PubMed Health⌕ Search

Biomedical subjects

P Vanderhoeft

Publications and source records attributed to P Vanderhoeft.

At least 19 recordsLinked to original sources
PubMed1990

Effort rupture of the diaphragm.

Effort rupture of the diaphragm is rare and accounts for only 1% of all diaphragmatic injuries. A 23 year old patient with bilateral rupture that followed sudden movement is described.

Adult↗
PubMed1990

Effects of embolus size on hemodynamics and gas exchange in canine embolic pulmonary hypertension.

We examined the effects of different-sized glass-bead embolization on pulmonary hemodynamics and gas exchange in 12 intact anesthetized dogs. Pulmonary hemodynamics were evaluated by multipoint pulmonary arterial pressure (Ppa)/cardiac output (Q) plots before and 60 min after sufficient amounts of 100-microns (n = 6 dogs) or 1,000-microns (n = 6 dogs) glass beads to triple baseline Ppa were given and again 20 min after 5 mg/kg hydralazine in all the animals. Gas exchange was assessed using the multiple inert gas elimination technique in each of these experimental conditions. Embolization increased both the extrapolated pressure intercepts (by 6 mmHg) and the slopes (by 5 mmHg.l-1.min.m2) of the linear Ppa/Q plots, together with an 80% angiographic pulmonary vascular obstruction. These changes were not significantly different in the two subgroups of dogs. However, arterial PO2 was most decreased after the 100-microns beads, and arterial PCO2 was most increased after the 1,000-microns beads. Both bead sizes deteriorated the distribution of ventilation (VA)/perfusion (Q) ratios, with development of lung units with higher as well as with lower than normal VA/Q. Only 100-microns beads generated a shunt. Only 1,000-microns beads generated a high VA/Q mode and increased inert gas dead space. Hydralazine increased the shunt and decreased the slope of the Ppa/Q plots after 100-microns beads and had no effect after 1,000-microns beads. We conclude that in embolic pulmonary hypertension, Ppa/Q characteristics are unaffected by embolus size up to 1,000 microns.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Penetration of aminoglycosides in uninfected pleural exudates and in pleural empyemas.

The concentrations of gentamicin, netilmicin, and amikacin were determined after one single intravenous injection in uninfected pleural fluid after thoracotomy and in purulent pleural empyemas. The mean peak concentrations in the pleural fluid after the injection of gentamicin (1.5 mg/kg), netilmicin (2.0 mg/kg), and amikacin (7.5 mg/kg) were 2.9 +/- 0.3 mg/L, 3.7 +/- 0.8 mg/L, and 11.0 +/- 3.1 mg/L, respectively. The pleural penetration of the drugs was very high (from 80.0 to 99.1 percent). By contrast, gentamicin and netilmicin were not detectable in empyema pus; in this exudate the mean peak level of amikacin was 5.7 +/- 2.2 mg/L, with the penetration of this drug being 31.0 percent. The concentrations of parenterally administered aminoglycosides are substantially lower in empyema pus than in sterile pleural fluid. The possibility of poor pleural penetration of some aminoglycosides, as well as the presence of local conditions in pleural empyema unfavorable to the bioactivity of these drugs, must be kept in mind when treating pleural infections.

Amikacin↗
PubMed1985

Hypophosphatemia after cardiothoracic surgery.

The incidence of hypophosphatemia during the first 48 h following cardiothoracic surgery was prospectively studied in 74 patients. Hypophosphatemia, defined by a serum phosphate below 2.50 mg/dl, was observed in 19 of 34 (56%) patients after thoracic surgery and in 20 of 40 (50%) patients after cardiac surgery. As a whole, hypophosphatemia occurred earlier after thoracic than after cardiac surgery. After thoracic surgery, hypophosphatemia was milder for patients in whom bleeding was more severe. The anticoagulant solution CPD used in stored blood was identified as an important source of phosphate. These results indicate hypophosphatemia is a common finding after cardiothoracic surgery. Since severe hypophosphatemia can be related to phosphate depletion, phosphate supplements could be warranted especially during thoracic surgery when blood transfusions are less than 1000 ml.

Adult↗
PubMed1979

Ventilation in dogs on cardiopulmonary bypass with and without lungs.

