Acute myocardial infarction resulting from the migration of a Greenfield filter.

A paraplegic patient who underwent the placement of Greenfield filters to prevent pulmonary emboli had one of the filters migrate proximally to the junction of the inferior vena cava and right atrium, then into the right atrium a few months later. This resulted in an acute myocardial infarction by apparently causing an intimal dissection of the posterior descending artery. Treatment, follow-up and causes of filter migration are discussed.

Inter-instrument comparison of blood gas analyzers and assessment of tonometry using fresh heparinized whole human blood.

Because of limitations associated with commercial blood gas quality controls and tonometry of stored blood, fresh heparinized blood was used to compare PO2 and PCO2 performance of ten blood gas analyzers. Function of nine gas mixer/tonometer systems was evaluated. These were used to create blood samples with target values for PO2 and PCO2. All ten analyzers had high precision; this magnified small differences between observed results and target values. Grand mean results from all ten analyzers were within 0.8 mm Hg of the target for PO2 of 40.0 and 100.0 and for PCO2 of 20.0 and 70.0 mm Hg. Eight automated blood gas analyzers gave clinically indistinguishable results for PO2 and PCO2 that were sufficiently accurate for clinical purposes. Also reported is the practicality of using tonometry of fresh heparinized blood in a per shift quality control program for PO2 and PCO2.

Comparison of canine cardiovascular response to inhaled and intraperitoneally infused CO.

We compared the hemodynamic and blood gas data from anesthetized dogs given 0.15% carbon monoxide (CO) to breathe (INH group) and from dogs injected with 100% CO intraperitoneally while breathing room air (ITP group). The animals were observed for a period of 150 min after reaching a level of 50% carboxyhemoglobin (HbCO). The time required to reach this level was similar for both groups, i.e., 102 +/- 54 and 90 +/- 21 min for the ITP and INH groups, respectively. The average HbCO% for the duration of the experiment was 58.3 +/- 2.4 and 62.9 +/- 1.5% for the ITP and INH groups, respectively. All the animals survived in each group. There was no significant difference in their hemodynamic response to CO, except for a higher mean systemic blood pressure in the INH group. This difference was also present during the base-line measurements, suggesting that it was not related to the effects of CO. Following the 150-min comparison period, we attempted to precipitate a terminal cardiovascular crisis by increasing the amount of CO given. The animals in the ITP group lived indefinitely as the result of a "plateau" effect in the level of HbCO%. The measured HbCO% level did not rise above 70% regardless of the amount of CO injected into the peritoneal space. Those in the inhalation group died with an average HbCO% of 80.0 +/- 3.5%. It is concluded that the toxic effect of CO is the result of impaired O2 delivery to the peripheral tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of low concentrations of chlorine on pulmonary function in humans.

Eight healthy unacclimated volunteers were exposed to chlorine gas in concentrations of 0.5 or 1 ppm, and several pulmonary function measurements were made. Comparisons were made by paired t test between the percent change from base-line values obtained at various times after chlorine exposure and the percent change from base line at analogous times after a sham exposure. With the sham vs. 0.5-ppm exposure, there were trivial changes observed. Total lung capacity (TLC) was lower before 0.5-ppm exposure than before sham exposure, and the percent decrease in carbon dioxide pulmonary diffusing capacity was smaller 24 h after 0.5-ppm exposure than 24 h after sham exposure. With the sham vs. 1-ppm exposure, there were many differences in percent change from base line that were significant at the P less than 0.05 level or better. These were in forced vital capacity (FVC), forced expiratory volume at 1 s (FEV1), peak expiratory flow rate (PEFR), forced expiratory flow rate at 50 and 25% vital capacity (FEF50 and FEF25, respectively), and airway resistance (Raw). There were, in addition, significant changes after only 4 h of exposure. These were in FEV1, PEFR, FEF50, FEF25, TLC, Raw, and the difference in nitrogen concentration. Most of the test results had returned to normal by the next day. We conclude that even though chlorine at low concentrations does not produce any serious subjective symptoms, it adversely affects pulmonary function transiently.

Comparison of fenoterol, isoproterenol, and isoetharine with phenylephrine aerosol in asthma.

The bronchodilator effect of fenoterol hydrobromide (0.5, 1.25, and 2.5 mg) was compared with either isoproterenol (2.8 mg) or isoetharine (5 mg) with phenylephrine (1.25 mg) in a double-blind placebo-controlled study. When delivered by an intermittent positive-pressure breathing device to 24 nonsmoking young adult asthmatic subjects, fenoterol produced significant improvement in forced expiratory volume at 1 second (FEV1), in maximum midexpiratory flow (FEF25-75%), and in forced expiratory flow at 25 per cent of vital capacity (FEF25%) for 6 to 8 hours, whereas isoproterenol and isoetharine with phenylephrine produced improvement for 1 and 2 hours, respectively. The lowest dosage of fenoterol was as effective as the highest but had fewer adverse effects.

