PubMed Health⌕ Search

Biomedical subjects

A Markström

Publications and source records attributed to A Markström.

10 recordsLinked to original sources
PubMed2006

A retrospective survey of outpatients with long-term tracheostomy.

BACKGROUND: The Respiratory Unit (RU) at Danderyd University Hospital opened in 1982, with the expressed goal of supporting outpatients with long-term tracheostomy. The primary aim of this retrospective study in tracheostomized patients was to compare the need for hospital care in the 2-year period before and after the tracheostomy. METHODS: Data were collected from patient medical records at the RU, from the National Board of Health and Welfare, Sweden and from the Official Statistics of Sweden. The subjects were RU patients in 1982 (Group 1, n = 27) and in 1997 (Group 2, n = 106) with long-term tracheostomy surviving at least 4 years after the tracheostomy. RESULTS: Both groups had few and unchanged needs for hospital care after tracheostomy. They spent > or = 96% of their time out of hospital. In 1997, (group 2) the number of patients, diagnoses and need for home mechanical ventilation had increased. Life expectancy was assessed for patients in Group 1. Data showed that they lived as long as an age-matched and gender-adjusted control cohort. CONCLUSIONS: Long-term tracheostomy may not increase the need for hospital care and does not reduce life expectancy. These clinical observations were made in a setting where patients had regular access to a dedicated outpatient unit.

Adult↗
PubMed2006

Bi-level positive airway pressure ventilation maintains adequate ventilation in post-polio patients with respiratory failure.

BACKGROUND: Patients suffering from post-polio syndrome still contribute significantly to the number of patients with chronic respiratory failure requiring home mechanical ventilation (HMV). Many of these patients are treated either with invasive (tracheostomy) or non-invasive (nasal mask) controlled mechanical ventilation i.e. volume-controlled ventilation (VCV). In this group of patients, we have previously shown that bi-level pressure support ventilation (bi-level PSV) decreases the oxygen cost of breathing. The aim of this study was to compare the effect of bi-level PSV, with special regard to the adequacy of ventilation and the oxygen cost of breathing, during the patients' ordinary VCV and spontaneous breathing. METHODS: Eight post-polio patients on nocturnal VCV were investigated. Five of them were tracheostomized and three of them used a nasal mask. Work of breathing was analysed by assessing differences in oxygen consumption (VO2) using indirect calorimetry. Blood gases were obtained regularly to assess adequacy of ventilation. RESULTS: Bi-level PSV decreases the oxygen cost of breathing in post-polio patients with respiratory failure without decreasing ventilation efficiency. Furthermore, PaCO2 decreased significantly using this mode of ventilation (P < 0.05). CONCLUSION: In this study, it was shown that bi-level PSV reduces the oxygen cost of breathing and gave a significant decrease in PaCO2 in PPS patients. These data suggest that bi-level PSV ventilation maintains adequate ventilation in patients who suffer from post-polio syndrome with respiratory failure.

Aged↗
PubMed2005

Bi-level positive airway pressure ventilation reduces the oxygen cost of breathing in long-standing post-polio patients on invasive home mechanical ventilation.

BACKGROUND: Today, patients with chronic respiratory failure are commonly treated with non-invasive bi-level positive airway pressure ventilation, supporting spontaneous breathing. However, in conformity with previous clinical routine, many post-polio patients with chronic respiratory failure are still treated with invasive (i.e. via a tracheostomy) controlled mechanical ventilation (CMV). The aim of the study was to investigate the effect of invasive bi-level positive airway pressure ventilation on the work of breathing compared with that during the patients' ordinary CMV and spontaneous breathing without mechanical support. METHODS: Nine post-polio patients on invasive (tracheostomy) nocturnal CMV were investigated. Work of breathing was analysed by assessing differences in oxygen consumption (VO2) using indirect calorimetry. Hereby, the oxygen cost of breathing during the various ventilatory modes could be estimated and related to one another. Data on energy expenditure were also obtained. RESULTS: The oxygen cost of breathing decreased by approximately 15% during bi-level positive airway pressure ventilation compared with CMV and spontaneous breathing. There was no difference between predicted (Harris-Benedict equation) and measured energy expenditure. CONCLUSION: Invasive bi-level positive airway pressure ventilation reduces the oxygen cost of breathing in long-standing tracheostomized post-polio patients, compared with CMV. Furthermore, the Harris-Benedict equation provides a reasonable prediction of energy expenditure in this group of patients.

