PULMONARY-FUNCTION ABNORMALITIES AFTER LYMPHANGIOGRAPHY

A case of acute respiratory distress syndrome due to lymphography with Lipiodol for chylothorax after esophagectomy

Background

Lymphography with Lipiodol is useful for chylothorax. There were many slight complications, but reports of acute respiratory distress syndrome (ARDS) after lymphography were few.

Case presentation

A 75-year-old man with esophageal cancer developed chylothorax after esophagectomy. Conservative treatment was ineffective, and he underwent lymphography with 8.5 mL of Lipiodol. He developed a high fever soon after lymphography, followed by severe ARDS requiring artificial respiration 5 days later. He recovered from ARDS but subsequently developed pulmonary fibrosis and was discharged with domiciliary oxygen therapy 3 months later.

Conclusion

Although ARDS is a rare complication of lymphography with Lipiodol, this procedure should be applied carefully in patients with chylothorax.

Diffusing capacity in the clinical assessment of chronic airflow limitation

CAL remains an important cause of morbidity and mortality. The diffusing capacity has ranked high in the assessment of CAL because it represents the best pulmonary function test to assess the integrity of the pulmonary capillary bed. Unfortunately, numerous physiologic, pathologic, and technical factors affect the test, thus limiting its sensitivity and specificity. HRCT techniques offer the potential to assess the extent of emphysema more accurately, but the technique requires greater standardization and is more expensive and less noninvasive than DLcoSB testing. Although the CIBA symposium considered DLcoSB "essential" in the investigation of the CAL patient, 16 the use of conventional DLcoSB testing in the seated position at rest is not currently advised as a routine screening procedure. The test must be performed in a center with high degree of quality control, and the results can be of value only by integrating the result into a comprehensive clinical assessment. Within this context, conventional DLcoSB testing may provide limited information about the extent of emphysema because reductions in DLcoSB correlate with the extent of emphysema by HRCT. When DLcoSB is normal, it may point in the direction of considering asthma as the cause of the airflow limitation. It may also provide information about disease severity and prognosis in O2-dependent CAL patients. The test should be a part of the investigation of the patient with unexplained dyspnea. It remains controversial how emphysema correlates with the degree of impairment in CAL, and further work needs to be done to clarify this relationship. This requires a reexamination of current CT methods 110 and the relationship between DLcoSB, structural changes in the lung, and HRCT evidence of emphysema. Refinements in DLcoSB testing methods, such as the measurement of DLcoSB-3EQ are linked to rapidly responding CO analyzers and computer-driven software, which will potentially improve the accuracy and reproducibility of the test, particularly in the presence of airway obstruction and nonuniform distribution of ventilation. Such refinements, which offer the possibility that tests of diffusion could become more useful markers of disease, include measuring DLcoSB when the pulmonary capillary recruitment is near maximal (head-down position, exercise), enhancing the sensitivity of the test to alterations in the lung periphery, standardizing previous volume history, developing more precise corrections for Hb and COHb, and developing an index of diffusion nonuniformity.

Lymphedema. Clinical signs, diagnosis, and treatment

Medical management of lymphedema is warranted in all dogs with suspected congenital lymphedema, before surgical intervention. Although pharmaceutical agents, such as the benzo-pyrones, have not been investigated for clinical use in dogs, such studies appear to be justified. None of the surgical techniques discussed will cure lymphedema. The only technique reported with any frequency in the dog has been excision of affected tissues, and although some successes have been reported with this procedure, others have found it to be of no benefit or severe complications have occurred. Excisional techniques require meticulous attention to prevent infection intraoperatively and postoperatively. Staging the procedure may decrease problems associated with devascularization of remaining tissues. Evaluation of other techniques may be warranted in dogs; however, no technique has proven to be consistently beneficial in human beings with lymphedema.

Quantitative assessment of lung damage due to bleomycin using computed tomography

Visual assessment and density measurements of the lung using computed tomography (CT) were made in 18 patients undergoing treatment with bleomycin for malignant teratoma of the testis. The results of both visual assessment and density measurements were compared with changes in gas transfer per unit lung volume (KCO). Visual assessment of severity of damage to the lungs caused by bleomycin is unrelated to changes in KCO but is characteristic of bleomycin damage and allows a confident diagnosis to be made. Quantitative density measurement by CT, however, is inversely related to changes in KCO and may therefore be used to monitor the physiological effect on the patient. Examination of the lung by CT in these patients can not only characterise and define the extent of lung damage due to bleomycin but can be used to give a quantitative measurement on which to monitor treatment.

