Obstructive disease

Siafakas NM (ed) (2006) Management of chronic obstructive disease. European respiratory monograph 38, vol 11... 

These dragp are used with caution in patients with tachycardia, cardiac arrhythmias, hypertension, hypotension, those with a tendency toward urinary retention, those with decreased liver or kidney function, and those with obstructive disease of the urinary system or gastrointestinal tract. The anticholinergic drugp are given with caution to the older adult. 

Antiemetics and antivertigo drag s are used cautiously in patients with glaucoma or obstructive disease of the gastrointestinal or genitourinary system, those with renal or hepatic dysfunction, and in older men with possible prostatic hypertrophy. Piromethazine is used cautiously in patients with hypertension, sleep apnea, or epilepsy. Trimethobenzamide is used cautiously in children with a viral illness because it may increase the risk of Reye s syndrome... 

Asthma is a reversible obstructive disease of the lower airway. With asthma there is increasing airway obstruction caused by bronchospasm and bronchoconstriction, inflammation and edema of the lining of the bronchioles, and the production of thick mucus that can plug the airway (see Pig. 37-1). There are three types of asthma ... 

Obstructive disease reduces peak expiratory flow rate (PEFR) and increases RV via gas trapping. The TLC may also be higher although this is difficult to demonstrate without values on the x axis. The important point to demonstrate is reduced flow rates during all of expiration, with increased concavity of the expiratory limb owing to airway obstruction. The inspiratory limb is less affected and can be drawn as for the normal curve but with slightly lower flow rates. 

In contrast to obstructive disease, restrictive disease markedly reduces TLC while preserving RV. The PEFR is generally reduced. Demonstrate these points by drawing a curve that is similar in shape to the normal curve but in which the flow rates are reduced. In addition, the left-hand side of the curve is shifted to the right, demonstrating a fall in TLC. 

An intrathoracic obstruction is more likely to allow gas flow during inspiration as the negative intrathoracic pressure generated helps to pull the airways open. As such, the inspiratory limb of the curve may be near normal. In contrast, the positive pressure generated during forced expiration serves only to exacerbate the obstruction, and as such the expiratory limb appears similar to that seen in obstructive disease. Both TLC and RV are generally unaffected. 

Parmet, A., and von Essen, S. (2002). Rapidly progressive, fixed airway obstructive disease in popcorn workers A new occupational pulmonary illness /. Occup. Environ. Med. 44, 216-218. 

Cromylyn differs from the majority of medications taken for obstructive diseases of the respiratory tract in that it is used only as a preventative agent. 

They are widely used for obstructive diseases of the respiratory tract however, they are not used for severe bronchial asthma attacks. 

Because of the anticholinergic action of these agents, use with caution and with appropriate monitoring in patients with glaucoma, obstructive disease of the Gl or GU tract, and in elderly males with possible prostatic hypertrophy. These drugs may have a hypotensive action, which may be confusing or dangerous in postoperative patients. 

Gl Obstructive disease (eg, achalasia, pyloroduodenal stenosis or pyloric obstruction, cardiospasm) paralytic ileus intestinal atony of the elderly or debilitated severe ulcerative colitis toxic megacolon complicating ulcerative colitis hepatic disease. 

Contraindications Bladder neck obstruction due to prostatic hypertrophy, cardiospasm, intestinal atony, myasthenia gravis in those not treated with neostigmine, narrow-angle glaucoma, obstructive disease of the GI tract, paralytic ileus, severe ulcerative colitis, tachycardia secondary to cardiac insufficiency or thyrotoxicosis, toxic megacolon, unstable cardiovascular status in acute hemorrhage... 

Contraindications Glaucoma, obstructive uropathy, obstructive disease of Gl-anti-cholinergic tract, paralytic ileus, intestinal atony of the elderly or debilitated patient, unstable cardiovascular status in acute hemorrhage, severe ulcerative colitis especially if complicated by toxic megacolon, myasthenia gravis, hiatal hernia associated with reflux esophagitis, hypersensitivity to any component of f he formulaf ion, acuf e infermiffenf porphyria. 

Patients should be excluded from beta-blocker treatment if they have significant cardiorespiratory diseases (asthma and other pulmonary obstructive diseases, congestive heart failures, angina), insulin-dependent di-... 

