Discordance between measured and calculated total carbon dioxide.

Recent studies on the agreement and correlation between measured and calculated total CO2 (TCO2) have yielded conflicting results. Pre-analytical variation could have been partially responsible. While keeping such variables at an absolute minimum, we found excellent correlation (r = 0.98) in 88 samples, with only a small variation in agreement between measured and calculated TCO2 values (SD = 1.1 mmol/L), which could be a function of variation in apparent pK (pK'). A subsequent evaluation of 913 consecutive samples, routinely analyzed, yielded similar results. These results suggest that some of the discrepancies reported in the literature could be ascribable to differences in sample types and sample handling. Rigid control of pre-analytical procedures is therefore a prerequisite in studies on this topic. The two methods were found to agree over a wide range of values, such that either of them could be used to evaluate clinical acid-base status accurately.

Experience with the intensive care management of organophosphate insecticide poisoning.

During the 5-year period 1975-1979, 41 out of a total of 157 patients treated for 'organophosphate poisoning' (26%) were admitted to intensive care units. Treatment comprised atropine (0,02-0, mg/kg every 15-30 minutes or 0,02 - 0,08 mg/kg/h by continuous intravenous infusion), intermittent mandatory ventilation (IMV) with continuous positive airways pressure (CPAP) where indicated, and general supportive measures including adjustment of electrolyte, fluid and acid-base balance. Oxime-type cholinesterase reactivators were administered to 10 patients. Serum cholinesterase (S-ChE) and erythrocyte acetylcholinesterase (E-AChE) activities were monitored continuously. Despite intensive therapy, 5 patients (12%) died. IMV and CPAP proved to be a near-ideal method of mechanical ventilation. Atropine administered by continuous infusion was found to be superior to intermittent administration during the acute phase, while oral administration of atropine proved adequate thereafter. Oxime-type reactivators were not found to be of any significant value. Clinical recovery (the point at which atropine could safely be discontinued) generally correlated with a recovery of E-AChE activity to 30% or more of normal. Sudden deterioration due to possible 'endogenous re-intoxication' was observed in some patients days after the initial exposure to an organophosphate insecticide.

A krypton-81m generator for organ ventilation and perfusion investigations.

A sterile pyrogen-free generator for ultra-short half-life 81mKr has been developed. During initial loading, the binding efficiency of 81Rb is 90--99%. The count rate during perfusion is 3 x 10(5) counts per minute for a 1,9 GBq (50 mCi) 81Rb generator. The generator has been used for routine and special investigations of lung perfusion and ventilation and for myocardial perfusion during catheterization.

[Malignant hyperthermia in a black child. A case report]. / Maligne hipertermie in 'n Swart kind. 'n Gevalbespreking.

A case of malignant hyperthermia in a Black boy is presented. He developed this condition during repair of a cleft palate, with halothane as the triggering agent. The importance of the high incidence of malignant hyperthermia in patients with certain musculoskeletal abnormalities is stressed. Despite a cool and well air-conditioned theatre, the patient's temperature was 41 degree C when the condition was suspected. At that stage general muscle rigidity was present. The patient was successfully treated with procainamide, sodium bicarbonate and hydrocortisone; surface cooling (with ice packs) was instituted and the stomach was washed out with ice-cold Ringer's solution. Over a period of 14 days serum creatine phosphokinase values decreased from 630 IU (on the day of the incident) to 12 IU. A muscle biopsy showed variation in muscle fibre size. Electron microscopical studies showed myofibrillar disruption and folding of the basement membrane. A modified version of Denborough's technique was used for the in vitro exposure of muscle strips to halothane and suxamethonium. Isometric contraction was measured and recorded. A severe contraction followed the exposure of muscle strips to halothane, which confirmed the diagnosis.

[Aspects of the treatment of postoperative oliguria]. / Aspekte in die behandeling van na-operatiewe oligurie.

The importance and differential diagnosis of postoperative oliguria are discussed. A plea is made for the recognition of undesired postoperative antidiuretic hormone (ADH) secretion as a separate entity in the aetiology of postoperative oliguria. Five patients are described who suffered from postoperative oliguria and in whom the diagnosis of undesired ADH secretion was made. The successful treatment of this condition with diphenylhydantoin is emphasized.

A comparison between the Bain and Magill anaesthetic systems during spontaneous breathing.

The efficiency of the Bain system has been compared with that of the Magill system in ten conscious subjects breathing spontaneously. Air was supplied at fresh flow rates of 150 ml/kg and decreased stepwise at four-minute intervals until a flow of 50 ml/kg was attained. Expired minute volume and end-tidal carbon dioxide concentrations were measured. No rebreathing could be demonstrated with the Magill stystem at flow rates above approximately 70 ml/kg. In contrast, rebreathing was evident at all flow rates with the Bain system. It is concluded that acceptable carbon dioxide levels during spontaneous breathing with the Bain circuit can only be maintained by considerable active hyperventilation when using flow rates of 150 ml/kg and less.

[Universal coaxial anesthetic system]. / 'n Verwisselbare koaksiale narkosesisteem.

A true universal co-axial anaesthetic system has been designed. This system may be used either as a Mapleson A circuit during spontaneous ventilation or as a Mapleson D circuit during controlled ventilation. Conversion to either system may be conveniently carried out by interchanging the pop-off valve and fresh gas inlet, without disconnecting the system from the patient. Resistance to flow of both tubes has been measured and was found to be within acceptable limits. The efficiency of this system in a Mapleson A arrangement was compared with that of a conventional Magill circuit during spontaneous breathing in 2 conscious volunteers. It was shown that no significant difference exists between these systems eith regard to rebreathing, and that the universal co-axial system may be used as efficiently and economically as the Magill circuit during spontaneous ventilation. The co-axial system can be easily connected to a circle system, combining the advantages of the two systems.

[Anesthesia for patients with intestinal obstruction]. / Narkose vir pasiënte met dermobstruksie

The pre- and intra-operative care of patients with acute intestinal obstruction is reviewed. The most important pre-operative problems are hypovolaemia, sepsis, electrolyte and acid-base imbalances. The evaulation and treatment of these disorders are discussed. The importance of preventing regurgitation and inhalation of stomach contents is emphasised and the methods which are used are described. The safest techniques of induction and maintenance of anaesthesia as well as muscle relaxation and intra-operative fluid therapy are indicated.