Consensus conference on artificial airways in patients receiving mechanical ventilation

Timing of tracheostomy as a determinant of weaning success in critically ill patients: a retrospective study

Introduction

Tracheostomy is frequently performed in critically ill patients for prolonged intubation. However, the optimal timing of tracheostomy, and its impact on weaning from mechanical ventilation and outcomes in critically ill patients who require mechanical ventilation remain controversial.

Methods

The medical records of patients who underwent tracheostomy in the medical intensive care unit (ICU) of a tertiary medical centre from July 1998 to June 2001 were reviewed. Clinical characteristics, length of stay in the ICU, rates of post-tracheostomy pneumonia, weaning from mechanical ventilation and mortality rates were analyzed.

Results

A total of 163 patients (93 men and 70 women) were included; their mean age was 70 years. Patients were classified into two groups: successful weaning (n = 78) and failure to wean (n = 85). Shorter intubation periods (P = 0.02), length of ICU stay (P = 0.001) and post-tracheostomy ICU stay (P = 0.005) were noted in patients in the successful weaning group. Patients who underwent tracheostomy more than 3 weeks after intubation had higher ICU mortality rates and rates of weaning failure. The length of intubation correlated with the length of ICU stay in the successful weaning group (r = 0.70; P < 0.001). Multivariate analysis revealed that tracheostomy after 3 weeks of intubation, poor oxygenation before tracheostomy (arterial oxygen tension/fractional inspired oxygen ratio <250) and occurrence of nosocomial pneumonia after tracheostomy were independent predictors of weaning failure.

Conclusion

The study suggests that tracheostomy after 21 days of intubation is associated with a higher rate of failure to wean from mechanical ventilation, longer ICU stay and higher ICU mortality.

Tracheostomy must be individualized!

Tracheostomy is one of the most frequent procedures carried out in critically ill patients with major advantages compared to translaryngeal endotracheal intubation such as reduced laryngeal anatomical alterations, reduced inspiratory load, better patient's tolerance and nursing. Thus, tracheostomy can enhance patient's care in patients who need prolonged mechanical ventilation and/or control of airways. The right timing of tracheostomy remains controversial, however it appears that early tracheostomy in selected severe trauma, burn and neurological patients could be effective to reduce the duration of mechanical ventilation intensive care stay and costs. Percutaneous tracheostomy techniques are becoming the procedure of choice in the majority of the cases, since they are safe, easy and quick, and complications are minor. However, percutaneous tracheostomies should be always performed by experienced physicians to avoid unnecessary additional complications. It is not clear the superiority of one percutaneous technique compared to another, but experience of the operator and clinical individual anatomical, physiopathological characteristics of the patient should be always considered. We believe that the operator should have experience of at least one intrusive and one extrusive percutaneous technique. The general "optimal" tracheostomy technique and timing do not exist, but tracheostomy should be targeted on the patient's individual clinical characteristics.

Early tracheostomy in intensive care trauma patients improves resource utilization: a cohort study and literature review

INTRODUCTION

Despite the integral role played by tracheostomy in the management of trauma patients admitted to intensive care units (ICUs), its timing remains subject to considerable practice variation. The purpose of this study is to examine the impact of early tracheostomy on the duration of mechanical ventilation, ICU length of stay, and outcomes in trauma ICU patients.

METHODS

The following data were obtained from a prospective ICU database containing information on all trauma patients who received tracheostomy over a 5-year period: demographics, Acute Physiology and Chronic Health Evaluation II score, Simplified Acute Physiology Score II, Glasgow Coma Scale score, Injury Severity Score, type of injuries, ICU and hospital outcomes, ICU and hospital length of stay (LOS), and the type of tracheostomy procedure (percutaneous versus surgical). Tracheostomy was considered early if it was performed by day 7 of mechanical ventilation. We compared the duration of mechanical ventilation, ICU LOS and outcome between early and late tracheostomy patients. Multivariate analysis was performed to assess the impact of tracheostomy timing on ICU stay.

RESULTS

Of 653 trauma ICU patients, 136 (21%) required tracheostomies, 29 of whom were early and 107 were late. Age, sex, Acute Physiology and Chronic Health Evaluation II score, Simplified Acute Physiology Score II and Injury Severity Score were not different between the two groups. Patients with early tracheostomy were more likely to have maxillofacial injuries and to have lower Glasgow Coma Scale score. Duration of mechanical ventilation was significantly shorter with early tracheostomy (mean +/- standard error: 9.6 +/- 1.2 days versus 18.7 +/- 1.3 days; P < 0.0001). Similarly, ICU LOS was significantly shorter (10.9 +/- 1.2 days versus 21.0 +/- 1.3 days; P < 0.0001). Following tracheostomy, patients were discharged from the ICU after comparable periods in both groups (4.9 +/- 1.2 days versus 4.9 +/- 1.1 days; not significant). ICU and hospital mortality rates were similar. Using multivariate analysis, late tracheostomy was an independent predictor of prolonged ICU stay (>14 days).

CONCLUSION

Early tracheostomy in trauma ICU patients is associated with shorter duration of mechanical ventilation and ICU LOS, without affecting ICU or hospital outcome. Adopting a standardized strategy of early tracheostomy in appropriately selected patients may help in reducing unnecessary resource utilization.

Early Tracheostomy versus Prolonged Endotracheal Intubation in Severe Head Injury

BACKGROUND

To see if early tracheostomy (fifth day) reduces duration of mechanical ventilation, ICU stay, incidence of pneumonia and mortality in comparison with prolonged intubation (PI) in patients with head injury.

METHODS

Patients were prospectively included in this study if they met the following criteria: isolated head injury, Glasgow coma scale (GCS) score < or =8 on first and fifth day, with cerebral contusion on CT scan. On the fifth day, randomization was done in two groups: early tracheostomy group (T group, n = 31) and prolonged endotracheal intubation group (I group, n = 31). We evaluated total time of mechanical ventilation, ICU stay, pneumonia incidence and mortality. Complications related to each technique were noted. Analysis of data were performed using Yates and Kruskall Walis tests. p < 0.05 was considered significant.

RESULTS

The two groups were comparable in term of age, sex, and Simplified Acute Physiologic Score (SAPS). The mean time of mechanical ventilatory support was shorter in T group (14.5 +/- 7.3) versus I group (17.5 +/- 10.6) (p = 0.02). After pneumonia was diagnosed, mechanical ventilatory time was 6 +/- 4.7 days for ET group versus 11.7 +/- 6.7 days for PEI group (p = 0.01). There was no difference in frequency of pneumonia or mortality between the two groups.

