Postoperative Tracheal Extubation

Although tracheal intubation receives much attention, especially with regard to management of the difficult airway, tracheal extubation has received relatively little emphasis. The scope and significance of problems occurring after tracheal extubation are real. Adverse outcomes involving the respiratory system comprise the single largest class of injury reported in the ASA Closed Claims Study [1]. Obvious adverse events related to tracheal extubation accounted for 35 of the 522 or 7% of the respiratory-related claims. Certainly additional morbidity related to extubation could be accounted for in other categories of adverse respiratory events, such as inadequate ventilation, airway obstruction, bronchospasm, and aspiration. Others have documented a 4%-9% incidence of serious adverse respiratory events in the immediate postextubation period [2,3] and preventable anesthesia-related etiologies were noted as important by Ruth et al. [2]. Mathew et al. [4], in a retrospective review of more than 13,000 anesthetics, noted that emergency tracheal reintubations occurred in only 0.19% of patients, and that the majority of tracheal reintubations were due to preventable anesthesia-related factors. Perhaps a greater percentage of patients experience postextubation difficulties but do not require reintubation of the trachea. Reasons for tracheal reintubation in the intensive care setting may differ, but the reported incidence in that arena is similarly 4% [5]. Anesthesiologists recognize the immediate postextubation period as one where patients are particularly vulnerable. Events such as laryngospasm, aspiration, inadequate airway patency, or inadequate ventilatory drive can occur and frequently result in hypoxemia. Such hypoxemia is most often corrected within minutes. Less frequently, postextubation hypoxemia can rapidly result in serious morbidity. In this report we will review the known physiologic and pathophysiologic changes associated with anesthesia and surgery that can influence respiratory function after tracheal extubation, the physiologic impact of extubation itself, criteria used for predicting successful extubation, and different techniques and interventions used for tracheal extubation. It is not our intent to review the complications of laryngoscopy and tracheal intubation. However, common complications of tracheal intubation, with special emphasis on the airway, will be discussed in detail as they frequently affect respiratory function after tracheal extubation. More uncommon and miscellaneous complications, such as problems related to the endotracheal tube cuff, recently have been reviewed [6]. Effects of Anesthesia and Surgery on Respiratory Function After Extubation After the "ideal" extubation, patients would exhibit adequate ventilatory drive, a normal breathing pattern, a patent airway with intact protective reflexes, normal pulmonary function, and the absence of any mechanical perturbations such as coughing. Unfortunately, all of these conditions are rarely, if ever, achieved in patients extubated after anesthesia. Understanding the potential interactions between anesthesia, surgery, and extubation on respiratory function helps define many of the complications that occur at this crucial juncture in anesthesia care. This section will include a discussion of the effects of anesthesia and surgery on the respiratory system which are common during extubation, with major emphasis on the airway and lung. Airway Changes Any form of airway dysfunction, such as obstruction after tracheal extubation, is an immediate threat to patient safety. Significant airway compromise leads to diminished minute ventilatory volumes and hypoxemia ensues in a variable, but often rapid fashion. A differential diagnosis of acute postoperative obstruction of the upper airway after extubation includes: laryngospasm, relaxed airway muscles, soft tissue edema, cervical hematoma, vocal-cord paralysis, and vocal-cord dysfunction Table 1. Airway obstruction from foreign body aspiration (e.g., temperature probe condoms) will not be reviewed but deserves mention.Table 1: Differential Diagnosis of Postoperative Airway ObstructionLaryngospasm Laryngospasm, defined by Keating [7] as a protective reflex, can be life-threatening when it occurs after extubation. Historically, a patient in Stage II anesthesia has been thought to be particularly vulnerable to laryngospasm [8]. Stimulation of a variety of sites from the nasal mucosa to the diaphragm can evoke laryngospasm [9]. Most commonly, laryngospasm is a reaction to a foreign body or substance near the glottis. Blood or saliva, even in small amounts, can elicit laryngospasm. It has been suggested that laryngospasm can be prevented by extubating a patient under deep anesthesia, while the laryngeal reflexes are depressed [8]. However, substantial proof of this tenet is lacking. Suzuki and Sasaki [10] contend that laryngospasm is solely attributable to prolonged adduction of the vocal cords mediated via the superior laryngeal nerve and cricothyroid muscle. Ikari and Sasaki [11] have that the of the laryngeal in laryngospasm in a during laryngeal occurs more during than 1. Others that laryngospasm of the in to adduction of the vocal of the from of the and muscles, which are by the laryngeal nerve [9]. and of laryngospasm be if complications such as hypoxemia or pulmonary