and patent airway (natural, endotracheal tube, or tracheostomy) may risk other breathing complications. Successful breathing requires satisfactory maintenance of both oxygenation and ventilation. Anesthesia providers monitor these two aspects of breathing very closely: oxygenation with pulse oximetry (SpO2) and ventilation (removal of CO2) with capnography. Every anesthesia technique has risks that could interfere with oxygenation, ventilation, or both (Morgan et al, 2006).


In some situations, difficulties with falling oxygenation may be temporarily overridden by increasing oxygen flow to the patient while ascertaining the problem’s source. Although every operating room denizen is familiar with loss of pulse-oximetry signal with certain artifacts (such as cautery), a true decrease in the SpO2 is a critical event. If oxygenation falls to the point where cells cannot maintain oxygen-based aerobic metabolism, cellular switch to anaerobic metabolism will create lactic acid byproducts. This increased acid environment and falling pH disrupts cellular and organ function, creating a critical downward physiologic spiral that must be reversed before death ensues.


If the breathing problem includes difficulty in removing CO2 (hypoventilation), the increased CO2 adds to the bloodstream’s acidity with potential for further cellular insult. In addition, rising CO2 contributes to decreasing level of consciousness (“CO2 narcosis”). An understanding of arterial blood gases in respiratory crisis helps perioperative nurses predict future steps likely to be requested by anesthesia providers, as well as the likelihood that a breathing problem could turn into a full arrest scenario. Anesthesia providers aim to prevent breathing issues, but accept that early recognition and treatment are essential when respiratory problems arise.



Laryngospasm


The classic description of laryngospasm as vocal cords snapping shut in spasm if the patient’s larynx becomes irritated in the light stages of anesthesia has been shown to also include other laryngeal structures (such as arytenoids and aryepiglottic folds) infolding upon themselves with the epiglottis covering these structures. An occluded airway results.


Laryngospasm can be provoked by secretions, sudden stimulation, pain, and airway manipulation. In patients who are most at risk for laryngo-spasm, such as children with airway surgery, many airway providers try to avoid the problem by extubating the child in a deeper plane of anesthesia, after return of spontaneous ventilation; they support the airway by face mask with 100% oxygen until the child awakens (Morgan, 2006).


First treatment for laryngospasm is a firm jaw thrust, which elevates the hyoid bone at the top of the trachea, unfolding the epiglottis and aryepiglottic folds; 100% oxygen is also delivered through a tightly fitting face mask with positive pressure. If the spasm does not break, a small dose of a short-acting neuromuscular blocker (succinylcholine) may be given, with ventilation assisted appropriately. Gentle suction of the oropharynx should ensure that no blood, secretions, or gastric contents are present to reirritate the larynx.


Perioperative nurses who are present during laryngospasm should be prepared to help with mask seal, as well as to communicate vital signs from the monitor (likely to be behind the anesthesia provider, who is concentrating on maintaining the airway).


A sputtering cough and gasp indicates the breaking of the spasm. However, the patient requires mask oxygenation and close monitoring until full return to consciousness. In an infant or child, a cry or yell for “Mommy” indicates both air movement and return to a higher level of consciousness. Laryngospasm may also occur in adults, although it is less common. After laryngospasm, patients must be monitored for development of negative-pressure pulmonary edema, as discussed later (Mirshab, 2002).



Stridor


Postintubation stridor (commonly called croup in children) is caused by edema of vocal cords or trachea. It is most common in children ages 1 to 4 years, appearing within 3 hours of extubation. The work of breathing is greatly increased by even a few millimeters of edema in a toddler’s airway, which mandates immediate treatment with nebulized racemic epinephrine. Intravenous dexamethasone may be given for prevention (Morgan et al, 2006). The condition is occasionally seen in adults and treated with the same regimen.



