Role of tracheotomy in ventilator - Article Example

Role of Tracheotomy in Ventilator- Dependent Patients in Pneumonia Recommendation/Guideline: Tracheotomy should be considered after an initial period of stabilization on the ventilator when it becomes apparent that the patient will require prolonged ventilator assistance. Tracheotomy then should be performed when the patient appears likely to gain one or more of the benefits ascribed to the procedure. Patients who may derive particular benefit from early tracheotomy are the following: ''Those requiring high levels of sedation to tolerate translaryngeal tubes; ''Those with marginal respiratory mechanics (often manifested as tachypnea) in whom a tracheostomy tube having lower resistance might reduce the risk of muscle overload; ''Those who may derive psychological benefit from the ability to eat orally, communicate by articulated speech, and experience enhanced mobility; and ''Those in whom enhanced mobility may assist physical therapy efforts. Studies- The following studies reiterate the above guideline- Table- Reference Patient Types/No. Design Outcome Lesnik et al201 Trauma/101 Randomized early (6 d) vs late (21 d) tracheotomy Ventilator days shorter with earlier tracheotomy Blot et a Neutropenic/53 Retrospective early (2 d) vs late (_ 7 d) tracheotomy or no tracheotomy LOS longer in patients undergoing early tracheotomy Koh et al Neurosurgical/49 Retrospective elective (9 d) vs failed extubation tracheotomy LOS shorter in elective tracheotomy Dunham and LaMonica Neurosurgical/49 Prospective early (4 d) vs late (14 d) or no tracheotomy No effect El-Naggar et al General acute respiratory failure/52 Prospective (3 d) vs delayed (_ 10 d) tracheotomy More patients weaned in delayed tracheotomy Rodriguez et al Trauma/106 Randomized early (_ 7 d) vs late (_ 7 d) tracheotomy LOS shorter in patients undergoing early tracheotomy but those weaned before late tracheotomy were not considered Sugerman et al Trauma/126 Randomized early (3-5 d) vs late (10-21 d) tracheotomy No effect Introduction Tracheotomy is commonly performed for critically ill, ventilator-dependent patients to provide long-term airway access. The benefits commonly ascribed to tracheotomy, compared to prolonged translaryngeal intubation, include improved patient comfort, more effective airway suctioning, decreased airway resistance, enhanced patient mobility, increased opportunities for articulated speech, ability to eat orally, and a more secure airway. Conceptually, these advantages might result in fewer ventilator complications (eg, ventilator-associated pneumonia), accelerated weaning from mechanical ventilation, and the ability to transfer ventilator-dependent patients from the ICU. Concern, however, exists about the risks associated with the procedure and the costs involved. The impact of tracheotomy on the duration of mechanical ventilation and on ICU outcomes in general has been examined by several different study designs, none of them ideal. Most studies are retrospective, although a few prospective studies have been performed. A serious problem is that many studies assigned patients to treatment groups on the basis of physician practice patterns rather than random assignment. Those studies that used random assignment frequently used quasi-randomization methods (eg, every other patient, every other day, hospital record number, or odd-even days). Studies have compared patients undergoing tracheotomy vs those not undergoing tracheotomy, and patients undergoing early tracheotomy vs those undergoing late tracheotomy. The definition of early vs late tracheotomy varies between studies. "Early" may be defined as a period as short as 2 days after the start of mechanical ventilation to as late as 10 days after the start. Patient populations included in studies also vary widely between investigations and include general surgical and medical patients in some studies and specific patient groups (eg, trauma patients or head-injured patients) in other studies. Most studies have design flaws in the collection and analysis of data, foremost of which is the absence of blinding. The absence of blinding is especially important considering that no study has used explicit, systematic protocols for weaning to control for any effects of tracheotomy on altering the approaches of clinicians to weaning. Finally, an outcome such as transfer to a non- ICU setting may depend on local resources, such as the availability of a non-ICU ventilator service. Because there is such a surprisingly small amount of quality data regarding the relative impact of tracheotomy in terms of patient outcome relative to prolonged translaryngeal intubation, past recommendations for timing the procedure to achieve these benefits have been based on expert consensus.181 Rationale and Evidence (Grade B) While carrying some risks, tracheotomies in ventilatordependent patients are generally safe. The problems associated with tracheotomy include perioperative complications related to the surgery, long-term airway injury, and the cost of the procedure. Patient series reported during the early 1980s182 suggested that tracheotomy had a high risk of perioperative and long-term airway complications, such as tracheal stenosis. More recent studies,183-185 however, have established that standard surgical tracheotomy can be performed with an acceptably low risk of perioperative complications. Regarding long-term risks, analyses of longitudinal studies suggest that the risk of tracheal stenosis after tracheotomy is not clearly higher than the risks of subglottic stenosis from prolonged translaryngeal intubation. 186 Also, the nonrandomized studies commonly reported in the literature bias results toward greater long-term airway injury in patients undergoing tracheotomy because the procedure was performed after a prolonged period of translaryngeal intubation, which may prime the airway for damage from a subsequent tracheotomy. 