Complications of assisted ventilation. A prospective study of 354 consecutive episodes

The Out-of-Hospital Esophageal and Endobronchial Intubations Performed by Emergency Physicians

BACKGROUND

Rapid establishment of a patent airway in ill or injured patients is a priority for prehospital rescue personnel. Out-of-hospital tracheal intubation can be challenging. Unrecognized esophageal intubation is a clinical disaster.

METHODS

We performed an observational, prospective study of consecutive patients requiring transport by air and out-of-hospital tracheal intubation, performed by primary emergency physicians to quantify the number of unrecognized esophageal and endobronchial intubations. Tracheal tube placement was verified on scene by a study physician using a combination of direct visualization, end-tidal carbon dioxide detection, esophageal detection device, and physical examination.

RESULTS

During the 5-yr study period 149 consecutive out-of-hospital tracheal intubations were performed by primary emergency physicians and subsequently evaluated by the study physicians. The mean patient age was 57.0 (+/-22.7) yr and 99 patients (66.4%) were men. The tracheal tube was determined by the study physician to have been placed in the right mainstem bronchus or esophagus in 16 (10.7%) and 10 (6.7%) patients, respectively. All esophageal intubations were detected and corrected by the study physician at the scene, but 7 of these 10 patients died within the first 24 h of treatment.

CONCLUSION

The incidence of unrecognized esophageal intubation is frequent and is associated with a high mortality rate. Esophageal intubation can be detected with end-tidal carbon dioxide monitoring and an esophageal detection device. Out-of-hospital care providers should receive continuing training in airway management, and should be provided additional confirmatory adjuncts to aid in the determination of tracheal tube placement.

Prospective study of risk factors for ventilator-associated pneumonia caused by Acinetobacter species

The incidence of ventilator-associated pneumonia (VAP) by Acinetobacter spp (VAPA) is increasing and has high morbidity and mortality. It is imperative to identify risk factors to be able to use prevention policies.

OBJECTIVE

The aim of this study was to identify specific risk factors for VAPA.

DESIGN

Prospective cohort study.

INTERVENTIONS

None.

SETTING

Two medical-surgical intensive care units.

MEASUREMENTS

During a period of 36 months, all patients with more than 48 hours on mechanical ventilation and suspected of having a VAP were enrolled. Only VAP with microbiological confirmation was analyzed.

RESULTS

Two hundred eighteen consecutive patients with clinical suspicion of VAP were enrolled. One hundred twenty-five VAPs were confirmed by culture--46 by Acinetobacter spp and 79 by other pathogens. The 36 potential risk factors for Acinetobacter spp were analyzed by univariate analysis. Logistic regression identified previous use of ceftriaxone (relative risk, 5.1; 95% confidence interval, 1.47-17.82) and previous use of ciprofloxacin (relative risk, 9.1; 95% confidence interval, 2.29-36.63) as significant independent predictors for the development of VAPA.

CONCLUSIONS

Previous use of ceftriaxone and ciprofloxacin are independent risk factors for the development of VAPA.

Impact of tracheotomy on sedative administration, sedation level, and comfort of mechanically ventilated intensive care unit patients*

OBJECTIVE

To assess the impact of tracheotomy on sedative administration, sedation level, and autonomy of mechanically-ventilated intensive care unit (ICU) patients.

DESIGN, SETTING, AND PATIENTS

In this observational study, the charts of all consecutive patients undergoing mechanical ventilation requiring tracheotomy over a 14-month period in our 18-bed tertiary care ICU were reviewed retrospectively. Patients' sedation levels (according to the Riker's 7-level sedation-agitation score) and intravenous (fentanyl and midazolam) and oral (clorazepate and haloperidol) sedative administration were measured daily during the 7 days before and after tracheotomy. We also recorded patients for whom chair positioning and oral alimentation became possible in the days following tracheotomy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Tracheotomy was performed on 72 (23.1%) of the 312 patients undergoing mechanical ventilation for > or = 48 hrs. After tracheotomy, median (25th, 75th percentiles) fentanyl and midazolam administration decreased from 866 (191, 1672) to 71 (3, 426) microg/(patient.day) and from 44 (16, 128) to 7 (1, 42) mg/(patient.day) (p < .001), respectively. Concomitant median time spent heavily sedated decreased from 7 (3, 17) to 1 (0, 6) hrs/day (p < .001), with no increase in agitation time. During the 7 days following tracheotomy, partial oral alimentation became possible for 35 patients (48.6%) and out-of-bed positioning became possible for 16 patients (22.2%).

CONCLUSION

On the basis of these observations, we conclude that tracheotomized mechanically ventilated ICU patients required less intravenous sedative administration, spent less time heavily sedated, and achieved more autonomy earlier.

Predictive factors for the success of noninvasive mask ventilation in infants and children with acute respiratory failure

OBJECTIVE

Noninvasive mask ventilation (NIV) is a treatment option in acute respiratory failure in adults. This study was performed to determine prognostic variables for the success of NIV in a group of infants and children with respiratory failure for a wide range of reasons.

DESIGN

Prospective, clinical study.

SETTING

Multidisciplinary, neonatal-pediatric intensive care unit of a university teaching hospital.

METHODS

Descriptive study of infants and children <or=16 yrs of age with acute respiratory failure requiring assisted ventilation. During 2002-2003, patients with hypoxemic or hyper-carbic respiratory failure, signs of respiratory distress, and described by the attending critical care physician as likely to require intubation, were eligible to receive mask ventilation as an alternative means of respiratory support. Patients were not selected for their underlying disease contributing to the respiratory problems. Depending on whether they failed NIV and had to be intubated, the children were assigned to nonresponders or responders groups. The two groups were compared regarding physiologic variables prospectively evaluated before NIV and at 1, 8, 24, and 48 hrs of NIV.

RESULTS

A total of 42 patients were included. Their median age was 2.45 yrs (range, 0.01-18 yrs). Twenty-one patients required mask ventilation only with continuous positive airway pressure and 21 with biphasic positive airway pressure. In both responders' and nonresponders' blood gas results, heart rate and respiratory rate improved significantly after initiation of NIV (p<.0001). The courses of these variables did not differentiate between the two groups. The overall success rate of NIV was 57%. After 1 hr of NIV, there was a significantly higher Fio2 in patients who failed NIV than in responders. An Fio2 of >80% after 1 hr of NIV predicted nonresponse with a sensitivity of 56%, specificity of 83%, and positive and negative predictive value of 71%.

CONCLUSION

NIV can be successfully applied to infants and children with acute respiratory failure in the setting of a pediatric intensive care unit. The level of Fio2 after 1 hr of NIV may be a predictive factor for the treatment success.

