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Unlabelled: During mechanical ventilation, mean airway pressure (MAP) can be increased by a variety of manoeuvres, for example increasing inspiratory time or elevating the positive end expiratory pressure (PEEP). It seemed likely that the effect on blood gases and lung function of a particular manoeuvre to increase MAP would be influenced by the presence of respiratory pathology and thus the manoeuvre best at improving respiratory status in children with an abnormal chest radiograph appearance would differ from that most efficacious in children without such a problem. The aim of this study was to test that hypothesis. Twenty-two children, median age 15 months (range 2.5 weeks-10 years) were examined. Group 1 (n = 10) had no chest radiograph abnormalities and group 2 (n = 12) lobar collapse and/or consolidation. The patients were studied at baseline settings and at an elevated MAP resulting from (in random order) an increase in inspiratory time (T1), pressure PEEP or peak inspiratory pressure (PIP). In group 1, elevating PIP improved oxygenation and carbon dioxide elimination (P < 0.01) and prolonging T1 improved oxygenation (P < 0.05). In group 2, only raising PEEP significantly improved oxygenation (P < 0.01), but this was associated with carbon dioxide retention (P < 0.01)., Conclusion: The presence of lung pathology does influence which manoeuvre should be used to elevate MAP to improve blood gases in the paediatric population.

We present a case report of an asymptomatic 12-year-old girl who was incidentally noted to have a collapsed upper lobe of her right lung during anaesthesia for angiography. After initial success at reexpansion using manual ventilation and suctioning, the lobe collapsed again some 15 min later. Physiological parameters remained stable throughout. Consent was obtained for fibreoptic bronchoscopy which was performed uneventfully and resulted in reexpansion of the lobe. We discuss the difficulty in identifying patients at risk of this complication, the need for therapeutic intervention and the issue of consent.

Ipsilateral bronchial intubation was used for reexpansion of unilateral pulmonary atelectasis in a newborn, who developed postoperative right atelectasis following extrapleural repair of tracheoesophageal fistula.

Study Objective: To define the most severe form of postlobectomy atelectasis and determine its incidence, predisposing factors, and clinical ramifications., Design: Retrospective case control., Setting: The thoracic surgery unit at a 900-bed tertiary care hospital., Patients or Participants: Two hundred eighteen patients undergoing pulmonary lobectomy or bilobectomy over a 7-year time period., Measurements and Results: Severe postlobectomy atelectasis (SPLA) was defined as complete ipsilateral lobar or bilobar collapse with whiteout of the involved lobe(s) and mediastinal shift on the chest radiograph. Data were collected consisting of patient age, lobe(s) resected, type of postoperative pain control, length of hospital and ICU stay, preoperative pulmonary function, and single- vs double-lumen tube intubation during surgery. The incidence of SPLA was 7.8%, comprising 24.6% of all postoperative complications seen. There was no statistically significant difference in patient age, preoperative room air PO2, and preoperative FEV1/FVC ratio for the SPLA group vs the group without this complication. Patients with SPLA had significantly longer ICU stays (112.7 h vs 28.4 h; p < 0.001) and hospital stays (14.7 days vs 9.3 days; p < 0.001) than the patients without complications. Patients undergoing right upper lobectomy, both alone or in combination with the right middle lobe, had a significantly higher incidence of SPLA when compared with all other types of resections (15.5% vs 3.0%; p < 0.005). There was no influence on the incidence of SPLA when the types of postoperative pain control regimen and endotracheal tubes used were examined., Conclusions: We conclude that SPLA as defined in this study is an important postoperative complication with a significant incidence. Although patients undergoing right upper lobectomy are markedly predisposed to this problem, the exact pathophysiology remains unclear. Factors shown to be causes of less severe forms of postoperative atelectasis do not seem to contribute to the formation of SPLA, indicating that these two complications may be two unrelated entities.

We report the case of a 35 years old female patient suffering from Staphylococcus aureus induced abortion in the 7th/8th week of gestation. Sepsis with acute respiratory failure (ARDS) developed, which could be treated successfully. Pneumonia, caused by Pseudomonas aeruginosa, induced a recurrence of ARDS, complicated by a persistent incomplete atelectasis of the left lung. Independent ventilation of both lungs with increased pressure on the left side combined with bronchoscopy guided instillation of 1 g of bovine surfactant (Alveofact), caused improvement of arterial oxygenation and radiological signs, signalling airation of collapsed lung areas.

