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Peter Doelken

Publications and source records attributed to Peter Doelken.

10 recordsLinked to original sources
PubMed2007

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.

Clinical Protocols↗
PubMed2006

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.

Animals↗
PubMed2006

Pleural ultrasonography.

Ultrasonography has achieved acceptance as a routine clinical tool for clinicians managing pleural disease. This article provides an overview of the field of pleural ultrasonography with an emphasis on clinical applicability and procedure guidance.

Fibrosis↗
PubMed2006

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.

Adult↗
PubMed2006

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.

Biomechanical Phenomena↗
PubMed2006

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.

Adult↗
PubMed2004

Safety of ultrasound-guided thoracentesis in patients receiving mechanical ventilation.

OBJECTIVE: To determine the safety of ultrasound-guided thoracentesis (UST) performed by critical care physicians on patients receiving mechanical ventilation. DESIGN: Prospective and observational. SETTING: ICUs in a teaching hospital. PATIENTS: Two hundred eleven serial patients receiving mechanical ventilation with pleural effusion requiring diagnostic or therapeutic thoracentesis. INTERVENTIONS: Two hundred thirty-two separate USTs were performed by critical care physicians without radiology support. Anteroposterior chest radiographs were reviewed for possible postprocedure pneumothorax. RESULTS: Pneumothorax occurred in 3 of 232 USTs (1.3%). The procedure was well tolerated in this critically ill population. CONCLUSIONS: UST performed in patients receiving mechanical ventilation without radiology support results in an acceptable rate of pneumothorax.

Humans↗
PubMed2004

Pleural manometry: technique and clinical implications.

INTRODUCTION: Pleural manometry during large-volume thoracentesis can prevent the development of excessively negative pleural pressures, which have been associated with re-expansion pulmonary edema; can diagnose an unexpandable lung; and can predict pleurodesis success. We currently perform pleural manometry simultaneously with both a vertical-column water manometer with an interposed resistive element, and a hemodynamic transducer connected to a standard physiologic system. We present the technique as well as the advantages and disadvantages of both systems in measuring pleural liquid pressures. TECHNIQUE: A flexible thoracentesis catheter is inserted in the most dependent portion of the pleural effusion. The water manometer consists of two lengths of IV tubing connected through a 22-gauge needle inserted into an injection terminal. The system is connected to the zeroing port of the pressure transducer, and both are carefully purged of air. The electronic system is zeroed at the level the thoracentesis catheter is introduced into the patient. Measurements are performed initially and after each 250 mL of fluid that is withdrawn. ACCURACY OF THE WATER MANOMETER: Forty consecutive patients who underwent therapeutic thoracentesis had pressure measurements. Pleural fluid removed ranged from 50 to 4,200 mL (mean, 1,445 mL). A total of 291 pressure measurements were acquired and analyzed. Mean pleural liquid pressure obtained by the water manometer had a strong positive correlation with the values obtained by a standard physiologic system (r = 0.97, p < 0.001). CONCLUSION: An overdamped water manometer is a valid method to measure mean pleural liquid pressure. Coughing invalidates pressure measurements with the water manometer; however, with the electronic method, periods of quiet breathing can be identified, allowing for the measurement of pleural pressure.

Adult↗
PubMed2004

Correction of error in respiratory resistance measurements made with the flow-interruption technique during mechanical ventilation: evaluation of the puritan bennett 7200 and 840 ventilators.

BACKGROUND: Calculation of total inspiratory resistance (Rtot) for patients on ventilatory support is typically based on measurement of airflow velocity and airway opening pressure during end-inspiratory occlusion by the inspiratory valve in the ventilator. Systematic error is introduced into Rtot measurements because the inspiratory valve closes over a period of time (not instantaneously, so gas continues to flow into the circuit while the valve is shutting) and because the circuit tubing is a distensible compartment between the occluding valve and the respiratory system. The Rtot-measurement error can be minimized with a rapidly-shutting occlusion valve positioned at the airway opening, or, alternatively, by mathematical correction that accounts for the valve-closure period and circuit tubing characteristics. METHODS: In a bench study we measured Rtot with the Puritan Bennett 7200 and 840 ventilators (using the inspiratory valves that are built into those ventilators) and compared those measurements to measurements made with a rapidly-shutting valve at the airway opening. We deemed the rapid-occlusion-valve measurements the best available (benchmark) values. We also studied the closure characteristics of the ventilators' inspiratory occlusion valves and created equations for mathematical correction of Rtot values measured with those valves. RESULTS: Compared to the benchmark measurements, the measurements from the Puritan Bennett 7200 averaged 23.2% relative error and 2.6 cm H2O/L/s absolute error. Measurements from the Puritan Bennett 840 averaged 7.3% relative error and 1.0 cm H2O/L/s absolute error. Mathematical correction for the circuit tubing and valve-closure time reduced the average relative and absolute error to 3.0% and 0.4 cm H2O/L/s, respectively, for the Puritan Bennett 7200, and to 4.5% and 0.3 cm H2O/L/s, respectively, for the Puritan Bennett 840. CONCLUSIONS: The Puritan Bennett 840 measures Rtot more accurately than the Puritan Bennett 7200. Our equations to mathematically correct Rtot measurements made with the PB7200 and PB840 are useful in settings where very accurate Rtot measurements are necessary.

Airway Resistance↗