Acta anaesthesiologica Scandinavica. Supplementum
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Continuous monitoring of O2 and CO2 in the airways of spontaneously breathing patients can be carried out by sampling air to a gas monitor through a catheter placed in the upper airway. The graphical display of O2 (oxygraphy) is a rather new facility. ⋯ Continuous monitoring of CO2 and O2 in the airway gives information about the pulmonary gas exchange and the efficacy of oxygen supply. Combined with arterial blood gas analysis the method allows determination of alveolar-arterial CO2 or O2 gradients.
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Acta Anaesthesiol Scand Suppl · Jan 1995
Base excess or buffer base (strong ion difference) as measure of a non-respiratory acid-base disturbance.
Stewart in 1983 (Can J Physiol Pharmacol 1983: 61: 1444) reintroduced plasma buffer base under the name "strong ion difference" (SID). Buffer base was originally introduced by Singer and Hastings in 1948 (Medicine (Baltimore) 1948: 27: 223). Plasma buffer base, which is practically equal to the sum of bicarbonate and albuminate anions, may be increased due to an excess of base or due to an increased albumin concentration. ⋯ Albumin anions contribute significantly to the anions, but calculation requires measurement of pH in addition to albumin and is usually irrelevant. The bicarbonate concentration may be used as a screening parameter of a nonrespiratory acid-base disturbance when respiratory disturbances are taken into account. A disturbance in the hydrogen ion status automatically involves a disturbance in the electrolyte status, whereas the opposite need not be the case.
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Acta Anaesthesiol Scand Suppl · Jan 1995
Comparative StudyPreliminary evaluation of a new continuous intra-arterial blood gas monitoring device.
Continuous intra-arterial blood gas monitoring is a new technique, possibly offering therapeutic advantages through improved monitoring in patients prone to hypoxaemia, hypercapnia and/or respiratory acidosis. Therefore, we studied the clinical applicability, reliability, precision and side effect of long-term continuous intra-arterial blood gas monitoring in patients suffering from severe acute respiratory distress syndrome. In 10 patients continuous intra-arterial blood gas monitoring based on fluorescent optodes technique was performed. ⋯ There was no significant time dependent drift in sensor precision over the study period. No negative side-effects related to IABG monitoring were observed. We conclude that long-term use of this new device is possible in patients and represents a reliable alternative to conventional in vitro arterial blood gas analysis, when continuous monitoring of blood gases and/or acid-base balance is critical.
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Acta Anaesthesiol Scand Suppl · Jan 1995
Comparative StudyEffect of neostigmine at different levels of mivacurium-induced neuromuscular blockade.
The effectiveness of neostigmine 40 micrograms/kg for antagonism of two different levels of neuromuscular blockade, induced by a bolus dose of mivacurium 0.15 mg/kg, was studied in 45 patients. The patients were anaesthetized with thiopentone, fentanyl, nitrous oxide in oxygen, and enflurane. Neostigmine was administered at either 10% recovery of the twitch height (TH10) at the adductor pollicis muscle (n = 14) or upon reappearance of the first response at the orbicularis oculi muscle (OO1) after train-of-four (TOF) stimulation (n = 16), the latter representing a deeper degree of neuromuscular blockade. ⋯ However, the time needed to reach a T4/T1 ratio > or = 0.8 was similar in both the early and late neostigmine administration groups, being 9 min faster than in the control group. It can be concluded that there is no advantage in administering neostigmine at profound neuromuscular blockade to achieve clinically adequate recovery (T4/T1 ratio > or = 0.8). However, the time between injection of mivacurium and TH25 may be shortened by using neostigmine at profound neuromuscular blockade, a procedure which may be useful in case of unpredictably difficult intubation, since diaphragmatic movements usually reappear at TH25.
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Acta Anaesthesiol Scand Suppl · Jan 1995
Comparative StudyMivacurium in short to intermediate surgical procedures.
Mivacurium, a new benzylisoquinoline muscle relaxant, appears to be close to the ideal for short to intermediate surgical procedures. Ideal properties of such an agent are discussed, in addition to indications for muscle relaxation in such procedures. Two studies are presented, showing the onset and offset times of mivacurium and its cardiovascular stability in both young and elderly patients. It is concluded that it is a well-tolerated and appropriate agent for use in short to intermediate surgical procedures in those patients with normal plasma cholinesterase function, despite a slight prolongation of action in the elderly.