Breathing at Depth: Physiologic and Clinical Aspects of Diving while Breathing Compressed Gas

When diving, human beings are exposed to hazards that are unique to the hyperbaric underwater environment and the physical behavior of gases at higher ambient pressure. Hypercapnia, hyperoxia, carbon monoxide intoxication, inert gas (predominantly nitrogen) narcosis, and decompression illness all may lead to impaired consciousness, with a high risk of drowning in this non-respirable environment. Proper physiologic function and adaptation of the respiratory system are of the utmost importance to minimize the risks associated with compressed gas diving. This article provides an introduction to the diving techniques, the physics, and the pertinent human physiology and pathophysiology associated with this extreme environment. The causes of the major medical problems encountered in diving are described, with an emphasis on the underlying respiratory physiology.

Thoracic sonography for pneumothorax: the clinical evaluation of an operational space medicine spin-off

The recent interest in the use of ultrasound (US) to detect pneumothoraces after acute trauma in North America was initially driven by an operational space medicine concern. Astronauts aboard the International Space Station (ISS) are at risk for pneumothoraces, and US is the only potential medical imaging available. Pneumothoraces are common following trauma, and are a preventable cause of death, as most are treatable with relatively simple interventions. While pneumothoraces are optimally diagnosed clinically, they are more often inapparent even on supine chest radiographs (CXR) with recent series reporting a greater than 50% rate of occult pneumothoraces. In the course of basic scientific investigations in a conventional and parabolic flight laboratory, investigators familiarized themselves with the sonographic features of both pneumothoraces and normal pulmonary ventilation. By examining the visceral-parietal pleural interface (VPPI) with US, investigators became confident in diagnosing pneumothoraces. This knowledge was subsequently translated into practice at an American and a Canadian trauma center. The sonographic examination was found to be more accurate and sensitive than CXR (US 96% and 100% versus US 74% and 36%) in specific circumstances. Initial studies have also suggested that detecting the US features of pleural pulmonary ventilation in the left lung field may offer the ability to exclude serious endotracheal tube malpositions such as right mainstem and esophageal intubations. Applied thoracic US is an example of a clinically useful space medicine spin-off that is improving health care on earth.

Un pneumoperitoine compliquant un pneumomediastin au cours de la ventilation non invasive

INTRODUCTION

Pneumoperitoneum is known to be a rare complication of invasive mechanical ventilation. However it has not previously been described as a consequence of non-invasive ventilation.

CASE REPORT

The authors report a case of pneumoperitoneum associated with pneumomediastinum occurring in a 64-year-old patient treated for 3 years with bilevel ventilation via a nasal mask (expiratory pressure = 9 cm H2O, inspiratory pressure = 15 cm H2O) for obesity hypoventilation syndrome. Respiratory and gastroenterological investigations did not demonstrate a cause for this complication which resolved spontaneously following the cessation of ventilation. Nine months later, clinical deterioration and a worsening of blood gas parameters led to a recommencement of non-invasive mechanical ventilation at the same levels as previously. Over two years of follow up there have been no clinical or radiological signs of a recurrence of pneumomediastinum or pneumoperitoneum.

CONCLUSION

In the absence of any other explanation, barotrauma due to nasal ventilation appears to be the most likely explanation for this complication.

A new pepsin assay to detect pulmonary aspiration of gastric contents among newly intubated patients

Aspiration of gastric contents by endotracheally intubated patients is associated with significant morbidity and mortality. Previous studies suggest that pepsin in tracheal aspirates may be a valuable marker of occult aspiration. We sought to show the sensitivity and specificity of a new, pepsin-specific assay in humans. A prospective, case-controlled study was conducted with subjects serving as their own controls. After planned endotracheal and nasogastric intubation for elective surgery, 20 participants had tracheal and gastric aspirates withdrawn. A blinded investigator tested samples for the presence of pepsin using the assay. Positive samples were then tested with pepstatin, a specific pepsin inhibitor, to ensure that positive results were due to pepsin. All tracheal aspirates tested negative and all gastric aspirates tested positive for pepsin. Pepstatin halted pepsin activity in all positive samples, ensuring that positive results were due to pepsin. A pepsin-specific assay is extremely reliable for detecting gastric contents in humans.

Changing Pattern of Ventilator Settings in Patients Without Acute Lung Injury

STUDY OBJECTIVES

To determine whether the widely accepted concept of using lower tidal volume (Vt) values in patients with ARDS or obstructive lung disease has affected the pattern of ventilator settings in mechanically ventilated patients who do not have one of these conditions.

DESIGN AND PATIENTS

We performed a retrospective chart review of all patients who had experienced out-of-hospital cardiac arrest and had received ventilatory support for > or = 1 day at a university-affiliated county hospital during the years 1990, 1991, 1992, 1995, 1998, 1999, and 2000.

RESULTS

In 139 such patients, the mean final Vt values used on the first day of mechanical ventilation were 11.7, 12.4, 11.3, 9.6, 9.7, 9.2, and 9.8 mL/kg in those years, respectively. Multivariate analysis revealed that increasing year (beta-coefficient = -0.24; p = 0.001) and the presence of pulmonary edema (beta-coefficient = -1.2; p = 0.001) were independent predictors of the use of lower Vt values. Patients managed with a low Vt (ie, < 10 mL/kg; mean [+/- SD] Vt, 8.4 +/- 1.3 mL/kg) had a significantly higher incidence of atelectasis than the patients who were managed with traditional, larger Vt values (ie, > or = 10 mL/kg; mean Vt, 11.8 +/- 1.5 mL/kg) [61.1% vs 36.7%, respectively; p = 0.02]. Multivariate analysis revealed that the mean Vt used on days 1, 2, and 3 (<10 mL/kg or > or = 10 mL/kg) was the only predictor of the development of atelectasis during the first 3 days of mechanical ventilation (odds ratio, 0.33; p = 0.015). There was no difference in the incidence of pneumonia, the number of days spent receiving mechanical ventilation, Pao(2)/fraction of inspired oxygen ratio, or respiratory system compliance between the low Vt group and the traditional Vt group.

CONCLUSION

Currently, physicians at our hospital use lower Vt values than they have in the past. This is associated with the increase in the incidence of atelectasis in the patients who received ventilation using low Vt values.

Procalcitonin kinetics as a prognostic marker of ventilator-associated pneumonia

We investigated the value of procalcitonin kinetics as a prognostic marker during ventilator-associated pneumonia (VAP). This prospective, observational study was conducted in a medical intensive care unit in a university hospital. All consecutive patients with microbiologically proven VAP who survived 3 days after its diagnosis were included and grouped according to clinical outcome: favorable or unfavorable, defined as death, VAP recurrence, or extrapulmonary infection requiring antibiotics before Day 28. Serum procalcitonin levels were measured on Days 1, 3, and 7 for all patients. Among the 63 patients included, 38 had unfavorable outcomes. On Day 1, they were more critically ill than patients with a favorable outcome. Serum procalcitonin levels decreased during the clinical course of VAP but were significantly higher from Day 1 to Day 7 in patients with unfavorable outcomes. Multivariate analyses retained serum procalcitonin levels on Days 1, 3, and 7 as strong predictors of unfavorable outcome. Based on these data, procalcitonin could be a prognostic marker of outcome during VAP.

