Search PubMed⌕ Search

Biomedical subjects

A Kari

Publications and source records attributed to A Kari.

At least 55 records · Page 3Linked to original sources
PubMed1992

Effect of tidal volume on gas exchange and oxygen transport in the adult respiratory distress syndrome.

The effect of tidal volume (VT) on gas exchange and oxygen delivery (DO2) was studied in nine patients with adult respiratory distress syndrome (ARDS) and in 10 postoperative open-heart surgery patients (CABG). During controlled mechanical ventilation, VT was initially 10 to 12 ml/kg, followed by an increase and reduction of 25% (1.25 VT and 0.75 VT, respectively). In both groups of patients, dead space (VD) correlated strongly with VT (p < 0.001), while the VD/VT ratio was independent of VT. PaO2 tended to increase in CABG patients and decrease in ARDS patients at 1.25 VT. Arterial oxygen saturation (SaO2) did not change at 1.25 VT but decreased at 0.75 VT (p < 0.001) in the ARDS group. Venous admixture (QS/QT) decreased with 1.25 VT and increased with 0.75 VT (p < 0.001). A relatively larger increase in cardiac output compensated for the increased QS/QT and the reduced SaO2, resulting in significantly higher DO2 with 0.75 VT (p < 0.01). A lower VT resulted in improved balance between pulmonary gas exchange and whole body oxygen supply.

Blood Gas Analysis↗
PubMed1992

Management outcome for vertebrobasilar artery aneurysms by early surgery.

Treatment of vertebrobasilar artery aneurysms remains fraught with complications, even in the present era of microneurosurgery. In a series of 1150 consecutive patients with cerebral aneurysms from a defined catchment area with 870,000 inhabitants, 93 with vertebrobasilar artery aneurysms were treated by two surgeons during a 14-year period. Sixty-three patients had surgery, 36 during the first week after bleeding. There was no surgical mortality among 33 good grade patients. Nine (14%) of the 63 surgical cases had died at 1 year. Forty-nine (53%) of the total group of 93 patients were functioning independently at 1 year. Overall management mortality was 37%. All 11 patients admitted in Grade V died. In spite of improvements in surgical techniques, we are far from achieving ideal results. Early diagnosis and surgery before rupture are urgently needed. Arteriosclerotic giant aneurysms remain untreatable.

Adolescent↗
PubMed1992

Saccular aneurysms of the distal anterior cerebral artery and its branches.

We report a series of 84 consecutive patients (41 women) with 92 distal anterior cerebral artery aneurysms (DACAA). All aneurysms were saccular. Four different locations of DACAAs were found: proximal, 5 aneurysms; frontobasal, 8; genu corporis callosi, 72; and distal, 7. Sixty-five patients presented with subarachnoid hemorrhage (SAH), the rest were incidental findings in patients with multiple aneurysms. Forty-five patients had single DACAAs. Multiple aneurysms (a total of 117) were found in 39 patients (46.4%), and DACAAs were responsible for SAH in 20 patients. Of the 65 patients with SAH, 54 underwent mainly early direct surgery, and 46 (85%) of these had good outcomes 1 year after surgery. Three patients remained severely disabled, and five patients (9%) died. All of the poor surgical results were obtained in patients with severe preoperative deficits. Exact measurements of DACAA sizes and necks were smaller than those of cerebral aneurysms in other locations. Aside from localization, microsurgery of these aneurysms presented no special difficulties, as compared with surgery of aneurysms in other locations.

Adult↗
PubMed1991

Current practice regarding invasive monitoring in intensive care units in Finland. A nationwide study of the uses of arterial, pulmonary artery and central venous catheters and their effect on outcome. The Finnish Intensive Care Study Group.

As part of a nationwide evaluation of intensive care, we examined patient- and hospital-related factors which could influence the patterns of utilization of arterial cannulae and central venous and pulmonary artery catheters. We also studied the possible impact of these interventions on the short-term outcome among 14,951 consecutive ICU admissions to 25 intensive care units (75% of all ICU beds) in Finland. There was considerable variation between individual units in the use of these devices even if the differences in severity of illness were taken into account. Arterial cannulation was used in 71.2%, PA catheterization in 10.6% and CVP monitoring in 49.3% of cases in teaching ICUs, excluding cardiac surgery, and in 38.5%, 2.6% and 33.1% of cases in non-teaching ICUs respectively. The factors predicting the use of invasive monitoring included extensive surgery causing a risk of cardiovascular instability, needs for mechanical ventilation, infusion of vasoactive drugs and complicated fluid therapy. Cardiovascular problems among non-operative patients increased the odds for PA catheterization but reduced them for arterial and CV cannulation. No clear-cut benefit could be found in the form of hospital mortality reduction from invasive haemodynamic monitoring, used as described in this study.

