Modifying endotracheal tubes to prevent ventilator-associated pneumonia.

PURPOSE OF REVIEW: The endotracheal tube (ETT) is the main avenue leading to airway contamination and subsequent ventilator-associated pneumonia (VAP) during mechanical ventilation. A number of modifications to the ETT are available, aimed at reducing the incidence of VAP. We review here available systems and devices, and clinical data regarding their efficacy. RECENT FINDINGS: Three main modifications of ETTs have been developed: coating with antimicrobials, adding a suction channel for the removal of oro-pharyngeal secretions, and modifying the design of the cuff. Each of these interventions has been shown to limit bacterial colonization of the distal airways and to decrease the incidence of VAP. Data on their ultimate effect on related clinical outcomes are still lacking. SUMMARY: Modifications of ETTs aimed at decreasing the onset of VAP show promising results. However, the lack of a significant effect on outcomes prompts us to use caution before recommending their widespread use.

Clinical and economic burden of postoperative pulmonary complications: patient safety summit on definition, risk-reducing interventions, and preventive strategies.

OBJECTIVE: Postoperative pulmonary complications are a major contributor to the overall risk of surgery. We convened a patient safety summit to discuss ways to enhance physician awareness of postoperative pulmonary complications, advance postoperative pulmonary complications as a substantive public health concern demanding national attention, recommend strategies to reduce the deleterious impact of postoperative pulmonary complications on clinical outcomes and healthcare costs, and establish an algorithm that will help identify patients who are at increased risk for postoperative pulmonary complications. DATA SOURCES: We conducted PubMed searches for relevant literature on postoperative pulmonary complications in addition to using the summit participants' experience in the management of patients with postoperative pulmonary complications. DATA SYNTHESIS: Postoperative pulmonary complications are common, are associated with increased morbidity and mortality, and adversely affect financial outcomes in health care. A multifaceted approach is necessary to reduce the incidence of postoperative pulmonary complications. Identifying a measurable marker of risk will facilitate the targeted implementation of risk-reduction strategies. CONCLUSIONS: The most practicable marker that identifies patients at highest risk for postoperative pulmonary complications is the need for postoperative mechanical ventilation of a cumulative duration >48 hrs.

An algorithm for the sedation of patients with obstructive sleep apnea by non-anesthesiologists.

OBJECTIVE: Patients with obstructive sleep apnea (OSA) are at risk for adverse events when moderate sedation is administered by nurse protocols (NAMS) under the guidance of non-anesthesiologists. An algorithm was applied for the appropriate section of patients to receive NAMS and the application of continuous positive airway pressure (CPAP). METHODS: An algorithm was developed for patients with OSA who were scheduled for gastroenterology, radiology, and cardiology procedures using NAMS. Those with normal airways and without contraindications for NAMS were classified as CPAP-independent (CPAP-I; not routinely used) or CPAP-dependent (CPAP-D; always used). CPAP machines were brought in by CPAP-D patients or supplied by the hospital and set at a patient's routine setting or 10 cm H2O if not known. CPAP-D patients for procedures for which CPAP could not be applied were done under anesthesia care. We retrospectively examined this program for the 2008-2018 period. RESULTS: Since the inception of this protocol in 2008, 803 patients with OSA safely underwent procedures using either personal CPAP or CPAP provided by the hospital. CONCLUSIONS: Patients with OSA can safely have NAMS for procedures when CPAP is applied based on a protocol that considers airway evaluation, the procedure, and whether there is dependence upon CPAP.

Lateral-horizontal patient position and horizontal orientation of the endotracheal tube to prevent aspiration in adult surgical intensive care unit patients: a feasibility study.

BACKGROUND: Recent data suggest that during mechanical ventilation the lateral-horizontal patient position (in which the endotracheal tube is horizontal) decreases the risk of ventilator-associated pneumonia, compared to the recommended semi-recumbent position (in which the endotracheal tube slopes downward into the trachea). We tested the feasibility of the lateral-horizontal patient position, measured the incidence of aspiration of gastric contents, and watched for any adverse effects related to the lateral-horizontal position. METHODS: Ten adult intensive care unit patients were ventilated for 64 hours in the standard semi-recumbent position, and ten for 12-24 hours in the lateral-horizontal position. Tracheal secretions were collected every 8 hours and every 4 hours, respectively, and tested for pepsin, which is a marker of gastric contents. We also recorded clinical, physiologic, and outcome variables. RESULTS: The patients remained stable during ventilation in the lateral-horizontal position, and no adverse events occurred. Pepsin was detected in the trachea of 7 semi-recumbent patients and in five of the lateral-horizontal patients (P = .32). The number of ventilator-free days was 8 days (range 0-21 days) in the semi-recumbent patients, versus 24 days (range 12-25 days) in the lateral-horizontal patients (P = .04). CONCLUSIONS: Implementing the lateral-horizontal position for 12-24 hours in adult intubated intensive care unit patients is feasible, and our patients had no adverse events. The incidence of aspiration of gastric contents in the lateral-horizontal position seems to be similar to that in the semi-recumbent position.

