TITLE: Effect of caregiver education on pulmonary rehabilitation, respiratory muscle
strength and dyspnea in lung cancer patients

  ABSTRACT:
[Purpose] This study evaluated the effects of caregiver education on pulmonary
rehabilitation of patients who have undergone lung resection for cancer. [Subjects]
Patients were divided into experimental (n = 22) and control
(n = 19) groups. [Methods] The caregivers of the experimental group
patients received education on pulmonary rehabilitation, while the control group patients
received general management advice for 4 weeks. [Results] Pulmonary muscle strength
(maximum inspiratory pressure and maximum expiratory pressure) was increased significantly
in the experimental group compared to the control group. Modified Borg scale scores were
decreased significantly in the experimental vs. control group. [Conclusion] Providing
caregivers with education pertaining to pulmonary rehabilitation was associated with
improved pulmonary function in lung cancer patients following lung resection.

BODY.INTRODUCTION:
Currently, complete surgical resection represents the only curative treatment for lung
cancer1). However, the majority of lung
cancer survivors who undergo lung resection experience pulmonary complications; one-third of
these patients report dyspnea, and one-fifth suffer from severely diminished pulmonary
function, including respiratory muscle weakness2). Pulmonary rehabilitation (PR) has been proposed as an adjunctive
therapy to decrease the risk of postoperative pulmonary complications3). However, patients may not be able to consistently engage in
PR, for personal or economic reasons (e.g., lacking the funds to travel to rehabilitation
centers)4). Therefore, there is a need
for alternative methods, such as home-based PR, to maintain physical functioning in a more
economical manner5). Previous studies have
focused mainly on PR for patients or hospital workers. Few studies have addressed PR
education for caregivers, who typically facilitate home-based exercises during the
outpatient period. This study evaluated the effects of caregiver education on PR (i.e.,
respiratory muscle strength and dyspnea) in lung cancer patients following lung
resection.

BODY.SUBJECTS AND METHODS:
Patients scheduled for lung resection at the Department of Thoracic Surgery of a national
university hospital, between March 2013 and November 2013, whose caregivers had not
previously received education pertaining to PR, were selected for the study. A total of 50
patients agreed to participate following an explanation of the study procedure, and written
informed consent was obtained from all participants. Ethics approval was obtained from the
Inje University Faculty of Health Science Human Ethics Committee. The subjects were randomly
assigned to experimental (n = 25) and control (n = 25)
groups the day before surgery. Of these, 3 and 6 subjects dropped out of the experimental
and control groups, respectively, during the 4-week study period, due to violation of the
exclusion criteria. Therefore, the final experimental and control groups were comprised of
22 and 19 subjects, respectively. The subjects' mean age was 60.22±10.89 years; their mean
height was 163.01 ± 8.77 cm, mean weight was 61.39±11.35 kg, and average BMI was 23.01±3.34.
They were evaluated 2 weeks (baseline) and 6 weeks after surgery. Caregiver education on PR
included guidance pertaining to splinted coughing, airway clearance and breathing, and
stretching and strengthening exercises. The control group received general advice from the
Department of Thoracic Surgery (once per week for 30 minutes) pertaining to pain management,
postoperative care, use of an incentive spirometer and nebulizer, and mobilization of the
upper limbs and trunk. In the case of subjects who were not able to visit the hospital, a
nurse telephoned them weekly to provide encouragement and clarification as necessary.
Respiratory muscle strength was assessed using a MicroRPM device (Micro Medical Ltd.,
Cambridge, UK). Maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP)
were measured using the method described by Black & Hyatt6), and these served as indices of inspiratory and expiratory muscle
strength. Dyspnea was evaluated using the modified Borg scale, ranging between 0 (no
dyspnea) and 10 (most severe dyspnea). Data were analyzed using
the SPSS for Windows software package (ver. 12.0; SPSS, Inc., Chicago, IL, USA). P<0.05
was set as indication of statistical significance. Data pertaining to the general
characteristics of subjects are provided as means ± SE, with intergroup homogeneity assessed
using χ2 and independent t-tests. Group differences in scores before the
experiment, and 2 weeks (baseline) and 6 weeks after surgery, were assessed using
repeated-measures analysis of variance.

BODY.RESULTS:
MIP, MEP and modified Borg scale values were more significantly improved in the
experimental group compared to the control group, but there were no group differences
(p<0.05, Table 1Table 1.Comparison of respiratory muscle strength and dyspneaMean± SDControlExperimentalMIP (cmH2O)Baseline62.5±21.463.8±18.24 weeks68.0±21.271.5±19.0*MEP (cmH2O)Baseline62.42±24.361.6±15.64 weeks66.5±32.571.2±16.8*MBorgBaseline3.08±1.162.45±1.464 weeks2.63±1.611.77±1.40**p<0.05).

BODY.DISCUSSION:
Refai et al.7) reported an association
between respiratory muscle weakness after lung resection and increased incidence of
pulmonary complications. Recovery of respiratory muscle function after surgery is important
because lung resection leads to impairments in these muscles. Nomori et al.8) reported a 4.3% increase in MIP, and 6.4%
increase in MEP, 2‒12 weeks after surgery. These data are consistent with our finding that
MIP and MEP increased between weeks 2‒6 in the control (8% and 6%, respectively) and
experimental (12% and 15%, respectively) groups. However, these group differences were not
significant. Previous studies demonstrated that smaller lung resection areas are associated
with greater differences in respiratory muscle strength before and after surgery8, 9). We
speculate that respiratory muscle strength did not differ significantly among our groups
because all subjects had undergone video-assisted thoracoscopic surgery, which requires a
minimal incision in the respiratory muscles interacting with the chest wall. Dyspnea caused
by lung resection is an important determinant of patients' quality of life10). Our study commenced 2 weeks after the
surgery; the experimental group was characterized by a decrease in dyspnea over time, but
this decrease was not significant compared to the control group. Differences between our
results and those of this previous study may be due to the use of indirect and direct
interventions, respectively. In conclusion, our data suggest that caregiver education on PR
can improve respiratory muscle strength and dyspnea.

Question: Compared to General management advice (control group) what was the result of Education on pulmonary rehabilitation (experimental group) on Pulmonary muscle strength?
Evidence: Modified Borg scale scores were
decreased significantly in the experimental vs. control group. 
Answer: significantly increased