CONCLUSION

In severe head injury early tracheostomy decreases total days of mechanical ventilation or mechanical ventilation time after development of pneumonia.

Predictive Factors and Long-Term Outcome of Respiratory Failure after Guillain-Barré Syndrome

OBJECTIVE

To analyze predictive factors and long-term recovery in patients with Guillain-Barré syndrome (GBS) who are in need of mechanical ventilation.

METHODS

In this 15-year retrospective study, 77 adult patients were identified with GBS. A comparison was made between the clinical data from patients who required mechanical ventilation and those who did not. Furthermore, the therapeutic outcomes of those 25 patients in need of mechanical ventilation during hospitalization at 1 year were determined using a modified Barthel index. A score below 12 was defined as a poor outcome, whereas a score of 12 or more was good.

RESULTS

The study revealed 32% of patients (25/77) in need of respiratory support during hospitalization. At a follow-up of 1 year among the 25 ventilated patients, 7 patients (28%) had normal or minor signs and symptoms, 6 had unassisted gait, 3 had assisted gait, 6 were wheelchair- or bed-bound, and 3 died. The cause of death was septicemia with septic shock in all 3 cases. Factors that predict respiratory failure in the study GBS patients were disability grade on admission and areflexia. Those ventilated patients who had low maximal inspiratory pressure (PImax) (<14.5 cmH2O) and maximal expiratory pressure (PEmax) (<13.5 cmH2O) values at the time of intubation and the presence of complications after mechanical ventilation inevitably had worse outcomes than those who had not.

CONCLUSION

If low values of PImax and PEmax at intubation were detected, aggressive respiratory management, which might include tracheostomy to allow more efficient bronchial clearing, and prevention of complications caused by prolonged course of mechanical ventilation are essential to maximize the potential for survival.

Incidence, etiology, and outcome of nosocomial pneumonia in ICU patients requiring percutaneous tracheotomy for mechanical ventilation

OBJECTIVE

To determine the epidemiology of pneumonia in patients with tracheotomy receiving short-term mechanical ventilation.

DESIGN

Observational prospective study.

SETTING

A 14-bed medical-surgical ICU.

SUBJECTS

Ninety-nine critically ill acute patients requiring percutaneous dilatational tracheotomy for mechanical ventilation.

INTERVENTIONS

Tracheal aspirate obtained 48 h before tracheotomy.

MEASUREMENTS AND MAIN RESULTS

Eighteen patients (18.1%) acquired pneumonia (median of 7 days after tracheotomy). Pseudomonas aeruginosa was the most frequently identified pathogen, found in eight of the episodes (four not documented by prior tracheal colonization), followed by other Gram-negative bacilli. The development of ventilator-associated pneumonia (VAP) was not anticipated by any clinical variable. A positive tracheal aspirate (TA) culture result obtained before tracheotomy was associated with a risk of acquiring pneumonia of 19.7%, whereas sterile TA cultures were associated with a risk of 14.3% (p > 0.20). VAP prolonged ICU stay or the ventilation period for a median of 19 days and 15 days, respectively. Overall mortality was 34.3%, but the presence of VAP did not increase the mortality rate.

CONCLUSIONS

Percutaneous tracheotomy in patients receiving short-term mechanical ventilation predisposes to pneumonia. Pneumonia was associated with prolonged ventilation and ICU stay, but was not associated with increased mortality. Pseudomonas is a common pathogen after tracheotomy, and this observation should be considered in selecting an antibiotic regimen, because TA obtained prior to the tracheotomy often failed to identify this pathogen.

Cervical spinal cord injury and deglutition disorders

The association of cervical spinal cord injury and swallowing disorders is clinically well recognized. This study was performed to determine the clinical significance and the outcome of deglutition disorders observed in the initial treatment of cervical spinal cord injury in our tertiary care spinal cord injury unit. All patients with cervical spinal cord injury admitted to our facility for initial care between January 1997 and December 2000 were included in our study. Prevalence of dysphagia and frequency of pneumonia were determined. An assessment of deglutition at discharge was performed. Dysphagia was diagnosed in 26 of the 73 patients with cervical spinal cord injury. Tracheostomy and duration of orotracheal intubation are associated with dysphagia. The disorder necessitated dietary restrictions in 18 patients. Six of these patients had to be discharged with a percutaneous enterogastric feeding tube; seven had persistent problems not resulting in dietary restrictions. The incidence of late pneumonia was significantly increased with two associated deaths. Dysphagia is a serious complication associated with prolonged requirement for ventilatory support. Patients have to be monitored closely because the incidence of pneumonia is increased. While the situation improves for most patients, a significant number of patients need a percutaneous enterogastric feeding tube as a permanent solution.

Favorable Short- and Long-Term Outcomes of Prolonged Translaryngeal Intubation in Critically Ill Children

In those children who require protracted mechanical ventilation, we use long-term intubation in order to avoid the consequences of tracheostomy in young children. A retrospective 9-year review was performed to document the efficacy and safety of this practice. A retrospective review of children admitted from January 1, 1991, to December 31, 1998, who required mechanical ventilatory support for at least 7 consecutive days was performed. Data are presented as mean +/- standard deviation. There were 98 children, ventilated for a total of 1967 days, who satisfied review criteria. They had an average age of 6.1 +/- 5.3 years (range, 3 months to 17 years) a total body surface area burn of 53 +/- 25% (range, 0-100%), and 71 of 98 (72%) had suffered an inhalation injury. They were ventilated for 19.7 +/- 16.8 days (range, 7-92 days) and were hospitalized for 67.8 +/- 48.9 days (range, 9-211 days). Ninety-three percent (91 of 98) of the patients were maintained on morphine infusions at a mean hourly rate of 0.35 +/- 0.33 mg/kg/hr (range, 0.01-4.38) and 78% (76 of 98) on midazolam infusions at a mean hourly rate of 0.14 +/- 0.17 mg/kg/hr (range, 0.01-1.82). Neuromuscular blocking agents were administered in 39% (38 of 98) of patients during all or part of 355 (18%) of the 1967 ventilator days. Patients were ventilated with an oral endotracheal (ET) tube in 82% of ventilator days and nasal ET tube in 18% of ventilator days. Two patients (2%) required tracheostomies for long-term management, and five patients (5.1%) died during the study period unrelated to airway issues. There were five unplanned extubation events, for an incidence rate of 2.54 per 1000 ventilator days. All patients were reintubated successfully. Thirteen ET tubes needed to be changed for issues such as leaking cuffs. Patients were followed up for a mean of 2.99 +/- 2.24 years (range, 1 month to 8 years). Possible sequelae related to prolonged intubation were noted in follow-up visits in 8 patients, including sinusitis (one; resolved without treatment), subglottic stenosis (one; required reconstructive surgery), persistent cough (three; all resolved spontaneously), occipital breakdown because of ET ties (one; healed after 1 month), soft voice (two; resolved spontaneously), and decreased pharyngeal sensation (one; resolved without treatment). Translaryngeal intubation is a safe and effective method to provide long-term ventilatory support in children.