Background and Purpose: The purpose of this study was to determine whether the addition of incentive spirometry (IS) to postoperative pulmonary physical therapy is more effective than physical therapy alone in reducing postoperative pulmonary complications in high-risk patients after coronary artery bypass grafting (CABG). Patients were given the spirometer and instructed in its use, as often occurs in clinical settings., Subjects: Patients with chronic airflow limitation following CABG (N = 185) participated., Methods: Subjects were randomly assigned to receive either postoperative pulmonary physical therapy (breathing exercises, secretion removal, mobility) or physical therapy combined with IS., Results: No difference was found between the two groups in atelectasis, spirometry, oxygen saturation, pulmonary infection, or hospital stay., Conclusion and Discussion: Incentive spirometry combined with physical therapy is no more effective than postoperative physical therapy alone in reducing atelectasis for this population. Use of the spirometer, however, was not monitored, and although the study mimicked practice as it often occurs, the effectiveness of the spirometer cannot be fully evaluated.

Complications have occurred in 30 (9.4%) of 318 patients, operated on for benign pulmonary tumor. In 5 patients rethoracotomy was conducted for haemothorax within 1-2 days, not influencing the duration of treatment. All the patients are alive.

Until recently, rigid bronchoscopy was considered too risky for premature infants. We report a 658 g infant with life-threatening mediastinal shift due to right pulmonary atelectasis. Rigid bronchoscopy revealed tenacious mucous plugs in the right main bronchus. The collapsed lung was successfully reinflated after bronchial lavage with a rigid bronchoscope, with the help of intermittent high-frequency jet ventilation (HFJV). The infant's mediastinal shift was reversed and the vital signs became stable. In our experience, rigid bronchoscopy combined with HFJV is a valuable diagnostic and therapeutic procedure for very small premature infants.

Study Objective: We assessed the use of a pleural catheter (Thoracic Vent) to determine its effectiveness in treating simple pneumothorax (PTX) and in preventing recurrent PTX., Design: A retrospective review was conducted of 84 patients treated with a pleural catheter for iatrogenic (52) and spontaneous (11 primary, 21 secondary) PTX between 1989 and 1994., Patients: There were 45 men and 39 women with a mean age of 50.4 years (range, 18 to 85 years)., Results: Mean time to lung reexpansion was 0.5 +/- 0.1 days. Forty-five (57%) patients manifested an air leak after catheter placement for 2.0 +/- 0.2 days. The duration of time to catheter removal was 3.3 +/- 0.2 days. Seventy-one (85%) patients had resolution of PTX with this therapy alone. Thirteen patients (15%) failed to resolve their PTXs and required subsequent tube thoracostomy alone (6) or surgical therapy (7). Four of 11 patients who required tube thoracostomy also failed to respond to this therapy. Treatment failure was more common among patients with spontaneous PTX than with iatrogenic PTX (34% vs 4%; p < 0.005). During a mean follow-up of 3.0 +/- 0.2 years, 6 (7%) patients suffered recurrent PTX an average of 23 days after initial therapy., Conclusion: This pleural catheter is effective in the management of simple iatrogenic and spontaneous PTX.

Video assisted thoracoscopic drainage and tale pleurodesis was used to treat a recurrent pleural effusion in a 60 year-old woman undergoing major gynecologic surgery. She developed reexpansion pulmonary edema immediately following surgery. Several important risk factors that were present in this patient are discussed. In addition to almost, complete collapse of the underlying lung for several weeks, thoracoscopy resulted in manipulations and rapid re-inflation of the underlying lung, which further increased the risk to the patient.

It is now widely accepted that mechanical ventilation may damage the lung, but the mechanism of lung damage is not clear. Possible causes include overdistension of aerated alveoli by inappropriately large tidal volumes (volutrauma), shear stresses generated during the recruitment and de-recruitment of lung units at the junction of aerated and collapsed lung, and infective or ischaemic necrosis of persistently collapsed lung. Computerized tomography allows noninvasive assessment of lung structure during and after acute lung injury, and may provide insight into the mechanism of lung damage. Using serial high resolution computed tomography we documented lung structure one month after recovery from severe protracted adult respiratory distress syndrome (ARDS) in three patients who required mechanical ventilation for between 86 and 97 days; the computed tomograms were repeated at between 5 and 14 months. All three patients had persistent abnormalities of lung structure which were most marked in the anterior regions of the lung. These findings suggest that overdistension of non-dependent lung regions in the main mechanism of lung damage persisting after recovery from severe protracted ARDS.