High Tidal Volume Ventilation Causes Different Inflammatory Responses in Newborn versus Adult Lung

We investigated the effect of high VT ventilation on adult and newborn rats by examining pulmonary injury and cytokine messenger RNA (mRNA). On the basis of compliance, edema formation, and histology, ventilation with 25 ml.kg(-1) was more injurious to adult rats than newborns. Ventilation with 40 ml kg(-1) minimally affected compliance in newborns but caused death in adults. Ventilation of adults for 30 minutes at 25 ml kg(-1) upregulated the mRNA expression of interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-2 (MIP-2), and IL-10, whereas in newborns such ventilation only increased mRNA expression of MIP-2 and IL-10. When VT was raised to 40 ml kg(-1) in newborns, IL-1beta mRNA levels were additionally increased at 30 minutes, whereas ventilation for 3 hours additionally increased IL-6 and TNF-alpha mRNA. In newborns, the addition of 100% oxygen (O2) to 30 minutes of ventilation blunted the high VT induction of IL-1beta, IL-10, and MIP-2 mRNA expressions, whereas at 3 hours, 100% O2 concentration synergistically increased the mRNAs for TNF-alpha and IL-6. Overall, adult rats are more susceptible to high VT-induced lung injury compared with newborns. In newborns, the inflammatory response is dependent on VT, duration, and supplemental O2. Thus, recommendations for VT limitation based on adult data may be inappropriate for newborns.

Incidence, risk factors and outcome of barotrauma in mechanically ventilated patients

OBJECTIVE

To determine the incidence, risk factors, and outcome of barotrauma in a cohort of mechanically ventilated patients where limited tidal volumes and airway pressures were used.

DESIGN AND SETTING

Prospective cohort of 361 intensive care units from 20 countries.

PATIENTS AND PARTICIPANTS

A total of 5183 patients mechanically ventilated for more than 12 h.

MEASUREMENTS AND RESULTS

Baseline demographic data, primary indication for mechanical ventilation, daily ventilator settings, multiple-organ failure over the course of mechanical ventilation and outcome were collected. Barotrauma was present in 154 patients (2.9%). The incidence varied according to the reason for mechanical ventilation: 2.9% of patients with chronic obstructive pulmonary disease; 6.3% of patients with asthma; 10.0% of patients with chronic interstitial lung disease (ILD); 6.5% of patients with acute respiratory distress syndrome (ARDS); and 4.2% of patients with pneumonia. Patients with and without barotrauma did not differ in any ventilator parameter. Logistic regression analysis identified as factors independently associated with barotrauma: asthma [RR 2.58 (1.05-6.50)], ILD [RR 4.23 (95%CI 1.78-10.03)]; ARDS as primary reason for mechanical ventilation [RR 2.70 (95%CI 1.55-4.70)]; and ARDS as a complication during the course of mechanical ventilation [RR 2.53 (95%CI 1.40-4.57)]. Case-control analysis showed increased mortality in patients with barotrauma (51.4 vs 39.2%; p=0.04) and prolonged ICU stay.

CONCLUSIONS

In a cohort of patients in whom airway pressures and tidal volume are limited, barotrauma is more likely in patients ventilated due to underlying lung disease (acute or chronic). Barotrauma was also associated with a significant increase in the ICU length of stay and mortality.

Value of the clinical pulmonary infection score for the identification and management of ventilator-associated pneumonia

OBJECTIVE

To evaluate the potential ability of an algorithm based on the clinical pulmonary infection score (CPIS) to identify and treat patients with bacterial ventilator-associated pneumonia (VAP) compared to a strategy based on quantitative cultures of bronchoscopic specimens.

DESIGN

Retrospective cohort study.

SETTING

Thirty-one critical care units across France.

PATIENTS

Two hundred and one patients clinically suspected of having VAP who had been included in the "invasive strategy" group of the French multicenter randomized trial and for whose quantitative cultures bronchoscopic specimens were obtained. CPIS was determined retrospectively, based on data that had been collected for the initial study.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

The clinical pulmonary infection score was determined on days 1 and 3, and compared in patients identified as having developed VAP or not, as defined by bronchoscopic specimen culture results. On day 3 138 of the 201 patients (69%) had a CPIS of more than 6 that would have required prolonged antimicrobial therapy based on the algorithm. In contrast, based on bronchoscopy, only 88 (44%) patients were considered to have VAP (kappa coefficient for concordance between the two strategies, 0.33). While the sensitivity of CPIS more than 6 on day 3 for identifying VAP was 89%, its specificity was only 47%, leading to potentially unnecessary treatment of 60 (53%) of the 113 patients without VAP as diagnosed by bronchoscopy.

CONCLUSION

A strategy based on the CPIS to decide which patients with suspected VAP should receive prolonged administration of antibiotics would appear to over-prescribe these agents, as compared to a strategy based on bronchoscopy.

Comparative evaluation of methods for ensuring the correct position of the tracheal tube in children undergoing open heart surgery

The length of the trachea varies and is relatively short in children, it is therefore difficult to determine the correct depth of tracheal tube placement. In 85 children, the tube was placed using one of the following methods: (i) after deliberate endobronchial intubation, withdrawal to the carina was confirmed by auscultation, and the tube was then withdrawn a further 2 cm (auscultation group); (ii) as above, except that withdrawal to the carina was confirmed by a decrease in peak inspiratory pressure (pressure group); (iii) the tube was placed with a 3.0-cm mark at the vocal cords (mark group). The mean (SD) distance from the tip of the tube to the carina was 1.91 (0.81) cm in the auscultation group, and 1.93 (0.67) cm in the pressure group. These were not significantly different (p > 0.05) from targeted distance of 2 cm. In the mark group, the tube was located 2.30 (0.98) cm above the carina in children younger than 36 months and was further from the carina [6.16 (1.0) cm] in older children. In 20% of patients initially randomly allocated to the mark group, the mark could not be visualised. In conclusion, the methods described above effectively achieve adequate tracheal tube depth in children.

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.

Factors predicting ventilator-associated pneumonia recurrence

OBJECTIVE

To determine the factors associated with ventilator-associated pneumonia recurrence in patients alive after 8 days of treatment for a first episode.

DESIGN

A 16-month, prospective, observational cohort study of patients diagnosed with a first ventilator-associated pneumonia episode. Predictors of recurrence were assessed by logistic regression analysis.

SETTING

Two intensive care units in a university hospital.

PATIENTS

Bronchoscopy was performed in 124 patients with clinically or radiologically suspected ventilator-associated pneumonia. Ventilator-associated pneumonia was confirmed by the presence of at least two of the following criteria: >/=2% of cells with intracellular bacteria found on direct examination of bronchoalveolar lavage fluid, protected specimen brush sample culture >/=103 colony-forming units/mL, or bronchoalveolar lavage culture >/=104 colony-forming units/mL. Ventilator-associated pneumonia recurrence was confirmed using the same microbiological criteria. Antibiotic treatment for ventilator-associated pneumonia lasted 14 days.