Respiratory dysfunction in Guillain-Barré Syndrome

Guillain-Barré Syndrome is the leading cause of nontraumatic acute paralysis in industrialized countries. About 30% of patients have respiratory failure requiring intensive care unit (ICU) admission and invasive mechanical ventilation. Progressive weakness of both the inspiratory and the expiratory muscles is the mechanism leading to respiratory failure. Aspiration pneumonia and atelectasis are common consequences of the bulbar muscle weakness and ineffective cough. The classical signs of respiratory distress occur too late to serve as guidelines for management, and measurements of vital capacity and static respiratory pressures are useful to determine the best times for starting and stopping mechanical ventilation. Several factors present at admission and during the ICU stay are known to predict a need for invasive mechanical ventilation. They include rapidly progressive motor weakness, involvement of both the peripheral limb and the axial muscles, ineffective cough, bulbar muscle weakness, and a rapid decrease in vital capacity. Specific treatments (plasma exchange and intravenous immunoglobulins) have decreased both the number of patients requiring ventilation and the duration of ventilation. The need for mechanical ventilation is associated with residual functional impairments, although all patients eventually recover normal respiratory muscle function.

Tracheotomy: timing and techniques

PURPOSE OF REVIEW

Until the past 40 years, the timing of tracheotomy was of little concern. It was an emergency procedure developed for the relief of airway obstruction. Following the development of positive pressure ventilation, tracheotomy became an elective procedure. Today, the optimal time for tracheotomy is a subject of dispute and continued investigation. As this operation has become one of the most commonly performed procedures in the intensive care unit, nonoperative dilational methods have gained acceptability. The purpose of this review is to analyze the recent literature and draw insight into the timing and technique of the current state of tracheotomy.

RECENT FINDINGS

Individualized assessment of patients should guide the timing of tracheotomy, with a preference toward early tracheotomy. Percutaneous dilational tracheotomy (PDT) can be performed with equivalent safety to open tracheotomy. Bedside open tracheotomy negates the cost-saving benefits of PDT. Endoscopic guidance in PDT decreases complications with needle placement and posterior tracheal wall injury. Major complications of PDT usually are associated with displacement of the tracheotomy tube.

SUMMARY

Tracheotomy indications have remained unchanged, but the timing of the procedure has advanced to individualized assessment with a predilection for earlier tracheotomy. The traditional operative technique is a much safer procedure today. Percutaneous dilational tracheotomy has become an acceptable alternative with proper patient selection. A multidisciplinary team with a surgeon provides the best care for the patient undergoing percutaneous tracheotomy.

Decannulation and survival following tracheostomy in an intensive care unit

We investigated the long-term outcome of patients requiring tracheostomy in an intensive care unit (ICU) in an attempt to identify risk factors that would indicate a low probability of early decannulation. A retrospective study was conducted of a consecutive series of 106 patients who underwent tracheostomy in the period between January 1, 2001, and December 31, 2001, during their admission to the ICU at the Royal Melbourne Hospital, Melbourne, Australia. There were 61 male and 39 female patients with a median age of 65 years. The indications for tracheostomy were prolonged mechanical ventilation (47), tracheobronchial toilet or risk of aspiration (45), and an unstable or obstructed airway (8). Thirty-seven patients died during the study period. All surviving patients were successfully decannulated (median cannulation time, 25 days). Patients with tracheostomies inserted for an unstable or obstructed airway had a significantly shorter cannulation time (median time of 13 days) as compared to the other two indications (mechanical ventilation, 25 days; risk of aspiration, 33 days; log-rank test, chi2(2) = 14.62 and p = .0007). Multivariate analysis showed that the effect of an unstable or obstructed airway was independent of the remaining group variables. We conclude that ICU patients who need a tracheostomy have a high mortality rate. Only the indication for tracheostomy insertion predicts early decannulation, and other patient variables are not significant predictors.

Percutaneous tracheostomy—special considerations

Percutaneous tracheostomy is safe and highly effective in well-trained hands in establishing a long-term artificial airway. Most alleged contraindications and some suggestions on how the procedures should be performed likely stem from early trials when only "perfect candidates" were chosen. Most of those contraindications should not be viewed as prohibitions, but as suggestions related to the skill level and training of the operator. We have used this technique in many situations where the small incision and tamponading effect of the tracheostomy tube has been quite beneficial, in selected patients with coagulapathies and severe venous congestion from superior cava syndromes as well as thyroid cancers, and in whom operative approaches would have been difficult. Knowing one's level of expertise and comfort in choosing and rejecting patients and procedures accordingly is the key to keeping PT a procedure with an excellent safety record. As the experience with PT grows, more and more perceived contraindications will disappear. Studies will address the role of PT in children and as a means of establishing emergent airway access. Also, the exact coagulation limits will need to be established. Few contraindications will most likely remain absolute, such as active infections over the proposed entry site, uncontrollable bleeding disorders and excessive ventilatory and oxygenation requirements. In our institution, taking into account these absolute contraindications, fewer than 5% of patients in need of a tracheostomy in the intensive care unit will undergo a primary open procedure.

Tracheotomy application and timing

Tracheotomy is one of the most commonly performed surgical procedures among critically ill patients. In the past, tracheotomy was delayed as long as possible in ventilator-dependent patients because of concerns regarding injury to the airway from the surgical procedure. Greater recognition of the benefits of tracheotomy in terms of greater patient comfort and mobility has promoted its earlier performance. No data identify an ideal time for tracheotomy. The decision to convert a patient from translaryngeal intubation to a tracheostomy requires anticipation of the duration of expected mechanical ventilation and the weighing of the expected benefits and risks of the procedure. The convenience of percutaneous tracheotomy performed in the ICU by critical care specialists without formal surgical training has further promoted the adoption of tracheotomy for ventilator-dependent patients. Regardless of the method for performing tracheotomy, meticulous surgical technique and careful postoperative management are necessary to maintain the excellent safety record of tracheotomy for critically ill patients.