Bronchospasm


Bronchospasm can occur just from the insult of placing an endotracheal tube into the trachea of a susceptible patient. Wheezing is the sound of air moving through narrowed airways, much like a whistle. Although wheezing is considered the classic sign of bronchospasm, the most dangerous presentation is a “silent spasm” in which the spasm is so intense that no air can be moved. This intense bronchospasm is most likely to occur with an asthmatic patient during intubation under general anesthesia, when a combination of factors related to disease, medications, and mechanical insult (laryngoscopy and intubation) combine to result in bronchospasm. Severe bronchospasm may result in reduced ability to oxygenate or ventilate the patient. The anesthesia provider will treat the bronchospasm with 100% oxygen and aerosol or metered-dose beta-adrenergic agents into the breathing circuit. The inhalational anesthetic agents are also bronchodilators. Steroid-dependent asthmatics may also receive a dose of intravenous hydrocortisone (Morgan et al, 2006). The severity of the episode and its response to treatment will be evaluated by the anesthesia provider and the surgeon before proceeding with surgery or for postoperative care planning. New postoperative arrangements for an intensive care bed may be required.



Aspiration of Gastric Contents


Many patients believe that nothing by mouth (NPO) status is imposed to prevent the inconvenience and discomfort of postoperative nausea and vomiting. They have not been educated about the serious morbidity and mortality that can follow aspiration of gastric contents; the low acidic pH of gastric acid may create a chemical pneumonitis that can be widely spread through the lungs if the aspirated volume is greater than 0.4 mL/kg and the pH is less than 2.5 (Morgan et al, 2006). If food particles, blood, small objects, or teeth are aspirated, severe hypoxemia can follow because of airway obstruction, development of atelectasis, and pneumonitis. In the most-dreaded scenario, the pathologic response accelerates into full-blown respiratory distress syndrome, which may culminate in death.


Patients who have received induction doses of sedative or anesthetic medication no longer have airway reflexes (cough, gag, swallow) to protect their airways. Others are at risk for aspiration because of emergency surgery shortly after eating or drinking or because of blood in the upper gastrointestinal (GI) tract or GI obstruction. Some patients are identified preoperatively to be at extra risk for aspiration of gastric contents. These include patients with reduced airway reflexes (drug or alcohol intoxication, central nervous system diseases, neuromuscular diseases, pregnancy, uncontrolled gastroesophageal reflux, or large hiatal hernia). These patients are often treated with medications to increase gastric emptying (e.g., metoclopramide), to reduce gastric acid (e.g., an H2 blocker such as ranitidine or famotidine), or to raise gastric pH (a clear antacid such as Bicitra). These medications reduce the chance for passive regurgitation of gastric contents into the larynx during induction of general anesthesia, before the airway is secured with a cuffed endotracheal tube.


In addition to the aforementioned medications to reduce risk, anesthesia providers will choose a technique to secure the airway in a manner that minimizes risk, if general anesthesia is required. If the patient’s airway has been assessed as potentially difficult to manage, the anesthesia provider may opt for awake intubation. This process includes topical LA to the airway by nebulizer, spray, or gargle, with the patient sitting upright. Small amounts of sedation may be given, but patient cooperation must be maintained as the fiberoptic bronchoscope is used to secure the airway with a cuffed endotracheal tube before induction of general anesthesia and placing into supine position for surgery. Perioperative nurses’ understanding of the anesthesia plan will include recognition of the twofold safety goal of difficult airway management and prevention of aspiration of gastric contents.


If the patient’s airway has been deemed nondifficult ahead of time, the anesthesia provider is likely to choose a rapid-sequence induction with the Sellick maneuver (i.e., cricoid pressure). Perioperative nurses are frequently called upon to provide cricoid pressure without recognizing that this simple act may have critical implications for patient safety.


It is essential to know how to identify the cricoid ring (which is the only tracheal ring that is a full circle; all the others are C-shaped, with the open section toward the spine). The large shield-shaped thyroid cartilage (“Adam’s apple”) is the most prominent landmark of the upper trachea with its bottom midmargin at the top of a small, soft elliptical space (Figure 12-3). This indentation is the cricothyroid space (where emergency cricothyroidotomy is done). The strip of cartilage just below the cricothyroid space is the cricoid ring. In a supine unconscious patient, firm pressure on this circular cricoid cartilage will occlude the esophagus and prevent regurgitation of gastric contents into larynx and lungs.


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Figure 12-3 Applying cricoid pressure.


(Redrawn from Witten C: Anyone can intubate, ed 4, San Diego, 1997, K-W Publications. In Rothrock JC: Alexander’s care of the patient in surgery, ed 13, St. Louis, 2007, Mosby.)

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Aug 5, 2016 | Posted by in ANESTHESIA | Comments Off on Anesthesia and Perioperative Safety

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