3.1 Prevalence and Epidemiology
In 13 studies in which NG was not implemented as standard protocol for all patients, the amount of ED YP administered NG feeding was between 6% - 66%.9,17,28,29,31,35-37,41-11,47 Other studies implemented NG feeding as standard practice.21-23,26,39 YP were often admitted to hospital for medical instability9,17,22,28,39,23,20,47,25 with medical instability being treated using NG either continuously or for sustained periods of time.22,44,23,20,24,25,26 In other cases, NG was implemented due to acute refusal of food or inability to meet oral intake.43,9,10,17,28,31 According to Maginot and colleagues17 NG was more likely to be required in severely malnourished patients where patients were treated by NG due to inability to manage oral intake in hospital. O’Connor and colleagues31 detected no correlation with high calorie initial feeding plans and increased use of NG feeding, where NG was implemented due to recommended oral intake not being met. Nehring and colleagues37 found that NG feeding was more likely to be required in: patients of a lower age at admission (14.3 compared to 15.3 years old, P<0.05), those with a shorter time period between disease onset and admission to hospital (P<0.0001), and longer time since last discharge (P<0.05). The reasons for initiating NG feeding are not discussed in this article. NG feeding is prescribed more commonly in Early onset (EO) AN than adult onset (20% compared to 0%, P<0.05) in a female epidemiological study.43 Clausen46 described NG as the most frequently used involuntary measure in psychiatric practice and is most commonly used in 15-17 year olds. Bayes and colleagues47 indicated that male requirements for NG are similar to those of females from a case report of 10 patients (high bias risk).
3 studies27,28,36 reviewed NG treatment for YP in different settings (one of which was high risk of bias28). Fuller and colleagues27 demonstrated discrepancies in treatment provided to YP in different settings with specialist ED units being less likely to use pumps to deliver continuous feeds, tending to give bolus feeds of higher volume. This may be due to difference in staff ability, resources available or differences in treatments between mental health (MH) and medical settings. Akgul and colleagues36 (Turkey) concluded a general paediatric ward was a viable alternative for treatment (including NG) of YP with medical instability as a result of ED when specialist mental health ward admission is not possible. Specialist ED units were superior due to expertise of staff and resources available. Street et al28 (UK) showed that patients admitted to a paediatric ward due to medical instability who were given NG due to acute refusal of oral intake may benefit from joint child and adolescent MH services (CAMHS) and paediatric input. These studies highlight that a MH ward with expertise in ED, where available, may be beneficial for treatment of ED requiring NG feeds compared to a medical ward setting if the YP is medically stable.
Almost all studies reporting initial weight gain were in a medical ward setting apart from Silber et al21 which was in a MH ward setting (and is high risk of bias). Studies focusing on refeeding protocols and daily calorie intake were mainly conducted in medical ward settings 9,17,22,24,31 (Table 3). Studies focusing on patient and staff experience of NG feeding40,45,48 were set in a MH setting apart from Neiderman and colleagues.40
This review detected that the majority of studies were conducted in affluent countries with a Caucasian majority. There were no studies from Asia, South America or Africa. In the UK three studies described NG use when there is a medical need for nutrition after oral intake is refused27,28,40 or oral diet does not fully meet the nutritional needs.31 Neiderman et al38 case reports (high risk of bias) described instances where 4 patients received NG due to medical instability. Falcoski et al30 (high risk of bias) also described 3 cases, representative of a larger group, where NG was used to manage medical instability. A similar approach was found in studies from Germany37,43 and Turkey.35,36 In Australian based studies, NG was given due to refusal of oral intake in two studies9,10 as well as to treat medical instability.26,47 A retrospective cohort study24 compared NG given continuously or as a nocturnal supplement with oral intake. Studies from North America also focused on medical instability for NG use.17,21,39,41
3.3 Reported Initial Weight Gain
Agostino et al study23 compared a higher calorie (1200-2000kcal) continuous NG fed cohort to lower calorie (800-1500kcal) oral intake; results showed greater initial weight gain in NG fed cohort with oral intake body mass change by -2.9 to +2.6kg average in the first week in the oral intake group. 51% patients in oral group lost or made no change to weight in first week. This was only 6% in NG fed cohort. There was no significant difference in groups baseline at the start. There was also greater weight gain in nocturnal NG refeeding than oral intake alone in Silber et al study21 (high risk of bias) where all male AN patients after a specific date received nocturnal NG feeding as standard practice.