Background: This study examined the results of open drainage of massive tuberculous empyema., Methods: During a 7-year period 47 patients with primary mixed chronic tuberculous empyema with near or total lung collapse were treated. The initial procedure was chest tube suction drainage, which permitted evaluation of the pleural cavity and the lung parenchyma despite minimal if any reexpansion of the lung. All patients were treated with antibiotics and multidrug regimens of antituberculosis agents. A pleurocutaneous window was established by removing sections of two ribs one intercostal space above the base of the pleural cavity. Irrigation was performed daily with dilute povidone iodine solution., Results: Twenty-eight patients achieved complete reexpansion of the lung after 4 to 30 months of drainage and are cured. Eleven are in various stages of reexpansion and probably will be cured. Eight patients did not achieve reexpansion. Criteria were established retrospectively on an ongoing basis that indicate when pulmonary reexpansion is possible., Conclusions: These totally collapsed "entrapped" lungs expanded to fill the entire pleural space despite the presence of bronchopleural fistulas and an "open" pleura. Reexpansion was progressive, gradual, and dependent on improved compliance, clearing of bronchial inflammation and obstruction, and pleural cleansing. Criteria are established that identify those patients in whom complete reexpansion may take place and the disease may be cured.

Unlabelled: A prospective four-year study was done in a neonatal intensive care unit (NICU) to evaluate a technique, called direct tracheobronchial suction (DTBS), for rapidly removal of obstructive secretions from the tracheobronchial tree in newborn infants with massive post-extubation atelectasis (PEA). Selected cases who met the following criteria were enrolled: 1) developing new massive atelectasis within 48 hours after extubation; 2) no response to vigorous chest physiotherapy(CPT) and continuous deterioration; and 3) no air-bronchogram in the atelectatic lung field. DTBS was carried on at bedside by direct insertion a 6.5 Fr suction catheter into tracheobronchial tree and suctioning. Clinical and laboratory assessments were made in each case prior to and at two hours after DTBS for comparison. A total of 145 (19.7%, 145/736)) PEA occurred in a consecutive 736 postextubated newborn infants. Thirty-one atelectasis (4.2%, 31/736) that developed in 18 infants were managed with DTBS. There was a significant higher incidence of PEA developed, as well as a higher ratio of PEA been treated by DTBS, in the group of body weight < 1,500 g than the group of > or = 1,500 g. All except one infants weighed less than 1,500 g, with a mean of 1,043 +/- 269 g. Sixteen infants had been intubated for more than seven days with a mean of 14.1 +/- 5.0 days. Nine infants required more than one session of DTBS. DTBS was quite effective in immediate removal of retained secretions and improvement of pulmonary condition. By clinical assessment, respiratory distress improved with increased audible air entry on the affected lung, decreased chest retractions, and a significant fall in respiratory rate and heart rate. Arterial blood gases analysis showed significant improvement of pH, partial pressure of carbon dioxide and oxygenation ratio. By chest radiograph, DTBS resulted partial or nearly complete resolution of the atelectasis in all cases. DTBS procedures were well tolerated by all infants without significant sequelae., Conclusion: This study suggests that DTBS is a simple and effective therapeutic modality to rapidly correct the massive PEA which resist to vigorous CPT in small infants.

Recognizing atelectasis has always been a challenge. Atypical patterns further our knowledge of this subject. The lung has two mechanisms to help keep the lobes inflated: collateral ventilation and trapped nitrogen both tend to inflate the lungs when the airways are obstructed. Peripheral upper-lobe atelectasis resembles apical pleural fluid. Instead of collapsing superomedially, the upper lobe collapses posterolaterally, marginated by either the middle lobe or the superior segment of the lower lobe. This pattern may also be produced by segmental atelectasis of the apical-posterior segments of the upper lobe. Combined right-upper- and middle-lobe atelectasis usually stems from malignancy and violates Felson's double lesion sign. Upper-lobe atelectasis may produce a localized pneumothorax (pneumothorax ex vacuo), analogous to the vacuum joint phenomenon. Conversely, a large pneumothorax may cause torsion of an upper-lobe bronchus, leading to atelectasis. It is important to distinguish between these two conditions in order to choose the appropriate treatment-bronchoscopy in the former and chest tube drainage in the latter. Round atelectasis is a form of peripheral atelectasis that is variable in size and is thought to occur either when the lung collapses around a cleft in the presence of a pleural effusion or when shrinkage of a pleural scar pinches the adjacent lung. Round atelectasis has many features of plate atelectasis and may represent a special form of this condition.

Atelectasis occurs frequently in patients with spinal cord injury (SCI). Impaired cough leads to ineffective clearance of secretions. If the secretions cannot be cleared and become thick and purulent, atelectasis may occur. Recombinant human DNase (rhDNase) has been shown to decrease purulent sputum viscosity in vitro. We report two SCI patients with respiratory failure due to recurrent atelectasis from purulent secretions in whom conventional treatment methods had failed. Administration of rhDNase resulted in successful resolution of atelectasis. These results suggest the need for a controlled clinical trial.

