Dysphagia DOI 10.1007/s00455-015-9625-2

ORIGINAL ARTICLE

Use of Thickened Liquids to Manage Feeding Difficulties in Infants: A Pilot Survey of Practice Patterns in Canadian Pediatric Centers Stephanie Dion1 • Janice A. Duivestein2 • Astrid St. Pierre1 • Susan R. Harris3

Received: 9 October 2014 / Accepted: 11 May 2015  Springer Science+Business Media New York 2015

Abstract Improved survival rates of sick or preterm infants have resulted in an increase of observed feeding difficulties. One common method for managing feeding difficulties in infants is to manipulate liquid viscosity by adding thickening agents to formula or expressed breast milk. Concerns regarding the lack of clinical practice guidelines for the use of this strategy have been raised in the literature and in clinical settings for several years. This study aimed to survey feeding clinicians working in major Canadian pediatric centers to identify current practice patterns for use of thickened liquids in managing feeding difficulties of infants and to justify the need for standardization of this practice. A web-based pilot survey was developed using Fluidsurveys software. The questionnaire contained 37 questions targeting the process of prescribing thickeners, choice of thickener, awareness of issues, and inconsistencies raised in the literature about thickener use and how to address them. A total of 69 questionnaire responses were analyzed using descriptive statistics and inductive thematic analysis methods. Our study results indicate that thickened liquids continue to be broadly used to manage feeding difficulties in Canadian infants, despite numerous areas of concern related to their use raised by our respondents. While clear practice patterns for assessment

& Stephanie Dion [email protected] 1

BC Children’s Hospital, 4480 Oak Street, Vancouver, BC V6H 3V4, Canada

2

Sunny Hill Health Centre for Children, 3644 Slocan Street, Vancouver, BC V5M 3E8, Canada

3

Department of Physical Therapy, Faculty of Medicine, University of British Columbia, 212-2177 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada

and management were observed among the respondents, some areas of practice did not reflect recent published research or experts’ opinion. Further research to develop a systematic approach for assessment, intervention, and follow-up is warranted to guide clinicians in this complex decision-making process. Keywords Dysphagia
Survey
Deglutition disorders
Rheology
Infant feeding
Thickened liquids

Introduction Advances in neonatal care have led to improved survival rates for sick infants, particularly preterm infants. As a result, increased feeding difficulties and swallowing disorders have been observed for that population [1, 2]. Infants presenting with swallowing disorders are at risk for failure to thrive, dehydration, and respiratory complications such as aspiration pneumonia [3]. One common strategy for managing feeding difficulties in infants is to manipulate liquid viscosity by adding thickening agents to formula or expressed breast milk, to allow for better coordination of sucking, swallowing, and breathing. Studies in adults and teenagers have found that thicker liquids are slower to reach the hypo-pharynx and remain there for a shorter period of time, improving swallowing function and safety for certain populations (e.g., cerebral palsy, brain damage, and neurodegenerative disease) [4–6]. In infants, limited studies are available on the effects of thickened liquids on swallowing function. Although a small-scale study published in 2001 showed that thickened liquids prevented aspiration in infants with respiratory syncytial viral bronchiolitis [7], a systematic review published a decade later (that included this earlier study) concluded

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that the safety and efficacy of thickened liquids for children with swallowing disorders have not yet been clearly established [8]. In the presence of a swallowing disorder, using thickened liquids for the purpose of oral stimulation is often a method that feeding clinicians use to foster oral feeding in infants. Two studies that did not specifically examine the use of thickened liquids suggested that oral stimulation or early introduction of oral feeding in preterm infants promotes progression of feeding skills [9, 10]. A variety of different healthcare professionals provide intervention for infants with feeding difficulties, including speech language pathologists (SLPs), occupational therapists (OTs), dietitians, pediatricians, and registered nurses. Various types of examinations, from bedside swallow assessments to formal video-fluoroscopic swallowing studies (VFSS), may lead to potential thickener prescriptions. Once a decision has been made to prescribe a thickener, feeding clinicians can choose from a variety of thickeners and levels of thickness. Follow-up or reassessment protocols also vary. These variable patterns of practice may impact greatly on infant safety and developmental outcomes. Instrumental evaluation of infants with swallowing disorders is typically completed through a VFSS; a contrast agent, most commonly barium, is mixed with other liquids to objectify swallowing physiology. However, recent research has shown that barium-impregnated liquids are not representative of infant formula, in terms of viscosity, density, and yield stress, regardless of thickener utilized [11, 12]. These studies emphasize the importance of increasing clinician awareness of the differences, to ensure the most appropriate thickened liquid recommendations [11, 12]. The type of thickener used and the liquid being thickened, along with the thickened liquid temperature and time elapsing after preparation, may impact overall liquid thickness [13, 14]. Measurement techniques to quantify viscosity include viscometers, consistometers, and line spread tests (LST), i.e., a simple tool measuring flow distance across a flat surface. However, these tools are not currently suitable for widespread application and caution is advised in using them for quantifying thickened liquids, as they require further research and development [15]. Recently, specific warnings related to thickened liquids in infants have led to concerns about their use. In 2012, Beal and colleagues reported on 22 premature infants who developed necrotizing enterocolitis (NEC) [16].The common antecedent among the infants was ingestion of SimplyThick, a commercial gel thickener used for thickening liquid. This lead the authors to propose a possible association between SimplyThick usage and increased risk of NEC for this population. Because of this warning, the manufacturer of SimplyThick is now labeling the product

