Aspiration pneumonia: experimental evaluation of albumin and steroid therapy.

An experimental model using an ex vivo perfused ventilated canine pulmonary lobe was used to study aspiration pneumonia. After intrabronchial acid instillation, the lobe weight tripled, air way pressure and pulmonary artery pressure doubled, and intrapulmonary shunting increased from 5.5% to 53.4%. If large quantities of albumin were added to the lobe perfusate 5 minutes after intrabronchial acid instillation, weight gain, air way and pulmonary artery pressure, and intrapulmonary shunting were unchanged from control levels. If large quantities of steroid were added to the lobe perfusate 5 minutes after intrabronchial acid instillation, the lobe weight doubled but air way pressure and pulmonary artery pressure, and intrapulmonary shunting were not significantly different from control values. It is surmised that intrapulmonary acid aspiration causes an immediate and marked changed in pulmonary capillary permeability. Albumin administration by counteracting this permeability change, and steroid administration by modifying the permeability change, are both beneficial following acid aspiration.     

Pulmonary haemodynamics and right ventricular function during cemented hemiarthroplasty for femoral neck fracture

Background: Bone cement implantation syndrome (BCIS) is characterised by hypoxia, hypotension and loss of consciousness occurring early after bone cementation. The haemodynamic perturbations during BCIS have not been extensively studied, particularly not in patients with femoral neck fracture. We evaluated the effects of cemented hemiarthroplasty, in these patients, on pulmonary haemodynamics, right ventricular performance, intrapulmonary shunting and physiological dead space. Methods: Fifteen patients undergoing cemented hemiarthroplasty because of femoral neck fracture were included. Surgery was performed under total intravenous anaesthesia in the lateral position. All patients were catheterised with a radial and pulmonary artery catheter, for continuous measurements of mean arterial pressure (MAP), pulmonary arterial pressure (PAP), cardiac output, mixed venous oxygen saturation, right ventricular end‐diastolic volume (RVEDV) and right ventricular ejection fraction (RVEF). Haemodynamic measurements and blood gas analyses were performed after induction of anaesthesia, during surgical stimulation before and immediately after bone cementation and prosthesis insertion, 10 and 20 min after insertion and during skin closure. Results: After bone cementation and prosthesis insertion, MAP (?10%), cardiac index (?10%) and stroke volume index (?10%) decreased, while PAPs (10–15%) and the pulmonary vascular resistance index (45%) increased. RVEF decreased by 10–20%, while the RVEDV index increased by 10%. Pulmonary haemodynamic and RV variables changed progressively with time, while intra‐pulmonary shunting and physiological dead space increased immediately after prosthesis insertion and then returned to baseline. Conclusions: Cemented hemiarthroplasty in patients with femoral neck fracture causes a pronounced pulmonary vasoconstriction and an impairment of RV function accompanied by pulmonary ventilation/perfusion abnormalities.     

Resolution of cirrhosis-related pulmonary shunting in two children with a transplanted liver

We treated two children with hypoxemia caused by intrapulmonary shunting associated with cirrhosis secondary to extrahepatic biliary atresia. Following orthotopic liver transplantation, digital clubbing and intrapulmonary shunting were resolved, as demonstrated by normalization of room air arterial blood gases, reduction in shunt fraction, and perfusion lung scanning with ^99mTc-labeled macroaggregates of albumin. We recommend that early liver transplantation be considered for young subjects with a severe hepatopulmonary syndrome.     

Hypertonic mannitol in the therapy of the acute respiratory distress syndrome.

Increased pulmonary artery pressure, an increase in pulmonary vascular resistance and an increase in physiologic dead space are consistent findings in patients with post-traumatic respiratory distress. Since mannitol has been shown to decrease renal vascular resistance following trauma, the effect of a bolus injection of 100 ml of 25% solution of this drug on pulmonary hemodynamics and physiologic dead space was investigated in 11 patients who had suffered multiple trauma. Five minutes after the injection, pulmonary vascular resistance fell (p less than .01), cardiac index increased (p less than .001) and physiologic dead space decreased (p less than .05). In contrast, the administration of 40 mg of furosemide produced no significant change in any of these parameters. Mannitol rapidly equilibrates in the extracellular space and exerts an osmotic effect across cell membranes. We postulate that the beneficial response to mannitol on the pulmonary vascular resistance and the improved perfusion of ventilated regions of the lung is due to a reduction in cell swelling and is not explainable by its diuretic effect. Improvement in the distribution of perfusion of pulmonary blood flow by mannitol may be a useful aid in the treatment of the post-traumatic form of the respiratory distress syndrome.     