Re-expansion pulmonary oedema is a recognised but rare complication following the rapid drainage of a large pleural effusion or pneumothorax [1,2], usually occurring on the side of re-inflation. The pathogenesis of the pulmonary oedema is poorly understood but is thought to be due to micro-vascular shearing resulting in neutrophil activation and adhesion to the vascular endothelium resulting in increased micro-vascular permeability [3-7]. Few reports appear in the literature of invasive haemodynamic monitoring following this catastrophe. We describe a patient who sustained fatal pulmonary oedema arising in the contralateral lung, with pulmonary flow catheter data documenting the initial circulatory collapse following the aspiration of a massive pulmonary effusion.

Chest physical therapy is used in the intensive care unit (ICU) to minimize pulmonary secretion retention, to maximize oxygenation, and to reexpand atelectatic lung segments. This article reviews how chest physical therapy is used with patients who are critically ill. A brief historical review of the literature is presented. Chest physical therapy treatments applicable to patients in the ICU are discussed. Postural drainage, percussion, vibration, breathing exercises, cough stimulation techniques, and airway suctioning are described in detail, with current references. The importance of patient mobilization is emphasized. The advantages of chest physical therapy over therapeutic bronchoscopy also are discussed. Two patient examples are used to demonstrate the beneficial effects that may be obtained with chest physical therapy. Following the removal of retained secretions, arterial oxygenation and partial pressure of arterial oxygen/fraction of inspired oxygen concentration ratios improved, and atelectasis resolved without the negative hemodynamic side effects of therapeutic bronchoscopy. Physical therapists trained in the ICU can safely perform chest physical therapy with the majority of patients who are critically ill.

Severe thoracic trauma is always an important risk factor for the development of acute pulmonary failure. The course is often complicated by barotrauma or volutrauma. We report on a 48-year-old patient who was transferred to us nine days after a bicycle accident because of a severe disturbance of gas exchange and atelectasis of the left lung refractory to therapy. The left lung could not be ventilated even after separate artificial ventilation on each side with positive end expiratory pressure. After administration of surfactant (50 mg Exosurf per kg body weight) and continued separate artificial ventilation on each side, there was a complete re-expansion of the left lung with an increase of the arterial pO2 value from 65 mm Hg to 416 mm Hg with a FIO2 of 1,0 and a decrease of the intrapulmonary venous admixture from 34% to 12% within a few hours. The extravascular pulmonary fluid was unaffected by the administration of surfactant (200 ml solution). The administration of surfactant preparations may be a new therapeutic approach in treatment of ARDS patients.

Intrapulmonary percussive ventilation (IPV) is a novel form of chest physiotherapy delivered by a percussive pneumatic device (IPV, Percussionaire, Sand Point, ID). There are few published reports about the use of IPV for diseases other than cystic fibrosis. We report our experience with three pediatric patients and one adult patient with persistent pulmonary consolidation refractory to conventional therapies. Three of the four patients had neuromuscular disease; one patient had segmental atelectasis due to aspiration. Three of the four patients showed clinical and radiographic improvement within 48 hours of starting IPV. The fourth patient experienced brief episodes of third-degree atrioventricular block, hypoxemia, and bradycardia during two IPV treatments. IPV was safely restarted and he slowly improved. We conclude that while IPV requires further clinical evaluation, it appears to be a safe and effective therapy for selected patients. However, close observation is essential during and after IPV treatments, especially in patients who have difficulty mobilizing or expectorating sputum.

Objective: To compare compliance and end-expiratory lung volume during reexpansion of normal and surfactant-deficient ex vivo atelectatic lungs with either gas or total liquid ventilation., Design: Controlled, animal study using an ex vivo lung preparation., Setting: A research laboratory at a university medical center., Subjects: Thirty-six adult cats, weighing 2.5 to 4.0 kg., Interventions: Heparin (300 U/kg) was administered, cats were killed, and lungs were excised en bloc. Normal lungs and saline-lavaged, surfactant-deficient lungs were allowed to passively collapse and remain atelectatic for 1 hr. Lungs then were placed in a plethysmograph and ventilated for 2 hrs with standardized volumes of either room air or perfluorocarbon. Static pulmonary compliance and end-expiratory lung volume were measured every 30 mins., Measurements and Main Results: Reexpansion of normal atelectatic lungs with total liquid ventilation was associated with an 11-fold increase in end-expiratory lung volume when compared with the increase in end-expiratory lung volume observed with gas ventilation (total liquid ventilation 50 +/- 14 mL, gas ventilation 4 +/- 9 mL, p < .0001). The difference was even more pronounced in the surfactant-deficient lungs with an approximately 19-fold increase in end-expiratory lung volume observed in the total liquid ventilated group, compared with the gas ventilated group (total liquid ventilation 44 +/- 17 mL, gas ventilation 2 +/- 8 mL, p = .0001). Total liquid ventilation was associated with an increase in pulmonary compliance when compared with gas ventilation in both normal and surfactant-deficient lungs (normal: gas ventilation 6 +/- 1 mL/cm H2O, total liquid ventilation 14 +/- 4 mL/cm H2O, p < .0001; surfactant-deficient: gas ventilation 4 +/- 1 mL/cm H2O, total liquid ventilation 9 +/- 3 mL/cm H2O, p < .01)., Conclusions: End-expiratory lung volume and static compliance are increased significantly following attempted reexpansion with total liquid ventilation when compared with gas ventilation in normal and surfactant-deficient, atelectatic lungs. The ability of total liquid ventilation to enhance recruitment of atelectatic lung regions may be an important means by which gas exchange is improved during total liquid ventilation when compared with gas ventilation in the setting of respiratory failure.

