Continuous monitoring of depth of sedation by EEG spectral analysis in patients requiring mechanical ventilation

Twenty-three patients undergoing intensive therapy had continuousEEG recording in an attempt to assess depth of sedation usingspectral analysis. Median power frequency (MPF) and spectraledge frequency (SEF) were calculated and correlated with theclinical sedation score and blood concentration of sedativedrug. Fifteen patients received isoflurane and eight midazolam.There was no correlation between MPF or SEF and sedation scoreor blood concentration of drug. These results suggest that nosimple measure of the EEG is likely to correlate with depthof sedation in critically ill patients.     

Use of the rocking bed in the treatment of neurogenic respiratory insufficiency

We describe 53 patients who received ventilatory support witha rocking bed. Diagnoses included previous poliomyelitis (30),muscular dystrophy (12), motor neurone disease (4), adult-onsetacid maltose deficiency (4) and a miscellaneous group (3). Patientspresented with respiratory insufficiency characterized by diaphragmweakness, progressive nocturnal hypoventilation and/or acuteor chronic respiratory failure. Domiciliary rocking beds wereused by 43 patients for a mean of 16.0 years (range 1 monthto 35 years). Most patients were able to breathe adequatelyby day when sitting or standing, but needed assistance by rockingbed for 6–11 h when lying down for sleep. The rockingbed was well-tolerated, and associated with both symptomaticrelief and amelioration of arterial blood gas abnormalities.Seventeen of these 43 patients discontinued its use, eitherbecause of discomfort (9) or increasing respiratory insufficiency(8). The rocking bed is a valuable adjunct in the managementof the respiratory insufficiency associated with neuro-musculardisease.     

EFFICIENCY OF BREATHING SYSTEMS A AND D IN THE CARDEN VENTMASTA VENTILATOR

We have compared the efficiency of the enclosed Magill attachment(System A) and the co-axial System D (Bain) in the Carden Ventmastaventilator using both systems, each under five different ventilatoryconditions, in each of five anaesthetized patients. Efficiencywas assessed in terms of the effective alveolar ventilationas a fraction of the fresh gas flow. For System A, efficiencyincreased from a mean of 0.37 when the total ventilation wasonly 50% of the fresh gas flow, to a mean of 0.74 when ventilationwas 2.3 times the fresh gas flow. The efficiency was substantiallyand significantly less with System D:75% of that for SystemA at the smaller total ventilation (95% Cl 65–85%) and65% at the larger (95% Cl 59–71%). A critical examinationis made of conflicting definitions and terminology of the efficiencyof breathing systems. (Br. J. Anaesth. 1993; 71: 741–746). ^*Department of Anaesthetics, East Glamorgan General Hospital,Church Village, Pontypridd, Mid Glamorgan CF38 1AB Department of Anaesthesia and Intensive Care, Royal AdelaideHospital, North Terrace, Adelaide, South Australia 5000     

The Nominal Group Technique: A Research Tool for General Practice?

Qualitative methods are increasingly recognized as valuable,yet practitioners face difficult decisions in their choice ofmethod and the process of analysis. The nominal group techniquecombines quantitative and qualitative data collection in a groupsetting, and avoids problems of group dynamics associated withother group methods such as brainstorming, Delphi and focusgroups. Idea generation and problem solving are combined ina structured group process, which encourages and enhances theparticipation of group members. The stages involved in conductinga nominal group are described, and practical problems of itsuse in a health care setting are discussed with reference toa study of the priorities of care of diabetic patients, carersand health professionals. Some potential applications of thetechnique in audit and exploratory research are also outlined.     

Lack of Peroxisome Proliferation in Marmoset Liver Following Treatment with Ciprofibrate for 3 Years

The effect of treatment of marmosets with ciprofibrate for 3years on activities of hepatic enzymes, hepatic histomorphology,and ultrastructure were investigated. Male and female mar mosetswere dosed with ciprofibrate (2, 10, and 20 mg/kg) by oral gavageonce daily for 3 years. No effect on liver weight (adjustedfor body weight) or liver morphology was observed. The activitiesof catalase, glutathione peroxidase, -glycero phosphate dehydrogenase,benzphetamine N-dernethylase, and ethoxyresorufln O-deethylasewere unaffected by treatment with ciprofibrate. Activity ofglutathione transferase was in creased in the low dosage groupbut unaffected in the mid and high dosage groups. Modest increasesin activities of peroxiso mal ß-oxidation (2.5-fold,maximal), carnitine acetyl transfer ase (1.7-fold, maximal),and carnitine palmitoyl transferase (2- fold, maximal) wereobserved. Cytochemical staining and quan titative image analysisfailed to indicate any effect on peroxisomal number, size, orvolume density. Similarly, there was no increase in lipofuscindeposition. This study provides data on the effects of a potentperoxisome proliferator on pri mate liver following a dosingperiod much greater than that used in previously published studiesand is further evidence that the marmoset is relatively insensitiveto the well-documented effects that ciprofibrate and other peroxisomeproliferators have on rat liver.