Effect of laboratory testing guidelines on the utilization of tests and order entries in a surgical intensive care unit.

OBJECTIVE: Diagnostic testing is frequently overused in the intensive care unit. We devised guidelines to optimize blood tests utilization, and designed this study to quantify their efficacy over time, their safety, and their possible benefits. DESIGN: Laboratory testing guidelines were created by consensus and implemented through repeated staff education. The guidelines included: a) the tests to be obtained daily: complete blood count, serum electrolytes, urea nitrogen, creatinine, and blood glucose concentration; b) the need to discuss laboratory testing at daily patient's rounds; c) the need to provide a written order for all tests. The number of tests performed, corresponding physician orders, and various outcome measures were collected for two 6-month study periods, before and after the first day of implementation of the guidelines. SETTING: Twenty-bed surgical intensive care unit in a tertiary care teaching hospital. PATIENTS: All patients admitted during the two study periods. METHODS: Laboratory tests and related physician orders, demographics, blood products transfusion, and outcomes were collected from hospital databases. In prospectively defined subgroups, additional outcome measures were obtained by ad-hoc chart review. RESULTS: One thousand one hundred seventeen patients were enrolled. After the institution of the guidelines, the number of laboratory tests decreased by 37% (from 64,305 to 40,877), and the number of respective physician orders increased by 38% (from 20,940 to 35,472), p < 0.001. These results were manifest within 1 month, sustained through the study period, and still present at 1 yr. No changes in outcomes or in the rates of selected complications were detected. Red blood cells utilization correlated linearly (r .47) with the number of blood tests performed in both study periods. CONCLUSIONS: Guidelines designed to optimize laboratory tests use in an intensive care unit can produce rapid and long-lasting effects, can be safe, and may affect the number of red blood cell units transfused.

Tracheostomy tube malposition in patients admitted to a respiratory acute care unit following prolonged ventilation.

BACKGROUND: Tracheostomy tube malposition is a barrier to weaning from mechanical ventilation. We determined the incidence of tracheostomy tube malposition, identified the associated risk factors, and examined the effect of malposition on clinical outcomes. METHODS: We performed a retrospective study on 403 consecutive patients with a tracheostomy who had been admitted to an acute care unit specializing in weaning from mechanical ventilation between July 1, 2002, and December 31, 2005. Bronchoscopy reports were reviewed for evidence of tracheostomy tube malposition (ie, > 50% occlusion of lumen by tissue). The main outcome parameters were the incidence of tracheostomy tube malposition; demographic, clinical, and tracheostomy-related factors associated with malposition; clinical response to correct the malposition; the duration of mechanical ventilation; the length of hospital stay; and mortality. RESULTS: Malpositioned tracheostomy tubes were identified in 40 of 403 patients (10%). The subspecialty of the surgical service physicians who performed the tracheostomy was most strongly associated with malposition. Thoracic and general surgeons were equally likely to have their patients associated with a malpositioned tracheostomy tube, while other subspecialty surgeons were more likely (odds ratio, 6.42; 95% confidence interval, 1.82 to 22.68; p = 0.004). Malpositioned tracheostomy tubes were changed in 80% of cases. Malposition was associated with prolonged mechanical ventilation posttracheostomy (median duration, 25 vs 15 d; p = 0.009), but not with increased hospital length of stay or mortality. CONCLUSION: Tracheostomy tube malposition appears to be a common and important complication in patients who are being weaned from mechanical ventilation. Surgical expertise may be an important factor that impacts this complication.

Internally coated endotracheal tubes with silver sulfadiazine in polyurethane to prevent bacterial colonization: a clinical trial.