MEASUREMENTS AND MAIN RESULTS

Clinical, radiologic, and biological data at intensive care unit admission, on the day of bronchoscopy (D1) and on D8, and outcome variables were prospectively recorded. Ventilator-associated pneumonia recurred in 28 patients (all of them still on mechanical ventilation on D8), 21 +/- 9 days after the first episode (82% after D14). Factors significantly associated with recurrence were: acute respiratory failure as initial reason for mechanical ventilation, D1 radiologic score >7, D8 radiologic score >8, adult respiratory distress syndrome on D8, mechanical ventilation persistence on D8, D8 temperature >38 degrees C, and D8 temperature >D1 temperature, but not disease-severity scores at inclusion and D8, or first-episode pathogen(s). Multivariate analysis identified D1 radiologic score >7 (odds ratio = 3.9; 95% confidence interval, 1.3-11.6), D8 temperature >38 degrees C (odds ratio = 4.4; 95% confidence interval, 1.4-13.4), and adult respiratory distress syndrome on D8 (odds ratio = 14.6; 95% confidence interval, 1.5-143.5) as predictors of recurrence.

CONCLUSIONS

Factors of ventilator-associated pneumonia recurrence evaluated on D8 of a 14-day course of antibiotics are linked to the severity of lung injury and persistence of fever, but not to first-episode pathogen(s).

Pneumothorax in the ICU: patient outcomes and prognostic factors

STUDY OBJECTIVE

To identify the prognostic factors for pneumothorax in patients in the ICU.

DESIGN

Retrospective cohort study.

SETTING

ICU at a university-based teaching hospital.

PATIENTS AND METHODS

Sixty patients developed pneumothoraces in the ICU during a period of 36 months. Medical records relating to patients' age, sex, underlying diseases, associated medical conditions, reasons for admission, acute physiology and chronic health evaluation (APACHE) II scores, procedures performed before the development of pneumothorax, occurrences of tension pneumothorax, duration of chest tube placement, chest tube removal, duration of ICU stay, and patient outcomes all were analyzed. A multivariate logistic regression model was applied with variables that were significantly associated with survival in the univariate analysis. The probabilities of chest tube removal were calculated using the Kaplan-Meier method.

RESULTS

Thirty-five patients (58%) had procedure-related pneumothoraces. The procedure that most commonly caused pneumothoraces was thoracentesis (n = 19; 54%), followed by central vein/pulmonary artery catheterization (n = 14; 40%) and bronchoscopy/transbronchial lung biopsy (n = 8; 23%). A multivariate logistic regression analysis also showed that pneumothorax due to barotrauma (p = 0.001), tension pneumothorax (p = 0.0023), and concurrent septic shock (p = 0.0476) were significantly and independently associated with death. The log-rank test revealed that the success rate of chest tube removal was higher in patients with procedure-related pneumothoraces (p = 0.0055).

CONCLUSIONS

Patients with procedure-related pneumothoraces had better outcomes. Patients with pneumothoraces occurring in the ICU due to barotrauma, or a complicating tension pneumothoraces, carry a higher risk of mortality.

Pseudomonas aeruginosa ventilator-associated pneumonia: comparison of episodes due to piperacillin-resistant versus piperacillin-susceptible organisms

We sought to determine the epidemiological characteristics of patients in an intensive care unit (ICU) who developed ventilator-associated pneumonia (VAP) caused by piperacillin-resistant Pseudomonas aeruginosa (PRPA; n=34) or piperacillin-susceptible P. aeruginosa (PSPA; n=101). According to univariate analysis, the factors associated with the development of PRPA VAP were presence of an underlying fatal medical condition, immunocompromised status, longer previous hospital stay, less-severe illness at the time of ICU admission, duration of mechanical ventilation before onset of VAP, number of classes of antibiotic received, and previous exposure to imipenem or fluoroquinolone. Multivariate logistic regression analysis identified the following significant independent factors: presence of an underlying fatal medical condition (odds ratio [OR], 5.6), previous fluoroquinolone use (OR, 4.6), and initial disease severity (OR, 0.8). We concluded that the clinical characteristics of patients who develop PRPA VAP differ from those of patients who develop PSPA VAP. Restricted fluoroquinolone use is the sole independent risk factor for PRPA VAP that is open to medical intervention.

Role of serial routine microbiologic culture results in the initial management of ventilator-associated pneumonia

Results of routine microbiologic cultures of specimens obtained before the onset of ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients might help to identify the causative microorganisms and thus to select effective initial antimicrobial therapy. To test this hypothesis, we prospectively studied 125 consecutive VAP episodes for which the causative microorganisms were determined using bronchoscopic techniques. Upon entry into the study, each patient's hospital chart was reviewed and culture results of all previously obtained microbiologic specimens were recorded (mean number +/- SD per patient, 45 +/- 38). A total of 220 microorganisms were cultured at significant concentrations (> or = 10(3)/10(4) colony-forming units [cfu]/ml) from bronchoscopic specimens and considered responsible for pneumonia. Of these 220 organisms, only 73 (33%) were recovered before VAP onset, sometimes from multiple sites in the same patient but mainly from prior respiratory secretion cultures (n = 53). Also previously isolated were 342 organisms that were not responsible for VAP, making prospective identifications of the true pathogens difficult. Among the 102 episodes for which prior respiratory secretion culture results had been obtained (mean time before VAP onset, 8 +/- 9 d), all the organisms ultimately responsible for pneumonia were previously recovered from only 36 (35%) of these specimens. Based on these data, the contribution of routine microbiologic specimens in guiding initial antimicrobial therapy decisions for patients with suspected VAP appears limited.

Weaning from prolonged mechanical ventilation

The development of weaning failure and need for PMV is multifactorial in origin, involving disorders of pulmonary mechanics and complications associated with critical illness. The underlying disease process is clearly important when discussing mechanisms of ventilator dependence; interventions therefore must be tailored to individual patients. Unfortunately, the main conclusion that can be drawn from the sum of the studies investigating patients on PMV to date is that an evidence-based approach to weaning is not possible and more research needs to be done. New studies need to incorporate severity-of-illness scores and an assessment of principal and comorbid conditions to allow for comparison of the findings from different centers. The best approach to a patient requiring PMV after exclusion of easily treatable conditions is not known. The literature regarding both acute and chronic cases suggests that a systematic approach to weaning involving the participation of multiple caregivers, including nurses, physicians, and respiratory, physical, and speech therapists facilitates liberation from MV. Although a gradual decrement in ventilator support would seem prudent, Scheinhorn et al have begun to identify a subpopulation of patients who can tolerate an acceleration of the weaning process. Given the known complications associated with MV, it is crucial that further research be performed to identify patients as soon as they are capable of breathing spontaneously. The literature demonstrates through multiple studies that satisfactory patient outcomes are attainable and can be achieved at LTAC facilities in a more cost-effective manner than in an ICU setting. The trend toward the concentration of patients into specialized regional weaning centers should facilitate the research process and continue to improve outcomes in this population.

A review of intensive care nurse staffing practices overseas: what lessons for Australia?

