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Biomedical subjects

H Bo

Publications and source records attributed to H Bo.

9 recordsLinked to original sources
PubMed2000

[Observation of biofilms inside tracheal tubes by electron microscopy and the relationship between biofilms and VAP].

OBJECTIVE: To observe the formation of biofilms inside tracheal tubes and to evaluate the effect of biofilm on the development of ventilator associated pneumonia (VAP). METHODS: Biofilms inside tracheal tubes from intubated patients were observed by scanning electron microscopy and transmission electron microscopy, meanwhile bacteria were detected in the specimens from the lower respiratory tract and the inside of tracheal tubes. RESULTS: 76% (19/25) of inner surface of tracheal tubes was coated with a confluent amorphous matrix by scanning electron microscopy. The average duration of trach-intubation in this group [(10.7 +/- 7.9) days] was longer than that in the other group [(2.1 +/- 0.8) days] in which tracheal tubes were not coated with the confluent amorphous matrix (P < 0.05). The presence of many bacteria(14/18) within these amorphous matrix was confirmed by transmission electron microscopy. Of the sixteen tracheal tubes, eleven tubes grew the same organisms that had been isolated from the secretions of the lower respiratory tract before extubation. In some VAP patients (7/8), organisms isolated from tracheal tubes were the same organisms which were pathogenic organisms of VAP. CONCLUSIONS: There was a close connection between the formation of bacterial BF and the long-term indwelling tracheal tubes. The presence of bacterial BF in the inner of tracheal tubes might be associated with the pathogenic organisms of VAP.

Adult↗
PubMed2000

[Influence of the subglottic secretion drainage on the morbidity of ventilator associated pneumonia in mechanically ventilated patients].

OBJECTIVE: To assess the influence of the subglottic secretion drainage on the morbidity of ventilator associated pneumonia in mechanically ventilated patients. METHODS: All cases requiring intubation in SICU were intubated with a special type endotracheal tube which has a small-bore cannula in its wall for subglottic secretion drainage. They were randomly divided into two groups received subglottic secretion drainage(SSD) and usual care(NON-SSD) respectively. Bacterial culture of samples from the oropharynx, subglottic secretions and lower respiratory tract were obtained periodically. The amount of subglottic secretion aspirated daily, ventilated days and the number of cases with VAP were recorded. Etiologic diagnosis of VAP was based on the quantitative bacterial culture of secretions obtained by protected specimen brush(PSB). RESULTS: The morbidity of VAP in the SSD group (n = 35) (23%) was lower than that in the NON-SSD group (n = 33) (45%) (P < 0.05). The difference was due to the significant reduction of VAP caused by gram-positive cocci and Haemophilus influenzae organisms. However, no difference was observed in the incidence of VAP caused by non-fermental bacteria. After intubation the onset of VAP was delayed in SSD group (14 +/- 8 day) as compared with the NON-SSD group (6 +/- 4 day) (P < 0.05). The same organisms were isolated by PSB among 61% (14/23) patients with VAP as what were previously isolated from the subglottic secretions. CONCLUSIONS: The presence of subglottic secretion may be an origin of the pathogenetic organisms of VAP. The morbidity of VAP in mechanically ventilated patients can be reduced by SSD, especially for VAP caused by gram-positive cocci and Haemophilus influenzae organisms. SSD may be a simple and effective method for prevention of VAP.

Glottis↗
PubMed1997

Variability of R-R, P wave-to-R wave, and R wave-to-T wave intervals.

We analyzed the effect of changing posture from supine to standing on the variability of R-R, P-R, and R-T intervals in 10 healthy volunteers using power spectral analysis. An electrocardiogram and respiratory trace were recorded before and after posture change. Variability in the P-R and R-T intervals was much less than in the R-R interval and demonstrated a lower-frequency (LF)-to-high-frequency (HF) ratio. Changing from a supine to a standing position showed no change in indexes of vagal influence on the P-R and R-T variability, in contrast to the well-documented decrease in the indexes of vagal influence on the R-R variability (HF power decreased from 2.33 to 0.41 ms2, P = 0.003; amplitude of the respiration-to-heart rate impulse response decreased from 31.6 to 14.4 ms.ml-1.s-1, P = 0.03; and LF/HF increased from 1.96 to 5.22, P = 0.005). We concluded from this study that the effects of standing were an observed reduction in vagal influence on the heart rate variability of the R-R interval and maintenance of lung volume-related vagal modulation of the P-R and R-T intervals.

Adult↗
PubMed1997

Heart rate variability following cardiac surgery fails to predict short-term cardiovascular instability.

The heart rate variability of 40 patients has been examined by spectral analysis following cardiac surgery. The heart rate variability was measured upon patient arrival in ICU in both a resting supine position, and following passive straight-leg raising. After 12 hours in ICU, the patients were classified as having been cardiovascularly stable or unstable according to a specially devised inventory. Their heart rate variability data was then examined to seek any predictor of instability. Passive straight-leg raising induced a decrease in spectral power across all of the component frequency bands. The LF/HF ratio rose with passive straight-leg raising, but failed to reach significance. None of these changes were sustained. There was no significant difference in heart rate variability patterns between the stable and unstable groups, and so no predictor was identified. Initial clinical assessment was also studied, and it too provided no reliable prediction of short-term cardiovascular instability.

Adolescent↗
PubMed1982

Supraliminal contrast sensitivity functions in recovered optic neuritis.

The supraliminal contrast sensitivity functions in patients with recovered optic neuritis were classified into three function types: 1) type with a decrease in sensitivity in the high and an increase in the low spatial frequency region, 2) type with flat shape as found in normal subjects, and 3) type with a decrease in the low and an increase in the high frequency region. These abnormal functions may be explained by an inhibitory interaction between two parallel channels of high and low frequency, which may have a dependence on the most central and the paracentral region in the visual fields, respectively. The measurements of the supraliminal contrast sensitivity functions are clinically useful for understanding the visual processes in cases with recovered optic neuritis.

Adult↗