O’Connor et al (UK) study31 examined the effects of a higher calorie refeeding protocol compared to standard protocol; it showed that calorie intake as low as 1200kcal per day did not cause any initial reduction in body weight. NGF was routinely used to supplement oral intake in this study. Madden et al25 (Australia) prescribed higher than standard protocol initial calories using routine continuous NG feeding aiming for 2400-3000kcal per day and did not identify any initial drop in weight of patients.
3.4 Patient and Staff Experience of Nasogastric Feeding
4 studies used qualitative methods to analyse patient, parent and professional opinions on NG feeding.10,40,45,48 Nursing assistant’s views centred around: NG being an unpleasant practice, becoming sensitized or desensitized, and the importance of developing coping mechanisms to manage the distress. Assaults on nursing assistants were also described (in a study with high risk of bias), such as head butting, hitting and abuse as a result of restraining patients during NG feeding.48 82% of Dietitians considered NG feeding a necessary procedure if oral diet is inadequate.10
YP viewed being NG fed as: an unpleasant experience, a necessary intervention, a psychological signifier of illness, and an emphasis in an underlying struggle for control by Halse and colleagues.45 Some described NG feeds as easier than eating as it “disguised” the amount due to no swallowing; others felt it was a form of punishment for not gaining enough weight. YP described manipulating the tube or syringing out the feed to prevent weight gain. Others found NG feeding a helpful motivator for oral intake.40 Neiderman and colleagues40 (high risk of bias) found 71% of YP in the study did not consent to being NG fed and 66% had to be restrained to NG feed, however later in their treatment many reflected that they understood the necessity of the procedure. Conversely the YP in Paccagnella and colleagues20 research stated NG was helpful, particularly initially when an oral diet was challenging to manage.
3.5 Feeding Regime and Calorie Intake
A variety of different feeding regimes were identified in this review which are summarised in Table 3. Refeeding protocols daily calorie intake varied greatly between studies particularly as many studies were evaluating the outcome of higher calorie refeeding protocols.9,17,22,24,31 Most studies tailored the calorie requirements to the individual patient, accounting for initial weight for height percentage and signs of medical instability. The majority commenced on daily intake of less than 2000kcal and increased periodically.
3.6 Nutritional Information of Enteral Nutrition Administered via Nasogastric Tube
Only 5 studies reported on the nutritional content of feeds in the review.17,20,23-25 YP in the NG cohort in Maginot and colleagues 17 and Agostino and colleagues23 were supplied with a formulation containing 44% carbohydrate. In Paccagnella and colleagues20 all YP displaying signs of medical instability were commenced on solely NG feeding again using a formulation containing 44% carbohydrate with 19.7% protein and 36% lipids. Madden et al25 described NG feeds containing 30% fats and less than 50% carbs. NG formula used in Parker et al24 commenced at 1kcal/mL, however 1.5kcal/mL and 2kcal/mL formulae were also used in order to increase total calorie intake. Dietary intake could also be supplemented with oral nutrition supplement drinks at 300-400kcal each.24 15/17 dietitians stated that they used vitamin and mineral supplementation prophylactically or therapeutically, More than 33% Australian dieticians reported that they administered this regardless of risk of refeeding syndrome in a cross sectional study.10
3.7 Complications Associated with NG Feeding
Complications associated with NG feeding found in this review are summarised in Table 3, with the most frequently described being nasal irritation or epistaxis, anxiety related to the procedure and electrolyte disturbance (which occurred with both oral and NG refeeding). Overall, this review found 5 studies9,17,23,24,29 reported some incidence of electrolyte disturbance, 3 studies21,29,39 described epistaxis and 2 studies39,40 described behavioural problems associated with the procedure. No study reported a YP developed RS and Nehring and colleagues37 concluded that NG feeding had no impact on growth, recovery or presence of psychiatric co-morbidities.