182,187-189 Finally, the cost of tracheotomy can be lowered if it is performed in the ICU rather than in an operating room, either by the standard surgical or percutaneous dilational technique.186,187 Even when tracheotomy is performed in an operating room, the cost may be balanced by cost savings if a ventilator-dependent patient can be moved from an ICU setting after the placement of a tracheostomy. The actual cost benefits of tracheotomy, however, have not been established because no rigorous cost-effectiveness analyses have been performed. Given the above conditions, it seems reasonable to conclude that none of the potential problems with tracheotomy is of sufficient magnitude to make tracheotomy any less clinically acceptable compared with other procedures that are commonly performed in critically ill patients. Potentially, the most important beneficial outcome from a tracheotomy would be to facilitate the discontinuation of mechanical ventilatory support. Supporting evidence comes both from observations on "intermediate" end points (eg, comfort and mobility, decreased airway resistance, and a lower incidence of ventilator-associated pneumonia) as well as ICU outcome studies examining the duration of mechanical ventilation, ICU length of stay (LOS), and mortality. This evidence is reviewed below. Improved Patient Comfort: No prospective outcome studies in general populations of ventilator-dependent patients using validated measurement tools have established that tracheotomy results in greater patient comfort or mobility, compared with prolonged translaryngeal intubation. Indeed, to our knowledge, only one study183 has attempted to document this by reporting that interviewed ICU caregivers believed ventilated patients were more comfortable after tracheotomy. Despite this lack of data, the general clinical consensus is that patients supported with long-term mechanical ventilation have less facial discomfort when nasotracheal or orotracheal endotracheal tubes are removed and a tracheotomy is performed. Furthermore, patient well-being is thought to be promoted by a tracheotomy through its effects on assisting articulated speech, oral nutrition, and mobility, which may promote the discontinuation of sedatives and analgesics. The maintenance of continuous sedation has been associated with the prolongation of mechanical ventilation,190 but the effects of tracheotomy on sedation usage have not been studied specifically. Decreasing Airway Resistance: Although the small radius of curvature of tracheostomy tubes increases turbulent airflow and airway resistance, the short length of tracheostomy tubes results in an overall lowering of airway resistance (and thus reduced patient muscle loading) when compared to standard endotracheal tubes in both laboratory and clinical settings.191-197 While the development of secretions will increase resistance in both tracheostomy and endotracheal tubes, easier suctioning and removable inner cannulas may reduce this effect in tracheostomy tubes.195 The existing data thus indicate that airway resistance and muscle loading may decrease in some patients after the performance of tracheotomy, but the clinical impact of this improvement in pulmonary mechanics on weaning has not been established. Conceivably, patients with borderline pulmonary mechanics may benefit from a tracheotomy because of decreased airway resistance, which becomes more clinically important with high respiratory rates. Impact of Tracheotomy on Ventilator-Associated Pneumonia: Early tracheotomy and, alternatively, the avoidance of tracheotomy by maintaining a translaryngeal endotracheal tube in place both have been proposed as strategies to promote the successful discontinuation of mechanical ventilation by avoiding ventilator-associated pneumonia. Few data support the conclusion, however, that the timing of tracheotomy alters the risk of pneumonia. Three prospective studies have evaluated the relative risk of pneumonia in patients randomized to early vs late tracheotomy.198-200 These studies examined 289 patients and found a relative risk for pneumonia (early tracheotomy group vs late tracheotomy group) of only 0.88 (95% interval, 0.70 to 1.10). Considerable methodological flaws in these studies, however, do not allow firm conclusions to be drawn regarding the effects of tracheotomy on pneumonia risk. Presently, no data support the competing contentions that early tracheotomy either decreases or increases the risk of ventilator-associated pneumonia. Outcome Studies: the Impact of Tracheotomy on Duration of Mechanical Ventilation: The results of a number of studies examining ICU outcome (ie, ventilator days, ICU LOS, mortality) have been reported and are summarized in Table 8.198-204 Several of these studies were appraised in a systematic review.205 The authors of this review concluded that insufficient evidence existed to support the contention that the timing of tracheotomy alters the duration of mechanical ventilation in critically ill patients. Also, the review identified multiple flaws in the available studies. There appears to be a clinical impression that the timing of tracheotomy promotes the discontinuation of mechanical ventilation in some ventilator-dependent patients, but not all. However, the quality of existing studies does little to support this clinical impression. In the future, because of the difficulty in blinding caregivers to the presence or absence of tracheotomy, studies should use explicit weaning protocols to control for different levels of approaches toward weaning that the presence of a tracheotomy may invoke. Studies also could be improved by more rigorous patient inclusion and exclusion criteria, better accounting for dropouts, the use of conventional randomization methods, multicenter designs to allow sufficient sample sizes to determine the interaction of underlying conditions, and multivariate analysis techniques. Cost-effectiveness analysis also would assist the determination of the value of tracheotomy for weaning. References- 198 Rodriguez JL, Steinberg SM, Luchetti FA, et al. Early tracheostomy for primary airway management in the surgical critical care setting. Surgery 1990; 108:655-659 199 Dunham MC, LaMonica C. Prolonged tracheal intubation in the trauma patient. Trauma 1984; 24:120-124 200 Sugerman HJ, Wolfe L, Pasquale MD, et al. Multicenter, randomized, prospective trial of early tracheostomy. J Trauma 1997; 43:741-747 201 Lesnik I, Rappaport W, Fulginiti J, et al. The role of early tracheostomy in blunt, multiple organ trauma. Am Surg 1992; 58:346-349 202 Blot F, Guiguet M, Antoun S, et al. Early tracheotomy in neutropenic, mechanically ventilated patients: rationale and results of a pilot study. Support Care Cancer 1995; 3:291- 296 203 Koh WY, Lew TWK, Chin NM, et al. Tracheostomy in a neuro-intensive care setting: indications and timing. Anaesth Intensive Care 1997; 25:365-368 204 El-Naggar M, Sadagopan S, Levine H, et al. Factors influencing choice between tracheostomy and prolonged translaryngeal intubation in acute respiratory failure: a prospective study. Anesth Analg 1976; 55:195-201 Read More