Sustained maximal inspiration (incentive spirometry) is used for the prevention and management of atelectasis in major abdominal and thoracic surgery. Patients with head and neck surgery are predisposed to postoperative disturbances in lung function after extensive surgical resection, immobilization, or significant chest wall deformity from various reconstructive procedures. The patient often requires tracheostomy or permanent laryngeal stoma. A prospective clinical study on patients with major head and neck surgery was conducted to evaluate the use of incentive spirometry to improve postoperative lung function. An adaptor was first designed to allow patients with tracheostomy tubes to use the spirometers. Parameters studied include vital signs, arterial blood gases (A-a gradient), and pulmonary function test. Significant improvement of lung function and lack of complication warrant the use of incentive spirometry in postoperative head and neck surgery patients.

The decrease in functional residual capacity (FRC) with anesthesia may cause lung volume to decrease below closing volume, thereby impairing oxygenation. Increasing end-expiratory pressure (EEP) reexpands atelectatic areas in anesthetized, ventilated patients, but its effect on pulmonary mechanics is less well understood. We studied the effect of varying EEP on the mechanical behavior of the respiratory system in patients undergoing either closed (Group 1) or open-chest (Group 2) surgical procedures. We measured airway opening pressure (PaO), flow (V), and esophageal pressure (Pes) (in Group 1 only) at EEPs of 0, 2.5, 5, and 10 cm H2O. Dynamic elastance (E) and resistance (R) for the respiratory system (RS), the lung (L), and the chest wall (CW) were estimated by fitting the equation P = RV + EV + K to the measured data by multiple linear regression where P was either Pao, Pes, or Pao-Pes. Group 1 EL decreased with increases in EEP to 5 cm H2O and then began to increase with EEP above this level. The same occurred in Group 2 before opening the chest. After opening the chest in Group 2, EL increased as EEP increased at all values above 0 cm H2O. The magnitudes of RRS and RL were similar in both groups of subjects and in each group these quantities decreased with increases in EEP. Dynamic EL responded differently to changes in EEP in subjects with open-chest and closed-chest procedures. We attribute this difference to overdistension of the remaining ventilable lung tissue at all levels of EEP in open-chest patients.

Segmental and lobar pulmonary atelectasis is a common occurrence in mechanically ventilated patients. Standard therapy for atelectasis relies on positive pressure ventilation, positive and expiratory pressure (PEEP), tracheobronchial toilet and regular chest physiotherapy. Various adjuncts to physiotherapy such as bronchoscopic clearance of secretions have not proved to be of additional benefit. Bronchoscopic clearance of secretions followed by insufflation of room air at 30 cm H2O into the atelectatic segment was employed on ten occasions in mechanically ventilated patients. Rapid re-expansion of the collapsed segment or lobe occurred in seven out of the ten treatments.

Postoperative pulmonary complications, specifically atelectasis and pneumonia, are the leading cause of postoperative morbidity and death. It is crucial that the clinician have a thorough understanding of the pathophysiology, risk factors, and scientific basis for currently used respiratory interventions to tailor the patient's care in the preoperative, intraoperative, and postoperative settings. Given the changing healthcare environment and increasing economic constraints, all respiratory interventions must be reevaluated for use in patient care, keeping in mind the factors of scientific basis, patient needs, appropriate utilization, and quality patient outcomes.