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with ‘‘not intended for use with preterm or infants under 12 months of age or children under the age of 12 years with a history of NEC’’ [17]. In Canada, the regulation states that powdered infant formulas are not recommended for use in infants at greatest risk, i.e., preterm, low-birth weight, or immuno-compromised infants, as they are not sterile products [18]. According to this regulation, most thickening agents (including infant cereals), as commercialized in a powdered form, would not qualify for use in vulnerable pediatric populations. Furthermore, based on a review by O’Connor [19], Health Canada does not recommend the use of rice cereals to thicken infant formula, due to increased caloric density and unknown implications of early introduction of rice protein into the diet. Other issues regarding thickener administration and side effects have been raised in studies involving adults. Garcia and colleagues examined issues involved in healthcare providers’ use of thickeners in the management of adult dysphagia, concluding that thickener instructions are too vague or general and may lead to inaccurate degrees of thickness [20]. Cichero reviewed literature on the impact of thickened liquids on hydration and other factors, demonstrating that adults with dysphagia are frequently dehydrated, even if the water ‘trapped’ by thickeners is liberated during digestion [21]. Concerns regarding the lack of clinical practice patterns guidelines (CPGs) for the use of thickened liquids in the management of feeding difficulties have been raised for several years. Results of a survey examining practice patterns of SLPs in using thickened liquids with adult populations by Garcia et al. [22] highlighted issues related to thickener choice and their preparation, staff training, and perceptions concerning factors that could affect patient compliance. Glassburn and Deem [23] looked at whether experienced SLPs were able to reliably mix nectar, honey, and pudding consistencies relative to their perception of these degrees of thickness. Unfortunately, extremely poor inter-rater repeatability was noted across the therapists in their attempts to mix nectar and honey consistencies in a reliable manner. This led the authors to suggest the need for a standard protocol to ensure consistent viscosities for evaluation and treatment of patients with dysphagia. More recently, Cichero and colleagues highlighted the fact that caution is required in using thickened liquids with infants, given the paucity of evidence about their use, and stressed the fact that interdisciplinary professional guidelines for this intervention are needed [24]. We could find no CPGs on the use of thickened liquids and only limited research on practice patterns for use of thickened liquids in management of infants with feeding difficulties. Evidence-based practice guidelines to ensure infant health and safety would be beneficial for clinicians. Prior to developing such guidelines, it would be useful to

S. Dion et al.: Use of Thickened Liquids to Manage Feeding Difficulties in Infants…

understand what practice patterns are currently in use for thickened liquids in managing feeding difficulties of infants in Canadian pediatric centers. The purpose of this study was to survey feeding clinicians across Canada to determine current practice patterns and to justify the need for standardization of this practice.

Methodology Participants The target group for this survey was feeding clinicians at Canadian centers offering acute and specialized pediatric care and using VFSS as a tool to assess swallowing in infants. We assumed that clinicians working in centers with VFSS equipment and expertise were typically the ones providing thickener recommendations. Clinicians involved in assessment/rehabilitation of infants of less than 12 months of age and occasionally/often involved in recommending thickened liquids for management of feeding difficulties were invited to participate. The professional practice leaders of SLPs, OTs, dietitians, or feeding team coordinators from pediatric centers of Canada offering VFSS were contacted by email or phone to enquire about approximate number of candidates meeting our inclusion criteria. Based on their responses, we anticipated that approximately 140 clinicians would meet inclusion criteria across the country. The practice leaders or feeding team coordinators were invited to forward an introductory letter with a link to the anonymous questionnaire to professionals meeting previously described criteria. Participants received full disclosure of the study’s purpose; their participation was voluntary and anonymous, meeting basic ethical considerations for human research [25]. Survey Development and Pilot Testing The survey consisted of an online anonymous questionnaire available in English and French, to facilitate completion in the two official languages of Canada. Based on our literature search, there were no previously validated questionnaires that were appropriate to meet the study’s purpose. Thus, a questionnaire was developed based on a review of the current literature on the use of thickened liquids for the management of feeding difficulties in infants. The literature review was extended to the adult population due to the paucity of information available on infants. Some questions were inspired by the questionnaire developed by Garcia et al. [22] when examining practice patterns of SLPs for using thickened liquids with adult populations; permission was received from the authors to

use and/or modify these questions. Questions targeted the process of prescribing thickeners, choice of thickener, awareness of issues, and inconsistencies raised in the literature along with how to address them. The questionnaire contained closed- and open-ended questions to assure a balance between completion time and accuracy. To assure content validity, four experienced clinicians from different fields (two OTs, one SLP, and one dietitian) reviewed the draft versions of the questionnaire and provided feedback. A statistician was also consulted to ensure appropriate question clarity, eliminate potential wording bias, maximize response rate, and ease the analysis process. A pilot version of the questionnaire was created using Fluidsurveys online software (http://fluidsurveys.com/) and was emailed to two clinicians to test its functionality. This process was repeated for the French version to ensure preserved validity with translation. The final survey consisted of 37 open- and closed-ended questions. The questionnaire was accessible online for 5 weeks, to reach a maximum number of respondents. Two reminder emails were sent over this time period.

