Safety of Propofol as an Induction Agent for Urgent Endotracheal Intubation in the Medical Intensive Care Unit.

PURPOSE: Propofol is known to provide excellent intubation conditions without the use of neuromuscular blocking agents. However, propofol has adverse effects that may limit its use in the critically ill patients, particularly in the hemodynamically unstable patient. We report on the safety and efficacy of propofol for use as an agent for urgent endotracheal intubation (UEI) in the critically ill patients. METHODS: We reviewed the outcomes of 472 consecutive UEIs performed by a medical intensive care unit (ICU) team at a tertiary care hospital from November 2008 through November 2012. Outcome data were collected prospectively as part of an ongoing quality improvement project. RESULTS: Propofol was used as the sole sedative agent in 409 (87%) of the 472 patients. In 18 (4%) of the 472 patients, other agents (midazolam, lorazepam, or etomidate) were used in addition to propofol. Of the 472, 10 (2%) intubations were performed with a sedative agent other than propofol, and 35 (7%) of the 472 intubations were performed without any sedating agent. Endotracheal tube insertion was successful in all 472 patients. Complications of UEI in those patients who received propofol were as follows: desaturation (Sao 2 < 80%) 30 (7%) of the 427, hypotension (systolic blood pressure < 70 mm Hg) 19 (4%) of the 427, difficult intubation (>2 attempts) 44 (10%) of the 427, esophageal intubation 24 (6%) of the 427, aspiration 6 (1%) of the 427, and oropharyngeal injury 4 (1%) of the 427. There were no deaths. Average dose of propofol was 99 mg (standard deviation 7.39) per person. CONCLUSIONS: Our results compare favorably with the complication rate of UEI reported in the critical care and anesthesiology literature and indicate that propofol is a useful agent for airway management in the ICU.

Pressure-Dependent Pneumothorax and Air Leak: Physiology and Clinical Implications.

Pressure-dependent pneumothorax is a common clinical event, often occurring after pleural drainage in patients with visceral pleural restriction, partial lung resection, or lobar atelectasis from bronchoscopic lung volume reduction or an endobronchial obstruction. This type of pneumothorax and air leak is clinically inconsequential. Failure to appreciate the benign nature of such air leaks may result in unnecessary pleural procedures or prolonged hospital stay. This review suggests that identification of pressure-dependent pneumothorax is clinically important because the air leak that results is not related to a lung injury that requires repair but rather to a physiological consequence of a pressure gradient. A pressure-dependent pneumothorax occurs during pleural drainage in patients with lung-thoracic cavity shape/size mismatch. It is caused by an air leak related to a pressure gradient between the subpleural lung parenchyma and the pleural space. Pressure-dependent pneumothorax and air leak do not need any further pleural interventions.

Association between Drainage-Dependent Prolonged Air Leak after Partial Lung Resection and Clinical Outcomes: A Prospective Cohort Study.

Rationale: Prolonged air leak (PAL) after partial lung resection can occur owing to surgical complications or in the presence of residual thoracic space. The former type results in drainage-independent PAL (DIPAL), whereas the latter type results in drainage-dependent PAL (DDPAL). DDPAL is described after thoracentesis in patients with nonexpandable lung, where the thoracostomy tube can be discontinued safely despite an ongoing air leak. This distinction is clinically relevant, as in the presence of DDPAL, tube thoracostomy can be safely discontinued without the need for further interventions. Objectives: To determine the frequency and clinical relevance of DDAPL and DIPAL in patients with PAL after partial lung resection. Methods: We prospectively identified consecutive patients with PAL after partial lung resection. Pleural manometry was performed 3-5 days after surgery. Pleural pressure was measured for 20 minutes after clamping the thoracostomy tube. DDPAL was diagnosed if the end-expiratory pleural pressure remained stable after plateauing in the absence of respiratory symptoms. Results: Of 225 patients who underwent lung resection, we identified 22 (10%) who had PAL. Twenty patients had adequate pleural manometry readings. The majority, 16/20 (80%), had DDPAL and had lower median hospital length of stay than those with DIPAL (6.9 vs. 11 days; P = 0.02). All patients with DIPAL required reexploration surgery, whereas only one patient with DDPAL underwent reexploration surgery. Conclusions: Most PALs after partial lung resection are DDPAL. Patients with DDPAL have lower hospital length of stay and less need for reexploration surgery than those with DIPAL.