Pulmonary atelectasis, as found during general anaesthesia, may be reexpanded by hyper-inflation of the lungs. The purpose of this study was to determine whether such a recruitment is maintained and whether this is accompanied by an improved gas exchange. We studied a consecutive sample of twelve lung healthy adults, scheduled for elective surgery. After induction of intravenous anaesthesia, the lungs were hyperinflated manually. The ventilationperfusion relationship (VA/Q) was estimated with the multiple inert gas method, and in six patients atelectasis was assessed by computed x-ray tomography. The mean pulmonary shunt was 7.5% of cardiac output after induction of anaesthesia and this decreased to 1.0% and 2.8% at 20 and 40 min after the recruitment manoeuvre. Perfusion of poorly ventilated lung regions (low VA/Q), however, increased from 3.7% to 10.6% and 7.8% at 20 and 40 min after the recruitment, respectively. The mean alveolar-arterial oxygen tension difference (PA-aO2) was 14.3 kPa after induction of anaesthesia and 11.1 kPa immediately after recruitment. Forty minutes later PA-aO2 was still 2.0 kPa lower than after induction of anaesthesia (95% confidence interval [CI] 0.3 to 3.8 kPa). PA-aO2 decreased more in obese patients. The mean area of atelectasis decreased from 9.0 cm2 after induction of anaesthesia to 0.1 cm2 immediately after recruitment, and there was a slow increase to 1.9 cm2 (95% CI 0.0 to 3.9 cm2) 40 min later. During general anaesthesia in lung healthy patients, most of the reexpanded atelectatic lung tissue remains inflated for at least 40 min. The recruitment manoeuvre decreases pulmonary shunt, but increases low VA/Q. The net effect on gas exchange is a small reduction of PA-aO2.

Objective: To determine whether volume recruitment maneuvers that induce significant lung reexpansion during high-frequency oscillatory ventilation are also of value during conventional positive-pressure ventilation., Design: Crossover comparison of volume recruitment maneuvers administered during high-frequency oscillatory ventilation and positive-pressure ventilation in normal and surfactant-deficient adult rabbits., Setting: Laboratory., Subjects: Nineteen adult New Zealand white rabbits (weight 2.3 to 3.3 kg)., Methods: Respiratory system compliance was measured plethysmographically before and after sustained inflations in six normal and five saline-lavaged anesthetized rabbits, using both ventilators over a range of mean and end-expiratory pressures., Results: Under conditions where sustained inflations during high-frequency oscillatory ventilation at 15 Hz increased respiratory system compliance 50 +/- 28%, sustained inflations during conventional positive-pressure ventilation at a rate of 30 to 40 breaths/min and tidal volumes of 14 to 17 mL/kg did not change respiratory system compliance (mean change 3 +/- 9%). Sustained inflations during conventional positive-pressure ventilation could not be made effective by increasing the positive end-expiratory pressure level to equal the mean pressure during high-frequency oscillatory ventilation. Sustained inflations on conventional positive-pressure ventilation remained ineffective up to positive end-expiratory pressure levels of 17.5 cm H2O. In lavaged rabbits, sustained inflations increased respiratory system compliance 49 +/- 14% during high-frequency oscillatory ventilation and 0 +/- 3% during conventional positive-pressure ventilation. Sustained inflations increased compliance significantly during conventional positive-pressure ventilation only when ventilating with tidal volumes of 7 mL/kg and low end-expiratory pressure., Conclusions: Active recruitment of lung volume during high-frequency oscillatory ventilation appears necessary, because small pressure/volume cycles adequate to support high-frequency gas transport are not able to reexpand atelectatic lung units without the aid of a sustained inflation. We conclude that volume recruitment maneuvers improve respiratory system compliance substantially during high-frequency oscillatory ventilation at 15 Hz, but these maneuvers offer potential risk and no benefit during conventional positive-pressure ventilation with large tidal volumes or when using smaller tidal volumes and high levels of positive end-expiratory pressure.

As early as 1974, Brian advocated the prone position for ventilated patients. He suggested that this position might enhance ventilation of the dorsal parts of the lungs, thereby improving oxygenation. These considerations have been confirmed by several experimental and clinical studies. Better secretion removal, decreased intrapulmonary shunting, and an increased FRC are thought to be responsible for the observed improvement of oxygenation. However, the prone position never became very popular in the clinical treatment of the adult respiratory distress syndrome (ARDS). Routine performance of thoracic CT scans in ARDS patients demonstrated preferential distribution of pathological densities in the dependent lung areas. The prone position therefore could possibly benefit these patients, as shown by two recent studies. The aim of our study was to evaluate the influence of repeatedly turning the patient to the prone position on gas exchange and thoracic CT findings in multiple-trauma patients. METHODS. Seven ventilated intensive care patients with severe ARDS (Murray Score > 2.5, Quotient > 0.7, mean airway pressure > 18 cm H2O, thoracic CT scan showing dorsal atelectases) were included in the study. Patients were turned from the supine to the prone position at 12-h intervals using an air-cushion bed (Mediscus, Austria). Redistribution of dystelectatic or atelectatic dependent lung areas was verified by means of repeated thoracic CT scans (Figs. 1, 8). RESULTS. The patients were intermittently turned for 6.5 +/- 1.1 days. The course of gas exchange is shown in Figs. 2 and 3. Initially, improvement of the respiratory quotient could only be achieved during prone positioning, from the 2nd day in the supine position as well. Intrapulmonary shunting showed a similar trend (Figs. 4 and 5). No significant changes in cardiovascular parameters could be observed. Control thoracic CT scans showed uniform reduction of atelectases in dependent lung areas (Figs. 1 and 8). The inspiratory fraction of oxygen could be reduced significantly as of the 2nd day (Fig. 7). Constant levels of positive end-expiratory pressure and tidal volume were associated with decreasing mean and plateau airway pressures (Fig. 6). DISCUSSION. Repeatedly turning the patient to the prone position produced long-lasting improvement of arterial oxygenation, which persists up to the end of the weaning process. This is in good accordance with other studies, however, this is the first study to report an observation period of more than 6 days of repeatedly turning the patient. These positive effects on gas exchange can be attributed to sudden improvement of the ventilation-perfusion ratio within the lung areas that become dependent after turning to the prone position. Due to reduced hydrostatic pressure and relative hyperventilation, previously collapsed alveoli are recruited in the lung areas that become non-dependent after turning to the prone position.