Results The questionnaires were completed between February 21 and April 1, 2014. Data were collected online via Fluidsurveys software. A total of 69 questionnaire responses were analyzed. Of those, 15 were incomplete: eight respondents completed C50 % of questions, and the other seven completing only the first six questions. Because one can only assume that results are representative of the intended population if missing data have no systematic relationship to any variable present or unmeasured (missing at random) [26], our incomplete questionnaires were analyzed for ‘‘mechanisms of missing-ness.’’ This analysis is detailed in the limitation section. In order to maintain all potentially usable information, incomplete questionnaires were retained for analysis. This represented an estimated response rate of 49.3 %, including incomplete questionnaires. Percentages included in the following results were calculated based on the respective completion rate for each question. Responses were analyzed using descriptive statistics. For open-ended questions, the inductive thematic analysis method was used [27] and data were placed into emerging categories to examine trends. A second researcher (one of the co-authors) was consulted to help reduce processing errors and to review categories for open-ended questions. Respondent Demographics Respondents who completed the survey were OTs (65.2 %), SLPs (18.8 %), and dietitians (14.5 %). One

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S. Dion et al.: Use of Thickened Liquids to Manage Feeding Difficulties in Infants… 4 (5.8%)

10 (14.5%)

13 (18.8%)

20 (29.0%) 20 (29.0%)

1 (1.4%)

4 (5.8%)

45 (65.2%)

4 (5.8% 17 (24.6%)

Diean Brish-Columbia/Yukon

Occupaonal therapist

Fig. 1 Proportions responded

Registered Nurse

Alberta

Speech Language Pathologist

Saskatchewan/Manitoba/Northwest Territories/Nunavut Ontario

of

different

healthcare

professionals

that

registered nurse also completed the questionnaire (Fig. 1). Certain provinces were paired together to preserve anonymity of results, as some provinces had only a limited number of feeding clinicians fitting our inclusion criteria. The highest response rates came from British Columbia (29.0 %), Quebec (29.0 %), and Ontario (24.6 %) (Fig. 2). Most respondents were experienced therapists; more than half had over 10 years of experience working with infants with feeding difficulties, and more than half had more than 10 infants per month in their caseload (Table 1). The most common diagnoses of infants seen for feeding difficulties were neurological conditions (24.6 %) and prematurity (23.2 %). About one-fifth of respondents (20.3 %) did not report seeing a single most common diagnosis, but instead described working with infants with a variety of different diagnoses (20.3 %). Assessing the Need for Thickened Liquids Respondents were asked to summarize the main features of their decision-making process when assessing the need for thickened liquids in infants presenting with feeding difficulties. The vast majority of respondents (71.1 %) did recommend the use of thickened liquids for infants with feeding difficulties. Among these, 82.6 % used VFSS as their primary evaluation method when making recommendations for the use of thickened liquids (Table 2). A small number of respondents (6.5 %) reported using clinical observations only, whereas 10.9 % of respondents used clinical observations initially, combined with VFSS at times. Most respondents (67.3 %) were aware of the viscosity difference between barium-impregnated liquids used in VFSS and barium-free liquids. Among these respondents,

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Quebec New-Brunswick/Nova-Scoa/Prince-Edward Island/Newfoundland

Fig. 2 Respondents’ province of practice Table 1 Demographics of survey sample Variable

%

Years of experience in selected field \2 years

5.9

2–4 years

10.3

5–9 years

27.9

10–14 years

23.5

15–24 years

22.1

[25 years

10.3

Number of infants seen per month 1–4

27.5

5–9

15.9

10–19 20–29

24.6 14.5

[30

17.4

Most common diagnosis seen Preterm infant

23.2

Neurologic conditions

24.6

Cardiac conditions

4.3

Airway/structural issues (e.g., laryngomalacia, vocal cord paralysis)

7.2

Variety of diagnoses Developmental delay Other

20.3 5.8 14.5

69.4 % adjusted for this difference when preparing bariumimpregnated liquids for VFSS. The main adjustments that they described were adding more liquid to thin down barium (13.9 %) and mixing in slightly less thickener

S. Dion et al.: Use of Thickened Liquids to Manage Feeding Difficulties in Infants… Table 2 Assessment process for thickened liquids Variable

%

3 (7.0%) 2 (4.7%) Funding agency criteria

8 (18.6%) 6 (14.0%)

Primary evaluation method when recommending Clinical observation only Video-fluoroscopic swallow study (VFSS) or modified barium swallow (MBS)

24 (55.8%)

6.5 3 (7.1%)

82.6

8 (19.0%) Cost consideraon

19 (45.2%) 5 (11.9%) 7 (16.7%)