are to be 1: in for with to respiratory the during with Ikari Airway obstruction related to of airway soft tissue is frequently associated with effects of anesthesia. Such obstruction is to be most due to of the airway of upper airway occurs by a that the the and normal an in of these of the diaphragm and of the and soft the to patients which in a in of the that associated with airway Airway has been prevented by of the in The of airway obstruction in a in the of these upper airway The tissue obstruction is a of but sites include the soft the as for upper airway obstruction after extubation is from of the of obstruction in patients, other and anesthesia et al. after in patients that obstruction is to of the patients experience obstruction from of the to airway that occurs during rapid in patients have of the with airway obstruction et al. reported in nerve which with in were airway In of airway obstruction during under cervical nerve dysfunction as a and have that obstruction occurs at the of the soft in patients et al. obstruction at the soft in of patients, the in of patients, and the in of patients and and that the of the to the the of airway the and by et al. in of the to the and is in the The soft to be the most of airway of the especially when it is can airway and after of anesthesia, soft obstruction of the airway during anesthesia. airway and with from of on the of the on and after of anesthesia. soft of with from of on the soft is a potential of postextubation airway obstruction The of is but suggested include mechanical from airway endotracheal nasal laryngeal and of the airway patients, and especially with may experience and related airway obstruction Surgery involving the or cervical may result in and airway in an to serious has been and obstruction can occur even after of after surgery is the of et al. a review of of postoperative upper airway obstruction after cervical of the patients of edema, while of the of cervical after surgery can airway Such can and airway obstruction after extubation. The of airway obstruction associated with cervical is the obstruction of and by the in can the of airway such as the by a is not et al. the postoperative of patients cervical and respiratory which immediate in of After of anesthesia, of these patients were to and could not be The patients of to the of these could not be and were difficult to reported of cervical a patient airway obstruction after A but not airway The airway obstruction thought to be to The incidence of cervical after is as with an percentage of these patients airway obstruction these patients to the for the absence of or respiratory not from as as edema, may by of the vocal cords and tracheal intubation difficult or In of the may not airway Such patients be extubated and when is that has surgery can of the and compromise postoperative airway function, especially after or surgery of a used in can result in as by of from associated during has been reported to to a in the may have in such that obstruction of of the in edema, and airway obstruction such the of an airway may of the and compromise reaction to used to is of can be as to to reintubation during in may or all of airway and can result in and airway vocal may after extubation vocal may upper airway obstruction is to injury of the laryngeal nerve in superior laryngeal nerve mediated adduction of the vocal Such an injury can occur with surgery surgery and endotracheal intubation are frequently as a of vocal paralysis, and suggested include endotracheal tube of the laryngeal nerve the of the of the endotracheal tube or to the vocal cords may the incidence of this from of can to vocal especially in that are the dysfunction is an uncommon of airway in by It has been by vocal laryngeal and of the are in The patient from the reported to of with a of an upper respiratory and with laryngeal or upper airway to but the is to of difficulties that result from adduction of the vocal cords during can be and require the of an or airway will obstruction with a in to but of the vocal cords during a is for a diagnosis for successful extubation of these patients include an extubation if adequate at the of extubation. the obstruction by and of a the patient to on the of breathing and if the diagnosis of as the of respiratory is have that laryngeal occurs after extubation or not effects are et al. patients surgery under patients postoperative of when to of or more after The majority of these patients of this been aspiration in of patients to after extubation, and et al. that of patients after extubation. surgery patients have a of aspiration when extubated than after surgery, even if This to when extubation is effects may to this incidence of aspiration in the postoperative In laryngeal is common and the of aspiration after extubation is not by the of airway reflex, can be by a of after surgery and anesthesia. recently reviewed anesthetics, tracheal intubation, or airway of and even can and pulmonary aspiration. et al. and et al. have that with of it is not the of this review to the impact of anesthesia on the of it is to the major ventilatory drive during tracheal extubation. Airway function is to the of breathing ventilation, is depressed by anesthesia. and are the common that can the ventilatory to Significant effects are often at the of tracheal extubation. the of as by the between of anesthetics, and in and