Aged↗
PubMed2001

Effects of sustained pressure application on compliance and blood gases in healthy porcine lungs.

BACKGROUND: Short periods of sustained increase in airway pressures (Press(up)) are believed to re-open lung areas that collapsed upon induction of anaesthesia. Recruitment of alveolar surface is usually assessed in terms of changes in the pressure-volume (PV) curve. The purpose of this study was to analyse PV-curves before and after a Press(up) and to ascertain whether such changes are compatible with the concept of recruitment of lung volume. METHODS: During ketamine anaesthesia, 12 healthy piglets were subjected to a Press(up) with end-expiratory pressure (PEEP) of 12 cmH2O and end-inspiratory pressure of 40 cmH2O. Before and after Press(up), PV-curves were obtained from a slow insufflation of 630 ml at zero PEEP (ZEEP). RESULTS: Compliance was non-linear both before and after Press(up) increasing up to 300 ml and sharply decreasing thereafter. After Press(up), the entire compliance curve was shifted to a higher absolute level. Up to 100 ml and a pressure level corresponding to the lower inflection point on the PV-curve (LIP), compliance was higher before Press(up). No effects on blood gases could be observed. CONCLUSION: If the similar shape of the compliance curve corresponds to a similar chain of re-opening and overdistension events, this would imply that all volume gained by Press(up) is lost within 10 min, without explaining the higher absolute compliance following Press(up). We speculate that a) re-opening of rapidly collapsing small airways determines the initial compliance increase; b) the lower compliance after Press(up) until LIP indicates reduced intratidal re-opening of lung regions; and c) changes in bronchomotor tone induced by Press(up) raise the absolute compliance, with a similar scenario of alveolar and small airway recruitment now taking place but at different degrees of airway stiffness.

Airway Resistance↗
PubMed2000

Impact of different inspiratory flow patterns on arterial C02-tension.

Ventilation with decelerating inspiratory flow is known to reduce the dead space fraction and to decrease PaCO2. Constant inspiratory flow with an end-inspiratory pause (EIP) is also known to increase the removal of CO2. The aim of the study was to elucidate the effect of the pause/no-flow period while both the pattern and rate of inspiratory flow was unchanged, and when the lung was ventilated with sufficient PEEP to prevent end-expiratory collapse. Surfactant depleted piglets were assigned to decelerating or constant inspiratory flow with 24 breaths per minute (bpm) or 12 bpm, or to constant flow, without and with an end-inspiratory pause of 25%. By adding an EIP the total time without active inspiratory flow of the respiratory cycle was kept unchanged. Gas exchange, airway pressures, functional residual capacity (using sulfurhexafluoride) and haemodynamics (thermo-dye indicator dilution technique) were measured. Irrespective of ventilatory frequency, PaCO2 was lower and serial dead space reduced with decelerating flow, compared with constant inspiratory flow. With an end-inspiratory pause added to constant inspiratory flow, serial dead space was reduced but did not decrease PaCO2. The results of this study corroborate the assumption that total time without active inspiratory flow is important for arterial CO2-tension.

Animals↗
PubMed1999

Tonsillectomy or tonsillotomy?--A randomized study comparing postoperative pain and long-term effects.

BACKGROUND: tonsillectomy (TE) is currently the most common treatment for children with snoring and sleep apnea. Many of these children have not had any severe throat infections. To cure such children from their obstructive problems, without influencing the immunological function of the tonsils, tonsillotomy (TT) with CO2-laser was performed in a randomized study comparing it to regular tonsillectomy, with special attention to postoperative pain and symptom recurrence. METHOD: 41 children 3.5-8 years-old were included--21 'TT's' and 20 'TE's'. They were all operated under the same anesthesia and followed the same postoperative scheme for analgesia. A visual analogue scale for pain measurements with faces was used for the first 24 h. After that, each day until pain-free, the parents registered the child's pain on a three graded scale, what the child was able to eat, and the amount of analgesic drugs used. RESULTS: all the children were cured from their breathing obstruction. The mean time used for the surgery was the same and no postoperative bleeding was seen in either group. 'TT children' were pain-free after 5 days and 'TE children' after 8 days. Eight to ten days after surgery, the TT-children had gained weight and the TE children lost weight significantly. The TE group used twice as much analgesic drugs as the TT group during the first postoperative week. The TT group was healed with normal-looking, but small tonsils after 8-10 days; the TE group often still showed edema and crusts. At the one-year follow-up 2/21 among the 'TT-children' snored, but did not require re-surgery. CONCLUSION: tonsillotomy is much less painful than TE and children recover more quickly. Results with respect to breathing obstruction are almost the same for both methods at 1-year follow-up.

