Biomedical subjects

M Geibel

Publications and source records attributed to M Geibel.

12 recordsLinked to original sources

PubMed2004

Quantitative and qualitative differences in morphological traits revealed between diploid Fragaria species.

BACKGROUND AND AIMS: The aims of this investigation were to highlight the qualitative and quantitative diversity apparent between nine diploid Fragaria species and produce interspecific populations segregating for a large number of morphological characters suitable for quantitative trait loci analysis. METHODS: A qualitative comparison of eight described diploid Fragaria species was performed and measurements were taken of 23 morphological traits from 19 accessions including eight described species and one previously undescribed species. A principal components analysis was performed on 14 mathematically unrelated traits from these accessions, which partitioned the species accessions into distinct morphological groups. Interspecific crosses were performed with accessions of species that displayed significant quantitative divergence and, from these, populations that should segregate for a range of quantitative traits were raised. KEY RESULTS: Significant differences between species were observed for all 23 morphological traits quantified and three distinct groups of species accessions were observed after the principal components analysis. Interspecific crosses were performed between these groups, and F2 and backcross populations were raised that should segregate for a range of morphological characters. In addition, the study highlighted a number of distinctive morphological characters in many of the species studied. CONCLUSIONS: Diploid Fragaria species are morphologically diverse, yet remain highly interfertile, making the group an ideal model for the study of the genetic basis of phenotypic differences between species through map-based investigation using quantitative trait loci. The segregating interspecific populations raised will be ideal for such investigations and could also provide insights into the nature and extent of genome evolution within this group.

Crosses, Genetic↗

PubMed1999

[Daytime mechanical ventilation in chronic ventilatory insufficiency].

BACKGROUND: Nocturnal hypoventilation is associated with chronic ventilatory insufficiency (CVI). Noninvasive mechanical ventilation (NIV) performed overnight relieves symptoms of hypoventilation and improves daytime blood gases in CVI. In order to test whether the efficacy of NIV depends on its being applied during sleep we conducted a prospective case controlled study comparing daytime mechanical ventilation (DV) in awake patients with nocturnal mechanical ventilation (NV) given in equal quantities. PATIENTS AND METHODS: We enrolled 34 clinically stable patients (age: 56.1 +/- 12.1 years, 20 female) with CVI due to both restrictive lung and chest wall disorders and neuromuscular disease. Using a prospective case-control design, matched subjects were allocated alternately to DV and NV. RESULTS AND CONCLUSIONS: There were no significant differences between the groups in the improvement of the measured parameters; (e.g. PaCO2; DV: from 57.6 +/- 4.3 to 44.0 +/- 4.6 mm Hg, NV: from 55.5 +/- 3.5 to 45.0 +/- 4.1 mm Hg, p < 0.0001). We conclude that in many respects, when compared to NV, DV in awake patients is equally effective for the treatment of CVI.

Adult↗

PubMed1999

[Scintigraphic demonstration of aspiration in long-term ventilation patients with tracheotomy].

The main complication of enteral feeding in prolonged mechanical ventilation via tracheostomy is the subsequent aspiration pneumonia. We used a scintigraphic method for the detection of enteral feeding aspiration and compared the results with clinical evidence of aspiration. The study population consisted of 62 consecutive tracheotomised patients (16 females, age: 64.1 +/- 11.1 years). The swallowing test was done in an upright or semirecumbent body position with the patients spontaneously breathing. The standard feed consisted of a liquid, semiliquid and solid meal which was labelled by 100 MBQ 99 TC. Scintigraphic aspiration (SA) was defined as positive if radioactivity was detected in the bronchial system. Clinical aspiration (CA) was defined as positive if there was cough, choking and distress after swallowing; furthermore, when receiving enteral feeding during suctioning or bronchoscopy. Both clinically significant aspiration (CA) and scintigraphic aspiration (SA) were found to be identical in 10 of 62 (16%) patients. CA, but not SA: 4/62 (6.5%). SA, but not CA (Subclinical aspiration): 4/62 (6.5%). Nor CA neither SA: 44/62 (71%) patients. Radiolabelled feed can be used as a feasible marker to detect aspiration. The test is a useful screening test and strategy to minimize aspiration. The scintigraphic method failed to identify all tracheotomised patients with clinically significant aspiration. However, scintiscanning did suggest that some patients had subclinical aspiration.

Deglutition↗

PubMed1998

Blood transfusion and lung function in chronically anemic patients with severe chronic obstructive pulmonary disease.