Efficacy and duration of action of procaterol, a new bronchodilator.

Procaterol, a new beta-adrenergic agonist, was tested in two different doses in patients with reversible airway obstruction. Single oral doses of 0.05 or 0.1 mg produce an increase in measured expiratory flow rates, and the peak and duration of action are both dose related. Side effects reported during this one-day study were similar to those described with other compounds of this class; they were considered to be mild by the patients and the investigator. From these results, further investigation of this agent in bronchoconstrictive disease appears warranted.

Modification of the effect of fiberoptic bronchoscopy on pulmonary mechanics.

Thirty-three patients who were to undergo diagnostic fiberoptic bronchoscopy were studied. Pulmonary function tests were performed before the procedure, after topical lidocaine anesthesia, and immediately and four hours after bronchoscopy. Nine patients received aerosolized isoproterenol (Isuprel) before the topical anesthesia, and nine received aerosolized atropine. Pulmonary function tests were also performed after this intervention. In those patients receiving no premedication, all the indices of expiratory flow were reduced significantly immediately after bronchoscopy, and after the topical anesthesia, the FEV1 and FVC were significantly reduced. In the atropine groups, the FVC and FEV1 increased significantly after atropine, and increased still further following topical lidocaine anesthesia. By four hours after bronchoscopy, however, the midmaximal expiratory flow ws significantly reduced. In the isoproterenol group, only the FEV1 was significantly improved by the drug, and this improvement persisted even after the lidocaine. It decreased transiently immediately after bronchoscopy, but by four hours, was significantly above baseline again. The FVC diminished significantly immediately after bronchoscopy. It is concluded that fiberoptic bronchoscopy deleteriously affects pulmonary function and that inhaled isoproterenol or atropine largely protects against these deleterious effects.

Isoflow-volume curves in the diagnosis of upper airway obstruction.

We evaluated the ability of air and helium-O2 maximal expiratory flow-volume curves to distinguish upper airway obstruction from the diffuse, peripheral airway obstruction of chronic obstructive pulmonary disease. The increase in expiratory flows at peak, 75, 50, and 25 per cent of the vital capacity during helium-O2 breathing compared to air breathing was determined in 5 normal subjects and 3 patients with chronic obstructive pulmonary disease while breathing through fixed resistances, and in 6 patients with documented tracheal obstruction. In the normal subjects, the helium response at all 4 points remained normal and was unchanged from baseline until the simulated obstruction was severe (6-mm orifice), at which point all ofthe helium responses increased by 50 per cent. The patients with chronic obstructive pulmonary disease maintained their low baseline helium responses until the obstruction was severe (6-mm orifice), when only the expiratory flows at peak, 75, and 50 per cent of the vital capacity increased by at least 50 per cent. Five of the 6 patients with upper airway obstruction had helium responses very similar to those of the normal subjects with similar degrees of simulated obstruction, but the one patient with concomitant airway obstruction extending well below the carina had very small helium responses at each point. We conclude that upper airway obstruction can usually be identified by high helium responses and that upper airway obstruction, if severe, can be identified even in the presence of more peripheral airway obstruction by a normal helium response at high lung volumes.

The effects of fiberoptic bronchoscopy with and without atropine premedication on pulmonary function in humans.

Pulmonary function studies, including arterial blood gas analysis, were performed in 21 patients undergoing fiberoptic bronchoscopy. Eight received premedication with atropine and 13 did not. In the atropine-treated group there was no significant deterioration in pulmonary function immediately after bronchoscopy compared with baseline. Compared with the values obtained after topical lidocaine anesthesia, however, there was a decrease in peak expiratory flow rate (PEFR) (20 +/- 20%), forced expiratory volume in one second (FEV1.0) (11 +/- 12%), forced expiratory flow between 25 and 75% of vital capacity (FEF25-75) (22 +/- 16%), and forced expiratory flow at 75% of exhaled vital capacity (FEF75) (28 +/- 38%) and an increase in residual volume (RV) (16 +/- 19%). In the no-atropine group, postbronchoscopy values showed a decrease in PEFR (13 +/- 19%), forced vital capacity (FVC) (13 +/- )9%), FEV1.0 (14 +/- 16%), and oxygen partial pressure (Pa02) (11 +/- 9%) and an increase in RV (19 +/- 31%) and alveolar-arterial oxygen pressure gradient (deltaAaPO2) (91 +/- 129%) compared with baseline values. In this group also, topical lidocaine anesthesia resulted in a decrease in FVC compared with baseline. We conclude that the deleterious effect of bronchoscopy on pulmonary function is counterbalanced by the beneficial effect of atropine and that atropine is therefore a useful premedication for fiberoptic bronchoscopy.