In view of market-driven health-care policies and the move to greater efficiencies within the health-care system, the cost of nursing care is being increasingly scrutinised. Different overseas practices are commonly cited as justification for changing practices within Australia. This study is based on a review of the literature on intensive care nurse staffing requirements in Australasia; specifically, New South Wales, the United States (US) and, to a lesser extent, Europe. It was found that looking to the US for cost-cutting strategies in intensive care units (ICUs) is based on a false premise: that we are comparing like with like. ICUs in the US have a different historical trajectory and culture, service wider constituencies, have technicians and unregistered personnel providing nursing care and do not provide demonstrably better outcomes or significant cost savings. Research indicates that continuous nursing care by trained professionals provides the best outcomes. If costs must be cut, technology, pharmaceuticals and laboratory tests should be targeted. Further, a greater commitment to the development of a 'progressive patient care' model in hospital planning is required, in order to establish or consolidate an intermediate level of nursing care between the ward and the ICU. Programs aiming to improve and continuously monitor patient care, such as adverse event monitoring, the prevention of unplanned extubation and facilitation of early extubation, should be instituted, as these have been shown to not only reduce ICU costs but also improve patient outcomes. (c) 2000 Harcourt Publishers Ltd.

Effect of unplanned extubation on outcome of mechanical ventilation

Unplanned extubation is a major complication of translaryngeal intubation, but its impact on mortality, duration of mechanical ventilation (MV), length of intensive care unit (ICU) and hospital stay, and need for ongoing hospital care has not been adequately defined. We performed a case-control study in a tertiary-care medical ICU, comparing 75 patients with unplanned extubation and 150 controls matched for Acute Physiology and Chronic Health Evaluation II score, presence of comorbid conditions, age, indication for MV, and sex. Forty-two (56%) patients required reintubation after unplanned extubation (74% immediately, 86% within 12 h). Thirty-three (44%) unplanned extubations occurred during weaning trials, and 30% of these patients needed reintubation (failed unplanned extubation). In contrast, 76% of patients with unplanned extubation occurring during ventilatory support required reintubation. Although mortality was similar to that of controls (failed unplanned extubation 40%, versus control 31%, p > 0.2), patients with failed unplanned extubation had a significantly longer duration of MV (19 versus 11 d, p < 0.01), longer stay in the ICU (21 versus 14 d, p < 0.05), and longer hospital stay (30 versus 21 d, p < 0.01), and survivors were more likely to require chronic care (64% versus 24%, p < 0.001). Successfully tolerated unplanned extubation was associated with a reduction in time from beginning of weaning to extubation (0.9 versus 2.0 d, p = 0.06), but with no difference in overall duration of MV, mortality, discharge location, ICU, or hospital stay as compared with these measures for controls. We conclude that unplanned extubation is not associated with increased mortality when compared with that of matched controls, although it does result in prolonged MV, longer ICU and hospital stay, and increased need for chronic care. These effects are due exclusively to patients who fail to tolerate unplanned extubation. Although successfully tolerated unplanned extubation decreased the duration of weaning trials, it had no other measurable beneficial impact on outcome.

Invasive and noninvasive strategies for management of suspected ventilator-associated pneumonia. A randomized trial

BACKGROUND

Optimal management of patients who are clinically suspected of having ventilator-associated pneumonia remains open to debate.

OBJECTIVE

To evaluate the effect on clinical outcome and antibiotic use of two strategies to diagnose ventilator-associated pneumonia and select initial treatment for this condition.

DESIGN

Multicenter, randomized, uncontrolled trial.

SETTING

31 intensive care units in France.

PATIENTS

413 patients suspected of having ventilator-associated pneumonia.

INTERVENTION

The invasive management strategy was based on direct examination of bronchoscopic protected specimen brush samples or bronchoalveolar lavage samples and their quantitative cultures. The noninvasive ("clinical") management strategy was based on clinical criteria, isolation of microorganisms by nonquantitative analysis of endotracheal aspirates, and clinical practice guidelines.

MEASUREMENTS

Death from any cause, quantification of organ failure, and antibiotic use at 14 and 28 days.

RESULTS

Compared with patients who received clinical management, patients who received invasive management had reduced mortality at day 14 (16.2% and 25.8%; difference, -9.6 percentage points [95% CI, -17.4 to -1.8 percentage points]; P = 0.022), decreased mean Sepsis-related Organ Failure Assessment scores at day 3 (6.1+/-4.0 and 7.0+/-4.3; P = 0.033) and day 7 (4.9+/-4.0 and 5.8+/-4.4; P = 0.043), and decreased antibiotic use (mean number of antibiotic-free days, 5.0+/-5.1 and 2.2+/-3.5; P < 0.001). At 28 days, the invasive management group had significantly more antibiotic-free days (11.5+/-9.0 compared with 7.5+/-7.6; P < 0.001), and only multivariate analysis showed a significant difference in mortality (hazard ratio, 1.54 [CI, 1.10 to 2.16]; P = 0.01).

CONCLUSIONS

Compared with a noninvasive management strategy, an invasive management strategy was significantly associated with fewer deaths at 14 days, earlier attenuation of organ dysfunction, and less antibiotic use in patients suspected of having ventilator-associated pneumonia.

Safety, efficacy, and cost-effectiveness of mechanical ventilation with humidifying filters changed every 48 hours: a prospective, randomized study

OBJECTIVE

To determine whether three hydrophobic and hygroscopic heat and moisture exchangers (HMEs) retain their heating and humidifying properties (assessed by psychrometric measurements of absolute humidity, relative humidity, and tracheal temperature) for 48 hrs without any drop in their bacteriologic efficiency.

DESIGN

Prospective randomized clinical trial.

PATIENTS

Sixty-one consecutive unselected mechanically ventilated intensive care unit patients.

INTERVENTIONS

Patients were randomly allocated to one of the three HMEs studied (Hygrobac-Dar from Mallinckrodt, n = 21; Humid-Vent from Gibeck, n = 20; and Clear-Thermal from Intersurgical, n = 20).

MEASUREMENTS AND MAIN RESULTS

Hygrometric parameters were measured by psychrometry after 3, 24, and 48 hrs of use. Peak airway pressure was recorded every 6 hrs and averaged over 24 hrs. Bacterial colonization of both patients and circuits was studied. Patients in all three groups were similar in terms of age, indications for, and overall duration of mechanical ventilation. Tracheal tube occlusion never occurred. Hygrometric data included 371 measurements whereas bacteriologic data included >700 samples and cultures. The Hygrobac-Dar HMEs gave a significantly higher absolute humidity whatever the time of measurement (3, 24, or 48 hrs) than the other two HMEs (p < .001). The Clear-Thermal HMEs gave the poorest hygrometric parameters (p < .01); five of them were replaced prematurely (24 hrs) because the absolute humidity was <25 mg H2O/L. This did not occur for the other HMEs. Mean peak airway pressures were identical in the three groups. The bacterial colonizations of both patient and circuit were similar (and negligible for circuits) for all three groups.

CONCLUSION

Some HMEs may be used safely for 48 hrs without change. However, this does not pertain to every brand of HME. Objective in vivo evaluation of their humidifying performances is decisive before extending their duration of use.