Does increased pulmonary blood flow redistribute towards edematous lung units?

Unilobar pulmonary edema secondary to increased capillary permeability was produced utilizing oleic acid infusion into the left lower lobe pulmonary artery of seven dogs. This model was used to determine whether random changes in cardiac output produced by opening and closing arteriovenous fistulae were associated with changes in fractional perfusion to the edematous lobe (as determined by differentially labeled radiomicrospheres) thus explaining changes in intrapulmonary shunt. With an increase in cardiac output from a mean (+/- SD) of 1.6 +/- 0.5 liters/min to 2.6 +/- 0.8 liters/min (P less than 0.01), mean (+/- SD) injured lobar shunt as measured from O2 contents of lower lobar pulmonary venous blood and mixed venous blood increased from 54.4 +/- 3.0% to 74.4 +/- 22.1% while total intrapulmonary shunt increased from 12.0 +/- 4.0% to 16.0 +/- 3.7% (P less than 0.01). This increase in intrapulmonary shunt was, however, not associated with preferential perfusion of the edematous lobe, the mean (+/- SD) of the perfusion to the edematous lobe expressed as a percentage of the cardiac output being 16.6 +/- 1.6% at the low cardiac output and 16.9 +/- 1.4% at the high cardiac output. It is concluded that redistribution of blood flow towards the edematous lobe does not occur with increases in cardiac output and therefore does not account for the increased intrapulmonary shunt.     

Hemodynamic observations during and after pulmonary artery banding

Analysis of cardiac catheterization in 25 patients with nonrestrictive ventricular septal defect (Prv/Plv > 0.6) shows that the pulmonary vascular resistance and systemic vascular resistance function as resistances in parallel. Furthermore, studies in the presence of right ventricular outflow obstruction, by either pulmonary artery band (9 patients) or pulmonary stenosis and ventricular septal defect with left-to-right shunting (12 patients), show that the right ventricular outflow obstruction (band) functions as a resistance in series with the pulmonary vascular resistance. The sum of pulmonary vascular resistance plus band resistance is in parallel with systemic resistance. This concept allows better explanation of the great pressure variability across bands observed at operation. It is impossible to completely evaluate a pulmonary artery band with pressures alone. Flow measurements are necessary for better understanding of pulmonary artery bands. The variability of clinical response after banding may be explained by the variations in pulmonary vascular resistance and systemic vascular resistance during and after pulmonary artery banding.     

Enlarged bronchial collateral artery complicating recovery after arterial switch for simple transposition of the great arteries

Enlarged bronchial collateral arteries can lead to significant left to right shunting resulting in pulmonary hypercirculation and hypoxemia and may complicate postoperative recovery after uneventful surgical repair. We describe a case of simple transposition of the great arteries in which the postoperative course was complicated by the presence of an enlarged bronchial collateral artery causing pulmonary oedema necessitating prolonged mechanical ventilatory support. Successful coil embolisation of the bronchial collateral resulted in resolution of the pulmonary oedema and successful extubation.     

Intrapulmonary shunt after cardiopulmonary bypass: the use of vital capacity maneuvers versus off-pump coronary artery bypass grafting