Kezelman and colleagues (Australia) 201826 used validated measures of anxiety and depression to assess the impact of these symptoms and core ED symptoms on weight restoration, using NG in adjunct to oral intake as part of a rapid refeeding regime. During admission symptoms reduced but this was not attributed to weight restoration in itself suggesting a high calorie rapid refeeding schedule would not exacerbate or ameliorate ED and other psychiatric symptoms.
3.8 Length of Time Receiving NG feeding
Agostino and colleagues23 delivered nutrition on a medical ward solely via NG for 14 days before commencing oral diet in addition to NG feeding. The average length of time on NG feeding in this study was 20.7 days; NG was terminated as YP accepted more than 50% oral caloric quota compared to theoretical reported quota. Madden et al22 determined the duration of NG feeding was a minimum of 14 days, using biochemical markers of medical instability in a hospital setting. Conversely, Akgul and colleagues36 described the average time YP required NG feeding as only 2.5 days before transitioning to an oral diet, where NG feeds are delivered on a hospital ward due to medical instability (Turkey).
3.9 Length of Stay Associated with NG Feeding
Length of stay was reported in studies from medical and MH ward settings, however, the specific package of treatment YP received in each study was different depending on the country of origin. For example, in Australian studies medical wards tended to include high levels of psychiatric treatment alongside medical treatment.26 Any hospital admission was significantly longer (P<0.0001) for a YP requiring NG feeding compared to those managing an oral diet in a German retrospective cohort study.37 However, this study does not discuss the reasons NG was implemented. Silber and colleagues21 highlighted that supplemental overnight NG feeding was associated with a shorter length of stay (LOS) for medical stabilisation, than those YP consuming oral intake alone (36 days compared to 39.9 days). Agostino and colleagues23 supported this, demonstrating that YP on medical wards having NG feeds had a mean LOS of 33.8 days compared to those in the same setting having an oral diet who had a mean of 50.9 days, however, the oral diet was lower in calories therefore taking longer for weight recovery and medical stabilisation.
Strik Lievers and colleagues44 concluded that factors affecting LOS on a psychiatric ward included duration of AN, need for intensive care, adherence to oral intake, presence of a comorbidity, and requirement for NG feeding when NG was implemented due to medical instability. In this study the mean LOS was significantly increased: 117 days for YP managing oral intake compared to 180 days for those requiring NG. They concluded that the requirement for NG was an indication of severity and resistance to oral feeding.44 Maginot et al study17 in a medical ward (where NG was implemented due to insufficient oral intake) suggested that NG feeding was used for YP with more severe medical problems, (such as intractable vomiting and superior mesenteric artery syndrome) and therefore took longer to transition to oral diet resulting in a longer admission.
3.10 Concurrent Therapy in Adjunct to Nasogastric Feeding
6 studies17, 22,26,29,38,39 discussed therapy as an adjunct to refeeding. In Madden and colleagues25 YP participated in family-based therapy (FBT) during their admission. Couturier and Mahmood 29 (psychiatric unit, Canada) highlighted that meal support therapy reduced the requirement for NG feeding from 66.7% to 11.1%, criteria for NG feeding was the same in both groups throughout and oral intake was encouraged. In Robb and colleagues study39 YP were provided with meal support, planned group activities, daily group therapy, individual therapy, FBT three times per week, and expressive therapy twice per week (NG delivered using supplementary nocturnal feeds). Gusella and colleagues41 (Canada) compared parent led therapy (PLT) to non-specific therapy (psychologist led talking therapy). PLT was based on FBT and included parents reducing child exercise and increasing oral intake. Results demonstrated that YP receiving PLT had a significantly reduced requirement for NG (P<0.05) (setting and indication for NG feeding not discussed). Maginot and colleagues17 (USA) concluded that YP receiving NG often required behavioural interventions in the acute refeeding phase to manage the refusal of oral intake. Patients in this study were fed via NG if oral intake was refused. Kezelman et al26 (Australia) described regular group therapy with an occupational therapist (OT) as well as a psychologist, and physiotherapy during nutritional rehabilitation with continuous followed by supplemental nocturnal NG feeds.