Acute ipsilateral pulmonary oedema is a well documented complication of the treatment of lung collapse secondary to pneumothorax, pleural effusion and atelectasis. We present a case of bilateral re-expansion pulmonary oedema following removal of an intrathoracic haematoma. High protein concentration of the oedema fluid suggests increased pulmonary vascular permeability as a cause of this pulmonary oedema.

Objective: To study the outcome of conservative and surgical management of spontaneous pneumothorax., Design: Retrospective study between January 1980 and December 1990, with a mean follow-up of 6.5 years., Setting: A tertiary-care university hospital with a referral thoracic surgical unit., Patients: All patients seen in the study period with spontaneous pneumothorax. Those with traumatic, iatrogenic or ventilator-associated pneumothoraces were excluded. There were 366 consecutive patients who had 508 episodes of spontaneous pneumothorax. Two hundred and thirty-nine patients had primary spontaneous pneumothorax (group 1); 127 had secondary spontaneous pneumothorax (group 2)., Interventions: Tube thoracostomy, apical resection with either pleurectomy or pleural abrasion., Main Outcome Measures: Recurrence and outcome after surgical management relative to recurrence, complications, operative technique and mean hospital stay were evaluated by clinical review and questionnaire by an independent observer., Results: No significant differences were noted between the two groups with respect to the incidence of recurrent spontaneous pneumothorax after the first or second episode, and no significant differences were noted between the two operative techniques with respect to recurrence, complications, operative technique or death rate. However the mean hospital stay was doubled for group 2 patients (9.9 versus 4.3 days)., Conclusions: Conservative treatment, including tube thoracostomy, was effective for primary and secondary spontaneous pneumothorax. Open surgery was effective in preventing recurrence in 95% of cases in both groups.

We report a simple, four-step procedure for bedside treatment of infants on mechanical ventilation who have various degree of lung collapse unresponsive to conventional instillation of saline followed by chest percussion with endotracheal suctioning. The technique involves hyperoxygenation by bagging with 100% oxygen, deep endotracheal instillation of 0.25-0.5 mL/kg sterile saline, bagging with momentary inspiratory hold, followed by release of the hold and simultaneous forced exhalation and vibration to simulate cough, and endotracheal suctioning. This procedure was repeated three to five times on the affected side and at least once on the unaffected side; it resulted in notably improved lung expansion in 48 of 57 infants, documented by chest radiographs. The 57 infants included 48 (84%) whose chest radiographs showed airways occluded by mucus ("no air bronchograms") and 7 (16%) whose chest radiographs showed patent airways ("air bronchograms"). The technique is less successful in the latter group of patients in whom material obstructing proximal and intermediate airways has already been removed or displaced to distal airways, or a parenchymal infection has developed.

Formation of atelectasis is one mechanism of impaired gas exchange during general anaesthesia. We have studied manoeuvres to re-expand such atelectasis in 16 consecutive, anaesthetized adults with healthy lungs. In group 1 (10 patients), the lungs were inflated stepwise to an airway pressure (Paw) of 10, 20, 30 and 40 cm H2O. In group 2 (six patients), three repeated inflations up to Paw = 30 cm H2O were followed by one inflation to 40 cm H2O. Atelectasis was assessed by analysis of computed x-ray tomography (CT). In group 1 the mean area of atelectasis in the CT scan at the level of the right diaphragm was 6.4 cm2 at Paw = 0 cm H2O, 5.9 cm2 at 20 cm H2O, 3.5 cm2 at 30 cm H2O and 0.8 cm2 at 40 cm H2O. A Paw of 20 cm H2O corresponds approximately to inflation with twice the tidal volume. In group 2 the mean area of atelectasis was 9.0 cm2 at Paw = 0 cm H2O and 4.2 cm2 after the first inflation to 30 cm H2O. Repeated inflations did not add to re-expansion of atelectasis. The final inflation (Paw = 40 cm H2O) virtually eliminated the atelectasis. We conclude that, after induction of anaesthesia, the amount of atelectasis was not reduced by inflation of the lungs with a conventional tidal volume or with a double tidal volume ("sigg"). An inflation to vital capacity (Paw = 40 cm H2O), however, re-expanded virtually all atelectatic lung tissue.

