Assessing and ensuring patient safety during breath-holding for radiotherapy

Objective:

While there is recent interest in using repeated deep inspiratory breath-holds, or prolonged single breath-holds, to improve radiotherapy delivery, breath-holding has risks. There are no published guidelines for monitoring patient safety, and there is little clinical awareness of the pronounced blood pressure rise and the potential for gradual asphyxia that occur during breath-holding. We describe the blood pressure rise during deep inspiratory breath-holding with air and test whether it can be abolished simply by pre-oxygenation and hypocapnia.

Methods:

We measured blood pressure, oxygen saturation (SpO₂) and heart rate in 12 healthy, untrained subjects performing breath-holds.

Results:

Even for deep inspiratory breath-holds with air, the blood pressure rose progressively (e.g. mean systolic pressure rose from 133 ± 5 to 175 ± 8 mmHg at breakpoint, p < 0.005, and in two subjects, it reached 200 mmHg). Pre-oxygenation and hypocapnia prolonged breath-hold duration and prevented the development of asphyxia but failed to abolish the pressure rise. The pressure rise was not a function of breath-hold duration and was not signalled by any fall in heart rate (remaining at resting levels of 72 ± 2 beats per minute).

Conclusion:

Colleagues should be aware of the progressive blood pressure rise during deep inspiratory breath-holding that so far is not easily prevented. In breast cancer patients scheduled for breath-holds, we recommend routine screening for heart, cardiovascular, renal and cerebrovascular disease, routine monitoring of patient blood pressure and SpO₂ during breath-holding and requesting patients to stop if systolic pressure rises consistently >180 mmHg and or SpO₂ falls <94%.

Advances in knowledge:

There is recent interest in using deep inspiratory breath-holds, or prolonged single breath-holding techniques, to improve radiotherapy delivery. But there appears to be no clinical awareness of the risks to patients from breath-holding. We demonstrate the progressive blood pressure rise during deep inspiratory breath-holds with air, which we show cannot be prevented by the simple expedient of pre-oxygenation and hypocapnia. We propose patient screening and safety guidelines for monitoring both blood pressure and SpO₂ during breath-holds and discuss their clinical implications.

Maternal supportive and interfering control as predictors of adaptive and social development in children with and without developmental delays

BACKGROUND

Parents of children with developmental delays (DD) have been found to use more controlling behaviour with their children than parents of children with typical development (TD). While controlling behaviour is related to poorer developmental outcomes in TD children, there is little research on how it predicts outcomes in DD children. Furthermore, existing research tends to use inconsistent or non-specific definitions of controlling behaviour, often combining parent control which follows the child's goal (e.g. supportive direction) and that which interferes with the child's goal (e.g. interference).

METHODS

Participants were 200 mother-child dyads observed at child age 3, with follow-up assessments of adaptive behaviour and social skills administered at child ages 5 and 6, respectively. We coded the frequency of both types of controlling behaviour based on mothers' interactions with their children with TD (n = 113) or DD (n = 87) at age 3.

RESULTS

Mothers in the DD group used more interfering but not more supportive directive acts compared to mothers in the TD group. Adaptive behaviour was assessed at child age 5 and social skills were assessed at age 6. Higher frequency of supportive directive acts predicted better adaptive functioning for the TD group and better social skills for the DD group. Higher frequency of interfering acts predicted lower adaptive and social skills for children with DD but not with TD.

CONCLUSIONS

Results are discussed in terms of the differential developmental needs of children with and without DD as well as implications for early intervention.

Does an oscillating positive expiratory pressure device improve sputum expectoration, lung function and HRQoL when compared to ACTs in bronchiectasis?

Background:

Non-cystic fibrosis (non-CF) bronchiectasis is a chronic respiratory disorder managed with regular physiotherapy airway clearance techniques (ACTs). No systematic reviews have determined the efficacy of oscillating positive expiratory pressure (PEP) devices for patients with non-CF bronchiectasis. This review aims to compare the effectiveness of oscillating PEP devices with ACTs in bronchiectasis.

Methods:

The electronic databases (CINHAL, MEDLINE, PubMed, AMED, EMBASE and Cochrane Library) were searched in November 2013 for peer-reviewed, English Language papers comparing oscillating PEP devices and ACTs. Studies included were systematic reviews, RCTs and meta analyses. Abstract and full text screening, quality assessment and data extraction was conducted by one reviewer. Methodological quality was assessed using the PEDro appraisal tool.

Results:

A total of five studies of 114 participants were identified. Two studies reported greater production of sputum volume using oscillating PEP and one study reported significant improvement in FEV1 after 4 weeks. None of the studies reported statistically significant results. All studies were of short duration and there was significant heterogeneity between studies in terms of interventions and outcome measures. The results were unable to demonstrate clear superiority of oscillating PEP devices over ACTs, although oscillating PEP devices were preferred to ACTs and reported to be more acceptable and tolerable.

Conclusions:

It was found that oscillating PEP devices were well tolerated and clearly preferred over ACTs. This could be attributable to the novelty of independently performing a new intervention. Due to the chronic nature of bronchiectasis, adherence to treatment is an important consideration. The review concludes that oscillating PEP offers a convenient and effective alternative to ACTs.

Implications:

Standardised research protocols need to be established to eliminate heterogeneity between studies and allow direct comparison for metaanalysis. Researchers need to agree on appropriate outcome measures that will accurately assess significant change, improving the validity and reliability of the results. Long-term studies using standardised outcome measures are required to investigate the effect of the intervention on disease progression of health-related quality of life.

