Myths and Facts about Respiratory System

Human respiratory system organs are very vulnerable, because they are constantly in contact with airborne bacteria and hazardous substances. About quite sensitive respiratory system diseases and functions, there are many myths and fair reviews. Let’s dot the «i» together with My Canadian Pharmacy.

Canadian Neighbor Pharmacy: Results and Discussion of the Portable Chest Roentgenogram for Quantitating Extravascular Lung Water in Critically III Adults

Extravascular lung waterMeasurements of extravascular lung water (n = 73) were compared with portable chest radiographic scores in 12 patients who were supine at the time of filming (Table 1). Chest roentgenograms were monitored and measurements of extravascular lung water were taken for two to six days for each patient. Extravascular lung water measured from 3.9 ml/kg to 44 ml/kg. Portable chest radiograph scores ranged from 120 points to 390 points. The average change in lung water was 2.2 ml/kg between successive measurements, and the average change in radiographic score was 20 points. The radiographic score in points is correlated with lung water measurement expressed in milliliters per kilogram (Fig 2), (r=0.51; p<0.05). The change in radiographic score (points) is plotted against change in lung water (Fig 3). No correlation was demonstrated between the change in lung water and the change in radiographic score (points) (r=0.1; p>0.05).


This study sought to evaluate the accuracy of portable chest roentgenograms as a readily obtainable noninvasive monitor of extravascular lung water. The accuracy of the technique for measurement of lung water and the reliability of the radiographic scoring system was critical for this analysis. For the purpose of this study, careful attention was paid to a consistent quality of the portable chest roentgenograms, so that the radiographic technique would not interfere with the evaluation of any change in lung water. In spite of these attempts, it is often difficult to obtain high-quality portable chest roentgenograms in the critically ill patient, whose condition may preclude transport to the radiology suite, who may cooperate poorly during radiographic exposure, and who frequently must remain supine during filming. In a series of 200 routine portable chest roentgenograms, Greenbaum and Mar-schall reported only 6 percent of the roentgenograms to be of such poor quality as to be nondiagnostic. Our clinical experience with critically ill patients in the intensive care unit has suggested a higher percentage of poor-quality roentgenograms.

Canadian Neighbor Pharmacy: Disscusion of Chest Wall Compliances on Transmission of Airway Pressure to the Pleural Space in Critically III Patients

lung complianceThe patients concerned by the present study exhibited a wide range of lung compliances, from subnormal (group 1) to grossly deteriorated (group 3). Deterioration of lung compliance is a common finding in ARF, resulting from alveoli flooded with pulmonary edema and loss of surfactant and consolidated pulmonary areas. The three groups could also be differentiated on the basis of less sophisticated criteria, such as Pa02 levels corrected for FIo2, and therapeutic level of PEEP. In addition to reduced compliance, two other findings characterized the most diseased lungs in the present study.

Canadian Neighbor Pharmacy: Discussion of Use of Sedatives and Neuromuscular Blockers in a Cohort of Patients Receiving Mechanical Ventilation

Longer ICU stayThe main findings of this prospective, international, multicentric, observational study are as follows: (1) 68% (3,540 of 5183 patients receiving mechanical ventilation) received a sedative at any time while receiving mechanical ventilation; (2) the persistent use of sedatives was associated with more days of mechanical ventilation, more weaning days, and longer length of stay in the ICU; (3) NMBs were used in 13% (686 of 5,183 patients); and (4) patients requiring NMB has a longer duration of mechanical ventilation, weaning time, ICU stay, and higher mortality.

The use of sedatives and analgesics are very common in the ICU; however, the frequency of use of these medications is not well known. Bertolini et al found that 60% of 2,932 patients admitted to 128 adult, general ICUs received a sedative or analgesic. The most common sedatives were propofol (40%) and diazepam (34%); the most common analgesics were fentanyl (36%) and morphine (22%). In their patients, the prevalence of sedation tends to decrease linearly overtime. Unfortunately no data of outcomes were described in this study. Similarly to Bertolini et al, we found that 68% of our patients received a sedative at any moment during the ICU stay. Most of the patients received the sedative for a short period of time, and two thirds (67%) received a combination of drugs, more commonly benzodiazepines and opiates. Patients who received sedatives had longer time on mechanical ventilation, a longer weaning period, and a longer ICU stay.

Canadian Health and Care Mall: Natural History of Silent Ischemia

coronary artery diseaseTherapeutic decisions in patients with coronary artery disease are frequently based on the severity of chest pain despite the lack of correlation between severity of symptoms and prognosis. There are many circumstances in which objective evidence for myocardial ischemia is present but symptoms are absent. Episodes of so-called “silent myocardial ischemia” are very frequent in some patients with other manifestations of coronary heart disease; for example, patients with angina have no symptoms in 70 to 80 percent of all recorded ischemic episodes. While the overall incidence, spontaneous variability, and relationship of symptomatic to asymptomatic ischemia are largely unknown, this condition is being increasingly recognized. The purpose of this review is to discuss the clinical aspects of silent ischemia and the rationale for treatment (Fig 1). This information can be used to develop a strategy to help the clinician deal with this problem.

