Erythrocyte 2,3-diphosphoglycerate depletion associated with hypophosphatemia detected by routine arterial blood gas analysis.

OBJECTIVE: To describe a clinical case where an extremely low erythrocyte 2,3-diphosphoglycerate concentration (2,3-DPG) was discovered by routine blood gas analysis supplemented by computer calculation of derived quantities. The finding of a low 2,3-DPG revealed a severe hypophosphatemia. DESIGN: Open uncontrolled study of a patient case. SETTING: Intensive care observation during 41 days. PATIENT: A 44 year old woman with an abdominal abscess. INTERVENTIONS: Surgical drainage, antibiotics and parenteral nutrition. MEASUREMENTS AND RESULTS: daily routine blood gas analyses with computer calculation of the hemoglobin oxygen affinity and estimation of the 2,3-DPG. An abrupt decline of 2,3-DPG was observed late in the course coincident with a pronounced hypophosphatemia. The fall in 2,3-DPG was verified by enzymatic analysis. CONCLUSION: 2,3-DPG may be estimated by computer calculation of routine blood gas data. A low 2,3-DPG which may be associated with hypophosphatemia causes an unfavorable increase in hemoglobin oxygen affinity which reduces the oxygen release to the tissues.

[Occurrence of hypophosphatemia in a Danish hospital population]. / Forekomst af hypofosfataemi i en dansk hospitalspopulation.

Hypophosphataemia is a potentially dangerous condition which may be present but unrecognized in prolonged periods. The incidence of hypophosphataemia among patients in a Danish hospital population was determined retrospectively by registering the number of blood samples with low serum phosphate values (less than or equal to 0.6 mmol l/l) in a Danish university hospital during a period without and in a period with an open casualty department. Case reports from patients with low serum phosphate values were reviewed with the object of revealing the causes of the hypophosphataemia and possible symptoms which might be related to the hypophosphataemic condition. A total of 192 patients were found with serum phosphate values less than or equal to 0.6 mmol/l but only 15 patients with severe hypophosphataemia (serum phosphate less than or equal to 0.3 mmol/l). No relationship between the serum phosphate concentration and the symptoms could be demonstrated. The commonest causes of hypophosphataemia were gastrointestinal loss and parenteral infusion of fluids. Quoting of low serum phosphate measurement is not recommended unless this analysis has been specially requested as the majority of cases even of severe hypophosphataemia are self-limiting and do not produce symptoms.

Hemodynamic effects of high frequency ventilation superimposed on intermittent positive pressure ventilation in dogs.

The hemodynamic effects of high frequency ventilation (HFV) superimposed on intermittent positive pressure ventilation (IPPV) in seven dogs before and after thrombin infusion were investigated. HFV was superimposed on a Servo 900 B ventilator by a Siemens Elema HFV prototype unit. Mean arterial blood pressure, heart rate, central venous pressure, pulmonary artery pressure, cardiac output, right and left ventricular pressures, pleural pressure, arterial blood gases, and right and left ventricular ejection fractions were recorded. Measurements were done during IPPV alone and during HFV superimposed on IPPV. The HFV frequencies were 5, 15, and 20 Hz at a constant minute volume of 5 1. When HFV was started, the IPPV minute volume was reduced to one third of the initial volume. No significant changes in the measured parameters were observed during the different ventilatory modes either before or after thrombin infusion which doubled the pulmonary vascular resistance. It is concluded that high frequency ventilation superimposed on IPPV might be a ventilatory mode that offers cardiovascular stability and reduces the risk of barotrauma.

Prevention of peroperative hypothermia in abdominal surgery.

It is important to reduce or prevent heat loss during anaesthesia, especially in patients with restricted cardiopulmonary reserves. To test a specially developed esophageal thermal tube (GK-esophageal thermal tube) for this purpose, 33 patients were randomly divided into two groups: Group A were given heat transferred to the central core during operation, using the GK-tube with circulating 41.7 degrees C warm water. Group B received no active warming. All patients were scheduled for major abdominal operation. In both groups there was a temperature fall in the induction phase. In Group B the temperature continued to fall slowly during operation, resulting in a median end-temperature of 34.9 degrees C. In Group A the temperature rose slowly after induction of heat via the tube, resulting in a median end-temperature of 36.8 degrees C in this actively warmed group. The temperature difference is significant (P less than 0.001). The median operating time was 3h 30 min in both groups. After 2 h of anaesthesia the median temperature in Group A was 36.1 degrees C and in Group B 35.0 degrees C. This difference is also significant (P less than 0.001). The described method was easy to use and without complications. We recommend this method to prevent peroperative hypothermia in all patients suspected to have limited cardiopulmonary reserves. The possible hazards and how to avoid these are described.

An oesophageal thermal tube for rewarming in hypothermia.

Five dogs were cooled externally with ice-bags to rectal temperatures of 21.8-24.8 degrees C. Rewarming was performed with a specially constructed double-lumen oesophageal tube with circulating water at 42 degrees C. With this device, rewarming of the dogs to 30 degrees C took place in 60-102 min (mean 82 min). Up to a temperature of 31 degrees C (the "cardiac safety temperature"), the rise in blood temperature was 4.5 degrees C/h +/- 0.79 (s.d.). Calculation of a "rewarming efficiency index" showed an inverse relationship between surface area and temperature rise per hour. The efficiency of this rewarming method is comparable to that of peritoneal dialysis. No after-drop in temperature was observed and there were no other complications during these experiments. Rewarming with an oesophageal thermal tube is very simple and safe to use.