A randomized, prospective evaluation of noninvasive ventilation for acute respiratory failure

We compared noninvasive positive-pressure ventilation (NPPV), using bilevel positive airway pressure, with usual medical care (UMC) in the therapy of patients with acute respiratory failure (ARF) in a prospective, randomized trial. Patients were subgrouped according to the disease leading to ARF (chronic obstructive pulmonary disease [COPD], a non-COPD-related pulmonary process, neuromuscular disease, and status postextubation), and were then randomized to NPPV or UMC. Thirty-two patients were evaluated in the NPPV group and 29 in the UMC group. The rate of endotracheal intubation (ETI) was significantly lower in the NPPV than in the UMC group (6.38 intubations versus 21.25 intubations per 100 ICU days, p = 0.002). Mortality rates in the intensive care unit (ICU) were similar for the two treatment groups (2.39 deaths versus 4.27 deaths per 100 ICU days, p = 0.21, NPPV versus UMC, respectively). Patients with hypoxemic ARF in the NPPV group had a significantly lower ETI rate than those in the UMC group (7.46 intubations versus 22.64 intubations per 100 ICU days, p = 0.026); a similar trend was noted for patients with hypercapnic ARF (5.41 intubations versus 18.52 intubations per 100 ICU days, p = 0.064, NPPV versus UMC, respectively). Patients with ARF in the non-COPD category had a lower rate of ETI with NPPV than with UMC (8.45 intubations versus 30.30 intubations per 100 ICU days, p = 0.01). Although the rate of ETI was lower among COPD patients receiving NPPV, this trend did not reach statistical significance (5.26 intubations versus 15.63 intubations per 100 ICU days, p = 0.12, NPPV versus UMC, respectively). In conclusion, NPPV with bilevel positive airway pressure reduces the rate of ETI in patients with ARF of various etiologies.

Assessing the need for reintubation: a prospective evaluation of unplanned endotracheal extubation

OBJECTIVE

Unplanned endotracheal extubation (UEE) is a common complication in medical intensive care units but very little data about UEE in surgical populations are available. Our hypothesis is that the surgical intensive care unit (SICU) population requires reintubation less frequently compared with the medical intensive care unit population. We prospectively gathered data on patients in a SICU in an attempt to identify the incidence of UEE and to study the need for reintubation after UEE.

METHODS

During an 18-month period, we prospectively identified SICU patients from a quality improvement database who required ventilatory support. All patients who self-extubated were included in the study.

RESULTS

Fifty-eight of 1,178 intubated patients experienced unplanned extubation 61 times during the 18-month period. A total of 22 patients (36%) required reintubation, whereas 39 patients (64%) did not. Thirty-three patients self-extubated while being actively weaned from ventilatory support. Of these, only 5 patients (15%) required reintubation and 28 patients (85%) did not (p < 0.01).

CONCLUSION

A total of 85% of patients who self-extubate during the weaning process did not require reintubation in our study. Those who have an FiO2 >50%, a lower PaO2/FiO2 ratio, had UEE occur by accident, or were not being weaned when UEE occurred required reintubation more frequently. These data suggest that some of our SICU patients are intubated longer than necessary, which may translate into more ventilator related complications, longer ICU stays and increased cost.

Efficiency and safety of mechanical ventilation with a heat and moisture exchanger changed only once a week

The cost of mechanical ventilation (MV) is high. Efforts to reduce this cost, as long as they are not detrimental for the patients, are needed. MV with heat and moisture exchangers (HME) changed every 48 h is safe, efficient, and cost-effective. Preliminary reports suggest that the life span of these filters may be prolonged. We determined prospectively whether a hygroscopic and hydrophobic HME (Hygrobac-Dar; Mallinckrodt) provided safe and efficient heating and humidification of the inspired gases when changed only once a week. Patients who were considered to require mechanical ventilation for more than 48 h were included in the study. HMEs were initially set for 7 d. Efficient airway heating and humidification were assessed by clinical parameters (number of tracheal suctionings and instillations required, peak airway pressures) and hygrometric measurements performed by psychrometry. Resistance was measured from Day 0 to Day 7. Bacterial colonization of circuits and HMEs was studied. A total of 377 days of mechanical ventilation with 60 HMEs was studied. Clinical parameters and hygrometric measurements did not change between Day 0 and Day 7. Mean absolute humidity was 30.3 +/- 1.3 mg H(2)O/L on Day 0 and 30.8 +/- 1.5 mg H(2)O/L on Day 7 (p = 0.7). Endotracheal tube occlusion never occurred. Three HMEs were replaced prematurely because of insufficient absolute humidity. This rare event occurred only in patients with COPD and after the third day of use. In addition, the absolute humidity delivered by the HMEs was significantly lower in patients with COPD than in the rest of the population. Resistance did not change from Day 0 to Day 7 (2.4 +/- 0.3 versus 2.7 +/- 0.3 cm H(2)O/L/s; p = 0.4). Bacterial samples of both circuits and ventilator sides of HMEs were sterile in most cases. We conclude that mechanical ventilation can be safely conducted in non-COPD patients using an HME changed only once a week, leading to substantial cost savings (about $110,000 per year if these findings were applied to the university-affiliated hospitals in Paris).

A review of intensive care nurse staffing practices overseas: what lessons for Australia?

In view of market-driven health-care policies and the move to greater efficiencies within the health-care system, the cost of nursing care is being increasingly scrutinised. Different overseas practices are commonly cited as justification for changing practices within Australia. This study is based on a review of the literature on intensive care nurse staffing requirements in Australasia; specifically, New South Wales, the United States (US) and, to a lesser extent, Europe. It was found that looking to the US for cost-cutting strategies in intensive care units (ICUs) is based on a false premise: that we are comparing like with like. ICUs in the US have a different historical trajectory and culture, service wider constituencies, have technicians and unregistered personnel providing nursing care and do not provide demonstrably better outcomes or significant cost savings. Research indicates that continuous nursing care by trained professionals provides the best outcomes. If costs must be cut, technology, pharmaceuticals and laboratory tests should be targeted. Further, a greater commitment to the development of a 'progressive patient care' model in hospital planning is required, in order to establish or consolidate an intermediate level of nursing care between the ward and the ICU. Programs aiming to improve and continuously monitor patient care, such as adverse event monitoring, the prevention of unplanned extubation and facilitation of early extubation, should be instituted, as these have been shown to not only reduce ICU costs but also improve patient outcomes.

Bedside evaluation of efficient airway humidification during mechanical ventilation of the critically ill

STUDY OBJECTIVE

To determine the correlation between simple rating of condensation seen in the flex-tube connecting the heating and humidifying device used with the endotracheal tube and hygrometric parameters (absolute and relative humidity and tracheal temperature) measured by psychrometry.

DESIGN

Prospective randomized clinical trial.

SETTING

Medical ICU of Louis Mourier Hospital, Colombes, France, a university-affiliated teaching hospital.

PATIENTS

Forty-five consecutive mechanically ventilated critically ill patients.