In 13 anesthetized or awake dogs, on cardiopulmonary bypass, we varied PaO2 and PaCO2 while continuously monitoring ventilatory responses and mechanics, to assess the dog's ability to maintain eupneic ventilation for any chemical drive. In a second group of 13 dogs on cardiopulmonary bypass we repeated the tests after removal of both lungs, to assess the importance of pulmonary feedback and mechanics. The VE/PO2 plot formed two hyperbolas, asymptotic to 39 Torr PO2 with lungs, and to 27 without; both intercepted zero ventilation near 200 Torr. Hyperoxic apnea occurred at, or below, PCO2 30 +/- 7 Torr under barbiturate and 20 +/- 4 Torr under morphine. Steady-state low PCO2 (10 Torr) turned off hypoxic drives as low as 20 Torr PO2. Empty-chest dogs had a low respiratory frequency (18 vs. 40), and near zero dynamic elastance; ventilatory work per minute and airway resistance were the same with and without lungs. Chest wall ventilatory responses are grossly independent of the presence of absence of lungs.

Airway Resistance↗
PubMed1976

Extracorporeal oxygenation with various experimental venoarterial bypasses during prolonged apnea.

This work compares various conventional venoarterial closed-chest circuits where satisfactory oxygenation of myocardium and brain in total apnea with extracorporeal circulation is concerned. Eleven dogs were studied during 3 hours of curare-induced apnea. We used single and double vena caval drainages connected to an oxygenator. A single-vein drainage yielded approximately 50 per cent and a double-vein drainage 75 per cent bypass. Two separate roller pumps fed arterialized blood variously into carotid and femoral arteries. In single-vein drainage, the oxygen partial pressure in the coronary artery was consistently poor and carotid oxygen partial pressure was poor for 100 per cent femoral infusion while more and more arterialized blood reached the carotid arteries in the other single-vein drainage circuits. In double-vein drainage, the coronary oxygen partial pressure for 100 per cent femoral infusion remained poor while, for the other circuit types, the coronary arteries received arterialized blood except where 100 per cent carotid infusion was concerned. The carotid oxygen partial pressure was sound for all groups in the double-vein drainage except for some obtained in 100 per cent femoral infusion. Consequently, where the bypass was large and the carotid and femoral arteries received a share of arterialized blood, both heart and brain received sound oxygenation.

Animals↗
PubMed1975

[Cardio-respiratory assistance with the extracorporeal membrane oxygenator for massive pulmonary embolism].

A 39 year old pneumectomized patient presents a massive pulmonary embolism, dies within 3 hours and is supported inefficiently by cardiac massage with recurrent mydriasis during 2 hours. At that time, under extracorporeal cardiopulmonary bypass with a membrane oxygenator, the cardiac activity recovers immediatly due to right decompression and coronary perfusion. The patient is conscious within 5 hours. The cardiopulmonary bypass with a membrane oxygenator appears to be the best therapy when the cardiac massage fails to restitute a normal myocardial function. No embolectomy was performed. The patient died when the bypass was stopped after 48 hours. We conclude that the prolonged peripheral extracorporeal bypass followed by embolectomy is the best therapy of pulmonary embolism.

Adult↗
PubMed1975

[Use of lande-edwards membrane oxygenators as artificial lungs].

Lande-Edwards membrane oxygenators were tested as artificial lungs in 6 dogs: the right heart directly perfused the oxygenators during an apneusis of one hour. During such a pulmonary by-pass right ventricular pressure doubles compared to initial value, with a moderate decrease in cardiac output; mean PO-2 rises from 40 to 67 mm Hg and PCO-2 decreases from 54 to 49 mm Hg through the oxygenator.

Animals↗
PubMed1975

Landé-Edwards membrane oxygenator without pump as total lung prosthesis.

Fourteen anesthetized dogs remained in apnea for 1 to 4 hours on total extracorporeal breathing through a Landé-Edwards membrane oxygenator (LEMO). The LEMO was directly perfused by the right heart in total pulmonary bypass, without a pump or reservoir, as an external artificial lung. A 2 sq. M. LEMO proved adequate for a dog weighing 10 kiolgrams. Pulmonary arterial pressure increased 60 per cent of the base-line value at the start of bypass because of transitory LEMO resistance, three times the normal pulmonary resistance; the pressure then returned to the initial value. Systemic arterial pressure dropped to 61 per cent on bypass. The heart did not fail. Cardiac output, central venous pressure, and the electrocardiogram remained unchanged. PO2 at the LEMO outlet was more than 200 mm. Hg. Oxygen transfer was less than 20 ml. per minute per square meter because of hemodilution and hypothermia. Dogs survived if bypass was arrested after 1 hour; if not, they died after an average of 3 hours, 20 minutes on bypass.

Animals↗