Inhalation technique

Review peak flow meter and inhaler technique... 

Direct airway administration of asthma medications through inhalation is most efficient and minimizes systemic adverse effects. Poor inhaler technique can result in increased oropharyngeal deposition of the drug with decreased efficacy and increased adverse effects. Figure 11-1 provides... 

Patients switched from an MDI to a DPI should be counseled that the DPI requires a rapid and forceful inhalation as compared to the slow inhalation used for an MDI. Patients using a DPI should also be counseled not to exhale into the device, as it will cause a loss of dose or decreased drug delivery. Because delivery technique with inhalers deteriorates over time, the health care provider should take every opportunity to reinforce appropriate inhaler technique. 

Please demonstrate your inhaler technique at every visit. 

D NOTE Inhaled dry powder capsules require a different inhalation technique. To use a dry powder inhaler, it is important to close the mouth tightly around the mouthpiece of the inhaler and to inhale rapidly. 

Evaluate therapy on a regular basis. Assess the patient s control of asthma by evaluating symptoms, PEF diary entries, and rescue medication use. Step long-term control therapy up or down based on these parameters. Before stepping up therapy, reassess the patient s inhaler technique to assure appropriate drug delivery. 

Obtain a thorough history of prescription, non-prescription, and dietary supplement use. Assess inhaler technique and adherence to the medication regimen. Ask the patient about effectiveness of medications at controlling symptoms and adverse effects. 

Review of drug therapy (dosages, adherence, inhaler technique, effectiveness, adverse effects, and drug interactions)... 

Assess inhaler technique at every visit. Have the patient demonstrate proper use of each device using a placebo inhaler or personal inhaler. Proper use of these devices is critical for therapeutic success. 

All patients on inhaled drugs should have their inhalation technique evaluated monthly initially and then every 3 to 6 months. 

Neuroimaging techniques assessing cerebral blood flow (CBF] and cerebral metabolic rate provide powerful windows onto the effects of ECT. Nobler et al. [1994] assessed cortical CBE using the planar xenon-133 inhalation technique in 54 patients. The patients were studied just before and 50 minutes after the sixth ECT treatment. At this acute time point, unilateral ECT led to postictal reductions of CBF in the stimulated hemisphere, whereas bilateral ECT led to symmetric anterior frontal CBE reductions. Regardless of electrode placement and stimulus intensity, patients who went on to respond to a course of ECT manifested anterior frontal CBE reductions in this acute postictal period, whereas nonresponders failed to show CBF reductions. Such frontal CBF reductions may reflect functional neural inhibition and may index anticonvulsant properties of ECT. A predictive discriminant function analysis revealed that the CBF changes were sufficiently robust to correctly classify both responders (68% accuracy] and nonresponders (85% accuracy]. More powerful measures of CBF and/or cerebral metabolic rate, as can be obtained with positron-emission tomography, may provide even more sensitive markers of optimal ECT administration. 

Other factors that determine the absorbed fraction of inhaled glucocorticoids include the age of the child, as lung deposition of inhaled drugs increases with age (80). Therefore, the minimum effective dose may fall as the child becomes older. Moreover, it is reasonable to hypothesize that systemic absorption will increase once asthma control is established (81). Furthermore, patient adherence and inhaler technique are two factors that can have a large influence on the amount of glucocorticoid inhaled and absorbed. 

Joshi GP. Inhalational techniques in ambulatory anesthesia. Anesthesiol Clin North America. 2003 21 ... 

In general, the creation of aerosols is technically difficult, expensive, and time-consuming. Moreover, patients need to learn specific inhalation techniques for the correct use of inhaler devices [26], and many have difficulty in using MDIs properly. Aerosol preparations are associated with significant losses of drug. Furthermore, due to the inertial impaction of the administered aerosol particles,... 

Patients who have difficulty in coordination with inhalers can use a spacer device. These remove the need for coordination between actuation of a pressurised metered dose inhaler and inhalation. The spacer device reduces the velocity of the aerosol and subsequent impaction on the oropharynx. In addition, the device allows more time for evaporation of the propellant so that a larger proportion of the particles can be inhaled and deposited in the lungs. The size of the spacer is important, the larger spacers with a one-way valve (Nebuhaler, Volumatic) being most effective. Spacer devices are particularly useful for patients with poor inhalation technique, for children, for patients requiring higher doses, for nocturnal asthma, and for patients who have poor coordination. 

No evidence to decide which device should be used in patients who cannot use pMDI. Inhaler technique must be reassessed and device found that is suitable for the patient. 

Hindle, M., Newton, D. A., and Chrystyn, H. (1993), Investigations of an optimal inhaler technique with the use of urinary salbutamol excretion as a measure of relative bioavailability to the lung, Thorax, 48, 607-610. 

Newman, S. P., Weisz, A. W., Talaee, N., and Clarke, S. W. (1991), Improvement of drug delivery with a breath actuated pressurised aerosol for patients with poor inhaler technique, Thorax, 46, 712-716. 

Gray, S.L. Williams, D.M. Pulliam, C.C. Sirgo, M.A. Bishop, A.L. Donohue, J.F. Characteristics predicting incorrect metered-dose inhaler technique in older subjects. Arch. Intern. Med. 1996,156, 984-988. 

Daniels, S. Meuleman, J. Importance of assessment of metered-dose inhaler technique in the elderly. J. Am. Geriatr. Soc. 1994, 42, 82-84. 

Practice using the inhaler in front of a mirror to ensure inhalation technique is correct (only when a dose is required ). If mist comes from the top of the inhaler or the sides of the mouth the technique is poor and another dose will be required. 

Practice the use of the inhaler in front of a mirror to ensure inhalation technique is correct. 

---