Clinical observations initially combined with VFSS at times 10.9 Most common reason for recommending thickened liquids Clinical signs of oral phase impairment

13.0 52.2

Radiological evidence of swallowing impairment (e.g., penetration, pooling, residue)

28.3

Oen Somemes

6.5

Clinical signs of pharyngeal phase impairment Radiological evidence of aspiration

Always

10 (23.3%)

Rarely

18 (41.9%) Ease of preparaon

Never

9 (20 9%) 1 (2.3%) 5 (11.6%)

13 (29.5%) 20 (45.5%) Availability through your center

(11.1 %). Two clinicians also reported that they were using a base barium mixture for VFSS that was standardized to be at the same viscosity as formula (from specific center guidelines). However, 22.2 % of clinicians did not clarify how they would adjust the viscosity. Primary Reasons for Recommending Thickened Liquids Use The most common reason listed for recommending a thickened liquid for infants was radiological evidence of aspiration (52.2 %) followed by radiological evidence of swallowing impairment (28.3 %, e.g., penetration, pooling, residue) (Table 2). Other less common reasons included clinical signs of oral phase impairment (6.5 %) and clinical signs of pharyngeal phase impairment (13 %). Recommendations for Reassessment of Thickened Liquids Use Respondents were asked when they would usually recommend review of the ongoing need for thickened liquids (following the initial recommendation). Most indicated that they would reassess after \3 months (47.7 %), or between 3 and 5 months (38.6 %). A smaller portion (13.6 %) reported that they would reassess after 5–11 months, while none said after 12 months. However, some respondents highlighted the fact that their timeline for reassessment was based on multiple factors and could vary from one infant to another. Reasons for Choosing Different Thickened Liquid This survey attempted to determine what criteria influenced respondent choices of thickener, and what brand/type of thickener they used most frequently (Figs. 3, 4). Most respondents reported often or always choosing a brand/type

2 (4.5%) 3 (6.8%) 6 (13.6%) 0

5

10

15

20

25

30

Fig. 3 Criteria for selecting brand or type of thickener

of thickener based on availability through their center (75.0 %) and ease of preparation (65.2 %). Consideration of cost was a less common criterion for selecting a thickener, as 45.2 % reported considering this factor only sometimes. Most respondents (69.8 %) would never or rarely choose a brand/type of thickener according to funding agency criteria. When asked if they selected thickener type/brand based on other reasons (in a subsequent question), 41.9 % mentioned considering the infant’s safety when recommending a specific product. Their responses varied, such as choosing the thickening agent with fewer documented risk factors, following the Health Canada advisory [18] and considering product contraindications (age restriction, history of prematurity, or NEC). Other reasons to select thickener brand/type are listed in Table 3. Thickener brands/types that were used most (often or always) were infant cereals (41.4 %) and Nestle Resource Thicken up Clear (26.8 %). Frequencies of use for other brands/types are shown in Fig. 4. When respondents were asked if they used other brands/types of thickeners than those listed in the questionnaire, a small portion reported using Kingsmill Quick Thick (10 %), while others (12.9 %) used Concentrated Enfamil A? thickened, a formula containing rice starch, instead of using thickeners. Respondents indicated that nectar consistency liquids were the most frequently recommended level of thickness (65.2 %), followed by half-nectar or thin nectar consistency (15.2 %). None of the respondents selected honey consistency liquids. Another segment of respondents (17.4 %) reported not recommending one consistency more than another.

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S. Dion et al.: Use of Thickened Liquids to Manage Feeding Difficulties in Infants… Fig. 4 Most common thickening agents used in the management of feeding difficulties in infants

3 (5.2%) 21 (36.2%) 12 20.7%) 9 (15.5%) 13 (22.4%)

Infant cereals

0 0 1 (2.0%) 2 (3.9%)

ThickenThin (expertFoods)

48 (94.1%) 0 0 1 (2.0%) 8 (15.7%)

Thik and Clear (NutraBalance)

Always 42 (84.2%)

Oen Somemes

10 (17.9%) 5 (8.9%) 10 (17.9%) (14.3%)

Resource Thicken Up Clear (Nestle)

Rarely Never 23 (41.1%)

1 (1.8%) 6 (10.7%) (26.8%) 7 (12.5%)

Resource Thicken Up (Nestle)

27 (48.2%) 0 6 (10.2%) 6 (10.2%) 11 (18.6%)

SimplyThick

36 (61.0%) 0

Table 3 Other criteria for selecting brand or type of thickener Criteria

%

Safety considerations

41.9

Texture or taste

14.0

Recommendations from another healthcare professional

7.0

Amount of calories

7.0

Constipation risk

7.0

Parental preference

4.7

Type of liquid being thickened

4.7

Reliability of measuring

2.3

Thickening agent ingredients

2.3

Preparation of Thickened Liquids The main parameters regarding the recommendation process for thickened liquids were targeted. Almost fourfifths (78.7 %) reported training family members to prepare thickened liquids, whereas some also reported training staff (45.2 %). In training staff, most would give verbal instructions (96.4 %), physical demonstration

