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Background: We investigated whether reversal of intraoperative atelectasis with the lung recruitment maneuver (RM) affects desflurane arterial concentrations during bariatric surgery., Methods: After anesthetic induction and maintenance with propofol, patients were randomized to receive alveolar RM at intervals (RM group) or not (controls). Desflurane 6% was initiated, and rate of increase of alveolar desflurane concentration (ratio of end-expiratory to inspiratory concentrations, F(A)/F(I)) and desflurane blood concentrations were measured in both groups. Blood and end-tidal desflurane concentrations were also measured after the discontinuation of anesthesia., Results: The RM group had higher intraoperative Pao(2)/Fio(2) compared with the control group (both, P < 0.001). During induction, the rate of increase in blood desflurane concentrations was rapid in both groups. At comparable mechanical ventilation settings, median times to achieve 0.5 mM (approximately 3%) were 2.1 and 1.59 min (P = 0.09) in the control and RM group, respectively. The times to achieve 0.7 mM (approximately 4.2%) desflurane were 15.9 and 9.3 min in the control and RM group, respectively (P = 0.08). Desflurane blood concentrations tended to be higher during the first 30 min after induction in the RM group (P = 0.066). During maintenance or emergence, the blood desflurane concentrations were not different between control and RM groups. Consequently, the time to eye opening did not differ between groups., Conclusion: Although the RM during bariatric surgery represents an effective method for improving intraoperative oxygenation, it does not significantly affect the desflurane blood concentrations during anesthesia or its elimination during emergence.

Objective: The purpose of lung recruitment manoeuvres is to open collapsed lung regions, improve gas exchange and optimise regional lung mechanics. This study investigates the efficacy of recruitment manoeuvres for improving regional ventilation distribution as characterised using electrical impedance tomography (EIT). DESIGN, SUBJECTS, INTERVENTIONS: A ventilated ovine smoke inhalation lung injury model was used. Respiratory mechanics and regional filling capacity of the lung were measured using EIT pre- and post- recruitment and compared to a control group., Measurements: EIT, expressed as the time course relation of the regional versus the global impedance change, measured the regional filling capacities of the lung., Main Results: After smoke inhalation injury, the dependent lung showed a significantly larger area of collapse and a reduced filling capacity compared to the non-dependent lung. After recruitment the ventilated volume increased and the dependent lung showed improved respiratory mechanics, whereas the non-dependent lung was more likely to be hyper-inflated during tidal breathing., Conclusions: Lung recruitment manoeuvres have a significant impact on regional lung mechanics and individual measurement of ventilation distribution using EIT may assist to improve ventilatory management.

The RTX respirator is a biphasic external cuirass-style ventilator that supports both inspiration and expiration at various cycle rates and pressures, as well as allowing application of the vibration and cough modes. With this respirator, the duration and pressure can be altered in both the inspiratory and expiratory phases, and it can promote the removal of secretions by switching between the vibration mode (which involves external high-frequency oscillation: EHFO) and the cough mode. We used this respirator to remove secretions in two elderly patients with extensive atelectasis. They were nursed in the lateral decubitus position with the cuirass attached to one side of the chest only. The vibration mode removed secretion to reduce the viscosity of secretions and loosen impacted bronchial secretions. The cough mode interrupts the vibration mode and forces secretions towards the pharynx. The lateral decubitus position was useful for postural drainage. The extensive atelectasis of both patients was improved by this procedure. The RTX respirator may be a useful tool for the management of elderly patients with sputum retention.

Atelectasis occurs in most patients during general anesthesia and is the main cause of hypoxemia. The objective of this review is to examine the causes and diagnosis of atelectasis and the different strategies for reducing or preventing this complication and improving oxygenation. Pulmonary atelectasis is mainly caused by 3 factors: compression, gas absorption, and lack of surfactant. Compression and gas absorption are, however, the 2 most commonly implicated factors. Lung collapse is accentuated if pure oxygen is inhaled during induction or if the patient is morbidly obese. Laparoscopic, thoracic, and upper abdominal interventions also carry risk of lung collapse. Various techniques may be used to prevent atelectasis or to reopen collapsed lung tissue. These include using positive end-expiratory pressure or a high tidal volume-thus providing a higher airway pressure (vital capacity maneuver)-or both in combination. Alveolar recruitment strategies have been tried in bariatric surgery, single-lung ventilation, laparoscopy, and adult respiratory distress syndrome. Their application has reduced or prevented atelectasis, thereby reducing postoperative pulmonary complications.

When a rapidly reexpanding lung has been in a state of collapse for more than several days, pulmonary edema sometimes occurs in it. This is called reexpansion pulmonary edema (RPE). In this article, I present my views on the history, clinical features, morphophysiological features, pathogenesis, and treatment of RPE. Histological abnormalities of the pulmonary microvessels in a chronically collapsed lung will cause RPE, as well as mechanical stress exerted during reexpansion. Although the most effective treatment method is to treat the histological abnormalities of the pulmonary microvessels formed in a chronically collapsed lung, the cause of these abnormalities is not clear, making it difficult to put forward a precise treatment method. However, reasonably good effects can be expected from a symptomatic therapy that reduces the level of mechanical stress during reexpansion. In the future, it is expected that the cause of histological changes of the pulmonary microvessels in a chronically collapsed lung will be revealed, and appropriate therapies will therefore be developed according to this cause.