Catheterization, Central Venous↗
PubMed1991

Respiratory changes after open-heart surgery.

Breathing pattern was studied non-invasively in 20 coronary artery bypass surgery patients before the operation and post-operatively after weaning from mechanical ventilation. Post-operatively minute ventilation (VE), breathing frequency (Fr) and mean inspiratory flow (VT/TI) increased (28%, 42%, 27%; p less than 0.01, p less than 0.001, p less than 0.01, respectively), while tidal volume (VT) decreased (15%, p less than 0.025). CO2 production (VCO2) and oxygen consumption (VO2) increased postoperatively (p less than 0.001 for both), contributing to the increase in ventilatory demand. Reduced variation of VT and Fr (p less than 0.001, p less than 0.01, respectively) and number of sighs (p less than 0.001) were characteristic of the post-operative breathing pattern. Post-operatively an increase in the contribution of rib cage (%RC) to tidal volume in the supine position was observed suggesting reduced motion of the diaphragm. All patients had atelectasis, 17 had pleural fluid and only 6 normal vascularity post-operatively. The shallow breathing in combination with increased ventilatory demand, impaired gas exchange and the surgical trauma of the thorax predispose to postoperative respiratory complications.

Coronary Artery Bypass↗
PubMed1991

INFORM: integrated support for decisions and activities in intensive care.

Many medical decision support systems that have been developed in the past have failed to enter routine clinical practice. Often this is because the developers have failed to analyse in sufficient detail the precise user requirements, because they have produced a system which takes too narrow a view of the patient, or because the decision support facilities have not been sufficiently well integrated into the routine clinical data handling activities. In this paper we discuss how the AIM-INFORM project is setting out to deal with these issues, in the context of the provision of decision support in the intensive care unit.

Artificial Intelligence↗
PubMed1991

Nitrogen and energy balance in septic and injured intensive care patients: response to parenteral nutrition.

We studied energy and nitrogen balance in 50 intensive care patients with sepsis (n = 18) or multiple trauma (n = 32). Most patients were mechanically ventilated during the study. Within 72h of admission the patients were randomised to receive one of 5 infusion regimens for 48h (group n = 9-11). The control group received hypocaloric glucose, two groups received 1.5g/kg/day of amino-acids, either with hypocaloric glucose on both days or with energy adjusted to pre-nutrition REE on the second day. The fourth group received 0.6g/kg/day of amino-acids and energy at REE, and the fifth group a high nitrogen (18g/day) regimen with a stepwise increase in energy intake from day 1 to day 2. Baseline REE was 118 +/- 18.9% of predicted. No significant differences in REE were observed between the diagnostic groups, treatments or measurements performed during mechanical or spontaneous ventilation. Nitrogen balance in the control group was -250.3 +/- 83.3 mg/kg on day 1 and 218.6 +/- 95.3 mg/kg on day 2. Nitrogen balance remained negative in all groups throughout the study (range of group means-218.6 to -48.5 mg/kg/day). Increasing energy intake equal to prenutrition REE at an amino-acid dosage of 1.5g/kg/day decreased the negative nitrogen balance by 66%. Further increase in energy balance had only a marginal effect on nitrogen balance.

Journal Article↗
PubMed1991

Peripheral tissue energy metabolism during recovery from hypothermia after cardiopulmonary bypass: effect of amino-acid infusions.

We studied the effects of amino-acid administration on the leg exchange of energy substrates and amino-acids during recovery from hypothermia after open heart surgery. Glucose (G, n = 5), glucose and conventional amino-acids (CA, n = 5) or glucose and branched chain amino-acids (BC, n = 5) were infused during recovery from hypothermia after open heart surgery. The leg exchange of energy substrates and amino-acids were measured after arrival at the intensive care unit, after rewarming, and 2h and 4h after rewarming during increasing amino-acid intake. Despite a normal stress response to surgery, reflected by increased energy expenditure and increased concentrations of insulin and catabolic hormones, amino-acids had no effect on the leg exchange of branched chain amino-acids, glutamine, alanine and energy substrates. This suggests that the transport of amino-acids and energy substrates into the cell are impaired after hypothermic cardiopulmonary bypass and intracellular substrates are utilised for the increased demand for energy during rewarming.

