Ola Winsö

Scandinavian glutamine trial: a pragmatic multi-centre randomised clinical trial of intensive care unit patients.

Background: Low plasma glutamine concentration is an independent prognostic factor for an unfavourable outcome in the intensive care unit (ICU). Intravenous (i.v.) supplementation with glutamine is reported to improve outcome. In a multi‐centric, double‐blinded, controlled, randomised, pragmatic clinical trial of i.v. glutamine supplementation for ICU patients, we investigated outcomes regarding sequential organ failure assessment (SOFA) scores and mortality. The hypothesis was that the change in the SOFA score would be improved by glutamine supplementation.

PORTAL BLOOD FLOW IN MAN DURING GRADED POSITIVE END – EXPIRATORY PRESSURE VENTILATION

The cardiovascular response to graded PEEP ventilation (5–10 cm H2O) was studied peroperatively in patients undergoing chllecystectomy (n=8) or hepatic tumour surgery (n=3). Portal blood flow was measured by the continuous thermodilution technique and cardiac output, in a sub-group of the patients, by impedance cardiography. A parallel reduction in cardiac output and portal blood flow was demonstrated in patients undergoing cholecystectomy as the result of the application of PEEP. Thus, ventilation with 5 cm H2O of PEEP elicited a 17% decrease in cardiac output and a 26% decrease in portal blood flow. During 10 cm H2O of PEEP cardiac output decreased by 22% and portal blood flow by 32%. However, there were no significant changes in preportal tissue perfusion pressure by the application of PEEP and preportal vascular resistance increased by 22% and 30%, respectively. This indicates that a vasoconstrictor response, elicited by PEEP, in the preportal tissue is the predominating mechanism for the observed decrease in portal blood flow. Systemic oxygen transport decreased by 214 ml/min during PEEP ventilation, but preportal tissue oxygen utilization was not significantly changed due to a concurrent increase (2.9%; p<0.05) in oxygen extraction.

Survey of routines for sedation of patients on controlled ventilation in Nordic intensive care units

Background:  Sedation strategies and practice for patients on controlled ventilation is variable from place to place as well as over time. Less sedation results in shorter ventilation time and new ventilatory modes permit more awake patients. Previous works estimated sedative and analgesic use in Nordic ICUs some years ago, but current practice is not known. We therefore designed this study to describe pharmacological and practical routines for sedation of patients on controlled ventilation.

Physiological responses to touch massage in healthy volunteers.

OBJECTIVES To evaluate effects of touch massage (TM) on stress responses in healthy volunteers. METHODS A crossover design including twenty-two (mean age=28.2) healthy volunteers (11 male and 11 female) cardiac autonomic tone was measured by heart rate (HR) and heart rate variability (HRV). Stress hormone levels (cortisol) were followed in saliva. We also measured blood glucose and serum insulin. Extracellular (ECV) levels of glucose, lactate, pyruvate and glycerol were followed using the microdialysis technique (MD). TM was performed on hands and feet for 80 min, during control, participants rested in the same setting. Data were collected before, during, and after TM and at rest. Saliva cortisol, serum glucose, and serum insulin were collected before, immediately following, and 1 h after intervention or control, respectively. RESULTS After 5 min TM, HR decreased significantly, indicating a reduced stress response. Total HRV and all HRV components decreased during intervention. Saliva cortisol and insulin levels decreased significantly after intervention, while serum glucose levels remained stable. A similar, though less prominent, pattern was seen during the control situation. Only minor changes were observed in ECV levels of glucose (a decrease) and lactate (an increase). No significant alterations were observed in glycerol or pyruvate levels throughout the study. There were no significant differences between groups in ECV concentrations of analyzed substances. CONCLUSIONS In healthy volunteers, TM decreased sympathetic nervous activity, leading to decreased overall autonomic activity where parasympathetic nervous activity also decreased, thereby maintaining the autonomic balance.