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10

20

30

40

50

60

(75.5 %), and would write individualized instructions (92.9 %) when recommending a thickened liquid for infants. Less than half provided a handout for staff with standardized instructions (39.3 %). Unfortunately, the question regarding how clinicians trained family members to prepare thickened liquids had to be withdrawn due to a problem with the online version of the questionnaire. Seventy-five percent of respondents recommended consumption of thickened liquid within a specific time after mixing, and 80.4 % specified what type of liquid (e.g., formula, expressed breast milk) should be thickened. However, only 25.0 % recommended offering the thickened liquids at a specific temperature. When questioned about how clinicians ensured consistent viscosity for thickened liquids, 84 % reported following instructions provided by the manufacturer on the thickener container/package; 19.6 % used the LST, 23.3 % relied on visual appearance or spoon dribble test (observation of the liquid running off the spoon). Three clinicians (5.4 %) reported using standardized recipes developed by their institution based on LST measurements.

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Areas of Concern and Areas of Satisfaction in Using Thickening Agents The final section of the survey asked about areas of concern regarding thickened liquid use for infants with feeding difficulties and overall satisfaction with this strategy. Most respondents were familiar with specific labels found on the thickener brands SimplyThick1 (85.7 %) and Nestle Resource Thicken up Clear2 (70.9 %). Of these respondents, most would inform caregivers about this warning if considering its use (93.8 % for SimplyThick; 85.2 % for Nestle Resource Thicken Up Clear). Clinicians mainly provided verbal information regarding the label (83.3 % for SimplyThick; 73.9 % for Nestle Resource Thicken Up Clear), whereas only a few respondents reported providing families with an informational document (6.7 %for SimplyThick; 17.4 % for Nestle Resource Thicken Up Clear). Two respondents reported requesting consultation from another healthcare professional (pediatrician or dietitian) to provide information to caregivers about these labels. One respondent stated the need to obtain written consent from the caregiver when considering using either SimplyThick or Nestle Resource Thicken up Clear. When asked if they had concerns of reduced fluid intake for infants using thickened liquids to address a feeding difficulty, more than half (52.7 %) stated that they did. More than two-thirds (68.5 %) mentioned additional concerns about using thickened liquids. The reasons most frequently cited included long-term effects of thickening agents on infants (11.1 %), family compliance (9.3 %), and reliability/changes in thickness (9.3 %). Other areas of concern reported less frequently (less than 6 %) included the infant’s ability/energy to consume thickened liquids and the risk of aspiration, inconsistencies in type/frequency of medical follow-up provided after the initial thickened liquid recommendation, constipation, increased oral-motor difficulties, and implications of off-label use. Overall, 75 % of respondents thought that thickened liquids were effective for addressing feeding difficulties when used as recommended. A smaller proportion (23.1 %) was not sure of this strategy’s efficiency and only one thought that thickened liquids were not effective. Most respondents (83.6 %) reported wanting clearer guidelines about the use of thickened liquids in the management of feeding difficulties in infants.

1

‘‘Not intended for use with preterm or infants under 12 months of age or children under the age of 12 years with a history of NEC’’ [17]. 2 ‘‘This product is only suitable for individuals greater than 3 years old’’ [33].

Discussion The main objective of this pilot survey was to gain a better understanding of the practice patterns for use of thickened liquids to manage feeding difficulties in infants in Canadian pediatric centers. The results obtained reflect the opinions primarily of experienced OTs, SLPs, and dietitians who practice with infants with feeding difficulties. The questionnaire was completed predominantly by OTs. This is consistent with our clinical impression that feeding clinicians working in Canadian centers offering acute and specialized pediatric care, using VFSS and meeting our other inclusion criteria are mainly OTs, followed closely by SLPs for certain centers. However, the fact that the author who distributed the questionnaire is an OT could have resulted in a higher response rate from OTs. We believe that the response rate per province for this pilot survey was generally representative of the practices, as some provinces had no or only one major pediatric center (with the exception of Alberta where response rate was fairly low). For one-quarter of these clinicians, prematurity was, not surprisingly, the most common diagnosis for infants with feeding difficulties. This is similar to the samples in the studies by Hawdon et al. [1] and Newman et al. [2]. Some clear trends were observed among our respondents with the assessment and recommendation processes. Numerous similar areas of concern related to the use of thickened liquids in infants were also expressed. Among our respondents who recommended thickened liquids, 82.6 % used VFSS as their primary evaluation method when making recommendations for their use (see Table 2). Because VFSS has been shown to be the ideal method for identification and quantification of swallowing disorders, it is often described as the gold standard for this type of evaluation [28]. Several studies with adults have shown the ability of VFSS to detect effects of compensatory strategies, such as the manipulation of liquid viscosity on the swallowing mechanism [29–31]. Our results that showed predominant use of this strategy were expected, given the fact that our respondents had access to VFSS at their centers. Over two-thirds of our respondents (67.3 %) reported being aware of the viscosity difference between bariumimpregnated liquids used in VFSS and barium-free liquids. Of these, 69.4 % attempted to adjust for this difference when preparing barium-impregnated liquids for VFSS. The main adjustments described were adding more liquid to thin down the barium (13.9 %) or mixing in slightly less thickener (11.1 %). Our respondents’ observations are consistent with findings from Cichero et al. [11], showing that liquid barium is more viscous and dense and has a higher yield stress (force required to make a liquid flow) than infant formula. Based on the results of