Acute complications of artificial airways

In conclusion, though there has been a dramatic reduction in the acute complications of artificial airways in the last hundred years, it remains crucial for the intensivist/anesthesiologist to have an implicit understanding of the anatomy and physiology of the process of ETI. As new techniques such as PDT are introduced, we must investigate their utility compared with the current standard of care in the most rigorous fashion. Additionally, as many of the complications of ETI can lead to increases in morbidity and mortality, prompt diagnosis and management are essential.

Differential presentation of post tracheostomy bleeding: a case series

The relief of upper airway obstruction is one of the indications for tracheostomy. However, this procedure is not without its complications. We present a case series where post tracheostomy bleeding results in life-threatening sequelae in the form of torrential haemorrhage and sudden airway obstruction from clot. The latter presentation can present a diagnostic conundrum that could prove fatal if not rapidly identified.

Prediction of prolonged ventilatory support in blunt thoracic trauma patients

OBJECTIVE

To identify predictors of prolonged (>7 days) mechanical ventilation (MV) in patients with blunt thoracic trauma.

DESIGN

Prospective analysis of consecutive patients.

SETTING

Adult intensive care unit (ICU) in a teaching, tertiary-care hospital.

PATIENTS AND PARTICIPANTS

Sixty-nine patients (53 men, 16 women) with thoracic trauma having a median age of 35 (range 17-85) years and a median injury severity score (ISS) of 29 (range 14-41) were enrolled in the present study. Associated injuries included head-neck (77%), extremities (72%), external (67%), abdomen-pelvis (67%), and face (55%).

INTERVENTIONS

Patient surveillance and data collection.

MEASUREMENTS AND RESULTS

Thirty-three (48%) of the 69 patients required prolonged ventilatory support, ranging in duration from 8 to 38 (median 18) days. Logistic regression analysis revealed that advancing age (odds ratio=1.04, p=0.04), severity of head injury (odds ratio=1.92, p=0.008), and bilateral thoracic injuries (odds ratio=12.80, p<0.0001) were significant and independent predictors of long-lasting MV. In contrast, gender, injuries affecting the other body regions (face, abdomen-pelvis, extremities, and external), laparotomy in patients with abdominal injury, or PaO(2)/FIO(2) on admission in the ICU, were unrelated to prolonged MV.

CONCLUSIONS

In thoracic trauma patients admitted in the ICU, prolonged mechanical ventilation was primarily determined by presence of bilateral chest injuries, age, and degree of neurotrauma. This information may help in planning the long-term care of such patients.

Otorhinolaryngological problems occurring within the intensive care unit

OBJECTIVE

An overview of common otorhinolaryngological (ORL) problems and procedures in the intensive care unit (ICU) is presented.

FOCUS

Diagnostic, management, and treatment aspects of some conditions are discussed with emphasis on the potential difficulties encountered in the ICU. Approach recommendations are outlined as well as a list of required basic equipment.

CONCLUSIONS

Otorhinolaryngology should be included in intensive care continuing medical education programs.

Outcome in pediatric tracheotomy

OBJECTIVE

To investigate the outcome and related factors in pediatric tracheotomy.

DESIGN

Retrospective chart review.

SETTING

Tertiary pediatric academic hospital setting.

PATIENTS

The study included 181 children below the age of 18 years who underwent 185 tracheotomies between 1991 and 1995.

MAIN OUTCOMES AND MEASURES

Presenting symptoms and signs, indications, duration of follow-up, therapeutic and interval procedures, early and late complications, mortality, time to and success in decannulation.

RESULTS

There were 108 (59.7%) male patients and 73 (40.3%) female patients. The average age of the children at the time of tracheotomy was 3.8 +/- 5.3 years. The majority of the children were less than 1 year of age (n = 99, 54.7%). Airway obstruction was the leading indication for tracheotomy (59.6%), followed by ventilatory support (30.4%) and pulmonary toilet (9.9%). The average duration of follow-up was 931 +/- 790 days. There were no perioperative complications. Early postoperative complications were seen in 28 (15.5%) children including 12 (6.8%) major complications and 22 (12.2%) minor complications. Late complications were seen in 115 (63.5%) children, including 8 (4.4%) major complications and 107 (59.1%) minor complications. Overall mortality rate was 13.3%, but only 1 tracheotomy-related death was caused by tube displacement. Therapeutic procedures were performed in 43% of the children, including laryngotracheal reconstruction (13%), laser excision of the lesion (5%), and supraglottoplasty (3.9%). Decannulation was accomplished in 116 (64.1%) of the children with an average of 365 +/- 388 days with tracheotomy.

CONCLUSION

Tracheotomy is relatively safe in the pediatric population. Decannulation may be possible relatively quickly with resolution of the underlying problem.

Early tracheostomy does not improve outcome in burn patients

Early tracheostomy (ET) has been claimed to reduce ventilator support or intensive care unit or hospital length of stay in intensive care unit patients. This study was performed to assess the potential benefits of ET in burn patients. From October 1996 to July 2001, we evaluated all intubated and acutely burned adults using a formula to predict the probability of prolonged ventilator dependence. We randomized each patient with a probability of prolonged ventilator dependence more than 0.5 to ET, performed on the next operative day, or to conventional therapy (CON), which consisted of continued endotracheal intubation as needed, with tracheostomy (TRACH) performed on postburn day (PBD) 14 if necessary. During this period, 44 patients were randomized, 23 to CON and 21 to ET. Groups did not differ in age, total burn size, or inhalation injury, although ET patients had larger full-thickness burns. ET patients underwent TRACH at a mean of PBD 4 vs PBD 14.8 for CON patients (P <.01). ET patients had a significant improvement in PaO2 /FiO2 ratios within 24 hours following TRACH (139 +/- 15 vs 190 +/- 12; P <.01). There were no differences in ventilator support, length of stay, incidence of pneumonia, or survival. However, six CON patients (26%) were successfully extubated by PBD 14 compared with one ET patient (P <.01). Although tracheostomy offers some advantages in terms of patient comfort and security, routine performance of ET in burn patients does not improve outcomes, nor does it result in earlier extubation. This may be partly caused by the comfort and convenience of tracheostomy.