Background: Chest physiotherapy (CPT) has been used in many neonatal nurseries around the world to improve airway clearance and treat lung collapse; however, the evidence to support its use has been conflicting. Despite the large number of studies there is very little evidence of sufficiently good quality on which to base current practice., Objectives: To assess the effects of active CPT techniques, such as percussion and vibration followed by suction compared with suction alone, on the respiratory system in infants receiving mechanical ventilation. Additionally, differences between types of active CPT techniques were assessed., Search Strategy: Our search included The Cochrane Library (Issue 2, 2007), MEDLINE (1966 to 2007), EMBASE (1988 to 2007), CINAHL, Science Citation Index, previous reviews including cross-references, abstracts, conference proceedings and grey literature., Selection Criteria: Trials in which ventilated newborn infants up to four weeks of age were randomly or quasi-randomly assigned to receive active CPT or suction alone. Infants receiving CPT for the extubation period were excluded., Data Collection and Analysis: Two review authors independently conducted quality assessments and data extraction for included trials. We analysed data for individual trial results using relative risk (RR) and mean difference (MD). Results are presented with 95% confidence intervals (CI). Due to insufficient data, we could not undertake meta-analysis., Main Results: Three trials involving 106 infants were included in this review. In one trial (n = 20) CPT was no better than standard care in clearing secretions. No increase in the risk of intraventricular haemorrhage was noted. Two trials compared different types of active CPT. One trial (n = 56) showed that non-resolved atelectasis was reduced in more neonates receiving the lung squeezing technique (LST) when compared to postural drainage, percussion and vibration (PDPV) (RR 0.25; 95% CI 0.11 to 0.57). No difference in secretion clearance or in the rate of intraventricular haemorrhage or periventricular leucomalacia was demonstrated. The other trial (n = 30) showed that the use of percussion or 'cupping' resulted in an increased incidence of hypoxaemia (RR 0.53; 95% CI 0.28 to 0.99) and increased oxygen requirements (MD -9.68; 95% CI -14.16 to -5.20) when compared with contact heel percussion. There was insufficient information to adequately assess important short and longer-term outcomes, including adverse effects., Authors' Conclusions: The results of this review do not provide sufficient evidence on which to base clinical practice. There is a need for larger randomised controlled trials to address these issues.

Acute lung collapse during open-heart surgery may potentially lead to problems such as inadequate gas exchange, increased pulmonary vascular resistance, increased afterload to the right ventricle, and difficulty in weaning from cardiopulmonary bypass (CPB). Therefore, expansion of the lungs is ensured prior to separation from CPB. We report the inability to manually expand a chronically collapsed lung during the repair of ascending aortic aneurysm. The collapsed lung did not pose difficulty in separation from CPB and in blood gas management during the perioperative period. We discuss perioperative management issues in such situations.

A respiratory morbidity such as atelectasis or pneumonia is possible to be predicted by calculated postoperative pulmonary function. The predicted postoperative 1 second forced expiratory volume (FEV1.0) is exclusively useful for predicting morbidity, but not for predicting mortality. The exercise capacity is a crucial parameter to predict survival. Thus, both parameters are helpful to make strategies for perioperative management. A prophylactic tracheostomy, a timely traheostomy and a timely bronchoscopy are applied by these parameters to treat postopeartive respiratory complications such as atelectasis or pneumonia.

Purpose: For patients with acute respiratory failure due to lung edema or atelectasis, Surplus lung water that is not removed during an initial stay in the Intensive Care Unit (ICU) may be related to early ICU readmission. Therefore, we performed a retrospective study of patient management during the first ICU stay for such patients., Materials and Methods: Of 1,835 patients who were admitted to the ICU in the 36 months from January, 2003 to December, 2005, 141 were patients readmitted, and the reason for readmission was lung edema or atelectasis in 21 patients. For these 21 patients, correlations were investigated between body weight gain at the time of initial ICU discharge (weight upon discharge from the ICU / weight when entering the ICU) and the time to ICU readmission, between body weight gain and the P/F ratio at ICU readmission, between the R/E ratio (the period using a respirator (R) / the length of the ICU stay after extubation (E)) and the time to ICU readmission, between the R/E ratio and body weight gain, and between body weight gain until extubation and the time to extubation., Results: A negative linear relationship was found between body weight gain at the time of initial ICU discharge and the time to ICU readmission, and between body weight gain at the time of ICU discharge and the P/F ratio at ICU readmission. If body weight had increased by more than 10% at ICU discharge or the P/F ratio was below 150, readmission to the ICU within three days was likely. Patients with a large R/E ratio, a large body weight gain, and a worsening P/F ratio immediately after ICU discharge were likely to be readmitted soon to the ICU. Loss of body weight during the period of respirator support led to early extubation, since a positive correlation was found between the time to extubation and body weight gain., Conclusion: Fluid management failure during the first ICU stay might cause ICU readmission for patients who had lung edema or atelectasis. Therefore, a key to the prevention of ICU readmission is to ensure complete recovery from lung failure before the initial ICU discharge. Strict water management is crucial based on body weight measurement and removal of excess lung water is essential. In addition, an apparent improvement in respiratory state may be due to respiratory support, and such an improvement should be viewed cautiously. Loss of weight at the refilling stage of transfusion prevents ICU readmission and may decrease the length of the ICU stay.