OBJECTIVES: It has been proved in human subjects and animals that atelectasis is a major cause of intrapulmonary shunting and hypoxemia after cardiopulmonary bypass. Animal studies suggest that shunting can be prevented entirely by a total vital capacity maneuver performed before termination of bypass. This study aimed to test this theory in human subjects and to evaluate possible advantages of off-pump coronary artery bypass grafting. METHODS: Twenty-four patients scheduled for coronary artery bypass grafting were randomly assigned to receive no total vital capacity maneuver (control group, n = 12) or standard total vital capacity maneuvers (TVCM group, n = 12). Additionally, 12 consecutive patients undergoing off-pump coronary artery bypass grafting (off-pump group) were studied. Systemic and central hemodynamics, the pattern of breathing, and ventilatory mechanics were evaluated after induction of anesthesia, after sternotomy, after cardiopulmonary bypass and skin closure, and 4 hours after extubation. RESULTS: The use of total vital capacity maneuvers reduced (P <.05) intrapulmonary shunting after termination of cardiopulmonary bypass. However, shunting increased (P <.05) in all groups (control group, 8.2% +/- 3.3% vs 25.6% +/- 8.1%; TVCM group, 8.7% +/- 3.4% vs 24.4% +/- 8.5%; and off-pump group, 7.8% +/- 2.8% vs 14.0% +/- 5.3%) after extubation, but the increase was significantly (P <.05) less pronounced in the off-pump group. Furthermore, pulmonary compliance decreased (P <.05) in all groups except the off-pump group after extubation. Duration of hospital and intensive care unit stay was significantly shorter (P <.05) in the off-pump group than in the other groups. CONCLUSION: The development of intrapulmonary shunting and hypoxemia after coronary artery bypass grafting can be substantially reduced by performance of total vital capacity maneuvers while patients are mechanically ventilated. However, off-pump coronary artery bypass surgery is superior in preventing shunting and hypoxemia after bypass grafting in the immediate and early postoperative periods, probably leading to substantially shorter intensive care unit and hospital stays.     

Transplantation of the left lung into the right hemithorax to facilitate immediate reconstitution of bronchial artery flow.

Immediate bronchial artery reconstitution may be important in the prevention of bronchial anastomotic problems in lung transplantation. To facilitate this reconstitution in circumstances requiring allograft replacement of the right lung, we developed a method for transplanting the left lung together with its bronchial arterial supply into the right hemithorax. With this method, left lungs were allotransplanted into the right hemithorax of nine immunosuppressed dogs. Six recipients survived 1 to 4 weeks. Death resulted from pneumonia or rejection, and there were no bronchial anastomotic problems. Roentgenograms showed that the bronchial artery was patent and that the inverted transplanted left lungs could conform exactly to the thorax without space problems or radiographic abnormalities. Except for the unusual position of the large pulmonary arteries, angiographic patterns, function, and perfusion of the transplanted lungs were often normal and equivalent to those of the recipient's normal left lung. Thus it is possible to transplant a left lung into either hemithorax and immediately reconstitute its bronchial arterial circulation. Bronchial anastomotic problems may thereby be decreased.     

Bilateral bronchioloalveolar lung carcinoma: is there a place for palliative pneumonectomy?

Objective: Bronchioloalveolar lung carcinoma (BAC) is characterized by bronchial and lymphatic dissemination explaining multifocal and bilateral spreading. Bilateral BAC is usually considered as a contraindication to surgery. Regarding poor efficacy of symptomatic and oncological treatments, we hypothesized that surgery might play a role to palliate hypoxemia associated with serious intrapulmonary shunting, as well as continuous bronchorrhea. Methods: We retrospectively studied here four consecutive patients, who underwent palliative pneumonectomy. Results: The shunt was confirmed again at the time of the surgery by a pulmonary artery occlusion demonstrating immediate improvement in arterial oxygen saturation from 89% at baseline to 98% after occlusion. Lung resections consisted of a left pneumonectomy in three cases and a right pneumonectomy in one. PaO₂ levels under 5 l/min oxygen therapy improved dramatically when comparing preoperative data (mean 50.5 mmHg) to post-operative results (mean 150  mmHg). One patient died postoperatively. Three patients, who experienced an uneventful immediate post-operative course, received chemotherapy after surgery. Improvement of quality of life is testified by the absence of both symptoms and any need for oxygen therapy for few months. Disabling symptoms reappeared at 1, 8 and 10 months. Survival of these patients was 3, 12 and 18 months. Conclusions: These results support the interest of consideration of a surgical resection for highly selected patients presenting with bilateral BAC and severe intrapulmonary shunting.     