A program to improve the quality of emergency endotracheal intubation.

OBJECTIVE: To assess the results of a quality improvement (QI) project designed to improve safety of emergency endotracheal intubation (EEI). DESIGN: Single center prospective observational. SETTING: 16-bed intensive care unit. PARTICIPANTS: Nine pulmonary/critical care fellows. INTERVENTIONS: For 3 years, EEI performed by the medical intensive care unit team were analyzed to identify interventions that would improve quality of the procedure. By segmental process analysis, the procedure of EEI was subjected to iterative change. Major components of process improvement were development of a combined team approach, a mandatory checklist, use of crew resource management (CRM) tactics, and postevent debriefing. Quality analysis and improvement included training of fellows using scenario-based training (SBT) with computerized patient simulator (CPS) to improve mechanical skills of intubation and team leadership. Fellows received 15 sessions of SBT with CPS using a combined checklist and team approach before assuming team leadership position during real-life EEI. MEASUREMENTS: For a 10-month period, fellows carried digital voice recorders to EEI; which, when combined with recording of continuous oximetry and BP monitoring were used to assess the quality of EEI. MAIN RESULTS: 128 EEI were performed of which 101 had full data recorded. Complications were 14% severe hypoxemia (<80% saturation), 6% severe hypotension (SBP<70 mm Hg), 1% death, 20% difficult EEI (≥ 3 attempts), 11% esophageal intubations, 2% aspiration, and 1% dental injury; 62% EEI were successfully achieved on first attempt, 11% required >3 attempts. CONCLUSIONS: EEI may be performed by pulmonary/critical medicine (PCCM) fellows with safety comparable to that described in other studies on EEI. Important parts of the program included the use of formal iterative QI approach, the use of intensive SBT with CPS, basic CRM, a comprehensive checklist, and a combined team approach. A key benefit of the program was to make the process of EEI fully transparent for ongoing quality and safety improvement.

Intrapleural therapy.

Numerous intrapleural therapies have been adopted to treat a vast array of pleural diseases. The first intrapleural therapies proposed focused on the use of fibrinolytics and DNase to promote fluid drainage in empyema. Numerous case series and five randomized controlled trials have been published to determine the outcomes of fibrinolytics in empyema treatment. In the largest randomized trial, the use of streptokinase had no reduction in mortality, decortication rates or hospital days compared with placebo in the treatment of empyema. Criticism over study design and patient selection may have potentially affected the outcomes in this study. The development of dyspnoea is common in the setting of malignant pleural effusions. Pleural fluid evacuation followed by pleurodesis is often attempted. Numerous sclerosing agents have been studied, with talc emerging as the most effective agent. Small particle size of talc should be avoided because of increased systemic absorption potentiating toxicity, such as acute lung injury. Over the past several years, the use of chronic indwelling pleural catheters have emerged as the preferred modality in the treating a symptomatic malignant pleural effusion. For patients with malignant-related lung entrapment, pleurodesis often fails due to the presence of visceral pleural restriction; however, chronic indwelling pleural catheters are effective in palliation of dyspnoea. Finally, the use of staphylococcal superantigens has been proposed as a therapeutic model for the treatment of non-small lung cancer. Intrapleural instillation of staphylococcal superantigens increased median survival by 5 months in patients with non-small cell lung cancer with a malignant pleural effusion.

Management of pleural effusion in the cancer patient.

The differential diagnosis of a pleural effusion is expanded in the cancer patient. A cancer patient may have a malignant pleural effusion, a pleural effusion indirectly caused by the cancer or its treatment, or a pleural effusion unrelated to the cancer. The approach to the cancer patient with a pleural effusion must take into account the impact of the pleural effusion on quality of life, type and stage of the underlying cancer, impact of biopsy procedures on cancer staging, availability of treatment of the underlying cancer, performance status, and patient preferences. Minimally invasive palliative treatment options for the management of symptomatic malignant pleural effusion, such as chronic indwelling pleural catheters, have not only changed the treatment of the effusion but also require a reassessment of what constitutes an adequate diagnostic evaluation prior to considering such treatment options. Of particular concern to the clinician is the cytologically negative exudative pleural effusion for which a cause could not be established after the initial diagnostic evaluation. The decision to proceed to more invasive diagnostic testing must be individualized and the clinician must consider the limitations of histopathological examination of tissue obtained by invasive procedures.