in ventilatory to of the than in and of of ventilatory to during extubation and from surgery However, of may the ventilatory and such an can a and at in of ventilatory has been reported to be the of ventilatory drive and the et al. of ventilatory in and that even of and the ventilatory to A more report that ventilatory drive may not be depressed by of in but not ventilatory drive occur with as and of ventilation, a on the respiratory The of the respiratory to is by The of the ventilatory to is and minute ventilatory to in are to the The and are by the the body minute and from in and respiratory is by ventilatory drive and the in respiratory drive associated with such as airway or respiratory can occur in patients from anesthesia have received and for this include a of or of and other after of in and have noted in during the in in and breathing have been to the acute ventilatory to and This is not as as that after of effects with can be by of the of of the and can ventilatory drive, by in the body is one of the body in ventilatory drive of ventilatory can occur after extubation extubation, patient and can result in patient these events have can and result in an with inadequate especially in with the of in of ventilatory drive Function The physiologic at pathophysiologic changes during anesthesia that can after tracheal extubation. changes frequently include in of and depressed changes are rarely, if ever, of can be at may result in patient morbidity. the impact of anesthesia and surgery on function can influence after tracheal extubation. The most and after extubation is an in which occurs as a result of the endotracheal tube with the upper airway Significant changes in occur by of or with of anesthesia Postoperative in are associated with surgery of the or It is is after tracheal extubation. et al. and and is not after extubation, it is et al. a in in of patients after The in after of anesthesia and after extubation may be by different The in after by et al. In that of The for this in after of anesthesia has been to a of the diaphragm and after of anesthesia not result in a in The postoperative in is related to dysfunction et al. reported that dysfunction after surgery could to and in a greater on for dysfunction is to be to inadequate In to dysfunction, of postoperative in is breathing of can and and of the and after of anesthesia, of in the of with from et al. during anesthesia with of the of in are often not in are often to and that and Such if at the of extubation, can compromise a to airway difficulties by the for and of hypoxemia. The incidence of most frequently defined as an than after extubation and from anesthesia is many as of and of after a will be at a care if is during and in a review of hypoxemia during and after anesthesia, postoperative and inadequate minute or airway obstruction, other of hypoxemia include of pulmonary and a in include pulmonary hypoxemia more frequently than and Although the of has been reported to postoperative hypoxemia the majority of have not that the of in anesthesia is associated with an incidence of postoperative hypoxemia of hypoxemia in patients from anesthesia reported by thought the of could the of during and from anesthesia the incidence of is but not of dysfunction associated with anesthesia and surgery can to postoperative hypoxemia. from the respiratory with have been to have tracheal intubation and surgery result in dysfunction and or in can to of extubation of a breathing patient can the of breathing by airway and minute The of an endotracheal tube respiratory and in minute after extubation by in respiratory and all of which to within Most if airway obstruction is tracheal extubation in a in the The impact of other such as an airway, on the is Although the in after extubation be as noted the of an endotracheal tube may breathing and the respiratory effects of anesthesia while the adequate minute to extubation may not be the is frequently occurs during tracheal extubation. is a more and often that a a occurs at which are often than and are not only but can be can in patients with an injury or can be at and result from an in that to the associated with from anesthesia, is potential associated with an in to in a in especially in patients, can rapidly not only due to the in minute but to the associated in and The of hypoxemia after the greater and to the to the with which it The of during the extubation of patients is an important and and is one of the of the Effects of Extubation have documented that tracheal extubation and in and Although such is patients may experience or et al. that patients with experience in 7% to after extubation. The changes in occurred in the absence of of et al. reported that patients with a of than an to the of postoperative tracheal extubation after patients in and have to or of related to tracheal extubation in patients after surgery extubation after section in with can of and in and pulmonary It that tracheal extubation and related changes the of and pulmonary in as often occurs during tracheal extubation. can to in which can with to the The effects of on and and have been by et al. patients were to to and to 35 to in these In to can be at by tracheal extubation. Although these changes are patients at may be by tracheal extubation. the potential for events to extubation, while most often not be Effects of Extubation It is that laryngoscopy