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Popa Nita and colleagues [32], ‘‘matching’’ the viscosities of barium-impregnated liquids and thickened beverages is possible and can be accomplished by developing/following systematic mixing protocols. Among our respondents, only two clinicians reported using such protocols, based on specific guidelines within their centers. Our survey results showed that despite Health Canada recommendations [18, 19] and product labels [17, 33], thickened liquids continue to be used for infants with feeding difficulties. Based on current standards of practice, it is likely that the feeding clinician respondents attempted to identify other strategies to reduce aspiration (e.g., positional modifications, change of bottle or nipple, external pacing) prior to recommending thickened liquids, as outlined in the recent literature review [8], but this was not discussed in the survey. The questionnaire did not directly enquire if the risk associated with swallowing disorders could at times outweigh potential concerns of using a thickener. Of note, the most popular thickening agent used by our respondents was infant cereal (always or often used by 41.4 %). This is an interesting finding, given the fact that Health Canada does not recommend the use of rice cereal to thicken infant formula. One clinician reported a shift in her practice toward the use of rice cereal as a thickening agent, following the recent warning of increased risk associated with use of xanthan gum. However, one respondent highlighted the fact that homogenous viscosity cannot be obtained with the use of rice cereal, while another respondent mentioned that rice cereal increases iron consumption above the daily recommended intake. In the open comment sections of the questionnaire, several respondents were critical of the lack of thickening agent options available for use in infants less than 12 months old. When training staff to prepare thickened liquids, a great proportion of our respondents reported using verbal instructions (96.4 %), physical demonstration (75.5 %), and individualized written instructions (92.9 %). These practices are well aligned with observations from Chadwick et al. [34] who analyzed the effect of training support staff to modify fluids accurately and concluded that written guidance improves accuracy, and is greatest when combined with modeling, observation, and feedback from a clinician. Seventy-five percent of our respondents recommended consumption of thickened liquid within a specific time after mixing, although they were not asked to specify their

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timeline. September and colleagues [35] recently determined that a starch-based thickener would require at least 10 min to reach optimal viscosity after being mixed with infant formula. Most of our respondents (80.4 %) specified what type of liquid to use when recommending thickened liquids. This finding is reassuring, given the fact that the type of liquid being thickened (e.g., formula, expressed breast milk, etc.) influences overall liquid thickness [13]. However, only 25.0 % recommended offering the thickened liquids at a specific temperature, despite findings from Cichero et al. [11] and Garcia et al. [36] that liquid temperature impacts viscosity. Only one-fifth (19.6 %) of our respondents used the LST to ensure consistent viscosity for thickened liquids, while most clinicians (84.0 %) indicated following instructions provided by the manufacturer on the thickener container/package. Lund, Garcia and Chambers [37] compared the LST to viscometer measurements for liquids modified to nectar- and honey-like consistency, testing an extended range of liquid types (including water and whole milk) and thickening agents. They concluded that, although the LST does not replace the use of rheometers/viscometers (costly and impractical) in measuring modified liquids for research purposes, it can be used as a simple clinical training tool to prepare modified liquids to a target-level consistency. In a recent study on the implications of modifying the amount of thickener in thickened infant formula, September et al. [35] suggested that thickener quantities could be weighed, to allow better control over consistency levels and ensure reproducibility. None of our respondents reported using such a strategy. Overall, 75 % of our respondents thought that thickened liquids were effective for addressing feeding difficulties in infants less than 12 months of age, when used as recommended. However, when asked if they had concerns about using thickened liquids with this population, most respondents questioned their use for several reasons. Concern of reduced fluid intake in infants was reported by 52.7 % of respondents in one specific question. Other reasons frequently cited in an open comment section included reduced fluid intake (52.7 %), long-term effects of thickening agents on infants (11.1 %), family compliance (9.3 %), and reliability/changes in thickness (9.3 %). These concerns are consistent with those discussed by others in recent research literature or expert reviews [11, 24, 32, 35, 38]. The second goal of this pilot survey was to justify the need for standardization of the practice of using thickened liquids. While clear patterns for some aspects of the

S. Dion et al.: Use of Thickened Liquids to Manage Feeding Difficulties in Infants…

evaluation and recommendation processes were observed among our respondents, these patterns did not necessarily reflect the latest expert recommendations, justifying the need for evidence-based practice guidelines. This need was also expressed by a large percentage (83.6 %) of respondents who reported wanting clearer guidelines about the use of thickened liquids in the management of feeding difficulties in infants. Five respondents (7.2 %) provided feedback regarding the questionnaire after completing the survey. They highlighted the fact that clinical context as well as clinicians’ experience influence recommendations and follow-up processes, making answers to the questions discussed not always ‘‘black or white.’’ This is a nuance to consider when discussing the need for professional guidelines, as it is important to assure a balance between use of standardized protocols and clinical judgment/experience in order to allow for the most appropriate and individualized recommendations for use of thickened liquids.