Chronic idiopathic pulmonary hilar fibrosis. A clinicopathological entity

Idiopathic pulmonary hilar fibrosis is a condition related to mediastinal fibrosis, characterized by localization of the fibrosing process to one or both pulmonary hila. This results in pulmonary hypertension and bronchial narrowing. Three patients suffering from this disease, in whom the diagnosis has been confirmed by thoracotomy, are reported. The clinical and pathological features are described and previously reported cases are reviewed. The syndrome is classified into two types, according to whether the obstruction affects mainly the pulmonary artery or veins. The disease is a self-limiting one but may lead to organic changes in the lungs causing severe disability.     

Angiographic and histopathological study on bronchial-to-pulmonary vascular anastomoses on explants from patients with cystic fibrosis after bronchial artery embolisation

Labelled backgroundHaemoptysis is a life-threatening complication of cystic fibrosis (CF). One treatment is bronchial artery embolisation (BAE) using embolic-microspheres (EMs). During BAE, pulmonary arteries can be seen on digital subtracted angiography while iodine containing contrast material injection is performed in the bronchial artery. This suggests that EMs could go from bronchial to nontarget pulmonary arteries. The aim was to evaluate if EMs could be found inside pulmonary arteries on lung explants after BAE in transplanted CF patients.MethodsRetrospective observational study including patients with CF who underwent lung transplantation and had previously needed BAE. Clinical, chest CT angiography, and angiographic data were reviewed from medical records. Pathology examination of lung explants was performed to analyze the EMs anatomical localisation.ResultsEight patients were included between 2013 and 2015, four males with a mean age of 29 (19-45) years. All patients had bronchial artery hypertrophy on CT and bronchial-to-pulmonary artery shunting during BAE. On pathology examination, EM ≤800 µm were found in the pulmonary arteries in all patients and were responsible for distal branch occlusions. Two pulmonary infarcts were observed on CT angiography after BAE and confirmed histopathologically.ConclusionsEM migration from the bronchial to pulmonary arteries is a common occurrence after BAE in patients with advanced stage CF. Although BAE is a highly effective means of controlling haemoptysis in CF, studies on the optimal particle size are needed to preserve pulmonary artery circulation, because these results suggest that low size EMs could lead to nontarget embolisation.     

Noninvasive conjunctival oxygen monitoring during carotid endarterectomy

Conjunctival oxygen tension (PcjO2) was measured continuously during carotid endarterectomy in 15 patients to evaluate its sensitivity in patients receiving shunts. These studies suggest that PcjO2 tracks brain perfusion during periods of carotid artery occlusion. Reduced PcjO2 was clearly demonstrated with systemic hypotension, carotid artery clamping, and carotid shunt obstruction and clamping. Monitoring of PcjO2 is noninvasive, easy to perform, offers no danger to the patient, and allows real-time assessment of the local tissue perfusion. It provides valuable information on the effectiveness of carotid oxygen transport and, in conjunction with arterial blood gas values, expresses carotid artery perfusion relative to systemic oxygen transport. Further investigations using the PcjO2 sensor may define criteria for intraoperative carotid arterial shunting in patients with tenuous cerebral perfusion, and for prompt intervention in patients with deteriorating perfusion prior to the onset of life-threatening cerebral ischemia.     

New surgical approach "intrapulmonary septation technic" for Fontan candidates with unilateral pulmonary arterial hypoplasia and/or pulmonary venous obstruction

Unilateral pulmonary arterial hypoplasia and/or pulmonary venous obstruction are serious hazards for Fontan candidates. For these patients, we have started new surgical approach "intrapulmonary septation technic". This consists of 3 components; (A) partial right heart bypass to well-grown side, (B) mandatory pulmonary blood flow to low-capacity side, (aorto-pulmonary shunt or others) and (C) a patch between partial right heart bypass and mandatory pulmonary blood flow. Thirteen patients underwent the approach. The source of partial right heart bypass was brought from superior vena cava (11 patients), inferior vena cava (1 patient) and fenestrated Fontan (1 patient). The mandatory pulmonary blood flow was supplied by aorto-pulmonary shunt (11 patients), pulmonary arterial banding (1 patient) and native pulmonary valve stenosis (1 patient). We added pulmonary artery enlargement (9 patients), release of pulmonary venous obstruction (8 patients) and/or atrio-ventricular valve plasty (5 patients), simultaneously. No hospital death. Early post-operative course was uneventful in all cases except 1, as pulmonary blood flow to low-capacity side had increased gradually after this intervention. Eight patients had reached Fontan operation. In this approach, nearly whole pulmonary artery can grow without any affect of volume overload through well-grown side from collateral arteries of low-capacity side. All procedures of "intrapulmonary septation technic" and reconstruction of pulmonary artery in Fontan operation can be easily performed in larger pulmonary artery of well-grown side, eliminating need for extensive dissection.     

