Search results
Results from the WOW.Com Content Network
IRDS affects about 1% of newborns and is the leading cause of morbidity and mortality in preterm infants. [5] Data have shown the choice of elective caesarean sections to strikingly increase the incidence of respiratory distress in term infants; dating back to 1995, the UK first documented 2,000 annual caesarean section births requiring ...
Low tidal volumes (V t) may cause a permitted rise in blood carbon dioxide levels and collapse of alveoli [10] because of their inherent tendency to increase shunting within the lung. Physiologic dead space cannot change as it is ventilation without perfusion. A shunt is a perfusion without ventilation within a lung region. [citation needed]
The table shown on the right can be used in a two-sample t-test to estimate the sample sizes of an experimental group and a control group that are of equal size, that is, the total number of individuals in the trial is twice that of the number given, and the desired significance level is 0.05. [4] The parameters used are:
Temporality: The effect has to occur after the cause (and if there is an expected delay between the cause and expected effect, then the effect must occur after that delay). Biological gradient (dose–response relationship): Greater exposure should generally lead to greater incidence of the effect. However, in some cases, the mere presence of ...
Airway resistance is not constant. As shown above airway resistance is markedly affected by changes in the diameter of the airways. Therefore, diseases affecting the respiratory tract can increase airway resistance. Airway resistance can also change over time. During an asthma attack the airways constrict causing an increase in airway resistance.
X would be a necessary cause of y when the occurrence of y implies that x needed to have occurred. However, only the occurrence of the necessary condition x may not always result in y also occurring. [2] In other words, when some factor is necessary to cause an effect, it is impossible to have the effect without the cause. [3]
The new study was based on an analysis of medical records spanning six years from more than 16,800 patients in the Boston area, none of whom were initially diagnosed with NAION.
Intuitively, the lower the number needed to harm, the worse the risk factor, with 1 meaning that every exposed person is harmed. NNH is similar to number needed to treat (NNT), where NNT usually refers to a positive therapeutic result and NNH to a detrimental effect or risk factor. Marginal metrics: NNT for an additional beneficial outcome (NNTB)