OBJECTIVE: To study in anemic patients with chronic obstructive pulmonary disease (COPD) whether blood transfusion reduces minute ventilation and work of breathing (WOB). DESIGN: We prospectively evaluated the minute ventilation and WOB in 20 anemic adults (hemoglobin of <11 g/dL). Ten patients had severe COPD and ten patients were without lung disease. Measurements were made before and after receiving red blood cell transfusion; post-transfusion measurements were made 24 to 36 hrs after the last transfusion. SETTING: The study was performed in the intensive care unit of a tertiary referral center for home mechanical ventilation and for patients considered difficult to wean from mechanical ventilation. PATIENTS: Twenty clinically stable patients (12 female, eight male) with chronic anemia were studied. Ten patients with COPD (mean forced expiratory volume in 1 sec: 0.55+/-0.1 [SD] L) were compared with ten patients without lung disease. All participants had adequate renal and left ventricular function. INTERVENTIONS: Patients received 1 unit of packed red blood cells for each g/dL that their hemoglobin value was less than an arbitrarily defined target value of 11.0 to 12.0 g/dL. Each unit was transfused over 2 hrs and < or =3 units in total was given. MEASUREMENTS AND MAIN RESULTS: Esophageal pressure was measured from a catheter which was positioned in the middle of the esophagus. Flow was measured using a pneumotachygraph connected to a mouthpiece while a nose clip closed the nostrils during the measurements. From these data, respiratory rate, minute ventilation, and inspiratory resistive WOB were computed. Arterial blood gas values, oxygen saturation, hemoglobin, and hematocrit were also measured, and oxygen content was calculated before and 24 to 36 hrs after transfusion. In patients with COPD, hemoglobin increased from 9.8+/-0.8 to 12.3+/-1.1 g/dL due to a mean transfusion of 2.2+/-0.4 (SD) units of red blood cells. There was a reduction in the mean minute ventilation from 9.9+/-1.0 to 8.2+/-1.2 L/min (p < .0001); correspondingly, WOB decreased from 1.03+/-0.24 to 0.85+/-0.21 WOB/L (p< .0001). The capillary P(CO2) increased from 38.1+/-6.0 to 40.7+/-6.8 torr (5.1+/-0.8 to 5.8+/-0.9 kPa) (p < .05). Similarly, capillary P(O2) changed from 56.9+/-8.9 to 52.8+/-7.0 torr (7.6+/-1.2 to 7.0+/-0.9 kPa) (p < .05). In anemic patients without lung disease, minute ventilation, WOB, and the capillary blood gas values did not change after increase of the hemoglobin by a similar degree. CONCLUSIONS: We conclude that red blood cell transfusion in anemic patients with COPD leads to a significant reduction of both the minute ventilation and the WOB. In these patients, transfusion may be associated with unloading of the respiratory muscles, but it may also result in mild hypoventilation.

Aged↗

PubMed1997

[Anemia increases work of breathing in patients with lung disease].

BACKGROUND: Pulmonary diseases with marked disorders in gas exchange or chronic overload of the respiratory pump needs increased ventilatory requirements. Additionally in these patients anemic may aggravate the ventilatory load. We thereby evaluated whether in these patients treatment of anemia (red blood cell transfusion: RBCT) leads to an improvement of the ventilatory load in comparison to the anemic patients without pulmonary disease. PATIENTS AND METHODS: We examined 21 patients with an anemia (Hb < 11 g%, 12 men). Fifteen patients had a pulmonary disease (group A), 6 patients suffered from anemia without pulmonary disease (group B). Subsequently within 8 hours the patients got 2 to 3 RBCT. We studied the patients on the day of admission and 24 to 36 hours after transfusion. The patients kept bed rest for spontaneous breathing 1 hour prior to the actual examination without supplemental oxygen. Hemoglobin, hematocrit, respiratory rate, respiratory minute volume and arterial blood gases were measured. On the following day we repeated the same procedures. RESULTS AND CONCLUSIONS: Anemia in patients with an increased ventilatory requirement causes an additional increase of work of breathing. In these patients-in contrast to patients without compromised lungs-2.2 red blood cell transfusions lead to an impressive reduction of VE (about 20%) and correspondingly also to a reduction of WOB.

Aged↗

PubMed1997

[Increased physical activity due to intermittent self-ventilation in chronic respiratory insufficiency].

