PubMed Health⌕ Search

Biomedical subjects

L H Cronau

Publications and source records attributed to L H Cronau.

9 recordsLinked to original sources
PubMed1979

Indicator dilution measurement of 5-hydroxytryptamine clearance by human lung.

A double indicator dilution method to measure 5-hydroxytryptamine (5-HT) clearance by lungs of anesthetized patients is described. Immediately after a bolus injection of [3H]dextran and [14C]5-HT into the right atrial port of a Swan-Ganz catheter, blood from the radial artery is fractionated and the tritium and carbon-14 of each fraction is measured. The difference between the normalized curves of dextran and 5-HT vs. time reflect the extent to which 5-HT is extracted by the lung. This method gave a mean value of 61 +/- 3% (n = 10) for extraction of 5-HT, compared to 59 +/- 4% measured simultaneously by means of the pulmonary artery-left atrial gradient of 5-HT. Variations among three successive determinations in each patient made postoperatively were not statistically significant. This technique is applicable whenever Swan-Ganz and radial or brachial artery catheters are placed for routine clinical management and, therefore, may have wide application for measurement of pulmonary amine (or kinin) extraction in conscious human subjects or experimental animals. Because pulmonay clearance may be compromised by endothelial damage, 5-HT extraction measured in this manner could reflect early damage to human pulmonary endothelium--perhaps before clinical evidence of damage, such as interstitial edema and respiratory distress, is evident.

Carbon Radioisotopes↗
PubMed1977

Pulmonary artery flow-guided catheters in the perioperative period. Indications and complications.

The risk factor of pulmonary artery catheterization was assessed in 392 critically ill patients. Major indications for catheterization in the operating room were marginal cardiovascular reserve, anticipated large fluid and blood loss, and hypotensive anesthesia. Immediate complications included cardiac arrhythmia, carotid artery puncture, and pneumotherax. Long-term complications included positive bacterial cultures, pulmonary infarction and neuropathy. None of the complications were directly responsible for the deaths in this series. Pulmonary artery monitoring in critically ill persons is a relatively safe procedure.

Adult↗
PubMed1977

Fate of prostaglandins E(1) and A(1) in the human pulmonary circulation.

It is recognized that the lung extracts norepinephrine and 5-hydroxytryptamine from the pulmonary circulation and that this process is affected by cardiopulmonary bypass. Since alterations in the lung's processing of vasoactive substances may be a mechanism of pulmonary injury sustained during operation, we investigated the lung's ability to extract or metabolize prostaglandin A1 (ga1) and prostaglandin E1 (PGE 1). Sixteen patients undergoing cardiac surgery were studied. In five patients, just before going on bypass, a 10 ml of blood was withdrawn at a constant rate, simultaneously from the pulmonary artery and left atrium. In 11 patients, 3H-PGE1 was injected just prior to bypass and, in five of these, again after coming off bypass. Extraction was calculated from tritium activity in the samples. Metabolites were quantitated by thin-layer chromatography after being identified by marker compounds run simultaneously in each chromatogram. The pulmonary extraction of PGA1 was 11.3 +/- 2.3% and there were no detectable metabolites in left atrial blood. Before bypass the extraction of PGE1 was 42.3 +/- 14.3% and after bypass 24.8 +/- 10.0% (P less than 0.005; Student's paired t test). PGE1 was extensively metabolized with 79.7 +/- 7.1% of total radioactivity appearing in the left atrium as metabolites before bypass and 89.1 +/- 2.0% appearing after bypass. This study indicates that PGA(1) is not metabolized by the lung and is only slightly extracted. On the other hand, PGE(1) is extensively extracted and metabolized. While the rate of metabolism is not significantly affected by cardiopulmonary bypass, the extractiom before bypass was significantly greater than after bypass.

Adult↗
PubMed1976

Markedly improved pulmonary function after open heart surgery in infancy utilizing surface cooling, profound hypothermia, and circulatory arrest.

The use of surface-induced profound hypothermia with limited cardiopulmonary bypass and circulatory arrest markedly diminished the need for mechanical ventilation for patients undergoing cardiac surgery. Eleven of twenty-two patients were extubated in the operating room and five more patients within 70 minutes postoperatively. Five patients required mechanical ventilation. Four of the five were extubated within 24 hours (mean, 19.05 hours); only one patient required mechanical ventilation greater than 24 hours. This experience would indicate that as the age of surgery is decreased, in conjunction with improved technics of cardiac surgery and anesthesia, the need for mechanical ventilation should be diminished.

Anesthesia, Inhalation↗
PubMed1976

5-Hydroxytryptamine extraction by the lung.

Both 5-hydroxytryptamine and norepinephrine are removed from blood during a single passage through the pulmonary vasculature of the dog; 5-hydroxytryptamine is removed to a greater degree than is norepinephrine. The magnitude of extraction of both 5-hydroxytryptamine and norepinephrine is similar to that previously determined in man. In the intact dog, imipramine inhibits the uptake of 5-hydroxytryptamine by the lung in a dose-dependent manner.

Animals↗
PubMedDate not supplied

Chemotherapy resistant sarcoma treated with whole body hyperthermia (WBH) combined with 1-3-bis(2-chloroethyl)-1-nitrosourea (BCNU).

Seventeen patients with chemotherapy-resistant metastatic sarcoma were treated with whole body hyperthermia (WBH) combined simultaneously with 1-3-Bis(2-chloroethyl)-1-nitrosourea (BCNU). All of the patients had chemotherapy resistant metastases to major organ sites. Patients were heated to 41.8-42.0 degrees C for 2 h using an insulated blanket heating technique. Two patients (12%) experienced partial responses (PR). In addition, four objective tumour responses (OR) lasting more than 4 months were documented. One patient with previously rapidly growing chondrosarcoma pulmonary metastases experienced stable disease (SD) for 38 months from the onset of treatment. Median survival of seven patients with responding tumours (PR, OR and SD) compared with 10 patients with progressive disease was 15 versus 2 months, respectively. Cumulative thrombocytopenia was a therapy-limiting toxicity of the combined treatment, and occurred in six of seven patients. Acute toxicities attributable to WBH alone included transient thrombocytopenia in all patients, non-cardiogenic pulmonary oedema in two patients, and mild hypotension in five patients. Acute granulocytosis was observed in all patients. No treatment related deaths occurred. These data suggest that WBH combined with chemotherapy is associated with disease response in patients with chemotherapy-resistant, widely disseminated sarcoma metastases.

Adolescent↗