Child↗
PubMed1999

Using the carbon dioxide laser for tonsillotomy in children.

Carbon dioxide laser tonsillotomies were performed on 33 children aged 1-12 years for the relief of obstructive symptoms due to tonsillar hyperplasia. As opposed to conventional tonsillectomy, only the protruding part of each tonsil was removed. A carbon dioxide laser delivering 20 W was used for the excision. Twenty-one children were seen in active short-term follow-up and the records of all the children were checked for possible surgery related events up to 20-33 months after surgery. Laser tonsillotomy was uniformly effective in relieving the obstruction, with good hemostasis. The tonsillar remnants healed completely within 2 weeks. No major adverse events occurred. Post-operative pain appeared slight and easily controlled. There was no gain in operating time compared with conventional tonsillectomy. The laser tonsillotomies were in most cases done in day surgery. No recurrence of obstructive problems was reported up to 20-33 months after surgery. It was concluded that tonsillotomy, using a carbon dixoide laser, is a valid treatment for obstructive symptoms caused by enlarged tonsils, which can be performed with little bleeding and post-operative pain. The improved hemostasis may enable a shift from in-patient to day surgery.

Acetaminophen↗
PubMed1995

Different ventilatory approaches to keep the lung open.

OBJECTIVES: To study the ability of different ventilatory approaches to keep the lung open. DESIGN: Different ventilatory patterns were applied in surfactant deficient lungs with PEEP set to achieve pre-lavage PaO2. SETTING: Experimental laboratory of a University Department of Anaesthesiology and Intensive Care. ANIMALS: 15 anaesthetised piglets. INTERVENTIONS: One volume-controlled mode (L-IPPV201:1.5) and two pressure-controlled modes at 20 breaths per minute (bpm) and I:E ratios of 2:1 and 1.5:1 (L-PRVC202:1 and L-PRVC201.5:1), and two pressure-controlled modes at 60 bpm and I:E of 1:1 and 1:1.5 (L-PRVC601:1 and L-PRVC601:1.5) were investigated. The pressure-controlled modes were applied using "Pressure-Regulated Volume-Controlled Ventilation" (PRVC). MEASUREMENTS AND RESULTS: Gas exchange, airway pressures, hemodynamics, FRC and intrathoracic fluid volumes were measured. Gas exchange was the same for all modes. FRC was 30% higher with all post-lavage settings. By reducing inspiratory time MPAW decreased from 25 cmH2O by 3 cmH2O with L-PRVC201.5:1 and L-PRVC601:1.5. End-inspiratory airway pressure was 29 cmH2O with L-PRVC201.5:1 and 40 cmH2O with L-IPPV201:1.5, while the other modes displayed intermediate values. End-inspiratory lung volume was 65 ml/kg with L-IPPV201:1.5, but it was reduced to 50 and 49 ml/kg with L-PRVC601:1 and L-PRVC601:1.5. Compliance was 16 and 18 ml/cmH2O with L-PRVC202:1 and L-PRVC201.5:1, while it was lower with L-IPPV201:1.5, L-PRVC601:1 and L-PRVC601:1.5. Oxygen delivery was maintained at pre-lavage level with L-PRVC201.5:1 (657 ml/min.m2), the other modes displayed reduced oxygen delivery compared with pre-lavage. CONCLUSION: Neither the rapid frequency modes nor the low frequency volume-controlled mode kept the surfactant deficient lungs open. Pressure-controlled inverse ratio ventilation (20 bpm) kept the lungs open at reduced end-inspiratory airway pressures and hence reduced risk of barotrauma. Reducing I:E ratio in this latter modality from 2:1 to 1.5:1 further improved oxygen delivery.

Analysis of Variance↗