Journal Article↗
PubMed1991

Nitrogen and energy balance in depleted patients undergoing major gastrointestinal surgery: response to TPN.

We studied energy and nitrogen balance during pre- and post-operative parental nutrition in 16 malnourished patients undergoing major abdominal surgery due to suspected gastrointestinal malignancy. The response to amino-acids alone (1.5g/kg; group AA) and energy alone (energy intake equal to pre-nutrition energy expenditure; group REE) was studied during the first day of pre- and post-operative nutrition. On the second day of parental nutrition both groups received amino-acids (1.5g/kg) and non-protein energy equal to pre-nutrition energy expenditure. Energy expenditure (EE) was increased both pre- and post-operatively (EE 112 +/- 15 and 121 +/- 14% of predicted, respectively). Nitrogen balance in group REE was more positive than in group AA on pre-operative day 2 (81.1 +/- 35.8 vs. 17.8 +/- 60.5 mg/kg; p < 0.05). N balance was better pre- than post-operatively on day 2 in both groups (17.8 +/- 60.5 vs. -49.6 +/- 49.2 mg/kg; group AA and 81.1 +/- 35.8 vs. 7.8 +/- 82.6 mg/kg; group REE; p < 0.05). Pre-operatively, administration of energy alone reduced EE (1489 +/- 301 vs. 1403 +/- 312 kcal/day; p < 0.05). We conclude that: 1) The patients were hypermetabolic both pre- and post-operatively. 2) Surgical trauma had a minor effect on EE. 3) Good nitrogen retention could be obtained both pre- and post-operatively at close to zero energy balance. 4) EE increased during the infusion of amino-acids more post-operatively than pre-operatively; non-protein energy at EE had no thermogenic effect. 5) Priming with energy improved nitrogen balance on the following day.

Journal Article↗
PubMed1991

Changes in whole body and tissue oxygen consumption during recovery from hypothermia: effect of amino acid infusion.

OBJECTIVE: To study the effects of amino acids on whole body and peripheral energy metabolism during recovery from post-operative hypothermia. DESIGN: Clinical study using three randomly assigned patient groups. SETTING: ICU of a university hospital. PATIENTS: Nineteen elective coronary bypass operation patients. INTERVENTIONS: Postoperatively, either glucose alone, glucose and a conventional amino acid solution, or glucose and a branch-chain amino acid enriched solution was infused. After ICU arrival (period 1) both conventional amino acid solution and branch-chain amino acid enriched solution groups received 0.15 g/kg-day of nitrogen as a conventional amino acid mixture (20% branch-chain amino acids). After rewarming (period 2), both groups received 0.18 g of nitrogen/kg-day for 2 hrs (branch-chain amino acid content 20% in the conventional amino acid solution and 35% in the branch-chain amino acid enriched solution), and for the following 2 hrs (period 3), 0.22 g of nitrogen/kg-day (branch-chain amino acid content 20% in the conventional amino acid solution and 50% in the branch-chain amino acid enriched solution). MEASUREMENTS AND MAIN RESULTS: Whole body oxygen consumption (VO2) increased during period 1 and continued to increase during period 2 (baseline, 133 +/- 20 mL/min.m2; period 1, 152 +/- 12 mL/min.m2; period 2, 158 +/- 21 mL/min.m2; period 3, 153 +/- 15 mL/min.m2; p less than .05, period 1 vs. baseline). VO2 in the leg increased during period 1 but remained constant thereafter (baseline, 16 +/- 8 mL/min.m2; period 1, 26 +/- 14 mL/min.m2; period 2, 23 +/- 6 mL/min.m2; period 3, 24 +/- 10 mL/min.m2; p less than .05, period 1 vs. baseline). Amino acid infusions had no thermogenic effect. A two-phase redistribution of VO2 and leg VO2 suggested increased visceral VO2 after rewarming. CONCLUSION: The amino acid infusions had no effect on the leg uptake of glucose, ketone bodies, and pyruvate and the leg release of lactate, free fatty acids, and triglycerides, which remained constant during the study.

Adult↗
PubMed1991

Septic shock and multiple organ failure.