Bleeding is one of the most feared complications of veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO), and is also a potential complication of flexible fiberoptic bronchoscopy (FFB). We retrospectively reviewed 14 patients who underwent FFB procedures with bronchial washings (BW) and bronchoalveolar lavage (BAL) to evaluate the safety of this procedure in children on ECMO. Standard FFB with BAL/BW technique was used after stabilization on ECMO. Three patients underwent two procedures each, and one patient underwent three, for a total of 19 procedures. No significant complications, such as bleeding have occurred. Three patients required additional ECMO support shortly after FFB. After the 16 procedures done for atelectasis, seven patients improved radiographically, three had increased opacifications, and six were unchanged. The remaining three patients had suspected pulmonary infections, and in each, therapeutic decisions were guided by the BAL results. Lung compliance was unchanged or improved after 11 of 13 procedures. We conclude that FFB with BAL/BW in children on ECMO is safe and may benefit certain patients.

The perioperative respiratory care of the cardiac surgical patient can present many challenges to the caring physician that he or she may not see among the usual patient population. Knowledge of the effects of the heart-lung machine on pulmonary performance, awareness of the anatomic changes brought on by the surgeon, and consideration of the patient's baseline cardiac and pulmonary function need to be addressed so that the pulmonary problems that they present can be managed optimally.

This report gives the results of a cost-efficiency analysis of a prospective longitudinal study evaluating two forms of prophylaxis against postoperative pulmonary complications in 876 patients undergoing abdominal surgery. It cost $12.19 per patient for conventional chest physiotherapy, and equivalent costs accrue when incentive spirometers are recycled and used on average 2.3 times (in the Royal Perth Hospital, incentive spirometers are recycled an average of 4.7 times). Maximum cost-containment can be achieved by carefully selecting patients for physical chest care and then instigating a programme of perioperative chest care utilizing recycled incentive spirometers. This approach does not compromise the clinical benefits of prophylactic chest care and allows physiotherapy resources to be directed toward patients with established pulmonary problems.

The intrapleural instillation of agents for pleural sclerosis has proved effective in preventing the reaccumulation of symptomatic malignant pleural effusions. Because manufacture of the most popular agent, tetracycline, was recently discontinued, a preliminary study was undertaken to evaluate an alternative agent, doxycycline, for treating symptomatic malignant pleural effusions. From November 1991 to September 1992, 21 patients with symptomatic malignant pleural effusions have undergone overnight chest tube drainage followed by intrapleural instillation of 10 mL 1% lidocaine and then doxycycline, 500 mg in 30 mL 0.9% saline solution. The chest tube was clamped 2 hours with patient repositioning every 15 minutes. Tubes were removed when drainage was less than 50 mL/8 h. Of surviving patients, a complete objective response at 1 month was obtained in 88% (15/17), who were free of a symptomatic or radiographic recurrence of the effusion. Complications included mild pain in 23% (5/21), moderate pain requiring analgesics in 19% (4/21), and mild fever in 5% (1/21). There were no treatment-related deaths. The mean time for chest tube removal was 1.7 +/- 0.7 days after the last treatment. Based on this preliminary study, we conclude that doxycycline is a highly effective agent for the palliative treatment of symptomatic malignant pleural effusions. Its safety profile and efficacy compare favorably with those of tetracycline and other agents used for pleural sclerosis.

Bronchoalveolar lavage with the fiberoptic bronchoscope is commonly used for the diagnosis of pulmonary infections in mechanically ventilated adults and children. However, its use for intubated infants is precluded because the small artificial airway does not permit the passage of the bronchoscope. We have developed a technique for nonbronchoscopic bronchoalveolar lavage, performed via a sterile, disposable feeding tube. We have used this technique in 15 infants with diffuse interstitial disease and/or atelectasis, while they were intubated and mechanically ventilated. The volume of the lavage effluent averaged 70.3% of the volume instilled. Specific diagnosis on the basis of the cytologic evaluation and/or culture of the lavage fluid was possible in 9 (60%) patients. Two patients with atelectasis showed radiographic evidence of improvement following the procedure. There were no complications. We conclude that nonbronchoscopic bronchoalveolar lavage is well tolerated, and clinically useful in small, mechanically ventilated infants with respiratory failure due to diffuse pulmonary disease. This technique provides a lower risk alternative to more invasive, and costly procedures.