The Relationship of Pleural Manometry With Postthoracentesis Chest Radiographic Findings in Malignant Pleural Effusion.

BACKGROUND: Both elevated pleural elastance (E-PEL) and radiographic evidence of incomplete lung expansion following thoracentesis have been used to exclude patients with a malignant pleural effusion (MPE) from undergoing pleurodesis. This article reports on a cohort of patients with MPE in whom complete drainage was attempted with pleural manometry to determine the frequency of E-PEL and its relation with postthoracentesis radiographic findings. METHODS: Seventy consecutive patients with MPE who underwent therapeutic pleural drainage with pleural manometry were identified. The pressure/volume curves were constructed and analyzed to determine the frequency of E-PEL and the relation of PEL to the postthoracentesis chest radiographic findings. RESULTS: E-PEL and incomplete lung expansion were identified in 36 of 70 (51.4%) and 38 of 70 (54%) patients, respectively. Patients with normal PEL had an OR of 6.3 of having complete lung expansion compared with those with E-PEL (P = .0006). However, 20 of 70 (29%) patients exhibited discordance between postprocedural chest radiographic findings and the pleural manometry results. Among patients who achieved complete lung expansion on the postdrainage chest radiograph, 9 of 32 (28%) had an E-PEL. In addition, PEL was normal in 11 of 38 (34%) patients who had incomplete lung expansion as detected according to the postthoracentesis chest radiograph. CONCLUSIONS: E-PEL and incomplete lung expansion postthoracentesis are frequently observed in patients with MPE. Nearly one-third of the cohort exhibited discordance between the postprocedural chest radiographic findings and pleural manometry results. These findings suggest that a prospective randomized trial should be performed to compare both modalities (chest radiograph and pleural manometry) in predicting pleurodesis outcome.

Pleural fluid analysis in chylous pleural effusion.

OBJECTIVES: Chyle is a noninflammatory, lymphocyte-predominant fluid that may cause a pleural effusion as a consequence of thoracic duct leakage into the pleural space. Although chyle is reported to have protein concentrations in the transudative range, chylous effusions are typically exudative, as defined by the standard criteria. We hypothesized that chylous effusions from a thoracic duct leak alone have low lactate dehydrogenase (LDH) concentrations due to the absence of inflammation and are lymphocyte-predominant, protein-discordant exudates. Consequently, pleural effusions that do not meet these criteria but with triglyceride concentrations of > 110 mg/dL or are positive for chylomicrons should be associated with other diagnoses contributing to pleural fluid formation. STUDY DESIGN: Retrospective. METHODS: The pleural fluid analyses of 876 consecutive thoracenteses were reviewed. All cases with a triglyceride concentration of > 110 mg/dL or the presence of chylomicrons were retrieved. The effusions were then classified as transudates, concordant exudates, protein-discordant exudates, and LDH-discordant exudates, and according to lymphocyte predominance (> 50%). The causes of these pleural effusions were determined after the review of the medical record. RESULTS: Twenty-two pleural effusions had elevated triglyceride concentrations and/or were positive for chylomicrons. Eleven effusions were lymphocyte-predominant, protein-discordant exudates, and two of these were associated with chylous ascites. The remaining effusions were transudates (n = 7) or concordant exudates (n = 4); all were associated with conditions known to cause pleural effusion apart from chyle leakage. CONCLUSION: Chylous effusions caused solely by conditions known to cause chylothorax were lymphocyte-predominant, protein-discordant exudates. Protein concentrations in the transudative range or elevated LDH concentrations were associated with a coexisting condition that may impact the management of these chylous effusions.

Clinical implications of unexpandable lung due to pleural disease.