Indicators for Tracheostomy in Patients with Traumatic Brain Injury

Our objective was to develop criteria to identify patients with traumatic brain injury (TBI) who require a tracheostomy (TR). From January 1994 to May 2000 all TBI patients requiring intubation on presentation and who survived <7 days were identified from our trauma registry. Demographics, Glasgow Coma Score (GCS), Injury Severity Score (ISS), and ventilator days, ICU days, hospital days, need for TR, and development of pneumonia were statistically analyzed. Of 246 patients with TBI 211 without TR and 35 with TR were identified (mean time to TR 13.3 ± 7.0 days). Logistic regression analysis identified presenting GCS ≤8, ISS ≤25, and ventilator days <7 as significant predictors for TR. Applying these three predictors to our population identified 48 patients (21 with TR, 18 without TR, and nine who died on the ventilator without TR) with a sensitivity of 60 per cent, a specificity of 87 per cent, a positive predictive value of 44 per cent, and a negative predictive value of 93 per cent. Patients with TR had lower presenting GCS and higher ventilator, ICU, and hospital days ( P < 0.05). Pneumonia rates were similar. Time to neurologic recovery (GCS ≤9) was longer for the TR patients as compared with the patients without TR. We conclude that patients with TBI presenting with a GCS ≤8, an ISS ≤25, and ventilator days <7 are more likely to require TR. Performing TR late did not reduce pneumonia rates or ventilator, ICU, or hospital days. By identifying the at-risk population early TR could be performed in an attempt to decrease morbidity and length of stay.

[Factors helping in the decision to change intubation for tracheotomy in critical patients]

We carry out a prospective study in order to determine the prognostic factors in the development of injuries of upper airways, and their influence in the decision to perform a tracheotomy. The time to tracheotomy was previously stated, according to the type of patient (neurological or non-neurological). This study includes the clinical data and the upper airways endoscopic exploration of 654 patients with oro-tracheal intubation and mechanical ventilation for more than 48 hours in a 6 year period. Three endoscopic explorations were carried out in the first month (early exploration), with two additional explorations at six and twelve months (late exploration). Using a multivariable statistical study we have analysed the prognostic factors and the risk groups for the development of later injuries of the upper airway of these patients. The later endoscopic exploration of the upper airways has shown injuries in 30 of 280 cases (11%). In this study, the main factor that determines the development of injuries of the upper airway was the time of intubation. The risk groups to develop later lesions of the upper airways include: patients with pathological background, patients with medical admissions, non-neurological patients and patients with serious lesions in the earlier endoscopic exploration. We conclude that it is necessary to state the time to perform a tracheotomy in patients with oro-tracheal intubation. It must be based on the own experience, the patient's clinical condition and the disease that caused hospital admission.

Cricothyroidotomy for elective airway management in critically ill trauma patients with technically challenging neck anatomy

INTRODUCTION

To assess the value of elective cricothyroidotomy for airway management in critically ill trauma patients with technically challenging neck anatomy.

MATERIALS AND METHODS

A retrospective chart review of patients admitted to the Trauma Service at a Level I Trauma Center who underwent cricothyroidotomy for elective airway management over a 40-month period from January 1997 to April 2000. Comparison was made with a cohort of Trauma Service patients who received a tracheostomy.

RESULTS

Eighteen patients met study criteria, and an unpaired t test revealed significance (P < 0.05) for age only. There was no difference with Injury Severity Score, number of days in the intensive care unit, number of days requiring ventilation post procedure or number of days intubated prior to procedure. The major difference was the more technically challenging neck anatomy in the patients undergoing cricothyroidotomy. Five out of 18 patients undergoing cricothyroidotomy died prior to discharge and two out of 18 died after discharge from complications unrelated to their airway. Two out of 18 patients undergoing tracheostomy died prior to discharge from complications unrelated to their airway. For a period of 1 week-15 months (average, 5.5 months), notes in subsequent clinic appointments were reviewed for subjective assessment of wound healing, breathing and swallowing difficulties, and voice changes. One patient with a cricothyroidotomy required silver nitrate to treat some granulation tissue. Otherwise, no complications were identified. Telephone interviews were conducted with eight of the 11 surviving cricothyroidotomy patients and nine of the 16 surviving tracheostomy patients. One tracheostomy patient required surgical closure 3 months after discharge; otherwise, the only noted change was minor voice changes in three patients in each group. All six of these patients denied that this compromised them in any way.

CONCLUSION

Elective cricothyroidotomy has a low complication rate and is a reasonable, technically less demanding option in critically ill patients with challenging neck anatomy requiring a surgical airway.

The role of tracheotomy in weaning

Tracheotomy is commonly performed in ventilator-dependent patients. Disadvantages to the procedure are perioperative complications, long-term airway injury, and the cost of the procedure. Benefits ascribed to tracheotomy vs prolonged translaryngeal intubation include improved patient comfort, more effective airway suctioning, decreased airway resistance, enhanced patient mobility, increased potential for speech, ability to eat orally, a more secure airway, accelerated ventilator weaning, reduced ventilator-associated pneumonia, and the ability to transfer ventilator-dependent patients from the ICU. None of these benefits, however, have been demonstrated in large-scale, prospective, randomized studies. It is proposed that there should be an anticipatory approach wherein tracheotomy is considered after an initial period of stabilization with the patient receiving mechanical ventilation when it becomes apparent that the patient will require prolonged ventilator assistance. Tracheotomy then is performed when the patient appears likely to gain one or more of the benefits ascribed to the procedure.

The role of dead space ventilation in predicting outcome of successful weaning from mechanical ventilation

BACKGROUND

The exact mechanism by which tracheostomy results in clinical improvement in respiratory function and liberation from mechanical ventilation remains unknown. Physiologic dead space, which includes both normal and abnormal components of non-gas exchange tidal volume, is a clinical measure of the efficiency of ventilation. Theoretically, tracheostomy should reduce dead space ventilation and improve pulmonary mechanics, thereby facilitating weaning from mechanical ventilation.

METHODS

This study compares arterial blood gases (ABG), pulmonary mechanics, including minute ventilation (VE) and dead space ventilation (Vd/Vt) within 24 hours before and after tracheostomy in 45 patients admitted to a surgical intensive care unit.