OBJECTIVE: To assess the frequency and mortality rates of septic shock in ICU patients and the clinical course of multiple organ failure associated with septic shock. DESIGN: Retrospective case survey. SETTING: Tertiary care center. PATIENTS: During a 2-yr period, 2,469 consecutive intensive care patients were studied regarding the frequency and hospital mortality rates of septic shock. A subset of 1,311 patients was further analyzed for the occurrence of organ system failures within 48 hrs of the onset of septic shock and again 4 to 7 days later. MEASUREMENTS AND MAIN RESULTS: The frequency rate of septic shock was 1.9% (n = 48), with a mortality rate of 72.9% (n = 35) in patients with septic shock. Deaths due to septic shock represented 14.6% of all deaths in the ICU during the study period. Eighteen patients died within 72 hrs of the onset of septic shock. Refractory hypotension was the cause of death in 15 of these 18 patients. Beyond 72 hrs, multiple organ failure accounted for eight of 17 deaths. The mean +/- SD number of organ systems failing at 48 hrs was 3.3 +/- 1.3 in survivors and 4.0 +/- 1.1 in nonsurvivors, and at 4 to 7 days was 2.1 +/- 1.5 in survivors and 4.0 +/- 1.5 in nonsurvivors (p less than .05). None of the specific organ system failures had prognostic value. The number of organ system failures was not related to the duration of hypotension, but had a weak correlation (r2 = .26, p less than .05) with the duration of vasoactive treatment at 4 to 7 days. The prolonged need for norepinephrine therapy was associated with an increased occurrence of renal failure. Thirty (62.5%) patients had positive blood cultures and a mortality rate similar to the mortality rate of patients with negative blood cultures. Patients with negative blood cultures died more often with hypotension (p less than .02). CONCLUSIONS: Septic shock is a major cause of death in intensive care patients. Refractory hypotension is a main cause of early deaths. Later on, multiple organ failure becomes the primary clinical problem and cause of mortality.

Adult↗
PubMed1991

Acute physiology and chronic health evaluation (APACHE II) and Glasgow coma scores as predictors of outcome from intensive care after cardiac arrest.

OBJECTIVES: a) To examine the accuracy of the Acute Physiology and Chronic Health Evaluation (APACHE II) and the Glasgow Coma Scores as predictors of the outcome of patients following resuscitation from cardiac arrest; b) to study the impact of the components of APACHE II on the prediction. DESIGN: A nationwide study in Finland with prospectively collected data on all patients admitted to intensive care after cardiac arrest during a 14-month period. Two thirds of the cardiac arrest patients included in the study were randomly selected to derive predictive models, and the remaining one third constituted the validation sample. SETTING: A total of 25 medical and surgical ICUs in Finland (13 in tertiary referral centers). PATIENTS: Six-hundred nineteen consecutive cardiac arrest patients. Fifteen patients less than 16 yrs were excluded. MAIN OUTCOME MEASURES: Variables included in the APACHE II or Glasgow Coma Scores were collected at the time of ICU admission and then three times after admission, at 24-hr intervals. ICU- and hospital-mortality rates and a 6-month mortality rate after ICU admission were studied. RESULTS: Of 604 study patients, 370 (61.3%) patients died in the hospital. The most accurate prediction of hospital outcome was based on data collected after the first day of ICU care, not on the admission values. Twenty-one (21.9%) of 96 patients with a low APACHE II score (less than or equal to 9) died compared with 66 (84.6%) of 78 patients with a high APACHE II score (greater than or equal to 25) (p less than .001). Of 160 patients with a normal Glasgow Coma Score (14 to 15), 45 (28.1%) died, whereas there were 114 (81.4%) nonsurvivors among 140 patients with a low Glasgow Coma Score of 3 (p less than .001). The performance of predictive models, including age, the Chronic Health Evaluation, and either the Acute Physiology Score (Acute Physiology Score model) or the Glasgow Coma Score (Glasgow Coma Score model) were compared with the prediction according to the APACHE II in the validation sample. When using 80% probability of death as a decision rule, the Acute Physiology Score model determined 35 of 153 patients to have high risk of death, 29 of whom died (the positive predictive value being 82.9%). The Glasgow Coma Score model predicted 34 patients to die, 26 of whom died (positive predictive value 76.5%), and the APACHE II score predicted seven deaths, five of whom actually died (positive predictive value 71.4%). CONCLUSIONS: The APACHE II scoring system cannot be recommended as a prognostic tool to support clinical judgement in cardiac arrest patients, but by modifying it, a more accurate prediction of poor outcome could be achieved. The Glasgow Coma Score explained to a great extent the predictive power of the APACHE II.