Atelectasis can impair arterial oxygenation and decrease lung compliance. However, the effects of atelectasis on endotoxemic lungs during ventilation have not been well studied. We hypothesized that ventilation at low volumes below functional residual capacity (FRC) would accentuate lung injury in lipopolysaccharide (LPS)-pretreated rats. LPS-pretreated rats were ventilated with room air at 85 breaths/min for 2 hr at a tidal volume of 10 mL/kg with or without thoracotomy. Positive end-expiratory pressure (PEEP) was applied to restore FRC in the thoracotomy group. While LPS or thoracotomy alone did not cause significant injury, the combination of endotoxemia and thoracotomy caused significant hypoxemia and hypercapnia. The injury was observed along with a marked accumulation of inflammatory cells in the interstitium of the lungs, predominantly comprising neutrophils and mononuclear cells. Immunohistochemistry showed increased inducible nitric oxide synthase (iNOS) expression in mononuclear cells accumulated in the interstitium in the injury group. Pretreatment with PEEP or an iNOS inhibitor (1400 W) attenuated hypoxemia, hypercapnia, and the accumulation of inflammatory cells in the lung. In conclusion, the data suggest that atelectasis induced by thoracotomy causes lung injury during mechanical ventilation in endotoxemic rats through iNOS expression.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: does re-expansion pulmonary oedema exist? Altogether 233 papers were found using the reported search, of which 13 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that re-expansion pulmonary oedema (REPO) does occur following re-expansion of a lung in pneumothorax and pleural effusion. The incidence of REPO following pneumothorax and effusion is between 0 and 1% in most studies. The British Thoracic Society guidelines suggest <1.5 l pleural fluid should be drained at a time. Provided no respiratory symptoms occur it is not unreasonable to drain larger volumes to dryness: caution should be taken to avoid high negative intrapleural pressures. Patients who appear to be at higher risk, which may warrant more gradual evacuation, are: those who have had large pneumothoraces; young patients; patients in whom the lung has been down for >7 days; and possibly those who need >3 l of pleural fluid drained.

Objective: We evaluated the potential benefit of continuous positive airway pressure (CPAP) to prevent postoperative pulmonary complications (PPCs), atelectasis, pneumonia, and intubation in patients undergoing major abdominal surgery., Summary Background Data: PPCs are common during the postoperative period and may be associated with a high morbidity rate. Efficacy of CPAP to prevent PPCs occurrence is controversial., Methods: Medical literature databases were searched for randomized controlled trials examining the use of CPAP versus standard therapy in patients undergoing abdominal surgery. The meta-analysis estimated the pooled risk ratio and the number needed to treat to benefit (NNTB) for PPCs, atelectasis, and pneumonia., Results: The meta-analysis was carried out over 9 randomized controlled trials. Overall, CPAP significantly reduced the risk of (1) PPCs (risk ratio, 0.66; 95% confidence interval [CI], 0.52-0.85) with a corresponding NNTB of 14.2 (95% CI, 9.9-32.4); (2) atelectasis (risk ratio, 0.75; 95% CI, 0.58-0.97; NNTB, 7.3; 95% CI, 4.4-64.5); (3) pneumonia (risk ratio, 0.33; 95% CI, 0.14-0.75; NNTB, 18.3; 95% CI, 14.4-48.8). In all cases the variation in risk ratio attributable to heterogeneity was negligible, although there was some evidence of publication bias., Conclusions: This systematic review suggests that CPAP decreases the risk of PPCs, atelectasis, and pneumonia and supports its clinical use in patients undergoing abdominal surgery.

Asbestos is a well-known cause of several neoplastic (malignant mesothelioma, lung cancer) and non-neoplastic (asbestosis, pleuropathies) occupational diseases. Lower-level exposure in the general environment may induce pleural plaques and thickenings, and is associated with an increased mesothelioma risk. We present two patients (a 68-year-old man and a 72-year-old woman) who developed asbestosis (in association with pleural plaques and calcifications), and a 78-year-old man who developed rounded atelectasis (with pleural plaques and benign effusion), after living for several decades in the proximity of large Italian asbestos-cement plant. None of them had been exposed to asbestos occupationally. Besides living in a contaminated area, the woman used to clean the work clothes of her brother, who was employed in the local asbestos factory. The three cases indicate that non-neoplastic, long-latency asbestos-related diseases which are usually observed as a consequence of occupational exposures, may rarely develop in subjects living in contaminated geographical sites and buildings. These unusual environmental diseases raise the diagnostic problem of differentiating them from other, more common respiratory illnesses, and impose the duties of patient notification, assessment and follow-up, to assess the possibility of progression of disease and increased neoplastic risk.