Limitations The results described in this study represent the opinions of clinicians working in major pediatric centers in Canada where VFSS is used as a tool to assess swallowing in infants. It is acknowledged that their practice might not be fully representative of all clinicians involved in the recommendation process for thickened liquids for the management of feeding difficulties in infants, possibly decreasing external validity of the study findings. Because one can only assume that results are representative of the intended population if missing data have no systematic relationship to any variable present or unmeasured (missing at random) [26], our incomplete questionnaires were analyzed for ‘‘mechanisms of missing-ness.’’ Of the 15 incomplete questionnaires, five had more than 50 % of the questions completed. Three respondents stopped the questionnaire approximately half way through; these three had mentioned in previous questions not recommending the use of thickened liquids for this population. In this case, we can hypothesize that data were not missing at random. Seven questionnaires were minimally completed, with respondents all stopping after question six which enquired if they were recommending the use of thickened liquids for infants with feeding difficulties in their practice. Interestingly, all these respondents had answered ‘‘yes,’’ i.e., that

they used thickeners, which does not explain why they would have stopped answering the questionnaire. Another limitation of this study was related to the questionnaire, which was new and had not been validated with a wide sample of respondents. Five respondents reported not having enough comment sections throughout the questionnaire to be able to elaborate on their decisionmaking process. Unfortunately, as mentioned previously, the question regarding how clinicians trained family members to prepare thickened liquids had to be withdrawn due to a problem with the online version of the questionnaire.

Conclusion This pilot survey has identified patterns of practice used by experienced clinicians in the use of thickened liquids for assessing and managing feeding difficulties in infants in Canada. Our results show that, although some of the practice patterns identified are in alignment with those found in recent research literature or experts’ opinion, other areas of practice do not reflect these recommendations. Our study results indicate that thickened liquids continue to be used broadly as a strategy to manage feeding difficulties in infants in Canada, despite concerns about their use raised by our respondents as well as by recent product warnings and in the literature [16–19, 33]. Clearer guidelines or development of a systematic approach for assessment, intervention, and follow-up are warranted and are desired by clinicians to assist with their complex decision-making process. To ensure optimal quality of care for infants with swallowing disorders, concerns from the feeding clinicians, off-label use of commercial thickeners, and the discrepancy between advances in research and clinical practice need to be addressed. A suitable alternative to commercially available thickener that would meet criteria of safety, rheology, and ease of use has yet to be proposed for this population and would be of great importance in future research. Replication of this study in other countries would be of interest to compare their practice patterns to those in Canada. Acknowledgment The authors thank Dr. Ben Mortenson for his input on the design validity of the questionnaire. Conflict of interest conflict of interest.

All authors are free of professional areas of

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Appendix: Transcript of the Online Questionnaire

1) What is your health care profession? (Please check one) __Dietician __Occupational therapist __Registered nurse __Speech language pathologist __Other (please list): ___________________________________

2) In which province or territories do you practice? (Please check one) __British-Columbia/Yukon __Alberta __Saskatchewan/Manitoba/Northwest Territories/Nunavut __Ontario __Quebec __New-Brunswick/Nova-Scotia/Prince-Edward Island/Newfoundland *All of the following questions refer to a population of infants of less than 12 months of age only: 3) How many years have you been working with infants with feeding difficulties? ____ year(s)

4) On average, how many infants with feeding difficulties would you see every month? ____ infant(s)

5) What is the most common diagnosis of infants that you see for feeding difficulties? (please check one) __Preterm infant __Cardiac condition __Neurologic condition __Airway/structural issues (example: laryngomalacia, vocal cord paralysis, subglottic stenosis) __Other (please specify) __________________________________________________________ 6) In your practice, do you recommend the use of thickened liquids for infants with feeding difficulties? (Please check one) __Yes __No (please skip to question #14)

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7) What primary evaluation method do you use when making recommendations for the use of thickened liquids for infants? (Please check one) __Clinical observations only __Upper gastrointestinal series (UGI) or Barium swallow __Videofluoroscopic swallowing study (VFSS) or modified barium swallow (MBS) __Fiberoptic endoscopic examination of swallowing (FEES) __Other (please specify): _________________________________________________________ 8) In your practice, what is the most common reason for recommending a thickener for infants? (Please check one) __Clinical signs of oral phase impairment __Clinical signs of swallowing impairment __Radiological evidence of aspiration __Radiological evidence of swallowing impairment (for example: penetration, pooling, residue) __Nasal reflux

9) Do you recommend thickened liquids based on other reasons? (please check one) __Yes (please list) _______________________________________________________________ __No

10) Based on what criteria do you select a brand/type of thickener? Never

Rarely

Sometimes

Often

Always

Availability through your center Ease of preparation Cost consideration Funding agency criteria