and intubation the in patients with However, the effects of tracheal extubation on have not been Although it is that extubation at in the of such effects be from other and reported that by in patients were et al. from to after endotracheal in intensive care The for than after that associated with endotracheal to by and tracheal extubation, especially when associated with or is to in often result from tracheal extubation as and can to or be associated with or in associated during and after extubation, can impact patients with The problems and of airway management in patients with cervical have been documented Although not the potential for during the extubation of such patients after cervical However, the as as the cervical surgery, can result in postoperative and airway injury or can drive and nerve and In the of tracheal extubation have not been and during tracheal extubation can all be especially in patients with The of adequate ventilatory drive and airway function after extubation is to be more difficult in patients or cervical Effects of Extubation that a and can result from the of anesthesia, tracheal intubation, and surgery has to of this the other the to tracheal extubation has received little et al. the impact of tracheal extubation on changes in of and in patients major were from to only after extubation. et al. an in which patients, or were with or and extubated at of anesthesia or Significant but in occurred in all patients but to greater in with and in extubated to in all patients extubated after anesthesia. Although in all patients after extubation, that an to tracheal extubation can This to be and in and to have a Extubation The to adequate respiratory function after extubation on many factors. In anesthesia and used to tracheal intubation and mechanical be In any of the for mechanical ventilation, they be (e.g., or (e.g., be that can adequate The setting often from the in that the to mechanical anesthetics, are In these are rapidly patients frequently require mechanical of and that with A discussion of the of patients from ventilatory is not the of this many of the criteria used to successful tracheal extubation are from the of such a patient will tracheal extubation after anesthesia of the as as the and impact of anesthetics, The system is of especially if dysfunction and immediate postoperative extubation. function criteria on and respiratory include breathing pattern, ventilatory drive, airway function, ventilatory and include in to adequate and respiratory the and The impact of and of adequate is for adequate and be achieved the are important and known to and criteria for predicting successful extubation are often lacking. single such as the be in but only as of function, and the patient as a used criteria used to to a patient will be breathing respiratory and the of successful extubation. of breathing a rapid breathing or a breathing of the and an that extubation will not be successful or that it is breathing is often to mechanical dysfunction and and patients and that the of minute by the in is a of extubation with of than successful tracheal extubation. In that the superior to minute ventilation, respiratory and or in predicting successful and extubation. or of the and can the of respiratory especially in of pulmonary Respiratory can this and in an to the and the diaphragm or breathing are in patients with airway Respiratory extubation after anesthesia is at in airway obstruction inadequate minute The of is to result in inadequate minute than airway obstruction often to adequate function by nerve and et al. nerve suggested that a of to with of adequate and extubation. However, the adequate and airway after tracheal extubation. for this include the that of the has not been to be The of than may the that to of patients have a of than such as in can the of The has been suggested to the of nerve Although of the is at predicting a than it is only in predicting a than the the when with a nerve and do not the diagnosis of The of a to nerve as a of successful tracheal extubation has not been documented to our of respiratory to extubation of the that can be an The by et al. the of by the as an of The to a the most of adequate with a of and and have the of the as a of adequate respiratory et al. small of to from to and the between the airway obstruction, and the and The to be the most of adequate airway and adequate minute could be when airway the of which the could not be after with in that the is the most of with different and for by the a of with from of airway with in after is often as a of adequate respiratory et al. in a small of patients that a of to to adequate minute ventilation, and suggested that could be a of ventilatory and that of patients in the with a of could be extubated and have et al. that when were of in to the of to minute ventilation, but not airway function, could be In airway obstruction a of at could be A could be only when patients a of A that the and the could not any between the The are by the that adequate minute to extubation is at not airway (e.g., an endotracheal is In nerve is a for the of and of is as a of successful extubation. of to adequate of function is and used much The of patients to a is the and most to to the of after and However, many patients are extubated to an which the of a patient to to a to a is often little the of and airway function, and little to a