OBJECTIVE: Coated medical devices have been shown to reduce catheter-related infections. We coated endotracheal tubes (ETT) with silver sulfadiazine (SSD), and tested them in a clinical study to assess the feasibility, safety, and efficacy of preventing bacterial colonization. DESIGN: A prospective, randomized clinical trial, phase I-II. SETTING: Academic intensive care unit (ICU). PARTICIPANTS: Forty-six adult patients expected to need 12-24 h of intubation were randomized into two groups. INTERVENTIONS: Patients were randomized to be intubated with a standard non-coated ETT (St-ETT, n=23; control group), or with a SSD-coated ETT (SSD-ETT, n=23). MEASUREMENTS AND RESULTS: Coating with SSD prevented bacterial colonization of the ETT (frequency of colonization: SSD-ETT 0/23, St-ETT 8/23; p<0.01). No organized bacterial biofilm could be identified on the lumen of any ETT; however, SSD was associated with a thinner mucus layer (in the SSD-ETT secretion deposits ranged from 0 to 200 microm; in the St-ETT deposits ranged between 50 and 700 microm). No difference was observed between the two groups in the tracheobronchial brush samples (frequency of colonization: SSD-ETT 0/23, St-ETT 2/23; p=0.48). No adverse reactions were observed with the implementation of the novel device. CONCLUSION: SSD-ETT can be safely used in preventing bacterial colonization and narrowing of the ETT in patients intubated for up to 24 h (mean intubation time 16 h).

Determinants of tracheostomy decannulation: an international survey.

BACKGROUND: Although tracheostomy is probably the most common surgical procedure performed on critically ill patients, it is unknown when a tracheostomy tube can be safely removed. METHODS: We performed a cross-sectional survey of physicians and respiratory therapists with expertise in the management of tracheostomized patients at 118 medical centers to characterize contemporary opinions about tracheostomy decannulation practice and to define factors that influence these practices. RESULTS: We surveyed 309 clinicians, of whom 225 responded (73%). Clinicians rated patient level of consciousness, ability to tolerate tracheostomy tube capping, cough effectiveness, and secretions as the most important factors in the decision to decannulate a patient. Decannulation failure was defined as the need to reinsert an artificial airway within 48 hours (45% of respondents) to 96 hours (20% of respondents) of tracheostomy removal, and 2% to 5% was the most frequent recommendation for an acceptable recannulation rate (44% of respondents). In clinical scenarios, clinicians who worked in chronic care facilities (30%) were less likely to recommend decannulation than clinicians who worked in weaning (47%), rehabilitation (53%), or acute care (55%) facilities (p = 0.015). Patients were most likely to be recommended for decannulation if they were alert and interactive (odds ratio [OR] 4.76, 95% confidence interval [CI] 3.27 to 6.90; p < 0.001), had a strong cough (OR 3.84, 95% CI 2.66 to 5.54; p < 0.001), had scant thin secretions (OR 2.23, 95% CI 1.56 to 3.19; p < 0.001), and required minimal supplemental oxygen (OR 2.04, 95% CI 1.45 to 2.86; p < 0.001). CONCLUSION: Patient level of consciousness, cough effectiveness, secretions, and oxygenation are important determinants of clinicians' tracheostomy decannulation opinions. Most surveyed clinicians defined decannulation failure as the need to reinsert an artificial airway within 48 to 96 hours of planned tracheostomy removal.

Computed tomography for early and safe discontinuation of cervical spine immobilization in obtunded multiply injured patients.