RESULTS

There was no difference noted in patients' ABG or VE. Pre- and posttracheostomy change in Vd/Vt was negligible (50.7 and 10 vs. 51.9 and 11; p = NS). On subgroup analysis, those patients that were weaned from mechanical ventilation with 72 hours of tracheostomy (T3) were compared with those patients weaned from mechanical ventilation 5 days or more after tracheostomy (T+5). Again, no difference was found in pulmonary mechanics or Vd/Vt pre- and posttracheostomy.

CONCLUSION

There is minimal improvement in pulmonary mechanics after tracheostomy. The change in physiologic dead space posttracheostomy does not predict the outcome of weaning from mechanical ventilation. Tracheostomy does allow better pulmonary toilet, and easier initiation and removal of mechanical ventilation and control of the upper airway.

Percutaneous dilational tracheostomy: a comparison of single- versus multiple-dilator techniques

OBJECTIVE

To compare the safety and efficacy of single- vs. multiple-dilator techniques in the performance of percutaneous dilational tracheostomy.

DESIGN

Prospective randomized trial.

SETTING

Intensive care units at a level 1 trauma center.

PATIENTS

Fifty consecutive patients requiring tracheostomy for airway control or prolonged mechanical ventilatory support.

INTERVENTIONS

Patients were randomized to receive a percutaneous dilational tracheostomy by either the single- or multiple-dilator technique described by Ciaglia.

MEASUREMENTS AND MAIN RESULTS

Percutaneous dilational tracheostomy was performed using the single-dilator technique in 6:01 +/- 3:03 mins and by the multiple-dilator technique in 10:01 +/- 4:26 mins (p <.0006). There were no statistically significant differences in complication rates between the two techniques. No major complications occurred with either technique.

CONCLUSION

The single-dilator percutaneous tracheostomy technique is a safe, cost-effective, and more rapidly performed method for bedside tracheostomy in the intensive care unit.

Mechanical ventilation in chronic obstructive lung disease

Exacerbations of COPD are a leading indication for MV in the intensive care unit. A thorough understanding of the pathophysiology of AVF in COPD is critical for physicians caring for these patients. In particular, physicians should understand DHI and use the ventilator and ancillary techniques to minimize its impact. Noninvasive positive-pressure ventilation should be considered strongly in relatively stable patients with an adequate mental status and manageable secretions. Once AVF resolves, patients should be removed from the ventilator as soon as is safe to do so to minimize the adverse effects of prolonged MV. An organized approach to weaning and identifying patients capable of independent breathing is crucial. Most patients with COPD and AVF benefit from MV and generally return to or approach their premorbid functional status. A significant subset, however, will not benefit from, or choose not to undergo, MV. Deciding upon appropriate therapeutic options for these patients relies heavily on effective communication between physician and patient. Comprehensive discussions before the development of AVF can assist decision-making after respiratory failure develops.

Ultrasound and bronchoscopic controlled percutaneous tracheostomy on trauma ICU

Tracheostomy is a common surgical procedure performed in long-term ventilated patients in intensive care. Since the role of percutaneous dilatational tracheostomy (PDT) on Intensive Care Unit (ICU) has become steadily more important in the last few years, a prospective study was started to evaluate the economic efficiency and to show the minimization of the complication rate of this procedure. In 72 patients we performed PDT as a bedside procedure. Initially the thyroid gland and the subcutaneous vessels were studied by ultrasound in every patient. The puncture of the trachea, the dilatational procedure and the insertion of the tracheal cannula were executed under bronchoscopic monitoring. Finally, a bronchoscopic control view followed via the new cannula to detect intratracheal complications. Mechanical ventilation was maintained during the procedure and controlled by continuous pulse oximetry. According to prior ultrasound findings the place to puncture the trachea was changed in 24% of the patients, in one case tracheostomy was performed as an open conventional procedure. The following complications could be observed: one case involving perforation of a cartilaginous ring, one case with venous bleeding of a small subcutaneous vein and two cases with punctures of the bronchoscope. There were no cases of miscannulation, penetration of the posterior tracheal wall or major bleeding requiring intervention or conversion. The followup study revealed that there was no sign of further complications in any patient. In addition, cost analysis demonstrated that there was a significant economical advantage of PDT in comparison with open standard tracheostomy. Standardized ultrasonographically and bronchoscopically controlled PDT turns out to be a safe, simple and cost effective bedside procedure on ICU. Because of ultrasound examination performed before the procedure, and bronchoscopic surveillance during the procedure, safety of this procedure can be enhanced, thus minimizing the rate of complications.

Predisposing factors for nosocomial pneumonia in patients receiving mechanical ventilation and requiring tracheotomy

STUDY OBJECTIVES

To assess the incidence of nosocomial pneumonia (NP) after tracheotomy in an ICU population and to determine NP risk factors during the ICU stay, particularly on the day of tracheotomy.

DESIGN

A retrospective study using prospectively collected data.

SETTING

A 16-bed multidisciplinary ICU.

PATIENTS

One hundred thirty-five patients requiring tracheotomy for mechanical ventilation (MV) weaning.

RESULTS

The mean (+/- SD) duration of MV before tracheotomy was 17.8 +/-13.4 days. Thirty-seven cases of NP occurred in 35 patients (25.9%), 8.7+/-7.3 days after the tracheotomy procedure. NP cases were classified as early NP (n = 19) if they occurred within 5 days after the procedure (mean, 2.7+/-1.1 days), and as late NP (n = 18) if they occurred beyond the fifth day (mean, 14.4+/-6.1 days). Multivariate analysis identified the following three independent factors associated with early NP: the presence of positive endotracheal aspirates (EAs) with pathogen levels of > or =10(5) cfu/mL (p = 0.0001); hyperthermia (temperature, > or =38.3 degrees C; p = 0.002) on the day of tracheotomy; and the continuation of sedation beyond 24 h after the tracheotomy (p = 0. 0001). Accountable pathogens of early NP were present in EA on the day of tracheotomy (p = 0.001). Cases of late NP were significantly associated with the duration of sedation before the procedure (p = 0. 002) and with hyperthermia (temperature, > or =38.3 degrees C) on the day of tracheotomy (p = 0.0005). The ICU admitting diagnosis, previous NP, duration of administration of antimicrobial agents and MV before tracheotomy, indication for tracheotomy, PO(2)/fraction of inspired oxygen ratio, and use of steroids on the day of the procedure were not associated with the occurrence of NP. The mortality rate of our population was 33.3%, and NP increased this percentage to 54.3%.