Several strategies have been developed to treat atelectasis, including positive end-expiratory pressure and deep inspirations. However, in some patients these recruitment strategies fail to improve lung function. Therefore, the authors studied whether recruitment maneuvers could resolve atelectasis following either passive airway closure or active bronchconstriction. Aerated lung areas were measured in 5 dogs at baseline, and after airway closure with either a bronchial blocker, or administration of methacholine, followed by deep inspiration. Finally, bronchoconstriction was reversed pharmacologically. Bronchial occlusion reduced aerated lung areas, which were reopened by deep inspirations. Following methacholine, aerated lung areas were also significantly reduced; however, deep inspirations had no significant effect. Passive atelectasis was easily resolved by deep inspirations. In contrast, active airway constriction that leads to atelectasis could not be overcome with recruitment maneuvers.

Background and Methods: The incidence of intraoperative pulmonary collapse is elevated in patients undergoing surgery under general anesthesia with muscle relaxation/paralysis. This complication is associated with worsening intraoperative gas exchange and, in some cases, the need for prolonged postoperative respiratory support. The objective of this report was to review the pathophysiological aspects of atelectasis during general anesthesia and possible therapeutic maneuvers that could prevent and treat this complication., Contents: This review discusses the concepts about the incidence of intraoperative atelectasis, factors that influence their development, both mechanical and those related to mechanical ventilator settings during the surgery, diagnostic criteria, and strategies to prevent and treat this complication., Conclusions: Understanding of the mechanisms related with the development of intraoperative pulmonary collapse, as well as its treatment, can contribute to reduce the incidence of postoperative pulmonary complications, the length of recovery and hospital costs.

Purpose of the Review: Neurosurgical patients frequently develop respiratory complications, adversely affecting neurologic outcome and survival. The review summarizes current literature and management of respiratory complications associated with brain injury., Major Findings: Respiratory complications are commonly associated with traumatic brain injury and subarachnoid haemorrhage. Lung-protective ventilation with reduced tidal volumes improves outcome in acute lung injury, and should be applied to neurosurgical patients in the absence of increased intracranial pressure. Weaning from the mechanical ventilation should be initiated as soon as possible, although the role of neurological status in the weaning process is not clear. Prevention of pneumonia and aspiration improves survival. In patients with difficult weaning, early bedside percutaneous tracheostomy should be considered., Further Investigations: Further studies are warranted to elucidate an optimal oxygenation and ventilation in brain-injured patients, weaning strategies, predictors of the failed weaning and extubation, respiratory support in patients with difficulties to wean, and early tracheostomy.

The risk of leaving an iatrogenic foreign body in the bronchus, while using a reusable flexible suction catheter tube during rigid bronchoscopy is reported. A 6-year-old girl underwent rigid bronchoscopy to rule out foreign body inhalation as the possible cause of her unilateral pneumonia and lung collapse. While performing the bronchoscopy the distal end of the plastic suction tube was caught in the ventilation hole of the bronchoscope and was sheared from the main suction tube. This was later recovered from the right main bronchus while clearing the thick secretions. This potential complication occurs with use of reusable plastic suction catheters.

Negative pressure generated during the expiratory phase of total liquid ventilation (TLV) may induce airway collapse. Evaluation of the effect of repeated airway collapse is crucial to optimize this technique. A total of 24 New Zealand White rabbits were randomly divided into four groups. Ventilation was performed for 6 hours with different strategies: conventional gas ventilation, TLV without airway collapse, and TLV with collapse induced in either 75 or 150 sequential breaths. In the treated groups, airway collapse was induced by increasing the perfluorocarbon drainage velocity while maintaining the minute ventilation constant. Airway pressure, gas exchange, and blood pressure were monitored at 30-minute intervals. At the end of the experiment, airway and lung parenchyma specimens were processed for light microscopy. No evidence of fluorothorax was noticed in any of the four groups at autopsy examination. Minimal signs of inflammation were noticed in all airway and lung parenchyma specimens, but no evident structural alteration was visible. Adequate gas exchange and systemic blood pressure were maintained during all the studies. Repeated airway collapse is not associated with structural changes in the respiratory system and does not alter the gas exchange ability of the lungs.

Background: We have previously shown, in normovolemic pigs, that a selective lung recruitment maneuver (S-LRM), i.e., insufflation of air-oxygen via a balloon catheter with its tip located in the bronchus of a collapsed lung lobe, effectively improves oxygenation and lung volume without affecting hemodynamics negatively. In this study, we examined the respiratory and circulatory effects of S-LRM during hypovolemia with compromised circulation., Methods: In eight ventilated (fraction of inspired oxygen, Fio2 1.0) and anesthetized pigs a balloon catheter was inserted in the bronchus of the right lower lung lobe. The lobe was selectively lavaged to create a dense lobar collapse. The pigs were then subjected to S-LRM (40 cm H2O airway pressure for 30 s) at normovolemia, after venesection of 20% and 40% of the blood volume, respectively. Blood gases, compliance of the respiratory system (Crs), vascular pressures, and cardiac output were registered before, during, and after the S-LRM., Results: Pao2, venous admixture, and Crs improved significantly with S-LRM at all three volume levels. No change in hemodynamics with S-LRM occurred in normovolemia and 20% hypovolemia. For 40% hypovolemia, cardiac output was unchanged by S-LRM, whereas minor decreases in mean arterial blood pressure were seen: 48 (37-52) mm Hg (median, 25th and 75th percentiles) 3 min before S-LRM, 40 (35-44) mm Hg at the end of S-LRM (P = 0.0207), and 47 (39-54) mm Hg 3 min after S-LRM., Conclusion: A S-LRM effectively improved oxygenation and Crs and had only minor circulatory side effects, even in severe hypovolemia in this animal model of lobar collapse.