BACKGROUND: Nocturnal mechanical ventilation (NMV) can reduce symptoms of hypoventilation and improve gas exchange in patients with chronic respiratory failure but there is no data concerning the impact of nocturnal mechanical ventilation on daily activity. We prospectively measured daily activity as judged by total steps per day. PATIENTS AND METHODS: Thirty stable patients (17 men, mean age 55.2 years, pCO2: 62.3 +/- 9.0 mmHg) with chronic respiratory failure. DIAGNOSIS: Kyphoscoliosis (n = 11), COLD (n = 7), neuromuscular diseases (n = 6), post-tbc sequelae (n = 6). Applying a pedometer over a 7 day period before and 3 months after initiating nocturnal mechanical ventilation the steps per day were counted. We also obtained arterial blood gases and applied the St. George's Respiratory Questionnaire (scoring range from 0 = complete health to 100 = worst possible). RESULTS AND CONCLUSIONS: The daily activity in patients with hypercapnic respiratory failure as judged by the total amount of steps per day increased by 120% after 3 months of nocturnal mechanical ventilation (from 1606.9 +/- 1341.3 to 3535 +/- 1813.8 steps per day, p < 0.0001). This was associated with a significant improvement in daytime blood gases and quality of life (QoL) as judged by questionnaire (total score: from 61.3 +/- 14.9 to 48.3 +/- 18.7, p = 0.0006). However no correlation between steps per day and QoL was found.

Adult↗

PubMed1997

Endoscopic placement of a tracheal oxygen catheter: a new technique.

OBJECTIVE: In patients with chronic obstructive pulmonary disease (COPD), intratracheal oxygen insufflation (ITO) is an established therapeutic approach. We developed a new endoscopic technique of intratracheal catheter placement. The aim of this pilot study was to demonstrate its short-term feasibility in acutely extubated patients with moderate to severe COPD who require oxygen therapy. DESIGN: A guide wire was inserted through a nasally passed bronchoscope and was positioned such that its tip was placed intratracheally. Using a "Seldinger technique", the tracheal catheter was then inserted over the wire to a point 2-3 cm proximal to the carina and positioned under direct vision from the bronchoscope inserted through the contralateral nose. After catheter insertion, the guide wire was removed. The patients scored catheter-associated local discomfort using a visual analogue scale. In a randomly assigned, crossover design, the effectiveness of the endoscopically (e) inserted ITO catheter was assessed by measuring the capillary blood gases, respiratory rate (RR), tidal volume (Vt) and minute ventilation (MV) after 1 h breathing room air without eITO and 1 h after eITO (flow: 3 l/min). MEASUREMENTS AND RESULTS: The eITO catheter was placed in all patients without complications and with only minimal discomfort in two patients (spontaneously reversible cough). Compared to breathing room air, capillary O2 pressure increased (from 54.7 +/- 9.4 to 82.8 +/- 21.8 mmHg) whereas Vt (from 458.7 +/- 86.8 to 358.3 +/- 75.1 ml) and MV (from 7.7 +/- 1.5 to 5.5 +/- 1.1 l/ min) decreased significantly (each p < 0.0001) with eITO in all patients. The capillary CO2 pressure and RR did not change. CONCLUSIONS: Acutely extubated patients in whom oxygen therapy is indicated may profit from eITO. This new technique works immediately and is thus an effective short-term intervention of potential value in the intensive care unit.

Bronchoscopy↗

PubMed1997

Evaluation of a movement detector to measure daily activity in patients with chronic lung disease.

This study was designed to evaluate the performance of movement detectors (pedometers) in measuring daily activity of patients with chronic lung disease. Three groups of subjects were studied: group 1: 25 patients with stable nonhypercapnic chronic obstructive pulmonary disease (COPD) (forced expiratory volume in one second (FEV1) = 47+/-9% predicted) studied twice, one month apart; group 2: 25 patients with chronic respiratory failure studied before and three months after nasal nocturnal mechanical ventilation; and group 3: 25 normal healthy subjects studied once. The median level of activity in the healthy subjects (group 3) was three times greater than in either group of patients (groups 1 and 2). Activity levels were not correlated with age, sex or employment status. The repeatability of the activity counts in the nonhypercapnic COPD patients was high (intraclass correlation coefficient=0.94) and in these patients activity correlated significantly with FEV1 (r=0.54, p=0.006). In the respiratory failure patients, daytime arterial carbon dioxide pressure (Pa,CO2) improved following nasal nocturnal mechanical ventilation (NMV) (pre NMV: 8.5+/-1.2 kPa; post NMV: 6.2+/-0.5 kPa), health status improved (p<0.004) and daily movement count doubled (p<0.0001). This increase correlated with change in Pa,CO2 (r-0.53, p=0.006), but not with improved health status. We conclude that motion detectors may provide repeatable measures of daily activity that are related to physiological impairment and improvement following treatment. Activity counts appear to be complementary to estimates of exercise limitation obtained using health questionnaires.

Activities of Daily Living↗

PubMed1997

Daytime mechanical ventilation in chronic respiratory insufficiency.