CONCLUSIONS

Our results could suggest that tracheotomy should be delayed in mechanically ventilated patients with bronchial colonization and hyperthermia, when sedation cannot be discontinued after the procedure, to prevent occurrence of early NP.

Early percutaneous tracheostomy after median sternotomy

OBJECTIVE

Tracheostomy offers significant advantages over endotracheal intubation in patients requiring long-term assisted ventilation. However, in patients who have undergone median sternotomy, it is believed that the danger of microbial contamination and consecutive infection of the sternal wound with microbes from the tracheostomy is high when conventional tracheostomy is performed. In contrast, percutaneous techniques are less likely to result in tracheostomy infection and thus bacterial contamination of neighboring structures. Nonetheless, to date there has been no prospective study confirming or disproving this assumption. Our study evaluated outcome after percutaneous tracheostomy in patients with a median sternotomy.

METHODS

A total of 144 cardiac surgical patients had elective percutaneous tracheostomy at the bedside until postoperative day 14, with 4 different techniques. Systematic microbiologic monitoring of the sternal and tracheal wounds was used.

RESULTS

In 13 patients sternal wound infection was suspected, but was confirmed in only 4 (2.8%) patients who actually showed microbial contamination of the sternum. In 2 of these patients, the identified microbes were not identical to those cultured from the trachea. The other 2 patients had sternal and tracheal cultures positive for methicillin-resistant Staphylococcus aureus. Cross-contamination of the sternotomy with microbes from the patient's airways was therefore ruled out. No patient had clinical signs of tracheostomy infection. Likewise, there were no cases of mediastinitis.

CONCLUSIONS

On the basis of our data, we conclude that cross-contamination of the sternal wound with microbes from the trachea is not a problem. Elective percutaneous tracheostomy is safe, even if performed during the first 14 days after median sternotomy.

When and how should we do a tracheostomy?

Tracheostomy is one of the most common surgical procedures in the intensive care unit. Since the introduction of percutaneous techniques, tracheostomy has become increasingly popular. The technique is relatively easy, and the early and late complication rates are relatively low.It is unknown at which moment tracheostomy can best be performed in the translaryngeally intubated patient. There are theoretic arguments for both early and late tracheostomy. The excellent results of percutaneous tracheostomy may influence the decision to perform a tracheostomy rather early, but prospective randomized studies are required to gather the necessary evidence.

Surgical airway management in the intensive care unit

Despite having been a known surgical procedure for over 5000 years, the specifics of how, when, and why to perform a surgical airway are still debated. With new procedures, equipment, and techniques, operative airway management is becoming more complex. New methods of surgical airway management have to be evaluated against the gold standard, which will always be the open tracheostomy performed in the operating room. Unlike Dr. Jackson in 1909, surgeons today have to evaluate these new procedures not only by their efficacy but also by their cost effectiveness.

The intensive care unit as an operating room

This article is an overview of the different procedures currently performed on the ICU patient and emphasizes percutaneous tracheostomy and percutaneous gastrotomy. The steps necessary to prepare the patient, the ICU staff, and intensivist to achieve a safe and successful procedure are described, as are the indications, technique, complications, safety, and advantages to perform these techniques in the ICU.

Post-intubation pulmonary function test in Guillain-Barré syndrome

The value of daily postintubation respiratory function tests in predicting duration of ventilation in 37 mechanically ventilated patients with Guillain-Barré syndrome (GBS) was studied. Patients ventilated for less than 3 weeks were compared with those ventilated more than 3 weeks. Daily vital capacity and maximal inspiratory and expiratory pressures were summed to an integrated pulmonary function (PF) score. We calculated the PF ratio, which represents the PF score at day 12 after intubation divided by the PF score on the day of intubation. The PF ratio was greater than 1 in all 10 patients ventilated less than 3 weeks and was less than 1 in 19 of 27 patients ventilated for longer (P = 0.0001, Fisher exact test). The sensitivity of a PF ratio less than 1 for predicting duration of ventilation greater than 3 weeks was 70%; the specificity and positive predictive value were 100%. This study thus suggests that serial postintubation respiratory tests can provide a measure of respiratory status in patients with GBS. These parameters may help predict duration of ventilation and need for tracheostomy. If, at day 12, the PF ratio is less than 1, it is highly unlikely that patients will be weaned within 3 weeks, and tracheostomy should be performed. If the ratio is greater than 1, tracheostomy should be deferred, because a substantial proportion of these patients may be successfully weaned from the ventilator within 3 weeks.

Patterns in costs and outcomes for patients with prolonged mechanical ventilation undergoing tracheostomy: an analysis of discharges under diagnosis-related group 483 in New York State from 1992 to 1996

OBJECTIVE

To analyze the costs and discharge status for patients with prolonged mechanical ventilation undergoing tracheostomy.

DESIGN

Retrospective analysis of a statewide database.

PATIENTS

All patients (n = 37,573) >18 yrs of age who had prolonged mechanical ventilation (procedure code 96.72) and were discharged from the hospital between 1992 and 1996 with a final DRG code of 483.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Rates of change in discharges and hospital reimbursements and the cost per survivor were examined by case payment groups and discharge year. A direct relation between volume and reimbursement rate was seen over time, although the patient age distributions remained relatively stable. The greatest increase in volume was from 1995 to 1996. For most years, there was a consistent inverse relation between age and survival, with older survivors being more likely to be discharged to residential healthcare facilities and younger patients more likely to be discharged home. There was a consistent direct relation between age and cost per survivor, mainly the result of improved survival rather than decreased reimbursements in later years.

CONCLUSIONS

More controlled reimbursements and improved overall survival rates for DRG 483 have contributed to the improved cost per survivor among all age groups over the period. Given the greater proportion of elderly that do not survive or who are placed into residential healthcare facilities, more scrutiny is needed concerning the use of DRG 483 resources so that care is better coordinated for these patients in the inpatient and postacute care settings.

Tracheostomy in Guillain-Barré syndrome

Specific treatment has been shown to shorten the duration of mechanical ventilation in Guillain-Barré syndrome (GBS) and could obviate the need for tracheostomy in a significant proportion of patients. However, the factors predictive of prolonged ventilation are undetermined, and the timing and use of tracheostomy in patients with GBS have not been systematically studied. The medical records of 60 patients ventilated for GBS were reviewed. Only 13 patients (22%) could be weaned within 3 weeks. Patients ventilated longer were significantly older (P = 0.04), and 21% had underlying pulmonary disease. Median duration of ventilation in patients treated with plasma exchange (n = 31) was not shortened. Fifty-two patients (87%) received a tracheostomy at a median of 9 days after intubation. In this series, where patients with comorbidity were included, tracheostomy was still necessary in the majority of ventilated patients. This procedure can be anticipated in elderly patients and in the presence of preexisting pulmonary disease.