Background: Persistent atelectasis in children is lacking a gold standard treatment. Intrapulmonary percussive ventilation (IPV) is presented as a promising chest physiotherapy technique in the treatment of atelectasis. This study aimed to follow the evolution of atelectasis resolution with noninvasive IPV in young children and to detect eventual adverse effects., Methods: Six children were hospitalized for respiratory distress with suspicion of atelectasis. A 15 min IPV treatment was immediately started at D1 twice a day for 5 days. Children were free of any other treatment. Chest X-Ray (CXR) was performed on the second day (D2) and was repeated 3 days later (D5). After the study, CXR were retrospectively reviewed by three specialists who had no knowledge of the clinical observations of the patients. They were asked to assess atelectasis by a score between 4 (complete collapse) and 0 (complete resolution). A clinical score on a maximum of 4 points was assessed by appetite deterioration, dyspnoea, mucus production and cough presence at D1 and D5 (1 point per symptom present). Paired t-test compared D1 and D5 results., Results: All patients returned home after 5 days IPV. SpO2 normalized (93.2 +/- 0.8 to 95.3 +/- 0.8; P = 0.002) and patients all improved clinically (score, 2.8 +/- 0.9 to 0.8 +/- 0.6; P < 0.05). Out of four patients with radiographic evidence of atelectasis, three improved their atelectasis score., Conclusions: No side-effect or adverse effect was observed during IPV treatments. IPV was safe and effective in atelectasis resolution in 3/4 of the cases. Patients all recovered a stable clinical state. CXR improved in 4/5 children. They were all discharged home after 5 days of IPV treatment.

Background: The traumatic diaphragmatic hernia (TDH) may appear acutely after a blunt or penetrating trauma, or it can remain missed also for many years. The discussion about the utility of a laparoscopic repair in acute and chronic TDH is controversial., Methods: In this paper, we present two cases of chronic TDH that were successfully treated with laparoscopy. The first patient was treated 1 year after a stab wound and the second one 10 years after a firearm injury., Results: In both cases, the diaphragmatic defects were easily laparoscopically detected and treated. The defects were repaired with a direct running suture owing to the acceptable dimensions of the tears. The mean operative time was 135 minutes (range, 75-195). The blood loss during the operations was unremarkable. No intraoperative complications occurred, and the conversion rate was null. The postoperative course was uneventful in the first patient, whereas the second patient, owing to the intraoperative respiratory problems, needed an accurate respiratory monitoring in the Intensive Care Unit. The mean length of stay after the operation was 7 days (range, 6-8). At follow-up, the clinical examination and the chest X-rays documented no recurrence., Conclusions: We recommend the use of laparoscopy in left chronic TDH repair, performing a direct suture of the diaphragm when possible.

We observed improvements in two cases of chronic atelectasis through use of nasal continuous positive airway pressure (nCPAP). Case 1 suffered from middle lobe syndrome accompanied by chronic atelectasis resistant to medical treatment. Case 2 suffered from respiratory failure caused by chronic atelectasis and airway infection complications thereof following a total pneumonectomy and post-pneumonectomy syndrome. The patient was placed on artificial ventilation, and atelectasis was improved by maintaining PEEP and airflow to the atelectatic region. Following extubation we obtained good pneumatization using nCPAP. nCPAP has been reported as effective not only in cases of sleep apnea, but also for cardiogenic pulmonary edema and post-operative atelectasis; we believe it holds great promise for chronic atelectasis as well.

Objectives: We discuss a method to provide medical education in bronchoesophagology by using high-fidelity patient simulation manikins., Methods: A sophisticated, life-sized infant manikin with realistic anatomic, physiologic, and hemodynamic responses to interventions was programmed to simulate endobronchial foreign body lodgment by blocking ventilation of one lung and manifesting audible stridor, asymmetric chest wall motion, and decreased oxygen saturation., Results: Otolaryngology residents participated in simulation exercises incorporating the cognitive and technical skills necessary for successful airway endoscopy, including technical proficiency and teamwork, to learn to coordinate endoscopy and ventilation and manage laryngospasm. Rather than relying on instructor description, the participants responded directly to the manikin. This sense of realism stimulated participants to rehearse to improve provider performance and patient safety. Simulation provided an agenda determined by the needs of the learners, exploration without direct risk to patients, immediate feedback, and objective documentation., Conclusions: Rapidly evolving medical simulation technologies support activated, effective adult learning; they will play an increasing role in medical education.