Adult↗
PubMed1991

Factors affecting surfactant responsiveness.

There is a wide variability in the therapeutic responsiveness to exogenous surfactant, a drug that has become generally available for the treatment of lung immaturity and respiratory distress syndrome. Recent studies have demonstrated evidence that therapies decreasing lung edema improve the effectiveness of surfactant substitution. In addition, exogenous surfactant may acutely decrease pulmonary perfusion since the airway pressures are effectively transmitted to airspaces, compressing alveolar capillaries, especially in hypovolemia. Therapies aimed at decreasing lung edema, improving cardiac output, and stepwise weaning from oxygen and ventilatory pressures are cornerstones in the successful management of patients undergoing surfactant therapy.

Ductus Arteriosus, Patent↗
PubMed1991

Hypermetabolism after coronary artery bypass.

We measured the changes in energy expenditure in the early postoperative phase after coronary artery bypass operations and the ventilatory response to the increased demand for respiratory gas exchange. Breathing pattern and gas exchange were measured noninvasively by respiratory inductive plethysmography and indirect calorimetry with a canopy. Eighteen patients were studied after weaning from mechanical ventilation. Energy expenditure increased by 18.3%, which is comparable to the response to major injury. Carbon dioxide production increased from 162 +/- 20 to 195 +/- 36 ml/min in the supine position (p less than 0.001), and similar changes were observed in the half-sitting position. Arterial carbon dioxide tension increased marginally (37.5 +/- 2.96 mm Hg preoperatively versus 39.7 +/- 4.87 mm Hg postoperatively; p less than 0.05), while oxygen tension decreased from 89.9 +/- 17.3 mm Hg to 62.9 +/- 13.4 mm Hg (p less than 0.001). Minute ventilation increased by 34% in the supine position (p less than 0.01) and by 28% in the half-sitting position (p less than 0.05), while tidal volume remained unchanged. We conclude that coronary artery bypass operations induce hypermetabolism and substantially increase ventilation and risk of arterial hypoxemia during the phase of compromised cardiovascular reserves.

Calorimetry, Indirect↗
PubMed1990

Frequency and reliability of alarms in the monitoring of cardiac postoperative patients.

Postoperative monitoring of cardiac operated patients requires appropriately functioning monitor alarms as well as intensive nursing activity. The limit alarms can be used for detection of life-threatening situations and monitoring of physiological changes in the patient's state. We studied the significance and the frequency of audible alarms during the postoperative intensive care of ten cardiac patients. Of 1307 occasions when such an alarm was activated during the study period of approximately 26 hours per patient, only 139 (10.6%) were significant. The highest proportion of significant audible limit alarms was found during the immediate postoperative period. Heart rate alarms were more reliable than alarms of the other parameters monitored in the study. Possibilities for improving the physiological monitoring and alarm system are discussed.

Cardiac Surgical Procedures↗
PubMed1990

Impaired utilization of exogenous amino acids after surgery for subarachnoid haemorrhage.

We studied the metabolic response to acute aneurysm surgery and its modification by parenteral nutrition. Forty-eight patients receiving perioperative corticosteroid treatment were randomly assigned to receive glucose alone (7.2 kcal/day, D5W + C), glucose and a conventional amino acid solution (7.2 kcal/day and 0.15 gN/day, CAA + C) or glucose and branched chain amino acid enriched solution (7.2 kcal/day and 0.14 gN/day, BCAA + C). Twenty patients without corticosteroid treatment received either glucose alone (7.2 kcal/day, D5W) or glucose and a conventional amino acid solution (7.2 kcal/day and 0.14 gN/day, CAA). Poor nitrogen utilization was indicated by strongly negative nitrogen balance in all groups and a failure of the infused amino acids to improve nitrogen balance. (Day 0; D5W + C: -9.3 +/- 3.6 g/day and CAA + C: -8.2 +/- 9.7 g/day vs CAA: -2.6 +/- 4.9 g/day, p less than 0.05, Day 1; D5W + C: -14.9 +/- 9 g/day vs CAA: -7.7 +/- 6.5 g/day, p less than 0.05, MANOVA). We conclude that subarachnoid haemorrhage and its surgical treatment induce a catabolic response and impaired utilization of exogenous nitrogen, further amplified by perioperative corticosteroids, which is in sharp contrast to the response to surgery not involving the central nervous system.

Adrenal Cortex Hormones↗