BACKGROUND: Evaluation of the cervical spine (c-spine) in obtunded severely injured trauma patients is controversial, and spine immobilization is frequently prolonged. We examined the effect of two different c-spine evaluation protocols on c-spine immobilization and clinical outcomes. METHODS: We prospectively evaluated consecutive intubated and mechanically ventilated patients admitted to the surgical intensive care unit (ICU) of a Level I academic trauma center with a diagnosis of multiple blunt injuries who had normal findings on high-resolution helical computed tomogram of C1 to T1 with reconstructions (HCTrecon). From July 1, 2003 to June 30, 2005 (n = 140), the findings of HCTrecon and either clinical examination or magnetic resonance imaging (MRI) were required to be normal to discontinue c-spine immobilization (clinical/MRI protocol). From July 1, 2005 to June 30, 2006 (n = 75), the policy was changed to require normal finding only on HCTrecon to discontinue c-spine immobilization (HCTrecon protocol). RESULTS: Patients evaluated by the clinical/MRI and HCTrecon protocols had similar baseline characteristics. Compared with clinical/MRI patients, HCTrecon patients had their c-spines immobilized for fewer days (median, 6 days vs. 2 days; p < 0.001), were less likely to experience a complication of c-spine immobilization (64% vs. 37%, p = 0.010), required shorter periods of mechanical ventilation (median, 4 days vs. 3 days; p = 0.011), and had shorter stays in the ICU (median, 6 days vs. 4 days; p = 0.028) and hospital (median, 16 days vs. 14 days; p = 0.043). There was no difference in hospital mortality (13% vs. 16%, p = 0.920) and no missed c-spine injuries in either group. CONCLUSION: Discontinuation of c-spine precautions based on the normal findings of HCTrecon decreases the duration of c-spine immobilization in obtunded severely injured patients and is associated with fewer complications, fewer days of mechanical ventilation, and shorter stays in the ICU and hospital.

Urgent tracheal intubation in general hospital units: an observational study.

STUDY OBJECTIVE: To determine the frequency of complications and outcomes of urgent intubations in general hospital units. DESIGN: Prospective, observational, cohort study. SETTING: University-affiliated hospital. PATIENTS: 150 patients who underwent tracheal intubation in the general care units. INTERVENTIONS: A standardized data collection form was used prospectively to record events at the time of intubation. Patient outcomes were extracted from the medical record. MEASUREMENTS AND MAIN RESULTS: The complication rate was 27%. The most common complications were multiple attempts (9% required>2 intubations) and esophageal intubation (9%). The complication rate for elective intubation (22%) was similar to the complication rate for emergent intubations (27%). Of patients intubated in the general care units, 52% survived and 33% of these were discharged. There was no significant difference (P=0.46) in survival between the patients intubated electively (59%) and emergently (50%). There was no significant difference (P=0.63) in survival between patients with (48%) and without complications (54%). CONCLUSIONS: Endotracheal intubation in general hospital units carries a high rate of complications, and patients who are intubated in general hospital units have a high mortality.

Hemodynamic effects of sildenafil in patients with congestive heart failure and pulmonary hypertension: combined administration with inhaled nitric oxide.

STUDY OBJECTIVES: In patients with pulmonary hypertension (PH) secondary to congestive heart failure, inhaled nitric oxide (NO) increases pulmonary vascular smooth-muscle intracellular cyclic guanosine monophosphate (cGMP) concentration, thereby decreasing pulmonary vascular resistance (PVR) and increasing cardiac index (CI). However, these beneficial effects of inhaled NO are limited in magnitude and duration, at least in part due to cGMP hydrolysis by the type 5 isoform of phosphodiesterase (PDE5). The goal of this study was to determine the acute pulmonary and systemic hemodynamic effects of the selective PDE5 inhibitor, sildenafil, administered alone or in combination with inhaled NO in patients with congestive heart failure and PH. DESIGN: Single center, case series, pharmacohemodynamic study. SETTING: Cardiac catheterization laboratory of a tertiary care academic teaching hospital. PATIENTS: We studied 11 patients with left ventricular systolic dysfunction due to coronary artery disease or idiopathic dilated cardiomyopathy who had PH. INTERVENTIONS: We administered oral sildenafil (50 mg), inhaled NO (80 ppm), and the combination of sildenafil and inhaled NO during right-heart and micromanometer left-heart catheterization. MEASUREMENTS AND RESULTS: Sildenafil administered alone decreased mean pulmonary artery pressure by 12 +/- 5%, PVR by 12 +/- 5%, systemic vascular resistance (SVR) by 13 +/- 6%, and pulmonary capillary wedge pressure by 12 +/- 7%, and increased CI by 14 +/- 5% (all p < 0.05) [+/- SEM]. The combination of inhaled NO and sildenafil decreased PVR by 50 +/- 4%, decreased SVR by 24 +/- 3%, and increased CI by 30 +/- 4% (all p < 0.01). These effects were greater than those observed with either agent alone (p < 0.05). In addition, sildenafil prolonged the pulmonary vasodilator effect of inhaled NO. Administration of sildenafil alone or in combination with inhaled NO did not change systemic arterial pressure or indexes of myocardial systolic or diastolic function. CONCLUSIONS: PDE5 inhibition with sildenafil improves cardiac output by balanced pulmonary and systemic vasodilation, and augments and prolongs the hemodynamic effects of inhaled NO in patients with chronic congestive heart failure and PH.