Pulsatile vs. non-pulsatile flow during cardiopulmonary bypass. A comparison of early postoperative changes

The aim of the study was to evaluate possible haemodynamic and metabolic effects of pulsatile flow in cardiopulmonary bypass. The subjects were 20 patients undergoing coronary artery bypass grafting. They had no complicating diseases. Ten consecutive patients with pulsatile perfusion were compared with ten consecutive patients with non-pulsatile perfusion. The haemodynamic parameters, chest X-rays, fluid balance and changes in circulating thrombocytes were unaffected by adding pulsatile flow to cardiopulmonary bypass. The arterial-venous oxygen content difference and intrapulmonary shunting were also unaffected. Whole-body oxygen consumption was higher in the pulsatile group immediately after bypass, but subsequently there were no differences. The haemoglobin and haematocrit values were higher in the non-pulsatile group two hours postoperatively, but did not differ in the rest of the observation period. The clinical course was similar in the two groups.     

Physiological dead space during general anaesthesia for Caesarean section

The physiological dead space and its components were determined during general anaesthesia for Caesarean section in seventeen patients and compared with similar values for seventeen patients undergoing abdominal hysterectomy under general anaesthesia. The physiological dead space was smaller in the pregnant patients, due to a smaller alveolar dead space. The anatomical dead space was similar in both groups. A lowered physiological dead space suggests that there will be a decrease in the pulmonary ventilation perfusion ratio (V/Q) during Caesarean section; this could result from better perfusion of the ventilated alveoli than in the non-pregnant group, due to the increased cardiac output of pregnancy. An improvement in alveolar perfusion should also produce more efficient carbon dioxide elimination in pregnant patients, when compared to non-pregnant subjects.     

Effect of ablated bronchial blood flow on survival rate and pulmonary function after burn and smoke inhalation in sheep

The bronchial circulation plays a significant role in the pathophysiological changes of burn and smoke-inhalation injury. Bronchial blood flow markedly increases immediately after inhalational injury. This study examines whether the ablation of the bronchial artery attenuates pathophysiological changes and improves survival after burn and smoke-inhalational injury in an ovine model. Acute lung injury was induced by 40% total body surface-area third-degree cutaneous burn and cotton smoke inhalation (48 breaths of cotton smoke, <40 °C) under deep anaesthesia. Twelve adult female sheep were divided into two groups: (1) sham (injured, non-ablated bronchial artery, n = 6); (2) ablation (injured, ablated bronchial artery, n = 6). Ablation of the bronchial artery was performed 72 h before the injury. The experiment was continued for 96 h. Burn and smoke-inhalation injury significantly increased regional blood flow in the bronchi. Ablation of the bronchial artery significantly reduced acute regional blood flow increases in the proximal and distal bronchi. All animals in the ablation group survived to 96 h. Four of these were successfully weaned off the ventilator. Three animals of the sham group met standardised euthanasia criteria at 60 h, while another met the criteria at 78 h. The lung wet-to-dry weight ratio, histology score and myeloperoxidase (MPO) activity were significantly increased by the insult, but ablation of the bronchial artery attenuated these changes. Burn and smoke-inhalation injury induced a significant increase in bronchial blood flow and accelerated airway obstruction, pulmonary vascular changes, pulmonary oedema and pulmonary dysfunction. Ablated bronchial circulation attenuated these pathophysiological changes.     

容量-呼气末二氧化碳分压波在危重患者中临床应用解析

背景容量-呼气末二氧化碳分压图（volume-capnogram,v-PETCO2）是根据呼吸周期中呼出气量对应CO2水平描记的单波图,是评价呼吸障碍患者死腔或分流的最有价值的无创性新工具。目的讲述v-PETCO2的基本原理、正常波形和异常波形的临床意义。内容v-PETCO2波的形态取决于CO2产生、运输（肺灌注）和弥...     