Pulmonary vascular changes following air embolism in the dog.

The effect of an intravenous injection of air in a dose of 1 ml/kg body weight was determined in 15 healthy mongrel dogs. In 4 control dogs the mean pulmonary artery pressure rose to 2-3 times the resting values at 30 seconds, and carbon monoxide diffusing capacity and pulmonary capillary blood volume decreased by half. In the animals pretreated either with heparin or with methysergide (antiserotonin group) the results were the same as in the control animals. In the vagotomized dogs, the rise in pulmonary artery pressure was not significant, and the decrease in pulmonary capillary blood volume was of lesser magnitude and shorter duration than in the control and the antiserotonin dogs. It is concluded that the intravenous injection of air in supine dogs causes a transient obstruction of small pulmonary arteries. Evidence is presented to implicate a vagal mechanism in both main aspects of the response, namely the pulmonary artery pressure rise, and the partial obstruction of the pulmonary capillary bed. These studies offer additional explanation of the symptoms of respiratory distress observed in rapid decompression.

Primary carcinoma of the trachea: physiologic diagnosis and review of the literature.

A patient with primary carcinoma of the trachea is described. The diagnosis was established physiologically by employing maximal expiratory flow-volume loops obtained while the patient was breathing air and a mixture of helium and oxygen.

Long-term evaluation of a new aerosol bronchodilator, carbuterol, and comparison with isoproterenol.

A new aerosol bronchodilator, carbuterol, was compared with isoproterenol during a three-month double-blind trial in 15 matched pairs of patients with relatively stable and partially reversible obstructive airways disease. Pulmonary function tests were performed at baseline and at 30 and 120 minutes after bronchodilator administration on days 1, 15, 28, 56, and 84. Isoproterenol and carbuterol produced improvement in all parameters at 30 and 120 minutes. The per cent changes produced by isoproterenol were superior at 30 minutes, while carbuterol was as effective as isoproterenol at 120 minutes. Atrial and ventricular premature contractions and palpitations were more frequent in the isoproterenol group. Evaluation of the patients' symptomatic responses showed carbuterol to be superior to isoproterenol. We conclude that carbuterol is a useful bronchodilator when aerosolized.

Long-term physiologic consequences of the adult respiratory distress syndrome.

Six survivors of the adult respiratory distress syndrome were studied. Measurements were made of lung volumes, flow rates, single-breath diffusing capacity for carbon dioxide (Dsb), arterial blood gas levels at rest and during exercise, the ratio of physiologic dead space to tidal volume (VD/VT), alveolar-arterial oxygen pressure difference (P[A-a]O2) and percent shunt (using an assumed arteriovenous oxygen content difference). At the time of study, which varied from 3 to 16 months after recovery, we found minor and inconsistent abnormalities in the lung volumes (reduced vital capacity in one patient, elevated residual volume [RV] in two, and reduced RV in three) and in the flow rates (reduced instantaneous forced expiratory flow after 50 percent of the forced vital capacity had been exhaled in two patients). In those tests having to do with transfer of gas, there were more abnormalities, consisting of a decreased Dsb in three patients, an elevated P(A-a)O2 in four, a low resting arterial oxygen pressure (PaO2) in two, a decrease in exercise PaO2 in three, an elevated shunt fraction (Qsan/Qt) in three, and an elevated VD/VT in one patient. Clinically, at the time of study, the patients all had returned to their status before illness.

Tumor emboli presenting as pulmonary hypertension. A diagnostic dilemma.

A case of recurrent tumor emboli secondary to choriocarcinoma is described. The patient presented with obvious pulmonary hypertension and was diagnosed and treated as a case of multiple pulmonary embolism. Information which suggested the possibility of tumor emboli was indeed present but recognized only retrospectively.

Diagnosis of upper airway obstruction by pulmonary function testing.

We compared 11 patients with upper airway obstruction (obstruction at or proximal to the carina) to 22 patients with chronic obstructive pulmonary disease and to 15 normal subjects utilizing spirometry, lung volumes, airway resistance, maximal voluntary ventilation, single-breath diffusion capacity, and maximal inspiratory and expiratory flow-volume loops. Four values usually distinguished patients with upper airway obstruction: (1) forced inspiratory flow at 50 percent of the vital capacity (FIF50%) less than or equal to 100 L/min; (2) ratio of forced expiratory flow at 50 percent of the vital capacity of the FIR50% (FEF50%/FIF50%) larger than or equal to 1; (3) ratio of the forced expiratory volume in one second measured in milliliters to the peak expiratory flow rate in liters per minute (FEV1/PEFR) larger than or equal to 10 ml/L/min; and (4) ratio of the forced expired volume in one second to the forced expired volume in 0.5 second (FEV1/FEV0.5) larger than or equal to 1.5. The last ratio can be determined with a simple spirometer.