when is for a patient can airway and ventilation, of a to extubation is as the of such Extubation The of tracheal extubation has received little This is all the more in of the and to the from aspiration during where airway function is The of substantial with regard to the or of tracheal extubation techniques in to the and of on the Extubation and In endotracheal tube and extubation techniques and associated pulmonary aspiration in patients different After intubation, were an the of different extubation techniques in aspiration of on the of the techniques in of aspiration. of these the that the of the the vocal The the Table the and the the and the and the while In other patient or the not The that (e.g., can the and be Others have that a of can the the cuff, and the vocal to this include the largest of in the and of the in a that the vocal cords and the to extubation However, the at the of of as as of and the suggested a where patients of after endotracheal and to Any endotracheal the would be the by the between the and the after and tube This would the extubated patient with a airway and In of and and and have that endotracheal can to hypoxemia. and Extubation The of extubation that a to extubation has received and most major tracheal extubation via this It is that the a near the be and the This often the postextubation respiratory to be a in the airway and vocal cords of and that of anesthesia can and to the and extubation. It is to if that has in the an endotracheal tube cuff, is by a to extubation. could or the or of this extubation or to the by a to in this has many especially of aspiration as the only not by but of during and after tracheal extubation, include the of or breathing airway or and the and of interventions after extubation Extubation Historically, the to the of anesthesia. the and are important (e.g., laryngospasm, are during by such as laryngoscopy and tracheal intubation or extubation. the that tracheal extubation occur when patients are or at of anesthesia. The common of anesthesia often the of the It is not to a and even with or proof of for extubating and of anesthesia is is and of tracheal extubation at deep or of anesthesia during the has only been in the patient et al. for in and complications after or deep extubation. were surgery or to be extubated for at and of than to extubation. extubated at deep of anesthesia of greater than at the of extubation. for after extubation. and after extubation, patients extubated deep than patients extubated to to were The incidence of postoperative laryngospasm, airway obstruction after extubation, or not different between patients extubated or that for surgery, conditions or the of the the of extubation A by et al. and with to the incidence of complications after and deep tracheal extubation. surgery or were A of patients deep with in the incidence of airway obstruction, laryngospasm, or the and extubated a incidence of airway obstruction and of any respiratory complications after were in the incidence of to than or between and patients extubated with a incidence of to than when extubated deep with and extubated deep and a incidence of at one respiratory than extubated deep extubation after anesthesia in a incidence of to than The that in with normal after or anesthesia in more hypoxemia than deep extubation. Anesthesia with in more and airway obstruction after extubation Table The if it is to a patient the of of may of the After or and or and it is that it is to patients at of at of anesthesia. of this could not be The for this from of the effects of anesthesia, and in the anesthetics, on and airway and from a retrospective that during anesthesia, patients more than suggested that a for patients with airway and for have the effects of on airway reflexes and that and or airway reflexes which could to by or by is to a for the in and airway reflexes and Although deep extubation may a of this and an for patients with airway is adequate any to this to the physiologic changes associated with tracheal extubation have been anesthetics, and in have received the most and that patients have a when anesthesia with to and laryngeal and with In a and more and in to and and to in the of to in to by the of In a of the effects of on or laryngospasm associated with extubation. Anesthesia and with in and to to the of of the patients an of of to extubation laryngospasm after of patients in the laryngospasm after extubation. rapidly laryngospasm in these The of were not in a by et al. the of on laryngospasm after extubation in The incidence of laryngospasm the between and et al. that from of in the to between and extubation, and that the of in the they The of of is such that it be to tracheal or extubation. Although a of of is as airway effects may and have been reported to laryngospasm The of to has been the of or has been to the in et al. that by or of the with a via However, the effects were not by the effects of 4% on normal and In all prevented by anesthetics, or as can by airway The effects of on and to tracheal extubation were by et al. and et al. In et al. of 4% the to to extubation. the tube they a of of 4% the of and or occurred or after extubation. In a to extubation, in in and and after extubation et al. the of a in the Significant of in and were in patients received the and after extubation. has been used to in associated with endotracheal and that to endotracheal