Canadian Health&Care Mall: Flow-Mediated Vasodilation – Variable Factors in FMD Measurement

Risk factors of FMDChanges in FMD have been described not only in the presence of classic risk factors, but also in a variety of other factors such as endogenous, exogenous, environmental, and familiar factors (Table 1). This observation is very interesting but makes a correct serial evaluation of FMD in the same subject or a comparison of FMD between subjects very difficult because of the special attention that should be paid to all factors that can influence FMD.

Age and gender are well-known classic risk factors. Diminished endothelial function with advancing age already has been described. The mechanisms remain uncertain but may relate to age-associated increases in reactive oxygen species production. In women, there is even an age-related decline in FMD.

Sustained arterial hypertension blunts FMD in conduit arteries in the peripheral and coronary circulation. The degree of coronary endothelial dysfunction depends on the severity and duration of arterial hypertension as indexed by the degree of left ventricular hypertrophy.” The pathogenesis of the association between endothelial dysfunction and hypertension is not fully understood. There is evidence that endothelial dysfunction may antedate and possibly contribute to the development of essential hypertension. However, the larger recent Framingham Heart study failed to determine whether endothelial dysfunction is a cause or a consequence of hypertension, or, alternatively, whether FMD and systolic BP are associated with a third factor, such as arterial stiffness.

Canadian Health&Care Mall: Ratio Scales of Breathlessness

pulmonary edemaBy asking subjects to estimate directly the magnitude of sensory stimuli such as light intensity, sound, taste, perceived force, etc, Stevens and others have established that man can quantify the magnitude of his sensory experience in a reliable and meaningful sense. When the magnitude of a muscle force doubles (F), the perceived or sensory magnitude (Y) increases threefold (Y = KFL7). The nature of this relationship is known not only for muscle force but for light intensity, sound intensity, taste, thermal sensation to mention a few. For equal physical magnitude ratios, there are equal sensory magnitude ratios which are constant. The uniqueness of the relationship for given sensory modality has established that within certain limits of precision, man can make an accurate quantitative interpretation of his sensory experience.

Canadian Neighbor Pharmacy: Peak Expiratory Flow With or Without a Brief Postinspiratory Pause

Peak expiratory flowPeak expiratory flow (PEF), the maximal flow that can be achieved during a forceful expiration at total lung capacity (TLC), is an important parameter that is used to monitor airway obstruction. PEF is determined in large part by the lung volume, lung elastic recoil, and muscular effort. Studies in healthy volunteers and patients with lung diseases showed that the type of inspiratory maneuver preceding forceful expiration could affect the magnitude of PEF. The values of PEF are significantly higher if the FVC maneuver is preceded by fast inspiration without a postinspiratory pause than when it is preceded by a slow inspiration with a 4 to 6-s postinspiratory pause. This dependence of PEF on the length of postinspiratory duration is best explained on the basis of the lung elastic recoil pressure, which is time-dependent, and, therefore, the longer pause will result in lower effective lung elastic recoil pressure prior to expiration and, thus, lower PEF. An additional mechanism that could also lead to greater PEF values with the fast inspirations is related to enhancements of expiratory muscle force output because of the stretch-shorten cycle.

Currently, the published guidelines’ for measuring PEF provide no precise recommendations about the speed of inspiration preceding expiration and the appropriate duration of the postinspiratory pause. Although long postinspiratory pauses (ie, > 3 s) are generally not used, pauses of < 2 s are often allowed prior to expiration in most pulmonary laboratories. The extent to which these brief pauses may similarly affect measurements of PEF is unknown.

Randomized Clinical Trial of Intramuscular vs Oral Methylprednisolone: Patients

Patients fulfilling the entry criteria were approached by treating physicians or trained research associates for enrollment into the trial. Written, informed consent was obtained from all participants. A data collection instrument was completed by trained research associates. All eligible patients received nebulized P-agonist agents and an IV injection of 1 mg/kg methyl-prednisolone as standard ED treatment.

Randomized Clinical Trial of Intramuscular vs Oral Methylprednisolone: Study Setting and Population

Patients were enrolled from the EDs of two hospitals with a combined adult ED census of 130,000 patients. Patients were considered to be eligible for study entry if they were 18 to 45 years of age and were expected to be discharged from the ED following treatment for an acute asthma exacerbation. This diagnosis was based on the American Thoracic Society Guidelines for the evaluation of impairment/disability in patients with asthma, and included both clinical symptoms and physical examination findings. Eligibility criteria also required a peak expiratory flow rate (PEFR) of < 70% predicted during the ED visit, and a minimum PEFR of > 40% predicted. PEFR entry criteria were included to define an appropriate study population that was ill enough to merit corticosteroid therapy, but was well enough to be managed as outpatients. Predicted values were calculated in the standard fashion, based on age and height. Patients who had other chronic lung diseases, who had known or suspected bacterial pneumonia, who had received systemic corticosteroid therapy in the past month, who currently used theophylline, mast cell stabilizers, or inhaled anticholinergic agents, who had a current illness precluding use of corticosteroids, or who had an allergy to methylprednisolone were excluded from the study.

Pages: 1 2 3 4 5 6 7 8 9 10 ... 72 73 74 Next