Unexpandable lung due to pleural disease may manifest itself as a hydropneumothorax after pleural drainage procedure or as an inability to completely drain a pleural effusion due to chest pain. The condition is a mechanical complication of a variety of pleural disorders. Of these, malignant lung entrapment and inflammatory lung entrapment are considered complications of active pleural disease, and management is primarily dependent on the nature of the active process. Trapped lung is a sequela of remote inflammation of the pleural space. Trapped lung is usually asymptomatic but may be the cause of dyspnea in some patients. The only available treatment of symptomatic trapped lung is surgical decortication. Surgical decortication should only be considered after other causes of dyspnea have been excluded.

Seat belt-induced chylothorax: a cause of idiopathic chylothorax?

Chylothoraces are associated with multiple etiologies including non-Hodgkin lymphoma and surgical trauma, representing 50% and 25% of all chylothoraces, respectively. Intrathoracic operations such as repair of coarctation of the aorta and esophagectomy are commonly associated with surgical trauma. Idiopathic chylothoraces may account for up to 15% of all chylothoraces. When a thorough evaluation finding is negative, further history to identify possible blunt, nonpenetrating trauma to the chest is warranted.

Characteristics of trapped lung: pleural fluid analysis, manometry, and air-contrast chest CT.

STUDY OBJECTIVES: To review the pleural fluid characteristics, pleural manometry, and radiographic data of patients who received a diagnosis of trapped lung in our pleural diseases service. DESIGN: Retrospective case series. METHODS: The procedure records of 247 consecutive patients who underwent pleural manometry at the Medical University of South Carolina between October 2002 and November 2005 were reviewed. Eleven patients in whom a diagnostic pneumothorax was introduced were identified. Manometry data, radiographic findings, pleural fluid analysis, final clinical diagnosis, and information regarding the initial pleural insult were retrieved from the medical record. RESULTS: All 11 patients had a clinical diagnosis of trapped lung. The causes of trapped lung were attributed to coronary artery bypass graft surgery, uremia, thoracic radiation, pericardiotomy, spontaneous bacterial pleuritis and repeated thoracentesis, and complicated parapneumonic effusion. Mean pleural fluid pH was 7.30, pleural fluid lactate dehydrogenase (LDH) was 124 IU/L, and pleural fluid total protein was 2.9 g/dL. Pleural fluid was paucicellular with mononuclear cell predominance. Pleural space elastance was increased in all cases and ranged from 19 to 149 cm H(2)O/L of pleural fluid removed. All demonstrated abnormal visceral pleural thickness on air-contrast chest CT. CONCLUSIONS: Trapped lung is a clinical entity characterized by the presence of a restrictive visceral pleural peel that was first described in 1967. The pleural fluid is paucicellular, LDH is low, and protein may be in the exudative range. The elevated total pleural fluid protein may be related to factors other than active pleural inflammation or malignancy and does not exclude the diagnosis.

Endobronchial ultrasound for the diagnosis of pulmonary sarcoidosis.

BACKGROUND: The diagnosis of pulmonary sarcoidosis can be established by a variety of techniques. Transbronchial lung biopsy is often the preferred approach, but it is frequently nondiagnostic and carries a risk of pneumothorax and bleeding. Mediastinoscopy is often suggested as the next diagnostic step but entails significant cost and associated morbidity. Endobronchial ultrasound (EBUS) with transbronchial needle aspiration (TBNA) is emerging as a safe, minimally invasive tool for the primary diagnosis of mediastinal and hilar lymphadenopathy. The purpose of this study was to assess the utility of EBUS-TBNA for pulmonary sarcoidosis. METHODS: Fifty consecutive patients who had been referred for EBUS-TBNA for suspected pulmonary sarcoidosis were included in the study. On-site cytology was used to assess the adequacy of the samples. The presence of noncaseating granulomas without necrosis in the appropriate clinical setting was deemed to be adequate for the diagnosis of pulmonary sarcoidosis. Patients with a negative EBUS-TBNA underwent further histologic biopsy or clinical follow-up to determine the final diagnosis. RESULTS: Eighty-two lymph nodes with a median size of 16 mm (range, 4 to 40 mm) were punctured. EBUS-TBNA demonstrated noncaseating granulomas without necrosis in 41 of 48 patients (85%) with a final diagnosis of sarcoidosis. EBUS-TBNA, therefore, has a sensitivity of 85% for the primary diagnosis of pulmonary sarcoidosis. CONCLUSIONS: EBUS-TBNA is a safe, minimally invasive tool for the primary diagnosis of pulmonary sarcoidosis that has a high diagnostic yield. EBUS-TBNA should be considered an appropriate alternative diagnostic technique for patients with suspected pulmonary sarcoidosis.