INTERVENTIONS

Patients undergoing mechanical ventilation were randomly assigned to receive humidification with one of the four heat and moisture exchangers (HMEs) tested or with a conventional heated humidifier.

MEASUREMENTS

The hygrometric performances of four HMEs (BB2215, BB50, and BB100 from Pall Biomedical, Saint-Germaine-en-Laye, France; and Hygrobac-Dar from Mallinckrodt, Mirandola, Italy) and a heated humidifier (Fisher & Paykel; Auckland, New Zealand) were studied after 3 h and also after 48 h of use for the Hygrobac-Dar and correlated to a clinical visual inspection rating the amount of condensation in the flex-tube of the endotracheal tube.

RESULTS

A total of 95 measurements in 45 patients were performed. The best hygrometric parameters were obtained with the heated humidifier (p < 0.001). The Hygrobac-Dar yielded significantly higher values for both humidities and tracheal temperature than the other three HMEs (p < 0.001). The performance of Hygrobac-Dar was unchanged after 48 h of use. There was a significant correlation between the condensation seen in the flex-tube and the hygrometric parameters measured by psychrometry (absolute humidity, rho = 0.7; relative humidity, rho = 0.7; tracheal temperature, rho = 0.5, p < 0.0001).

CONCLUSION

In mechanically ventilated ICU patients, visual evaluation of the condensation in the flex-tube provides an estimation of the heating and humidifying efficacy of the heating and humidifying device used, thus allowing the clinician bedside monitoring of airway humidification.

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.

Acute respiratory distress syndrome: CT abnormalities at long-term follow-up

PURPOSE

To document abnormalities at computed tomography (CT) in adult survivors of acute respiratory distress syndrome (ARDS), to determine the relationships between CT patients during the acute phase and at follow-up, and to assess the effects of mechanical ventilation on the development of CT abnormalities.

MATERIALS AND METHODS

Thin-section CT scans were obtained during the acute illness and at follow-up in 27 patients with ARDS. The extent and distribution of individual CT patterns were independently analyzed.

RESULTS

At follow-up CT, a reticular pattern was the most prevalent (23 patients [85%]) and extensive CT abnormality, with a striking anterior distribution (more anterior distribution than posterior distribution, P < .001). A reticular pattern at follow-up was inversely correlated with the extent of intense parenchymal opacification on scans obtained during the acute illness (Spearman r = -0.26; P < .001). The extent of a reticular pattern at follow-up CT was independently related to the total duration of mechanical ventilation (P = .02) but was most strongly related to the duration of pressure-controlled inverse-ratio ventilation (P < .001).

CONCLUSION

A reticular pattern, with a striking anterior distribution, is a frequent finding of follow-up CT in ARDS survivors and is most strongly related to the duration of pressure-controlled inverse-ratio ventilation.

Comparison of two endotracheal tube securement techniques on unplanned extubation, oral mucosa, and facial skin integrity

OBJECTIVE

To determine the effect of 2 standard methods (i.e., twill tape versus adhesive tape) of securement on unplanned extubation, oral mucosa, and facial skin integrity of the orally intubated patient.

DESIGN

A prospective, quasi-experimental design was used for the pilot study.

SETTING

The setting for the pilot study included critical care units of 3 community hospitals and 1 veterans' hospital in a midwestern city.

SUBJECTS

A total of 52 orally intubated adult subjects were enrolled in the study from the 4 clinical sites over a 6-month period of time. The participants in the study consisted of 30 men and 22 women. The subjects ranged in age from 22 to 85 years, with a mean age of 62.3 years. The mean length of intubation was 89.6 hours.

OUTCOME MEASURES

The outcome measures of the study were (1) unplanned extubation, (2) oral mucosa status, and (3) facial skin integrity.

INTERVENTIONS

Endotracheal tube securement with either the twill tape or the adhesive tape securement method.

RESULTS

With use of multiple analysis of variances (MANOVA) and repeated analyses of variances (ANOVAs), there were no significant differences by time or type of endotracheal tube securement method on oral mucosa or facial skin integrity. A chi-square analysis demonstrated no significant association between the 2 types of endotracheal tube securement when comparing their efficacy in preventing unplanned extubation.

CONCLUSION

The findings of this pilot study demonstrated both methods of endotracheal tube securement to be comparable in preventing unplanned extubation and in maintaining oral mucosa status and facial skin integrity.

Cardiac arrest as a possible sequela of critical airway management and intubation

Immediate cardiac arrest may occur as a result of the physiological consequences of critical airway management, which may include one or all of the following: (1) sedation and/or paralysis, (2) tracheal intubation, and (3) positive pressure ventilation. Two patients are reported, both with myocarditis, who developed cardiac arrest within minutes of simple intubations. Their arrests were not related to technical difficulties of critical airway management. Any disease process that creates a preload-dependent cardiovascular system also creates a situation wherein critical airway management may cause cardiac decompensation. All medications administered to sedate patients and facilitate intubation, as well as mechanical ventilation itself, can cause a decrease in preload. This may be a significant mechanism through which immediate decompensation occurs. Potential conditions that cause preload-dependent cardiovascular systems, as well as alternate therapeutic considerations, are outlined. In these patients intubations should not be delayed, but should be done with extreme caution in anticipation of possible cardiac arrest.

[Tracheal intubation in prehospital resuscitation: importance of rapid-sequence induction anesthesia]

OBJECTIVE

To investigate complications of emergency endotracheal intubation (EEI), possibly facilitated by rapid-sequence induction, in the prehospital critical care setting: 1) the difficulty of intubation; 2) the cardiorespiratory consequences of intubation; 3) the relationship between the occurrence of complications and prognosis.

STUDY DESIGN

Prospective non randomized, open study.

PATIENTS

All patients treated over a 5-month period by a physician-manned ambulance service and requiring EEI.

METHODS

Patients were allocated either in with cardiac arrest (CA) group or a group with maintained spontaneous circulation (SC). Difficulty of intubation was assessed by the number of attempts.

RESULTS

Two hundred and twenty-four consecutive EEI were carried out by physicians (46%) and residents (38%) not trained in anaesthesia, anaesthetists (8%), or nurse anaesthetists (7%). Trachea was intubated after a maximum of three attempts in all patients. Success rate at the first attempt was 91%. It was 92% in CA patients (n = 76) and 90% in SC patients (P = 0.59). Anaesthetic induction, with (n = 112) or without (n = 12) succinylcholine, was used to facilitate 84% of intubations in SC patients. Complications occurred in 30 patients (20%). There was no relationship between the latter and hospital mortality, duration of ventilatory support, duration of stay in the intensive care unit.

CONCLUSION

In this study, EEI in SC patients was frequently facilitated by rapid sequence induction and was associated with a high success rate at the first attempt, as in CA patients. Morbidity was low. All physicians involved in emergency airway management should be skilled in this technique.

Liberation from mechanical ventilation: a decade of progress

Multiple complications associated with mechanical ventilation mandate that clinicians expeditiously define and reverse the pathophysiologic processes that precipitate respiratory failure and then, detect the earliest point that a patient can breathe without the ventilator. Over the past decade, numerous laboratory and clinical studies have been reported that may inform transformation of the "art of weaning" to the science of liberation. We review these studies and use them to formulate a systematic approach to assure early, safe, and successful liberation of patients from mechanical ventilation.

