Erik Jacobsen

Fournier's gangrene: 5 patients treated with hyperbaric oxygen.

The classic syndrome of Fourniers gangrene was observed in 5 men with involvement of the external genitals and lower abdominal wall. Mixed flora of anaerobic and aerobic microorganisms were grown, and extensive necrosis of the skin and subcutaneous gas were present in all patients. Soon after hospitalization all 5 patients were treated by excision of all necrotic and undermined tissue, intravenous broad-spectrum antibiotics and hyperbaric oxygen administered at 3 atmospheres of pressure. One patient died of septic shock without any response to the therapy. The infection subsided shortly after the hyperbaric oxygen was instituted in the remaining 4 patients, who were cured. It is proposed that the treatment of Fourniers gangrene should be limited to centers capable of administering hyperbaric oxygen therapy. Our series does not prove that hyperbaric oxygenation is necessary for successful treatment but evidence suggests a beneficial effect of such therapy for nonclostridial gas gangrene.

Bi-level positive airway pressure treatment of obstructive sleep apnoea syndrome

We evaluated the effect of non-invasive nocturnal ventilation with the bi-level positive airway pressure (BiPAP) ventilator in 12 overweight patients with verified obstructive sleep apnoea syndrome (OSAS) and nocturnal hypercapnia. All patients exhibited subsequently less overnight CO2 accumulation (p < 0.0001), the desaturation event frequency was reduced (p < 0.002), daytime O2 tension rose (p < 0.001), daytime CO2 tension was reduced (p < 0.01), and apnoeas were eliminated. All symptoms characterising the syndrome, when present at the beginning of the therapy, were eliminated during the treatment. Patient compliance was high. This study showed that OSAS patients with hypercapnia can be effectively treated by BiPAP ventilation during sleep.

Oxygen uptake and carbon dioxide elimination after acetazolamide in the critically ill.

Acetazolamide, which reversibly inhibits carbonic anhydrase, is a useful diuretic in alkalotic and over-hydrated patients. In two earlier investigations we have consistently found increases in the arterial and venous oxygen saturation and tension when patients were treated with acetazolamide 15 mg·kg-1. A plausible explanation of this phenomenon is that acetazolamide diminishes oxygen consumption. In the present study we measured oxygen uptake in 10 critically ill patients. We found a minor and statistically insignificant decrease in oxygen consumption. Nevertheless SvO2 increased from 0.77 to 0.83 and PvO2 from 5.9 kPa to 6.8 kPa. It is still not possible from this investigation to determine the origin of the improvement in blood oxygenation. The inhibition of carbonic anhydrase caused a CO2 retention of 5.8% of the total CO2 production. An increase in body stores of CO2 of this magnitude is without clinical significance.

Influence of Hypoxia and Hyperoxia on Subcutaneous Adipose Tissue Blood Flow in Man

Subcutaneous adipose tissue blood flow (ATBF) was measured by the 133Xe washout method in normal men breathing oxygen at partial pressures from 0.1 to 2 atmospheres. Breathing oxygen at partial pressures of 0.1 and 1 atm. increased and reduced ATBF by 56% and 26%, respectively as compared to air breathing. These effects were highly significant. Breathing of oxygen at 2 atm. partial pressure had no consistent effect on ATBF, although considerable changes--positive or negative--could been seen in some experiments. Oxygen-breathing at 1 atm. partial pressure is associated with a slight hyperventilation and fall in PACO2. This was shown to be without importance for the effect of oxygen on adipose tissue blood flow.

Ventilation in ARDS and asthma: the optimal blood gas values.

Artificial ventilation of patients with acute respiratory diseases, i.e. ARDS and severe asthma, may involve the risk of pulmonary oxygen toxicity as well as volutrauma. The relationship between ventilator treatment and volutrauma suggests that only in patients with normal lungs the aim of ventilator treatment should be an arterial carbon dioxide tension and pH within the normal ranges. In patients suffering from a lung disease the clinical target must be based not only upon the arterial blood gases but also upon airway pressure and respiratory tidal volume. Thus during artificial ventilation of a patient with an acute pulmonary disease the following arterial pH and pCO2 optima are proposed: pH 7.35, with a range from 7.1 to 7.4; pCO2 is related to pH but an acceptable range is 5-12 kPa. The lowest acceptable fraction of inspired oxygen and thereby the safe lower level of arterial pO2 for an individual patient depends on many factors. The lower limit may be about 3 kPa, but the arterial pO2 should not be evaluated as an isolated parameter. It is related to the general oxygen transport capability of arterial blood, extractable oxygen, cardiac output and the microcirculation.

Continuous Measurement of Po2, Pco2 and pH During Total Body Perfusion in Dogs

Continuous measurement of blood Po2, Pco2, and pH can be made either with intravascular electrodes or with electrodes placed in a flow cuvette. The two methods are reviewed. In this study a system based on the Radiometer flow cuvette was used. The continuous recording was checked at intervals against results obtained by conventional electrode analyses of individual blood samples. The continuous recording and individual checks were virtually identical. Checks on electrode calibration were made after 4–5 hours use, and no significant electrode drift was noted. During perfusion with Rygg-Kyvsgaard bubble-oxygenator, variations in Po2, Pco2 and pH were measured continuously in dogs to register any changes, which might occur in the transition to and from perfusion, and which would be too rapid for measurement by the single sample technique. Apart from catheterization of the venae cavae through the right atrium the heart was undisturbed. In the first minutes of perfusion marked falls in all three parameters wer...

Computing the Oxygen Status of the Blood from Heated Skin pO2

The non-invasive measurements of pO2 (transcutaneous oxygen) has been shown to be different from arterial pO2 due to dependence upon various factors in the skin.1 Recently a mathematical mode2 has been confirmed in adult ICU patients.3 By means of this model, describing the relation between arterial- and skin pO2, other oxygen parameters of the blood can be calculated from skin pO2 (pO2 (S)) measurements and thereby the oxygen status of the blood may be evaluated by three parameters, i.e. the partial pressure of oxygen (pO2), saturation of hemoglobin with oxygen (sO2) and the concentration of total oxygen (ctO2) all obtained non-invasively.