Perioperative hypoxaemia is a common but serious problem with well recognised causes. However, an anomalous bronchus causing lobar collapse as a cause is seldom mentioned. A healthy young male patient was anaesthetised for a knee operation. He required re-intubation immediately postoperatively for hypoxia. He was found to have right upper lobe collapse. Fibreoptic examination of the trachea demonstrated an anomalous bronchus as the cause. Intra-operatively, the endotracheal tube had been inserted too deeply and the bronchial orifice had been obstructed by the tip. It took several hours for the lung to re-expand. Greater awareness of this potential complication is needed.

Objectives: To investigate respiratory and hemodynamic changes during lung recruitment and descending optimal positive end-expiratory pressure (PEEP) titration., Design: Prospective auto-control clinical trial., Setting: Adult general intensive care unit in a university hospital., Patients: Eighteen patients with acute respiratory distress syndrome., Interventions: Following baseline measurements (T0), PEEP was set at 26 cm H2O and lung recruitment was performed (40/40-maneuver). Then tidal volume was set at 4 mL/kg (T26R) and PEEP was lowered by 2 cm H2O in every 4 mins. Optimal PEEP was defined at 2 cm H2O above the PEEP where Pao2 dropped by > 10%. After setting the optimal PEEP, the 40/40-maneuver was repeated and tidal volume set at 6 mL/kg (T(end))., Measurements and Main Results: Arterial blood gas analysis was done every 4 mins and hemodynamic measurements every 8 mins until T(end), then in 30 (T30) and 60 (T60) mins. The Pao2 increased from T0 to T(end) (203 +/- 108 vs. 322 +/- 101 mm Hg, p < .001), but the extravascular lung water (EVLW) did not change significantly. Cardiac index (CI) and the intrathoracic blood volume (ITBV) decreased from T0 to T26R (CI, 3.90 +/- 1.04 vs. 3.62 +/- 0.91 L/min/m2, p < .05; ITBVI, 832 +/- 205 vs. 795 +/- 188 m/m2, p < .05). There was a positive correlation between CI and ITBVI (r = .699, p < .01), a negative correlation between CI and central venous pressure (r = -.294, p < .01), and no correlation between CI and mean arterial pressure (MAP)., Conclusions: Following lung recruitment and descending optimal PEEP titration, the Pao2 improves significantly, without any change in the EVLW up to 1 hr. This suggests a decrease in atelectasis as a result of recruitment rather than a reduction of EVLW. There is a significant change in CI during the maneuver, but neither central venous pressure, heart rate, nor MAP can reflect these changes.

Purpose of Review: To report the impact of atelectasis on perioperative outcomes. Atelectasis occurs in the dependent parts of the lungs of most patients who are anesthetized. Development of atelectasis is associated with decreased lung compliance, impairment of oxygenation, increased pulmonary vascular resistance and development of lung injury. Here, we examine the etiology, contributing factors, consequences, diagnosis and treatment of atelectasis., Recent Findings: Atelectasis describes the state of absent air in alveoli attributable to collapse, but recent findings suggest that alveoli are filled with foam and fluid. It is now known that atelectasis plays an important role beyond abnormal gas exchange and that prevention or reversal of atelectasis in some populations of postoperative patients may improve outcome., Summary: Atelectasis in the presence of preexisting lung disease or limited cardiopulmonary reserve may have significant consequences. Increasing understanding of the underlying nature of atelectasis and its contribution to acute lung injury will improve our approach to the prevention and management of atelectasis.

Purpose: The necessity of a postoperative chest tube for the treatment of pneumothorax after a radical nephrectomy is controversial., Materials and Methods: A five-year retrospective study was performed on 91 patients, having undergone a radical nephrectomy. We examined the existence and length of a pleural rent, presence of a postoperative thoracostomy tube, postoperative pneumothorax, postoperative pneumonia, postoperative atelectasis, pain scores, hemoglobin saturation, and length of hospital stay with univariate and multivariate analysis., Results: Incidence of a pleural rent occurred in 29 (36%) of open radical nephrectomy cases; 4 of the 29 cases had a postoperative thoracostomy tube. There was no significant difference in hemoglobin saturation levels between cases that had no pleural rent, a pleural rent without a thoracostomy tube, and a pleural rent with a postoperative thoracostomy tube. A pleural rent without a postoperative chest tube had significantly lower rates of pain score, atelectasis, pneumonia, pleural effusion, and length of hospital stay compared to individuals with a postoperative chest tube. Patients with a chest tube had a significantly higher incidence of pain, atelectasis, pneumonia, effusion, and length of hospital stay., Conclusion: Iatrogenic pleural rents treated without a postoperative chest tube show a significant decrease in postoperative complications of pneumonia and atelectasis, pain score and length of hospital stay. These patients show no significant increases in postoperative complications; therefore, it appears that postoperative chest tube placement after a pleural injury occurs is of no advantage.