The continuous thermodilution method for measuring high blood flows

The continuous thermodilution method for the measurement of blood flow from 300 to 1500 ml/min was evaluated in vitro and in vivo. In vitro experiments indicated that thermotransport within the catheter, causing a temperature measurement error, can occur. Flow model measurements were used for consequent modification of the original thermodilution formula for calculation of flow. In the in vivo investigations the thermodilution and electromagnetic methods were compared for measurement of pig portal blood flow. Using the modified formula for the flow calculations, good agreement was found between the two methods (r = 0.958). For the continuous thermodilution method in vivo the standard deviation of a single measurement was 19 ml/min and the coefficient of variation 1.6%.

Cutaneous sympathetic vasoconstrictor reflexes for the evaluation of interscalene brachial plexus block

Background: Although signs of sympathetic blockade following interscalene brachial plexus block include Horner’s syndrome, increased skin temperature and vasodilatation, the degree of sympathetic blockade is not easily determined. The aim of this study was, therefore, to use activation of cutaneous finger pad vasoconstrictor reflexes for description and quantification of the degree of sympathetic blockade following unilateral interscalene brachial plexus block.

Does Dopamine Suppress Stress-Induced Intestinal and Renal Vasoconstriction?

Dopamine interference with intestinal and renal sympathetic reflex vasoconstrictor responses was studied in cats anaesthetized with diazepam, fentanyl and nitrous oxide. Vasoconstriction was induced by electric stimulation of the hypothalamic defence‐alarm area and by stimulation of somatic and visceral afferents. In addition, intestinal vasoconstriction was elicited by direct stimulation of postganglionic sympathetic efferent nerves. In the intestine, dopamine administration (7.5 μg ‐ kg‐1 ‐min‐1) was not associated with an attenuation of the investigated sympathetic vasoconstrictor responses, although dopamine per se decreased intestinal vascular resistance by 36 ± 4%. Due to this dopamine‐induced background vasodilation, the intestinal blood flow level during stimulation procedures and concomitant dopamine infusion was higher than during similar stimulations prior to dopamine (for defence‐alarm area stimulation 45 ± 16%, for afferent nerve stimulation 79 ±22% and for efferent postganglionic nerve stimulation 66 ± 16%). In the kidney, dopamine per se had only minor effects on vascular resistance and on changes in vascular tone elicited by the stimulation procedures. The renal blood flow level in response to the stimulation procedures was not significantly affected by dopamine. In conclusion, dopamine may contribute to a sustained intestinal blood flow level when administered during supervening stress‐related sympathetic activation.

Immediate and 5-year cumulative outcome after paediatric intensive care in Sweden

Background: Little has been reported about intensive care of children in Sweden. The aims of this study are to (I) assess the number of admissions, types of diagnoses and length‐of‐stay (LOS) for all Swedish children admitted to intensive care during the years 1998–2001, and compare paediatric intensive care units (PICUs) with other intensive care units (adult ICUs) (II) assess immediate (ICU) and cumulative 5‐year mortality and (III) determine the actual consumption of paediatric intensive care for the defined age group in Sweden.

Assessment of the Surgical Apgar Score in a Swedish setting

Background: Predicting major post‐operative complications is an important task for which simple and reliable methods are lacking. A simple scoring system based on intraoperative heart rate, blood pressure and blood loss was recently developed to fill this gap. This system, the Surgical Apgar Score, shows promising results both in terms of validity and in terms of usefulness. The goal of this study was to study both these components in a Scandinavian setting.

Optimised sample handling in association with use of the CMA 600 analyser.

A large degree of variability for batched analysis of serially collected microdialysis samples measured with the CMA 600 analyser has been described. This study was designed to identify sources of variability related to sample handling. Standard concentrations of four solutes were placed in microdialysis vials and then stored and analysed at intervals. Results were analysed for variability related to vial and cap type, duration and temperature of storage, centrifugation and re-analysis. The main results were that centrifugation of samples reduced variability. When a batch of 24 samples was analysed, the use of crimp caps reduced evaporation. Samples in glass vials with crimp caps could be stored in a refrigerator for up to 14 days without large variability in concentration compared to plastic vials which demonstrated variability already when stored for more than 1 day. We conclude that variability in microdialysis results can occur in relation to storage and analysis routines if routines are not optimised concerning evaporation. Centrifugation before analyses, glass vials with crimp caps even during frozen storage, and attention to minimal times for samples to be uncapped during analysis all contribute to minimise variability in the handling and analysis of microdialysis samples.