Respiratory mechanics and ventilator waveforms in the patient with acute lung injury.

Acute lung injury/acute respiratory distress syndrome is a syndrome of low respiratory compliance. However, longstanding knowledge of applied respiratory mechanics and refined imaging techniques have shown that this is clearly an oversimplified view. Though the average compliance of the respiratory system is reproducibly low, regional mechanics may vastly differ; lung, airway, and chest wall mechanics may be variably affected; finally, these abnormalities may be very dynamic in nature, being influenced by time, posture, and the way positive-pressure ventilation is applied. Modern mechanical ventilators are equipped to display pressure, flow, and volume waveforms that can be used to measure respiratory compliance, airway resistance, and intrinsic positive end-expiratory pressure. These basic measurements, once the domain of applied physiologists only, are now available to aid clinicians to choose the appropriate ventilator settings to promote lung recruitment and avoid injury during lung-protective ventilatory strategies. High-resolution lung imaging and bedside recording of physiologic variables are important tools for clinicians who want to deliver specialized care to improve the outcome of critically ill patients in acute respiratory failure.

Lung recruitment: the role of recruitment maneuvers.

There is increasing appreciation that lung-protective strategies are beneficial in patients with acute respiratory distress syndrome. Using low tidal volume in these patients improves survival. However, low tidal volume ventilation may promote alveolar de-recruitment. This has led some to advocate the use of "open lung" strategies that stress the use of high positive end-expiratory pressure levels and recruitment maneuvers. A recruitment maneuver is a sustained increase in airway pressure with the goal to open collapsed lung tissue. A variety of approaches have been used as recruitment maneuvers, including increasing the level of positive end-expiratory pressure, sustained inflation maneuvers, sigh breaths, spontaneous breathing, and others. There have been a number of recent reports describing improvements in arterial oxygenation with the use of recruitment maneuvers. However, the impact of recruitment maneuvers on patient-important outcomes such as survival is unknown.

Effects of routine monitoring of delirium in a surgical/trauma intensive care unit.

BACKGROUND: Delirium is prevalent in surgical and trauma intensive care units (ICUs) and carries substantial morbidity. This study tested the hypothesis that daily administration of a diagnostic instrument for delirium in a surgical/trauma ICU decreases the time of institution of pharmacologic therapy and improves related outcomes. METHODS: Controlled trial of two concurrent groups. The Confusion-Assessment Method for ICU was administered daily to all eligible patients admitted to our surgical/trauma ICU for 48 hours or longer. The result was communicated to one of the two preexisting ICU services (intervention service) and not the other (control service). Primary outcome was the time between diagnosis of delirium and pharmacologic treatment. Secondary outcomes included duration of delirium, mechanical ventilation, and ICU stay. RESULTS: Delirium occurred in 98 (35%) of 283 consecutive patients. Time between diagnosis and therapy did not differ between intervention (35 [35] hours) and control (40 [41] hours) groups. There was a difference in the number of delirium days treated in the intervention (73%) versus control (64%) groups (p = 0.035). The intervention group had significantly lower odds to neglect treating delirium when delirium was present (odds ratio, 0.67; 95% confidence interval, 0.45-1.00; p = 0.05). In the subgroup of trauma patients, the odds ratio of negligence was 0.37 (95% confidence interval, 0.14-0.99; p = 0.048), indicating lower probability for trauma patients to be untreated. There was no difference in the average duration of delirium, mechanical ventilation, and ICU stay. CONCLUSION: In our surgical/trauma ICU, daily screening for delirium did not affect the timing of pharmacologic therapy. Although the intervention resulted in a higher number of delirious ICU patients being treated, particularly trauma patients, there was no effect on related outcomes. LEVEL OF EVIDENCE: Therapeutic study, level IV.

The clinical significance of delirium in the intensive care unit.

Delirium is prevalent among intensive care unit patients. It prolongs length of stay, increases costs, and is independently associated with higher mortality rates. While its specific biological pathways are largely unknown, environmental and iatrogenic determinants have been repeatedly recognized. Removal of the known triggers and pharmacologic intervention constitute available therapies. This review focuses on the clinical significance of delirium in critically ill patients, from its prevalence to its long-term impact, the ways that we have to diagnose it, and the available therapeutic options.