11) Do you select it based on other reasons? (please check one) __Yes (please list)_______________________________________________________________ __No 12) When you recommend thickened-liquids for infant, what consistency do you recommend most frequently? (please check one) __½ nectar (i.e., thin nectar consistency) __Nectar consistency __Honey consistency __Other (please list): _____________________________________________________________

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13) After your initial recommendation, when do you usually recommend review of the ongoing need for a thickener? (Please check one) __Less than three months __Between 3 and 5 months __Between 6 and 11 months __12 months or more

14) How frequently do you use these brands/types of thickener in the management of feeding difficulties in infant? Never

Rarely

Sometimes

Often

Always

SimplyThick (SimplyThick) Resource Thicken Up (Nestle) Nestle Resource Thicken Up Clear (Nestle) Thik and Clear (NutraBalance) ThickenThin (Expert Foods) Infant cereals

15) Do you use other brands/types of thickener in the management of feeding difficulties in infants? (please check one) __Yes (please list)_______________________________________________________________ __No

16) Do you train staff to prepare thickened liquids for infants? (please check one) __Yes __No (please skip to question 18)

17) When you train staff to prepare thickened liquids for infants: Do you give verbal instructions? Yes/No Do you give a physical demonstration? Yes/No Do you give a handout with standardized instructions? Yes/No Do you give individualized written instructions? Yes/No

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18) Do you train family members to prepare thickened liquids for infants? (Please check one) __Yes __No (please skip to question #20)

19) When you train family members to prepare thickened liquids for infants: Do you give verbal instructions? Yes/No (please circle) Do you give a physical demonstration? Yes/No (please circle) Do you give a handout with standardized instructions? Yes/No (please circle) Do you give individualized written instructions? Yes/No (please circle) 20) In your practice, do you recommend offering the thickened-liquid at a specific temperature? (Please check one) __Yes __No

21) In your practice, do you recommend consuming the thickened-liquid within a specific time after mixing? (Please check one) __Yes __No

22) In your practice, do you specify what type of liquid (breast milk, type of formula, water) should be mixed with thickener? (Please check one) __Yes __No 23) In your practice, how do you ensure consistent viscosity? (Please check all that apply) __I follow instructions provided on thickener __I use line spread test measurement 24) Do you use other tools to ensure consistent viscosity (“thickness”)? (Please check one) __Yes (please list)_______________________________________________________________ __No

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25) Are you familiar with the label found on the thickener brand SimplyThick (“not intended for use with preterm or infants under 12 months of age or children under the age of 12 years with a history of NEC”)? (Please check one) __Yes __No (please skip to question #28)

26) Do you inform caregivers about this warning? (Please check one) __Yes (please list)__________ __No (please circle) (please skip to question #28) 27) How do you inform caregivers about this warning? (Please check one) __I verbally inform the caregivers __Our facility prepared an informational document that is given to caregivers __Other strategies (please describe): ________________________________________________ 28) Are you aware of the warning for the use of Nestle Resource Thicken Up Clear (“This product is only suitable for individuals greater than 3 years old”)? (please check one) __Yes __No (please skip to question #31)

29) Do you inform caregivers about this warning? (Please check one) __Yes (please list)_______________________________________________________________ __No (please skip to question #31)

30) How do you inform caregivers about this warning? (Please check all that apply) __I verbally inform the caregivers __Our facility prepared an informational document that is given to caregivers __Other strategies (please describe):_________________________________________________

31) In your practice, have you noted a difference in viscosity or “thickness” between bariumimpregnated liquids (used in UGI or VFSS) and barium free liquid? (please check one) __Yes __No (please skip to question 34)

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32) Do you adjust for this difference when preparing thickened barium-impregnated liquids? (Please check one) __Yes (describe how): ________________________________________________________ __No 33) Do you adjust for this difference when you recommend feeding an infant thickened-liquid following a UGI or VFSS? (Please check one) __Yes (describe how): ___________________________________________________________ __No 34) Do you have concerns about reduced fluid intake for infants using thickened liquids to address a feeding difficulty? (Please check one) __Yes __No __Not sure 35) Do you have additional concerns about using thickened liquids? (please check one) __Yes (please explain): ___________________________________________________________ __No 36) Overall, would you say that thickened liquids are effective for addressing feeding difficulties when used as recommended? (Please check one) __Yes __No __Not sure 37) Would you like to have clearer guidelines about the use of thickened-liquids in the management of feeding difficulties in infants? (please check one) __Yes __No References 1. Hawdon JM, Beauregard N, Slattery J, Kennedy G. Identification of neonates at risk of developing feeding problems in infancy. Dev Med Child Neurol. 2000;42:235–9. doi:10.1111/j.14698749.2000.tb00078.x. 2. Newman LA, Keckley C, Petersen MC, Hamner A. Swallowing function and medical diagnoses in infants suspected of Dysphagia. Pediatrics. 2001;6:E106. doi:10.1542/peds.108.6.e106.

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Stephanie Dion

MRSc, OT

Janice A. Duivestein

BSR OT/PT, MRSc

Astrid St. Pierre

MRSc, OT

Susan R. Harris

PhD, PT, FAPTA, FCAHS