Model analysis of intra-acinar gas exchange

A previously described multibranch-point model, incorporating branching asymmetry within an acinus, has been extended to include gas exchange at the alveolar surface. Using a transport equation for simultaneous convection and diffusion within the gas phase and independent perfusion of all nodes, we obtained steady-state solutions for the temporal and spatial distributions of O2 and CO2 tensions within an acinus during a respiratory cycle. Results for conditions corresponding to both rest and moderate exercise indicated a significant inhomogeneity of gas concentrations within a single acinus. The coefficient of variation of PACO2 at end-inspiration during exercise reached 11.3%. Despite this non-uniformity the computation of a negligible PAO2 - PAO2 difference indicated no impairment in gas exchange. The simulations are consistent with the hypothesis that in the normal lung the whole acinus acts functionally as a gas exchanging unit and ventilation-perfusion inequality has an interacinar basis.

Alteration of pulmonary function in intravenous drug abusers. Prevalence, severity, and characterization of gas exchange abnormalities

We examined the influence of chronic intravenous drug abuse on respiratory function in 512 consecutive drug addicts by obtaining respiratory histories, pulmonary function tests and chest roentgenograms. Two hundred and fourteen (42 per cent) had carbon monoxide-diffusing capacities (DLCO) of less than 75 per cent predicted (mean 65.7 per cent), and in 38 per cent reduced DLCO was the sole pulmonary function test abnormality. Obstructive lung disease attributed to asthma or chronic bronchitis was observed in 6 per cent and a restrictive defect due to interstitial lung disease was observed in 7 per cent. Exercise limitation due to dyspnea among those patients with altered pulmonary function was uncommon except in those with obstructive or restrictive lung disease. Roentgenographic evidence of pulmonary hypertension was not observed in any of the patients. Gas exchange measured at rest and during exercise in 11 patients with a low DLCO and in three patients with restrictive lung disease and a low DLCO revealed an increased alveolar-arterial oxygen difference but normal minute ventilation, dead space-to-tidal volume ratio and absence of abnormal right-to-left shunts. We conclude that alterations in pulmonary function in drug addicts due to foreign particle emboli are very common but that significant respiratory symptoms are unusual and that abnormalities in gas exchange during exercise are mild.

Effect of Intralipid-induced lipaemia on the arterial oxygen tension in preterm infants

10% Intralipid was infused (1 g/kg body wt.) intravenously for 15 min with Razel pumps to each of eight selected newborn preterm infants whose general condition and pulmonary status were stable for at least 24 h before study. Six of the eight infants showed greater than 10 mmHg reduction in oxygen tension of umbilical arterial blood. These reductions were correlated with elevated triglyceride concentrations. The findings suggest that Intralipid-induced lipaemia has the potential to lower the oxygen tension of the blood and hence patients with pre-existing pulmonary insufficiency may be at risk from hypoxaemia.

Pulmonary dysfunction after lymphangiography

Pulmonary function tests were done on 15 patients before and after bipedal lymphangiography. Lymphangiography was associated with an approximate 10 per cent reduction in lung volume. This phenomenon persisted for 48 to 72 hours. The probable mechanism for this reduction is closure of terminal airways or alveolar ducts or both and is reversible by beta-adrenergic drugs. The reduction does not correlate with the severity of pre-existing pulmonary disease. The degree of pulmonary impairment can be assessed roughly by measurement of the vital capacity. An operation can be performed safely 3 to 5 days after lymphangiography.

Relationship between Intralipid-induced hyperlipemia and pulmonary function

One unit (500 ml) of 10% Intralipid (an intravenous soy bean oil-egg yolk lecithin preparation) was infused into 20 normal subjects over 4 hr. Serum triglyceride concentration and plasma optic density (at 700 nm) increased to maximal levels of 339 +/- 102 mg/100 ml and 1.14 +/- 0.41, respectively, at the completion of the infusion, and returned to basal levels in most subjects within 4 hr. Pulmonary membrane diffusion was decreased in six subjects at rest and with exercise at 25 and 50% maximum oxygen uptake. Only one subject showed a minor change in PO2 and none showed clinical signs of ischemia. The changes in pulmonary diffusion reverted to basal levels when serum lipids were cleared. Heparin (60 IU/kg) prevented the marked increase in serum lipids and, as a consequence, the changes in pulmonary function. Changes in pulmonary function from Intralipid-induced lipemia are similar to those known to result from diet-induced lipemia. The findings suggest that in the presence of normal vasculature and pulmonary function, Intralipid-induced lipemia should cause no clinical consequences. However, patients with preexisting pulmonary or vascular disease may be at greater risk after Intralipid-induced lipemia.

Hospital topics. Pulmonary function after lymphography

The effects of lymphography on ventilatory function and gas transfer factor were studied in nine patients. Serial measurements made up to one month showed no change in the forced expiratory volume in one second or vital capacity. A small but reversible fall in transfer factor was found. The greatest reduction was at 24 or 48 hours. It was concluded that patients with normal lungs are unlikely to encounter difficulties but that patients with severe lung disease require careful assessment before lymphography.

Pulmonary oil embolization following Pantopaque ventriculography in a patient with a ventriculovenous shunt. Case report

✓ A case of pulmonary oil embolization subsequent to Pantopaque ventriculography is reported in a patient with a ventriculovenous shunt. The possibility of this complication and its sequelae are discussed.