Contribution of the bronchial circulation to lung preservation

Short preservation time still severely limits lung transplantation. To determine the effect of bronchial arterial flush preservation, we studied 54 dogs using the isolated perfused working lung model. After baseline measurements, lungs were flushed with lactated Ringer's solution (60 ml/kg at 8 degrees C) by one of three methods: pulmonary artery perfusion, bronchial artery perfusion through a 15 cm closed aortic segment, or simultaneous pulmonary-bronchial artery perfusion. These groups were further subdivided and tested after 0, 4, and 17 hours of storage at 4 degrees C (n = 6 each). Lungs were ventilated (flow rate 140 ml/kg/min; inspired oxygen fraction 0.21) and continuously reperfused with normothermic deoxygenated autologous blood in a closed loop. Measured variables were hemodynamics, aerodynamics, and leukocytes in bronchoalveolar lavage. Survival time was determined from initial reperfusion to failure of the lung to oxygenate. After 0 and 4 hours of storage, there was no significant difference in survival times. After 17 hours, lungs subjected to pulmonary-bronchial artery perfusion survived longer than those perfused via either the pulmonary or bronchial arteries alone (120 +/- 24 versus 38 +/- 14 or 52 +/- 16 minutes; p less than 0.01). Pulmonary artery pressure and resistance in all groups except at failure were never different from baseline values in the intact animal. Shunts in the pulmonary-bronchial artery perfusion groups were closest to baseline at onset (8% +/- 4%) and remained lower throughout reperfusion than in the groups subjected to pulmonary or bronchial artery perfusion alone. After 17 hours, static compliance of pulmonary artery-perfused lungs was worse than baseline (1.1 +/- 0.2 x 10(-2) versus 3.2 +/- 0.7 x 10(-2) L/cm H2O/sec; p less than 0.05), whereas compliance in the pulmonary-bronchial artery perfusion groups remained constant (3.6 +/- 1.5 x 10(-2) L/cm H2O/sec). Elastic work performed by lungs subjected to pulmonary-bronchial artery flushing at onset was significantly lower when these lungs were reperfused immediately (201 +/- 14 versus 295 +/- 35 gm-m/min for pulmonary artery-flushed lungs) or after 4 hours of storage (229 +/- 30 versus 290 +/- 24 gm-m/min for pulmonary artery-flushed lungs). Bronchoalveolar lavage after 17 hours in the group subjected to pulmonary bronchial artery flushing demonstrated leukocyte counts similar to those of intact lungs (45 +/- 5 versus 29 +/- 8/mm3) and significantly less than in lungs subjected to pulmonary or bronchial artery flushing (137 +/- 18 or 82 +/- 10/mm3, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)     

Doxapram improves pulmonary function after upper abdominal surgery

The effects of doxapram on postoperative pulmonary function were studied in 40 ASA I and II patients randomly allocated to receive either doxapram 1.8 mg· kg^-1. h^-1 or placebo for 2 h immediately after elective cholecystectomy. The two groups displayed similar reductions of carbon dioxide production at 2 h and 6 h postoperatively, whereas oxygen consumption remained at preoperative levels for 24 h. Minute ventilation was similarly reduced in the two groups at 2 h and 6 h postoperatively, with corresponding increases in Paco₂. Pao₂ was similarly and significantly decreased in both groups postoperatively, whereas P(A-a)o₂ remained unchanged at 2 h and 6 h in doxapram-treated patients. FRC was reduced postoperatively in both groups, significantly more so in the control group at 6 h. Various indices of intrapulmonary gas distribution, including the functional (nitrogen) dead space, underwent similar changes in the two groups. By contrast, the physiological dead space was reduced in doxapram-treated patients at 2 h, 6 h and 24 h postoperatively, whereas no significant changes were seen in the control group. The ventilatory equivalent for CO₂ was significantly lower in the doxapram-treated group, implying higher ventilatory efficiency. Our findings indicate that infusion of doxapram postoperatively attenuates the impairment of pulmonary function postoperatively, chiefly via effects on V'_A/Q' ratios. No side effects of doxapram were observed.