Purpose: The present study investigated the effects of positive end-expiratory pressure (PEEP) on the inflammatory response in two different lung injury models: edematous lung induced by oleic acid (OA); and atelectatic lung induced by whole-lung lavage (LAV)., Methods: Japanese white rabbits (n = 28) were allocated to one of the two lung injury (OA or LAV) groups, and each group was treated with intermittent positive pressure ventilation, using zero end-expiratory pressure (ZEEP) or PEEP (1 cm H(2)O above the lower inflection point [LIP]). Thus, the animals were divided into LAV-ZEEP, LAV-PEEP, OA-ZEEP, and OA-PEEP groups. Blood and bronchoalveolar lavage fluid (BALF) were sampled 3 h after ventilatory treatment to analyze interleukin (IL)-8 levels., Results: Pa(O) (2) was significantly decreased after the induction of lung injury, but was significantly higher in the PEEP groups compared to the ZEEP groups for each lung injury. Serum IL-8 levels were elevated in both experimental models. Serum IL-8 levels were significantly lower in LAV-PEEP than in LAV-ZEEP, whereas no difference was noted between OA-PEEP and OA-ZEEP. BALF IL-8 levels were lower in LAV-PEEP than in LAV-ZEEP. PEEP above LIP attenuated the elevation of IL-8 in BALF and serum in atelectatic lungs, but did not attenuate these increases in the edematous lungs., Conclusion: These results suggest that the protective effects of PEEP on injured lungs may depend on the underlying lung pathology.

A 31-year-old man underwent general anesthesia for sinus surgery. Anesthesia was induced with midazolam and butorphanol, and an endotracheal tube was orally placed with a bronchoscope, due to difficulty with temporomandibular joint opening. Ventilation difficulty and increased peak inspiratory pressure were noticed shortly after tracheal intubation, and bronchoscopy was performed for diagnosis. The bronchi were filled with a clear mucous secretion. Removal of the secretion improved respiration and decreased the peak inspiratory pressure. A chest roentgenogram taken prior to extubation showed right upper lobe atelectasis. A diagnosis of sinobronchial syndrome was made postoperatively. The etiology of the acutely developed atelectasis was unclear. However, the latent syndrome may have induced excessive airway secretion with stimuli such as endotracheal intubation.

Background: Immobility is associated with complications involving many body systems., Objective: To review the effect of rotational therapy (use of therapeutic surfaces that turn on their longitudinal axes) on prevention and/or treatment of respiratory complications in critically ill patients., Methods: Published articles evaluating prophylaxis and/or treatment were reviewed. Prospective randomized controlled trials were assessed for quality and included in meta-analyses., Results: A literature search yielded 15 nonrandomized, uncontrolled, or retrospective studies. Twenty prospective randomized controlled trials on rotational therapy were published between 1987 and 2004. Various types of beds were studied, but few details on the rotational parameters were reported. The usual control was manual turning of patients by nurses every 2 hours. One animal investigation and 12 clinical trials addressed the effectiveness of rotational therapy in preventing respiratory complications. Significant benefits were reported in the animal study and 4 of the trials. Significant benefits to patients were reported in 2 of another 4 studies focused on treatment of established complications. Researchers have examined the effects of rotational therapy on mucus transport, intrapulmonary shunt, hemodynamic effects, urine output, and intracranial pressure. Little convincing evidence is available, however, on the most effective rotation parameters (eg, degree, pause time, and amount of time per day). Meta-analysis suggests that rotational therapy decreases the incidence of pneumonia but has no effect on duration of mechanical ventilation, number of days in intensive care, or hospital mortality., Conclusions: Rotational therapy may be useful for preventing and treating respiratory complications in selected critically ill patients receiving mechanical ventilation.

Purpose: To investigate the efficacy and safety of intrapulmonary percussive ventilation (IPV) in obese patients, we assessed their respiratory and hemodynamic functions during IPV superimposed on conventional ventilation., Materials and Methods: Ten obese patients with acute respiratory failure due to compression atelectasis who had not improved by conventional ventilation were treated with IPV. Hemodynamic parameters, ventilator settings, and intracranial pressure (n = 1) were recorded every hour. Arterial blood gas was analyzed every 3 hours. The efficacy and safety of IPV was assessed at the start of weaning., Results: Before IPV, Pao(2)/Fio(2) ratio remained low (189 +/- 63 mm Hg), which significantly increased to 243 +/- 67 mm Hg at 3 hours from the initiation of IPV (P < .01). Furthermore, it continuously increased to 280 +/- 50 mm Hg at 24 hours (P < .01). Intrapulmonary percussive ventilation induced significant increase in dynamic compliance from control value of 30 +/- 8 mL/cm H(2)O at 0 hours to 35 +/- 9 mL/cm H(2)O at 12 hours (P < .05) and to 38 +/- 8 mL/cm H(2)O at 24 hours (P < .01). Heart rate and mean arterial pressure were not significantly changed during IPV. Improvement of compression atelectasis was confirmed by their chest computed tomographic scans. Adverse effects such as pneumothorax and intracranial hypertension were not seen., Conclusions: These results demonstrated that IPV was effective and safe in improving compression atelectasis without adverse effects in obese patients.