Ventilator-associated pneumonia

Mechanically ventilated patients are at a substantially higher risk for developing nosocomial pneumonia. Overall, there is a relatively constant 1&!TN!150;3% risk per day of developing pneumonia while receiving mechanical ventilation. The sensitivity and specificity of clinical criteria alone for diagnosis of ventilator-associated pneumonias (VAP) is low. Several techniques have been developed to sample and quantitate the lower respiratory tract to improve the diagnostic yield. Gram-negative bacillary pneumonias account for the majority of the VAP. Strategies for prevention of VAP such as use of sucralfate for stress ulcer prophylaxis and selective decontamination of the digestive tract have been the focus of many clinical studies. Cost-effective preventive measures are needed to combat the increasing antimicrobial resistance, growing population of immunocompromised patients and increasing number of mechanically ventilated patients.

A prospective study of unplanned endotracheal extubation in intensive care unit patients

OBJECTIVE

To evaluate incidence, factors associated with unplanned endotracheal extubation (UEE), and prognostic factors for reintubation.

DESIGN

A prospective study over a 32-mo period.

SETTING

A 16-bed general intensive care unit of a tertiary university hospital.

PATIENTS

Adult subjects undergoing endotracheal intubation for >48 hrs.

INTERVENTIONS

Observation of patients who presented unplanned extubation.

MEASUREMENTS AND MAIN RESULTS

Over the 32-mo period, there were 59 episodes of UEE in 55 patients (frequency 7.3%). Deliberate self-extubation occurred in 46 episodes (77.9%), while there were 13 episodes (22.1%) of accidental extubation. Twenty-seven (45.8%) episodes occurred in patients who were receiving full mechanical ventilatory support and 32 (54.2%) episodes occurred during the weaning period from mechanical ventilation. Reintubation was required in 27 (45.8%) episodes of UEE. The need for reintubation after UEE was 36.9% in deliberate self-extubation patients and 76.9% in accidental extubation patients (p = .01). Only 15.6% (5/32) of patients who presented UEE during weaning required reintubation, while reintubation was mandatory in 81.5% (22/27) of patients who presented UEE during full mechanical ventilatory support (p < .001). A multiple logistic regression analysis was performed to determine the variables independently associated with the need for reintubation: days of mechanical ventilation were significantly associated with the need for reintubation, and weaning was associated with no need for reintubation. The model correctly classified the need for reintubation in 84.7% (50/59) of cases.

CONCLUSIONS

Reintubation in UEE patients strongly depends on the type of mechanical ventilatory support. The probability of requiring reintubation if UEE occurs during full ventilatory support is higher than if UEE occurs during weaning. These data suggest that some patients are under mechanical ventilation longer than necessary.

Unplanned extubation: risk factors of development and predictive criteria for reintubation

OBJECTIVES

To define patients at risk for unplanned extubation; to assess the influence of nursing workload on the incidence of unplanned extubation; and to determine predictive criteria for patients requiring reintubation.

DESIGN

A prospective, case-control study, with 10 and 15 mos of data collection.

SETTING

University medical intensive care department.

PATIENTS

In the first study, which lasted 10 mos, unplanned extubation occurred in 40 (14%) of 281 ventilated and intubated patients; 36 cases were sufficiently documented to be compared with 74 intubated and ventilated controls. In the second study, which lasted 15 mos, the reintubated patients (n=23) of a series of 62 unplanned extubation patients were compared with those who were not reintubated (n=39).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The following parameters were recorded: gender, age, main reason for admission, Simplified Acute Physiology Score II, route of intubation (oral or nasotracheal), tube diameter, ventilatory mode, FiO2, frequency and tidal volume delivered by the ventilator immediately before unplanned extubation, arterial blood gases performed 24 hrs before unplanned extubation, the presence of any sedation with, in this case, the last Ramsay score, the presence of hand restraints, the presence of weaning of ventilation, the accidental or deliberate nature of unplanned extubation, the Glasgow Coma Score at the time of unplanned extubation, the duration of ventilation before unplanned extubation, total duration of ventilation and stay in the intensive care unit, and the patient's survival or death. The nursing workload was evaluated using a score derived from the Projet de Recherche en Nursing and adapted to intensive care. Unplanned extubation patients were more frequently intubated orally than controls (33.3% vs. 14.9%, respectively; p< .05). In the population of sedated patients, unplanned extubation patients were more frequently agitated than controls (60% vs. 19%, respectively; p < .05). The nursing workload did not differ between days with and days without unplanned extubation. Twenty-three (37%) of the 62 cases of documented unplanned extubation were reintubated. Predictive factors of reintubation are, in decreasing order of importance: Glasgow Coma Score of <11, accidental nature of unplanned extubation, and a PaO2/FiO2 ratio <200 torr (<26.7 kPa).

CONCLUSIONS

Patients at risk for unplanned extubation are characterized by oral intubation and insufficient sedation. In the department studied, and with the specific score used, we did not observe a relationship between the nursing workload and the incidence of unplanned extubation. A Glasgow Coma Score of <11, the accidental nature of unplanned extubation, and a PaO2/FiO2 ratio <200 torr (<26.7 kPa) are factors associated with a risk of reintubation.

Unplanned tracheal extubation outside the operating room: a quality improvement audit of hemodynamic and tracheal airway complications associated with emergency tracheal reintubation

The incidence of hemodynamic and airway complications associated with tracheal reintubation after an unplanned extubation has not been established. Patients whose tracheas were emergently intubated outside the operating room were reviewed over a 27-mo period via a quality improvement vehicle to evaluate hemodynamic and airway complications. Data from a subset of patients (n = 57) who underwent tracheal reintubation after unplanned (self-) extubation were collected for analysis. Of the reintubations, 93% took place within 2 h of self-extubation. Of the patients, 72% had hemodynamic alterations and/or airway-related complications, including hypotension (35%), tachycardia (30%), hypertension (14%), multiple laryngoscopic attempts (22%), difficult laryngoscopy (16%), difficult intubations (14%), hypoxemia (14%), and esophageal intubation (14%). In addition, one surgical airway and one case of "cannot ventilate, cannot intubate" leading to cardiac arrest and death were recorded. These findings suggest that patients requiring reintubation will likely do so soon after self-extubation and that reintubation can be fraught with significant hemodynamic and airway complications. Less than one third of patients undergo a mishap-free reintubation. Strategies to decrease the self-extubation rate in the intensive care unit are needed to improve patient safety and to lessen the potential impact of emergency airway management.

IMPLICATIONS

Self-extubation by patients requiring mechanical ventilation can be life-threatening, and replacing the breathing tube often leads to hemodynamic and airway complications. Using this quality improvement audit, 57 self-extubating patients and the complications associated with replacing the breathing tube, which are numerous and can lead to significant morbidity and mortality, were analyzed.