Pulmonary complications of mechanical ventilation

Although life-saving, mechanical ventilation may be associated with many complications, including consequences of positive intrathoracic pressure, the many aspects of volutrauma, and adverse effects of intubation and tracheostomy. Optimal ventilatory care requires implementing mechanical ventilation with attention to minimizing adverse hemodynamic effects, averting volutrauma, and effecting freedom from mechanical ventilation as quickly as possible so as to minimize the risk of airway complications.

Changes in the work of breathing induced by tracheotomy in ventilator-dependent patients

Tracheotomy is widely performed on ventilator-dependent patients, but its effects on respiratory mechanics have not been studied. We measured the work of breathing (WOB) in eight patients before and after tracheotomy during breathing at three identical levels of pressure support (PS): baseline level (PS-B), PS + 5 cm H2O (PS+5), and PS - 5 cm H2O (PS-5). After the procedure, we also compared the resistive work induced by the patients' endotracheal tubes (ETTs) and by a new tracheotomy cannula in an in vitro bench study. A significant reduction in the WOB was observed after tracheotomy for PS-B (from 0.9 +/- 0.4 to 0.4 +/- 0.2 J/L, p < 0.05), and for PS-5 (1.4 +/- 0.6 to 0.6 +/- 0.3 J/L, p < 0.05), with a near-significant reduction for PS+5 (0.5 +/- 0.5 to 0.2 +/- 0.1 J/L, p = 0.05). A significant reduction was also observed in the pressure-time index of the respiratory muscles (181 +/- 92 to 80 +/- 56 cm H2O. s/min for PS-B, p < 0.05). Resistive and elastic work computed from transpulmonary pressure measurements decreased significantly at PS-B and PS-5. A significant reduction in occlusion pressure and intrinsic positive end-expiratory pressure (PEEP) was also observed for all conditions, with no significant change in breathing pattern. Three patients had ineffective breathing efforts before tracheotomy, and all had improved synchrony with the ventilator after the procedure. In vitro measurements made with ETTs removed from the patients, with new ETTs, and with the tracheotomy cannula showed that the cannula reduced the resistive work induced by the artificial airway. Part of these results was explained by a slight, subtle reduction of the inner diameter of used ETTs. We conclude that tracheotomy can substantially reduce the mechanical workload of ventilator-dependent patients.

Preferred Route of Tracheostomy—Percutaneous versus Open at the Bedside: A Randomized, Prospective Study in the Surgical Intensive Care Unit

Percutaneous tracheostomy has been touted as the preferred route of tracheostomy. However, to date, no prospective randomized study comparing bedside percutaneous (BP) to bedside open (BO) tracheostomy has been performed. Surgical intensive care unit (sICU) patients were randomized to receive either a BP or a BO tracheostomy. Patients were monitored for complications. Procedure time was documented. A group of medical ICU patients had open tracheostomies in the operating room (OR) and served as contemporaneous controls. Over 11 months, there were 24 surgical ICU patients randomized to receive either BP tracheostomy or BO tracheostomy, 12 in each group. Forty-six medical ICU patients received standard open tracheostomy in the OR. The number of ventilator days before placing the tracheostomy was similar between the BP and BO groups, 9.8 and 12.4, respectively. The clinical indications for tracheostomy were similar between the two groups. The procedure time for the BP group was 14.5 minutes, whereas 25.2 minutes for the BO group. There were no postprocedure complications in the BP and BO groups. There was a trend toward more complications in the BP group, including the loss of the airway, leading to death. The procedure time and complications were similar between the BO and OR groups. These data do not support that BP tracheostomy is the preferred route of tracheostomy when compared with BO tracheostomy. These data support that experienced surgical intensivists can perform BO tracheostomies with lower risk and cost, when compared with BP tracheostomy.

Percutaneous tracheostomy

BACKGROUND: Percutaneous tracheostomy (PT) has gained an increasing acceptance as an alternative to the conventional surgical tracheostomy (ST). In experienced hands, and with proper patient selection, it is safe, easy and quick. COMPLICATIONS: Perioperative complications are comparable with those of ST and these are mostly minor. An important advantage of PT over ST is that there is no need to move a critically ill patient to the operating room and the rate of stomal infection is very low. Although data on late complications of PT are not yet sufficient, available reports show a favourable result. TECHNIQUES: Ciaglia's method is the most commonly applied, but no study has shown superiority of any of the percutaneous techniques described. The decision on which method to use should solely be made depending on the clinical situation and the experience of the operator. The learning curve demands caution, attention to detail and adequate experience on the part of the intensive care physician. Although PT is unfortunately declared 'easy', it must be left in the hands of experienced physicians to avoid unnecessary complications, and the risk of overimplementation should be kept in mind.

Provision of long-term mechanical ventilation

When patients suffer prolonged mechanical ventilation, physicians are faced with a series of decisions beginning in the intensive care unit (ICU) and extending into a broadening spectrum of post-ICU levels of care. This article reviews current thinking and outcome data on when and how to perform the tracheostomy, as well as when and where the patient should be transferred from the ICU for continued weaning efforts or support. Decannulation after success in weaning and continuation of ventilation at home are also addressed.

The timing of tracheotomy: a systematic review

STUDY OBJECTIVE

To examine the impact of the timing of tracheotomy on the duration of mechanical ventilation, the secondary changes to the trachea, and the clinical course of critically ill patients in the ICU.

DESIGN

A systematic review of the literature.

METHODS

Two independent reviewers conducted a MEDLINE search for relevant literature in the form of randomized or observational controlled clinical studies. Studies were selected for review by criteria determined a priori; and the methodologic quality of selected studies was evaluated by duplicate independent review, also using criteria determined a priori.

RESULTS

Five studies were identified, of which three were quasirandomized and none were blinded. Agreement between reviewers of methodologic quality was high (kappa=0.87).

CONCLUSIONS

There is insufficient evidence to support that the timing of tracheotomy alters the duration of mechanical ventilation or extent of airway injury in critically ill patients.