Search for evidence of lung chemoreflexes in man: study of respiratory and circulatory effects of phenyldiguanide and lobeline

1. Respiratory and circulatory effects of phenyldiguanide (PDG), sodium cyanide and lobeline have been studied in eighteen patients.

2. PDG, when injected into the main pulmonary artery, produced stimulation of breathing together with bradycardia and hypotension. A mean injection-response time of 5·2 s was close to the pulmonary artery-ear lobe circulation time in the same patients.

3. Sodium cyanide produced respiratory and circulatory effects similar to PDG and with the same injection-response time. It was concluded that both drugs act on the carotid body.

4. Lobeline sulphate produced apnoea with or without cough in twelve of the fifteen patients studied, with a mean injection-response time of 2·1 s; this was shorter than the pulmonary artery-ear lobe circulation time. This response preceded the well-known hyperpnoea.

5. The short injection-response time of lobeline is consistent with the hypothesis that lobeline stimulates pulmonary receptors before it acts on the carotid bodies, and that there are receptors in the human lung that are depolarized by chemical agents.

6. The cough response was replaced by apnoea when the dose of lobeline was decreased.

7. Whereas PDG did not produce any abnormal sensation in the body, lobeline caused a sensation of fumes or smoke in the lower throat or burning over the manubrium sterni. Neither drug produced a sensation of breathlessness.

Congenital lobar emphysema

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Percutaneous right and left heart catheterization in children. Experience with 1,000 patients

One thousand patients, ranging in age from 4 months to 26 years, underwent percutaneous catheterization of the femoral artery and femoral vein. Cardiac catheterization was combined with selective angiocardiography in all patients.

The catheter entered the right ventricle in 972 of 990 patients (98%) and the left ventricle in 832 of 856 (97%), including 82 of 89 patients (92%) with aortic stenosis.

There were no deaths, perforations of the heart, or loss of tissue. The peripheral pulse was decreased in 6% (49 of 856) and absent in 2% (17 of 856). Other complications included two uneventful perforations of the aortic arch, two lacerations of the femoral artery, three lacerations of the femoral vein, a false aneurysm of the femoral artery, and a cerebrovascular accident.

Our findings indicate that, in children more than 2 years old and weighing more than 10 kg, the percutaneous method is safe, informative, and associated with less arterial circulatory complications than the approach from the surgically exposed artery.