Purpose of Review: To address lung recruitment according to pressure/volume curves, along with regional recruitment versus hyperinflation evidence from computed tomography and electrical impedance tomography., Recent Findings: Cyclical tidal volume recruitment of atelectatic lung regions causes acute lung injury, as do large breaths during pneumonectomy. Using the lower inflection point on the static pressure/volume inflation curve plus 2 cmH2O as a positive end-expiratory pressure setting limits hyperinflation in acute lung injury, but may not provide enough positive end-expiratory pressure to avoid cyclical recruitment/derecruitment injury in more severe acute lung injury regions. Both computed tomography and electrical impedance tomography can help titrate positive end-expiratory pressure in these regions, thereby assuring an 'open lung' ventilatory pattern. Regional pressure/volume curves show that adequate positive end-expiratory pressure for severe acute lung injury regions may not be reliably determined from whole lung pressure/volume curves. Balancing positive end-expiratory pressure requires both arterial PO2 and PCO2 values to determine at what level hyperinflated regions become seriously underperfused (develop very high ventilation-perfusion ratios), adding to the hypercarbia from increased deadspace., Summary: Positive end-expiratory pressure levels must be high enough to minimize recruitment/derecruitment cycling. Balancing recruitment versus overdistension may require thoracic tomography, to assure sufficient improvement in oxygenation while limiting hypercarbia.

We report 10 cases of pulmonary atelectasis diagnosed by chest computed tomography in patients with neurological or muscular disease. Atelectasis was frequently seen in hypotonic patients who could not roll over on their own. The atelectases located mostly in the dorsal bronchopulmonary segments, adjacent to the heart or diaphragm. Atelectasis diminished in two patients after they became able to roll themselves over. Gravity-related lung compression by the heart and intra-abdominal organs on persistent supine position can cause pulmonary atelectasis in patients with neurological or muscular disease who can not roll over by their own power. To confirm that the prone position reduces compression of the lungs, chest computed tomography was performed in both the supine and the prone position in three patients. Sagittal images with three-dimensional computed tomographic reconstruction revealed significant sternad displacements of the heart and caudal displacements of the dorsal portion of the diaphragm on prone position compared with supine position. The prone position, motor exercises for rolling over, and biphasic cuirass ventilation are effective in reducing gravity-related lung compression. Some patients with intellectual disabilities were also able to cooperate in chest physiotherapy. Chest physiotherapy is useful in preventing atelectasis in patients with neurological or muscular disease.

Objective: To describe the beneficial clinical effect of the use of surfactant in a patient with severe unilateral pulmonary hemorrhage after iatrogenic lung injury during corrective surgery for congenital heart defects., Design: Case report., Setting: Pediatric cardiac intensive care unit of a tertiary care hospital., Patient: An 11-wk-old boy., Interventions: Intratracheal instillation of 4 mL (100 mg) of surfactant (Survanta) per kilogram of body weight to treat profound and refractory hypoxia and hypercapnia despite high-ventilation pressures, high respiratory rate, and the use of nitric oxide caused by severe pulmonary hemorrhage and atelectasis., Measurements and Main Results: The aggressive ventilation variables could be reduced within the following 2 hrs after surfactant use (from Fio2 0.8, peak inspiratory pressure 36 cm, positive end-expiratory pressure 10 cm, respiratory rate 50, tidal volume 63 mL, and nitric oxide 10 ppm to Fio2 0.4, peak inspiratory pressure 28 cm, positive end-expiratory pressure 10, respiratory rate 40, tidal volume 38 mL, and nitric oxide 5 ppm). There was rapid improvement of clinical variables (inotropic support, chest radiograph) as well as oxygenation (Pao2 from 56 to 149 mm Hg), CO2 exchange (Paco2 from 85 to 39 mm Hg), and acidosis (from pH 7.13 to 7.44)., Conclusions: The administration of surfactant may be a promising approach to treat severe respiratory failure caused by severe pulmonary hemorrhage.

Liquid ventilation using perfluorochemicals (PFC) offers clear theoretical advantages over gas ventilation, such as decreased lung damage, recruitment of collapsed lung regions, and lavage of inflammatory debris. We present a total liquid ventilator designed to ventilate patients with completely filled lungs with a tidal volume of PFC liquid. The two independent piston pumps are volume controlled and pressure limited. Measurable pumping errors are corrected by a programmed supervisor module, which modifies the inserted or withdrawn volume. Pump independence also allows easy functional residual capacity modifications during ventilation. The bubble gas exchanger is divided into two sections such that the PFC exiting the lungs is not in contact with the PFC entering the lungs. The heating system is incorporated into the metallic base of the gas exchanger, and a heat-sink-type condenser is placed on top of the exchanger to retrieve PFC vapors. The prototype was tested on 5 healthy term newborn lambs (<5 days old). The results demonstrate the efficiency and safety of the prototype in maintaining adequate gas exchange, normal acido-basis equilibrium, and cardiovascular stability during a short, 2-hour total liquid ventilator. Airway pressure, lung volume, and ventilation scheme were maintained in the targeted range.