Defining a Ventilation Strategy for Flexible Bronchoscopy on Mechanically Ventilated Patients in the Medical Intensive Care Unit.

BACKGROUND: Flexible bronchoscopy (FB) in intubated patients on mechanical ventilation increases airway resistance. During FB, two ventilatory strategies are possible: maintaining tidal volume (VT) while maintaining baseline CO2 or allowing reduction of VT. The former strategy carries risk of hyperinflation due to expiratory flow limitation with FB. The aim of the authors was too study end expiratory lung volume (EELV) during FB of intubated subjects while limiting VT. METHODS: We studied 16 subjects who were intubated on mechanical ventilation and required FB. Changes in EELV were measured by respiratory inductance plethysmography. Ventilator mechanics, EELV, and arterial blood gases, were measured. RESULTS: FB insertions decreased EELV in 64% of cases (-325±371 mL) and increased it in 32% of cases (65±59 mL). Suctioning decreased EELV in 76% of cases (-120±104 mL) and increased it in 16% of cases (29±33 mL). Respiratory mechanics were unchanged. Pre-FB and post-FB, PaO2 decreased by 61±96 mm Hg and PaCO2 increased by 15±7 mm Hg. CONCLUSIONS: There was no clinically significant increase in EELV in any subject during FB. Decreases in EELV coincided with FB-suctioning maneuvers. Peak pressure limiting ventilation protected the subject against hyperinflation with a consequent, well-tolerated reduction in VT, and hypercapnea. Suctioning should be limited, especially in patients vulnerable to derecruitment effect.

Effect of thoracentesis on respiratory mechanics and gas exchange in the patient receiving mechanical ventilation.

BACKGROUND: This study reports the effect of thoracentesis on respiratory mechanics and gas exchange in patients receiving mechanical ventilation. STUDY DESIGN: Prospective. SETTING: University hospital. PATIENTS: Eight patient receiving mechanical ventilation with unilateral (n = 7) or bilateral (n = 1) large pleural effusions. INTERVENTION: Therapeutic thoracentesis (n = 9). MEASUREMENTS: Resistances of the respiratory system measured with the constant inspiratory flow interrupter method measuring peak pressure and plateau pressure, effective static compliance of the respiratory system (Cst,rs), work performed by the ventilator (Wv), arterial blood gases, mixed exhaled Pco2, and pleural liquid pressure (Pliq). RESULTS: Thoracentesis resulted in a significant decrease in Wv and Pliq. Thoracentesis had no significant effect on dynamic compliance of the respiratory system; Cst,rs; effective interrupter resistance of the respiratory system, or its subcomponents, ohmic resistance of the respiratory system and additional (non-ohmic) resistance of the respiratory system; or intrinsic positive end-expiratory pressure (PEEPi). Indices of gas exchange were not significantly changed by thoracentesis. CONCLUSIONS: Thoracentesis in patients receiving mechanical ventilatory support results in significant reductions of Pliq and Wv. These changes were not accompanied by significant changes of resistance or compliance or by significant changes in gas exchange immediately after thoracentesis. The reduction of Wv after thoracentesis in patients receiving mechanical ventilation is not accompanied by predictable changes in inspiratory resistance and static compliance measured with routine clinical methods. The benefit of thoracentesis may be most pronounced in patients with high levels of PEEPi.

Pathophysiology of pneumothorax following ultrasound-guided thoracentesis.