Chronic respiratory insufficiency (CRI) is associated with nocturnal hypoventilation. Treatment with noninvasive mechanical ventilation (NIMV) performed overnight relieves symptoms of hypoventilation and improves daytime blood gases in CRI. In order to test whether the efficacy of NIMV depends on it being applied during sleep, we conducted a prospective case-controlled study comparing daytime mechanical ventilation (dMV) in awake patients with nocturnal mechanical ventilation (nMV) given in equal quantities. We enrolled 34 clinically stable patients (age 56.1+/-12.1 yrs, 20 females, 14 males) with CRI due to restrictive lung and chest wall disorders and neuromuscular disease. Using a prospective case-control design, matched subjects were allocated alternately to dMV and nMV. After 1 month of NIMV there was considerable symptomatic improvement in both dMV and nMV patients. There were no significant differences between groups in the improvement in daytime arterial carbon dioxide tension (Pa,CO2) (dMV from 7.5+/-0.6 to 5.7+/-0.6 kPa; nMV from 7.2+/-0.5 to 5.8+/-0.5 kPa, p<0.0001) and during the unassisted spontaneous night-time ventilation in terms of transcutaneous Pa,CO2 (dMV from 8.4+/-1.2 to 6.6+/-0.7 kPa; nMV from 8.2+/-1.2 to 6.8+/-0.5 kPa, p<0.0001). We conclude that in many respects, when compared to nocturnal mechanical ventilation, daytime mechanical ventilation in awake patients is equally effective at reversing chronic respiratory insufficiency. Since long-term safety issues were not addressed in this study, we recommend that nocturnal mechanical ventilation should remain the modality of choice for noninvasive mechanical ventilation.

Adult↗

PubMed1997

[Predictive value of laryngoscopy with reference to the severity of obstructive sleep apnea].

The diagnosis of sleep-related breathing disorders is based primarily upon targeted history-taking and upon night-time polysomnography. Diagnostic measures should be completed by laryngopharyngoscopy (LPS). Frequently in cases of relevant obstructive sleep-related breathing disorders, a collapse of the pharyngeal lumen may be detected already in the waking state: either during spontaneous breathing or through adequate provocation (snoring manoeuvre). Furthermore, endoscopy of the upper airways will yield indirect clues as to nocturnal snoring and possible obstructive apnoeas. Although the predictive value of LPS regarding the degree of obstructive sleep-related breathing disorders seems low compared with polysomnography, it appears reasonable to perform it to exclude further relevant ENT findings. With LPS, local and regional obstacles of the kind of the intended positive pressure ventilation (narrowing of the nasal ducts, septum deviation and hyperplasia of the turbinates) are demonstrable which may warrant surgical correction. LPS, which has a low complication rate, facilitates interdisciplinary cooperation in the care for patients suffering from obstructive sleep-related breathing disorders.

Airway Obstruction↗

PubMed1996

[Intermittent self-ventilation in torsion scoliosis. Possibilities and limits].

BACKGROUND: In patients with hypercapnic respiratory failure due to restrictive lung diseases home mechanical ventilation leads to improvement of daytime blood gases and symptoms. In this paper we regard the possible pitfalls and complications associated with intermittent mechanical ventilation in patients with kyphoscoliosis. PATIENTS AND METHODS: From 1990 to 1994 we treated 30 patients suffering from severe kyphoscoliosis with home mechanical ventilation. RESULTS AND CONCLUSIONS: 1. As our cases show in the prehospital phase before initiating home mechanical ventilation there is still room for the outpatient pneumologists to improve their knowledge and awareness of symptoms and treatment of chronic respiratory failure. 2. In the subsequent inpatient phase and specialised center must be aware and experienced in regarding possible problems inherent with home mechanical ventilation. 3. After discharge during chronic home mechanical ventilation a good cooperation between the center, patient, relatives, general services and general pulmolgists is necessary. The centers should offer training courses for the caring persons and general pneumologists.

Adult↗

PubMed1995

[Increase in hypercapnia in exercise--an unloading strategy?].

BACKGROUND: Chronic hypercapnia seems to preserve the overloaded respiratory pump from manifest muscle failure. In order to get information about the regulation of the ventilation under exercise we investigated clinical stable hypercapnic patients. PATIENTS AND METHODS: Twenty-one patients (20 males, 53.7 +/- 13.2 years) with obesity-hypoventilation syndrome (8), chronic obstructive lung disease (4), scoliosis (3), myopathy (2) and post-Tbc (2) were examined. Ventilation parameters (fb, Vt, VO2), respiratory muscle strength (PImax, PEmax), arterial blood gases (pO2, pCO2), respiratory quotient (RQ) and lactate were measured at rest and at the end of 5 minutes of maximal bicycle exercise. The control group consisted of 10 healthy persons. RESULTS AND CONCLUSIONS: A significant augmentation of the pre-existing hypercapnia under exercise (reflecting hypoventilation in relation to the predicted value) was observed in all patients with chronically overloaded respiratory muscles. This mechanism seems to be wise because it protects the respiratory pump from failure.

Adult↗