ABSTRACT
BACKGROUND: Carbon dioxide (CO2) retention during exercise is uncommon in mild to moderate lung disease in cystic fibrosis (CF). The ability to deal with increased CO2 is dependent on the degree of airflow limitation and inherent CO2 sensitivity. CO2 retention (CO2R) can be defined as a rise in P(ET)CO2 tension of > or =5 mm Hg with exercise together with a failure to reduce P(ET)CO2 tension after peak work by at least 3 mm Hg by the termination of exercise. AIM: To ascertain if carbon dioxide retention during exercise is associated with more rapid decline in lung function. METHODS: Annual spirometric and exercise data from 58 children aged 11-15 years, with moderate CF lung disease between 1996 and 2002 were analysed. RESULTS: The mean FEV1 at baseline for the two groups was similar; the CO2R group (n = 15) was 62% and the non-CO2 retention group (CO2NR) was 64% (n = 43). The decline in FEV1 after 12 months was -3.2% (SD 1.1) in the CO2R group and -2.3% (SD 0.9) in the CO2NR group. The decline after 24 months was -6.3% (SD 1.3) and -1.8% (SD 1.1) respectively. After 36 months, the decline in FEV1 was -5.3% (SD 1.2) and -2.6% (SD 1.1) respectively. The overall decline in lung function was 14.8% (SD 2.1) in the CO2R group and 6.7% (SD 1.8) in the CO2NR group. Using the primary outcome measure as a decline in FEV(1) of >9%, final multivariate analysis showed that the relative risks for this model were (95% CIs in parentheses): DeltaP(ET)CO2 11.61 (3.41 to 24.12), peak VO2 1.23 (1.10 to 1.43), and initial FEV(1) 1.14 (1.02 to 1.28). CONCLUSION: Results show that the inability to defend carbon dioxide during exercise is associated with a more rapid decline in lung function.
Subject(s)
Carbon Dioxide/metabolism , Cystic Fibrosis/metabolism , Exercise Test , Forced Expiratory Volume , Adolescent , Child , Cystic Fibrosis/physiopathology , Female , Humans , Lung/metabolism , Lung/physiopathology , Male , Odds Ratio , Pulmonary Gas Exchange , Retrospective Studies , Risk Assessment , Spirometry , Time FactorsABSTRACT
The meniscofemoral ligaments (MFL) of the knee have both functional and clinical importance, but have been poorly described. We examined 42 human cadaver knees: there was at least one MFL in every joint and both ligaments were present in 27. The anterior MFL was present in the knees in all 18 males and in 17 of the 24 females. The posterior MFL was present in 16 males and 22 females. Measurement of the ligaments showed that they were of significant size. The mean midpoint width for the anterior MFL was 5.09 +/- 1.41 mm in males and 2.99 +/- 1.29 mm in females. The mean width of the posterior MFL was 5.48 +/- 2.13 mm in males and 3.79 +/- 2.56 mm in females. The average length of the anterior MFL was 27.09 +/- 2.15 mm in males and 24.38 +/- 3.39 mm in females, and the posterior MFL was 31.13 +/- 2.54 mm and 27.59 +/- 3.74 mm, respectively. There were anatomical variations in 16 (38%) knees (62.5% female, 37.5% male), more commonly in the posterior ligament. We conclude that the meniscofemoral ligaments are anatomically and probably functionally important structures in the human knee.