Proton-counting radiography for proton therapy: a proof of principle using CMOS APS technology

Despite the early recognition of the potential of proton imaging to assist proton therapy (Cormack 1963 J. Appl. Phys. 34 2722), the modality is still removed from clinical practice, with various approaches in development. For proton-counting radiography applications such as computed tomography (CT), the water-equivalent-path-length that each proton has travelled through an imaged object must be inferred. Typically, scintillator-based technology has been used in various energy/range telescope designs. Here we propose a very different alternative of using radiation-hard CMOS active pixel sensor technology. The ability of such a sensor to resolve the passage of individual protons in a therapy beam has not been previously shown. Here, such capability is demonstrated using a 36 MeV cyclotron beam (University of Birmingham Cyclotron, Birmingham, UK) and a 200 MeV clinical radiotherapy beam (iThemba LABS, Cape Town, SA). The feasibility of tracking individual protons through multiple CMOS layers is also demonstrated using a two-layer stack of sensors. The chief advantages of this solution are the spatial discrimination of events intrinsic to pixelated sensors, combined with the potential provision of information on both the range and residual energy of a proton. The challenges in developing a practical system are discussed.

Parent-child problem solving in families of children with or without intellectual disability

OBJECTIVE

To examine differences in child social competence and parent-child interactions involving children with intellectual disability (ID) or typical development (TD) during a Parent-Child Problem-Solving Task.

DESIGN

Mothers and their 9-year-old children (n = 122) participated in a problem-solving task in which they discussed and tried to resolve an issue they disagreed about. The interactions were coded on child and mother problem solving and affect behaviours, as well as the dyad's problem resolution.

RESULTS

Children with ID (n = 35) were rated lower on expression/negotiation skills and higher on resistance to the task than children with TD (n = 87). Mothers in the ID group (vs. TD group) were more likely to direct the conversation. However, there were no group differences on maternal feeling acknowledgement, engagement, warmth or antagonism. The ID dyads were less likely to come to a resolution and to compromise in doing so than the TD dyads. These group differences were not attributable to differences in children's behaviour problems.

CONCLUSIONS

Children with ID and their mothers had more difficulty resolving problems, and this increased difficulty was not explained by greater behaviour problems. Additionally, with the exception of directiveness, mothers of children with ID displayed similar behaviours and affect towards their children during problem solving as mothers of children with TD. Results suggest that the Parent-Child Problem-Solving Task is a useful way to assess social skills and associated parental behaviours in middle childhood beyond self-report. Implications for future research and intervention are discussed.

Abstract P6-08-07: Out-of-pocket spending, dermatologic quality of life, and treatment satisfaction in breast cancer radiotherapy patients

Objective: Skin toxicity is one of the most common acute side effects of breast cancer radiotherapy (RT). Past research has largely neglected non-medical out-of-pocket (OOP) spending associated with this side effect. We therefore developed a Skin Toxicity Costs (STC) questionnaire to assess such spending. The primary goal of the present study was to use the STC to estimate non-medical out-of-pocket spending associated with acute skin toxicity in breast cancer RT patients. Secondary goals included exploration of the associations between the STC, dermatologic quality of life, and satisfaction with RT.

Methods: 185 consecutive female breast cancer RT patients (Stage 0-III) participated in the research from 2008 to 2013. All participants received a course of standard fractionated external beam RT. Demographics: mean age = 55.4; 74% White, 10% African American, 16% Other; and 10% Latina. In regard to employment, 46% reported working full-time, 12% part-time, and 42% were not employed. 68% had at least a college degree and 66% reported a household income of ≥ $60,000/year. On their penultimate day of RT, participants completed the STC, the Dermatologic Life Quality Index (DLQI), and a Patient Satisfaction Questionnaire (PSQ). Patients also completed a demographics questionnaire and an Importance of Appearance Scale (IAPP) at the commencement of RT. Note: all patients were provided with skin creams free of charge through the clinic.

Results: Analyses revealed no differences in the STC, DLQI, or PSQ based on recruitment site (all ps &gt; .45). Results revealed that 83% of the sample reported OOP spending associated with skin toxicity. Mean STC spending was $245.11 (95% CI: 135.34 to 354.87; Median = $75.00). Multiple regression of demographic factors (ethnicity, race, marital status, employment, education, income) and IAPP revealed that IAPP and marital status uniquely predicted STC spending (ps &lt; .02; total model R2 = .24), such that increased STC was associated with increased importance of appearance and being unmarried. Controlling for IAPP and marital status, STC was significantly associated with DLQI (p&lt;.001), such that increased STC was associated with decreased dermatologic quality of life. Lastly, we examined whether the STC was associated with treatment satisfaction controlling for IAPP, marital status, and DLQI. Results revealed that only STC was uniquely associated with patient satisfaction (p&lt;.001; total model R2 = .39), such that patients with higher STC scores were less satisfied with their RT.

Discussion: Results are consistent with recent research suggesting that OOP spending can be considered a “financial toxicity” of cancer treatment, and is associated with lower levels of satisfaction with cancer care. However, the present study is the first to examine this issue with a focus on skin toxicity-related spending in breast cancer patients. The results suggest that OOP spending is linked to patient satisfaction with care. OOP may be a marker of skin toxicity. Future research seeking to manage skin toxicity may have the beneficial downstream consequence of reducing OOP spending and improving overall satisfaction with RT.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-08-07.