NICE (National Institute for Health and Clinical Excellence) (2004) Chronic obstructive pulmonary disease - Management of chronic obstructive disease in adults in primary and secondary care. Available at http //www.nice.org.uk/nicemedia/ pdf/CGOl 2 niceguideline.pdf [Accessed 4 June 2008],... 

Q4 Patients with an obstructive disease often have to use expiratory muscles to help overcome expiratory airflow obstruction. Which accessory muscles are used and how does the shape and size of the chest eventually change in obstructive disease ... 

Forced vital capacity (FVC) measures the maximum volume of air expelled from the lung in a single forced expiration there is no time limit. Forced expiratory volume in one second (FEVi) measures the volume of air which can be expelled from the lung in one second. In a normal individual 80% of the vital capacity can be expired in one second, but patients with obstructive disease have difficulty in emptying the lung and this value is significantly reduced. 

Lung volumes are changed differently by restrictive and obstructive disease. In restrictive disease most volumes and capacities are decreased to the same extent and the ratio of FEV1/FVC is within the normal range (> 0.8). In obstructive disease FEVi is greatly reduced and the FEVi/FVC ratio is... 

Qi In obstructive disease, tests of expiratory function are the most useful. These include peak expiratory flow measurement, FVC and FEVi-In obstructive disease all these values are likely to be reduced. Normal peak flow in a mature man is approximately 500 to 6501 min-1. This may fall to <2001 min-1 in obstructive disease. FVC is likely to be 4-51 in a male adult and may fall to 1 -21. FEVi would be predicted to be 80% of FVC in a normal male, but in obstructive disease it is <70% of FVC. 

Q10 Beta-adrenoceptor antagonists are contraindicated in patients with asthma or respiratory obstructive diseases, bradycardia, heart block or heart failure. Adrenergic agonists are contraindicated in patients with closed-angle glaucoma and should be used cautiously in patients with hypertension or heart disease. Parasympathomimetics cause poor night vision and dimming of vision, because of development of miosis, headache and brow ache. Carbonic anhydrase inhibitors have a weak diuretic action and can induce depression, drowsiness, paraesthesia, electrolyte disturbance such as hypokalaemia, acidosis and lack of appetite. 

Reactive oxygen species released by neutrophils may play a role in conditions, such as inflammatory bowel disease and chronic pulmonary obstructive disease. A thiazole that inhibits in vitro production of superoxide by human neutrophils is currently being investigated in the clinic. In a convergent scheme, bromination of acyl pyridine carboxylic acid... 

Teefey, S., Baron, R.L., Schulte, S.J., Patten, R.M., Molloy, M.H. Patterns of intrahepatic bile duct dilatation at CT correlation with obstructive disease processes. Radiology 1992 182 139—142... 

The approach most commonly used to evaluate effects on distal airways in clinical and occupational medicine is the maximum forced expiratory maneuver, which allows measurement of airflows as a function of lung volume from total lung capacity to residual volume. Typically, the forced vital capacity (FVC) and the forced expiratory volume at 1 s (as a % of FVC) (FEVi) are measured. Peak expiratory flow is a frequently used measure since simple portable devices permit self-evaluation by patients with obstructive disease. Decreased airflow rates are seen with emphysema, chronic bronchitis, and following... 

Angle closure glaucoma, GI obstruction, paralytic ileus, intestinal atony, severe ulcerative colitis, prostatic hypertrophy, myasthenia gravis, megacolon, children less than 3 years Caution Treated open-angle glaucoma, heart disease, hypertension, patients with tachycardia, arrhythmias, prostatic hypertrophy, liver/renal impairment, obstructive diseases of the GI or GU tract, urinary retention... 

The use of aerosol delivery systems continues to be a desirable means of administering locally acting agents to the lungs. Since the early 1990s there has been a surge of interest in the pulmonary delivery of proteins and peptides for systemic activity but to date none of these products have made it to market [1], During this period the major commercial successes have been in the form of dry powder systems [2] and alternative propellant systems [1], as will be discussed later in the chapter. The incidence of asthma and chronic obstructive disease continues to rise and the need for improvement and diversity of therapies remains a priority in their treatment [3]. 

---