STUDY OBJECTIVES: Pneumothorax following ultrasound-guided thoracentesis is rare. Our goal was to explain the mechanisms of pneumothorax following ultrasound-guided thoracentesis in a setting where pleural manometry is routinely used. METHODS: We reviewed the patient records and procedure reports of 401 patients who underwent ultrasound-guided thoracentesis. When manometry was performed, pleural space elastance was determined. A model assuming dependence of the pleural space elastic properties on respiratory system elastic properties was used to isolate cases with presumed normal pleural space elastance. Elastance outside mean +/- SD x 2 of the isolated sample was considered abnormal. Four radiographic criteria of unexpandable lung were used: visceral pleural peel, lobar atelectasis, basilar pneumothorax, and pneumothorax with ipsilateral shift. RESULTS: There were 102 diagnostic thoracenteses, 192 therapeutic thoracenteses with pleural manometry, and 73 therapeutic thoracenteses without manometry. There was one pneumothorax that occurred from lung puncture and eight unintentional pneumothoraces, all of which showed radiographic evidence of unexpandable lung. Four of eight unintentional pneumothoraces had abnormal elastance; none had excessively negative pleural pressure (< -25 cm H(2)O). CONCLUSIONS: Unintentional pneumothoraces cannot be prevented by monitoring for symptoms or excessively negative pressure. These pneumothoraces were drainage related rather than due to penetrating lung trauma or external air introduction. We speculate that unintentional pneumothoraces are caused by transient, parenchymal-pleural fistulae caused by nonuniform stress distribution over the visceral pleura that develop during large-volume drainage if the lung cannot conform to the shape of the thoracic cavity in some patients with unexpandable lung. These fistulae appear to be pressure dependent, and the resulting pneumothoraces rarely require treatment. Drainage-related pneumothorax is an unavoidable complication of ultrasound-guided thoracentesis and appears to account for the vast majority of pneumothoraces occurring in a procedure service.

Pleural effusions in a series of 181 outpatients with sarcoidosis.

OBJECTIVES: Pleural effusion (PE) is considered to be a rare manifestation of pulmonary sarcoidosis. We performed thoracic ultrasonography prospectively in consecutive outpatients with sarcoidosis to determine the frequency of PEs caused by sarcoidosis and to define their pleural fluid characteristics. DESIGN: Consecutive outpatients aged >/= 18 years with biopsy-proven sarcoidosis underwent ultrasonography. SETTING: University hospital, outpatient sarcoidosis clinic. RESULTS: One hundred eighty-one outpatients were enrolled into the study. The subjects were predominately African-American and female. Most were between 30 and 60 years of age. The Scadding radiograph stages were fairly evenly distributed across all five stages (0 through 4). Five (2.8%) of 181 patients were found to have pleural fluid. Two patients had a unilateral left-sided PE, and three patients had bilateral PEs. Pleural fluid analysis (PFA) was performed in four patients. The PFA showed a lymphocyte-predominant exudate using protein criterion in only two patients, which is consistent with sarcoidosis-related PE; one patient underwent pleural biopsy, which was consistent with the diagnosis of sarcoidosis. A sarcoidosis-related PE was seen in 1 of 9 patients (11.1%) who had an exacerbation of pulmonary sarcoidosis compared to 1 of 172 patients (0.6%) who did not have an exacerbation (p < 0.4). CONCLUSION: PEs are rare in outpatients with sarcoidosis, even when a sensitive technique, such as ultrasonography, is used. The frequency of PEs was 2.8% (5 of 181 patients) with only 2 of the 181 PEs (1.1%) caused by sarcoid pleural involvement. PE in patients with sarcoidosis should not be assumed to be related to sarcoidosis. Discordance between levels of pleural fluid total protein and lactate dehydrogenase may be a characteristic finding in patients with sarcoid PE. An exacerbation of pulmonary sarcoidosis was not an independent risk factor for the development of sarcoid-related PE.

Pleural manometry.

The goals of therapeutic thoracentesis are to remove the maximum amount of pleural fluid to improve dyspnea and to facilitate the diagnostic evaluation of large pleural effusions. Pleural manometry may be useful for immediately detecting an unexpandable lung, which may coexist when any pleural fluid accumulates. Pleural manometry may improve patient safety when removing large amounts of pleural fluid. The basics of pleural space mechanics are discussed as they apply to the normal pleural space and to pleural effusion associated with expandable and unexpandable lung. This article also discusses the instrumentation required to perform bedside manometry, how manometry may decrease the risk of re-expansion pulmonary edema when large amounts of fluid are removed, and the diagnostic capabilities of manometry.