Category Archives: Effects of humidified

Randomized double-blind trial of the effects of humidified: DISCUSSION (4)

Humidification
Although replication of this study with a larger sample would confirm or refute present study findings, larger studies are difficult to justify based on anticipated cost savings. Consequently, we recommend that patient outcomes be monitored with routine short term nonhumidified oxygen therapy, especially for possible adverse occurrences such as dry nose and nosebleed. Findings from this study contribute new information compared with previously published studies of less rigorous design. The sample size of the present study was sufficient to achieve statistical significance and is larger than that of other studies focused on oxygen humidification reported in the literature.

Randomized double-blind trial of the effects of humidified: DISCUSSION (3)

Humidification
The lack of clinical relevance for the severity of dry nose with nonhumidified oxygen and the improvement reported by patients over three days with other symptoms/problems whether oxygen therapy was humidified or not suggests guidelines for clinicians. We recommend nonhumidification for short term low flow oxygen therapy (ie, up to three days). However, when oxygen therapy is ordered, patients should be assessed individually for their propensity for dry nose and nosebleed and, based on this assessment, clinicians may elect to order humidified oxygen for individual patients.

Randomized double-blind trial of the effects of humidified: DISCUSSION (2)

Oxygen
All symptoms except dry nose improved over time whether oxygen therapy was humidified or not. Because subject effects were accounted for in the analysis, these patterns can not be attributed to progressive attrition in symptom-prone patients during the study. Patients’ most frequent complaints at the level of “some” or greater discomfort were relative to dry mouth, cough and phlegm. Humidification did not appear to have an obvious clinical advantage in alleviating these symptoms. You will always enjoy getting proventil albuterol, being 100% sure you are safe.

Randomized double-blind trial of the effects of humidified: DISCUSSION (1)

Oxygen
Based on a pilot project, it was anticipated that a larger number of subjects would receive oxygen therapy for at least three days. However, oxygen therapy for a shorter time period (ie, 24 h or less) and decreasing lengths of stay resulted in high attrition rates, particularly noticeable with surgical patients.

Randomized double-blind trial of the effects of humidified: RESULTS (2)

Of the 16 patients who withdrew, six stated a sense of increased dryness as the reason. Four others were unwell (“too tired”, etc), two became confused, two were “not interested”, one preferred dry oxygen and one had miscellaneous reasons.

Symptom and problem scores: The primary symptom of interest was nasal dryness. Mean symptom scores for nasal dryness (Figure 1) indicate a statistically significant decrease (P=0.018) in dryness symptoms in the humidification group relative to the nonhumidification group in the first period. This difference is characterized by a slight, insignificant increase in symptoms in the nonhumidified group compared with a significant decrease (P=0.002) in the humidified arm from baseline to day 1. The same pattern difference did not occur in the second period after treatment crossover, as evidenced by a statistically significant period-treatment interaction (P=0.043) (Figure 1).

Randomized double-blind trial of the effects of humidified: RESULTS (1)

Subjects: In total 1576 nonintubated patients ordered to receive low flow supplemental oxygen were evaluated for study. Of these, 1182 did not meet inclusion criteria; 237 of the remaining 394 eligible patients became voluntary subjects after receiving information about the study. There were 157 patient refusals, with reasons stated as follows: not interested (n=63); unwell (n=40); preferred humidity (n=37); unable to comprehend concept (n=6); and miscellaneous (n=11). Most of the patients who refused had respiratory (n=77), gastrointestinal (n=30) or circulatory (n=24) disorders. The final sample included 150 medical and 87 surgical patients from seven patient care units. Data were gathered over 10 months including autumn, winter and spring.

Randomized double-blind trial of the effects of humidified: PATIENTS AND METHODS (3)

Patient symptoms
The questionnaire used for data collection was based in part on information described by Campbell et al and on the clinical expertise of the co-investigators. After being critiqued by university-based experts in medicine, nursing and educational psychology, the questionnaire was pilot tested and revised. Questionnaires were administered at the time subjects commenced oxygen therapy (day 0 – baseline data) and daily thereafter. Subjects were asked about five possible symptoms – dry nasal passage, dry mouth, dry throat, headache and chest discomfort – and they rated each symptom according to a five-item Likert scale.

Randomized double-blind trial of the effects of humidified: PATIENTS AND METHODS (2)

Patient symptoms
Procedure: Only the respiratory therapist commencing the oxygen administration knew of the patient’s random assignment to group. Patients received oxygen using two flowmeters attached to a duplex outlet. Only one flowmeter was attached to a humidification bottle so that randomization to either treatment was possible.

Randomized double-blind trial of the effects of humidified: PATIENTS AND METHODS (1)

Patient symptoms
A randomized double-blind experimental study design was used. The independent variable was the method of low flow oxygen administration. The treatment group received nonhumidified oxygen whereas the control group received humidified oxygen according to standard hospital practice. Dependent variables included symptoms of dry nose, dry mouth, dry throat, headache, chest discomfort and other possible problems (nosebleed, cough, phlegm).

Randomized double-blind trial of the effects of humidified: Introducion (2)

Patient symptoms
Previous researchers have questioned the use of tap versus sterile water with oxygen humidification as well as the optimal frequency of changing systems based on contamination rates . The impact of humidification on patients’ symptoms also has been investigated with high and low flow oxygen administration. Campbell et al questioned whether humidification was necessary for patients receiving oxygen at the rate of 5 L/min or more, and Estey studied 34 patients who received either dry or humidified oxygen therapy of 4 L/min or less.

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