Table 1 Analysis of accuracy of Clinical Protocol #36’s representation of research

“A Swedish study noted that most women with inflammatory mastitis had complete resolution of symptoms without need for antibiotics or other interventions. The authors attributed this finding to a focus on symptomatic control, appreciation of the physiological anti-inflammatory response, and regular communication between patient and clinician [Kvist 2007]” [1, p. 366].

In Kvist et al. 2007 participants with breast inflammation received intervention from midwife which included:

• Unspecified fit and hold advice;

• Advice which aimed to decrease intervals between feeds;

• Advice about emptying the breast by manual expression; and

• Advice about warm showers and pumping the breast [10].

“A systematic review concluded that although breast massage may reduce pain, it should not be recommended as standard of care because it requires extensive training to master atraumatic approach [Anderson et al 2019]. The most successful technique [Gua Sha] approximates manual lymphatic drainage with light sweeping of the skin rather than deep tissue massage [Witt et al 2016; Ezzo et al 2015]” [1, p. 368]

Anderson et al. conclude: “The overall effect of breast massage on reported outcomes is uncertain” [11, p. 1679].

• Gua Sha scrapes lightly from the base of the breast towards the nipple with a specialised soft instrument; patients reported decreased pain 5 and 30 min afterwards. This is opposite to light massage from nipple towards the axilla delivered in Manual Lymphatic Drainage and Therapeutic Breast Massage in Lactation (referred to as ‘lymphatic drainage’ in Clinical Protocol #36).

“Consider lymphatic drainage to alleviate interstitial edema [Ezzo et al 2015]. Figure 21” [1, p. 372]

“Figure 21. Technique of lymphatic drainage” [1, p. 371]

Ezzo et al’s 2015 Cochrane review analysed studies which combined Manual Lymphatic Drainage (MLD) with compression bandaging for breast-cancer related lymphoedema in the upper limb after surgical axillary node dissection or radiation therapy; found no benefits for limb pain and heaviness of lymphedema; contradictory or inconclusive evidence concerning improved function and quality of life [12].

• Recommending ‘lymphatic drainage’ on the basis of Ezzo et al. conflates limbs after breast cancer surgery or radiotherapy with the radically different tissue environment of the lactating breast.

• Systematic reviews of efficacy of MLD in 2020 and 2021 also show little benefit, suggesting prolonged tissue compression alone is the active ingredient [13,14,15,16].

• Witt et al. doesn’t demonstrate efficacy of ‘lymphatic drainage’ massage (also Therapeutic Breast Massage for Lactation TMBL) for breast inflammation [17], including because:

o Component evaluating TBML for plugged ducts (n = 17) and mastitis (n = 7) is pre- and post-study of small numbers;

o TBML intervention includes milk removal by infant or by hand expression, stimulating ductal dilations which explains possible efficacy [4];

o TBML delivered as part of a comprehensive breastfeeding intervention/consultation by IBCLC and/or breastfeeding medicine physician;

o Component evaluating engorgement shows no improvement in pain at day 2 or week 12.

“Fig. 19. Ice and decreased removal of breast milk reduce ductal narrowing” [Zakarija-Grkovic & Stewart 2020] [1, p. 370]

“Consider ice for symptomatic relief” [1, p. 370]

Cochrane review 2020 cold gel pack treatment for engorgement:

• Uncertainty about effectiveness of cold gel packs on breast pain because very low certainty of evidence;

• May be more effective than routine care for breast hardness in engorgement, but low-certainty evidence;

• Little difference in women’s satisfaction compared to routine care [18].

In breast inflammation generally:

• Warmth may increase stromal tension and duct compression by increasing blood flow; ductal dilation is not influenced by warmth, unless warmth is used as part of nipple stimulation.

• Cold application decreases ductal diameters in the nipple, risking decreased milk transfer [19] [20].

• No evidence to support application of compresses, hot or cold.

“Sunflower or soy lecithin 5–10 g daily by mouth may be taken to reduce inflammation in ducts and emulsify milk [Mitchell & Johnson 2020; Chan et al 2003]” [1, p. 369]

No evidence cited to support efficacy and no plausible physiological mechanism.

• In a methodologically weak retrospective audit by Mitchell & Johnson, 34 women were treated for nipple blebs, claimed to be caused by mammary dysbiosis, including with lecithin (all) and antibiotics (44%) [21].

• In Chan et al. 2003 study, lecithin directly added to a test tube of milk from mothers of prematurely born infants resulted in less loss of fat because the milk fats were less likely to adhere to the collecting device [22].

“Therapeutic ultrasound or TUS uses thermal energy to reduce inflammation and relieve edema. TUS may be an effective treatment for conditions arising in the mastitis spectrum [Mogenson et al 2020]” [1, p.370]

Mogenson et al. is narrative review of non-pharmacological approaches to pain, engorgement and plugging in lactation, not data which supports the use of TUS [23].

• Mechanisms by which TUS is proposed to “[use] thermal energy to reduce inflammation” not clarified.

• Diepeveen et al. 2019 noted little empirical evidence to support the use of TUS in lactation-related breast inflammation despite common use by Australian physiotherapists [24].

• McLachlan et al. 1991 reported TUS no more effective than placebo for engorgement [25].

• A 2012 retrospective study of 25 mothers found that 23 had resolution of plugged duct following TUS but serious methodological weaknesses [26].

• Appropriate ultrasound frequency unknown; penetration depth investigated in non-breast tissue only.

“Consider probiotics” [Crepinsek et al 2020; Oikonomou et al 2020; Amir 2016; Barker et al 2020; Fernandez et al 2016; Hurtado & Fonolla 2018]” [1, p. 370]. Levels of evidence: 1–2. Strength of recommendation: B

“Bacterial mastitis represents a progression … to an entity necessitating antibiotics or probiotics to resolve” [1, p. 363]

“Probiotics have been shown not to alter composition of human milk microbiome [Crepinsek et al 2020; Oikonomou et al 2020; Amir 2016; Barker et al 2020]” [1, p. 372]

Citation of Hurtado & Fonollo is Letter to Editor, not a study; likely meant to be Hurtado et al. 2017 [27]

• Barker et al. 2020 review identified 5 RCTs investigating probiotic consumption for treatment (3 studies) or prevention (2 studies) of mastitis, including Fernandez et al. 2016 [28] and Hurtado et al. 2017; noted significant methodological limitations concerning baseline characteristics, study hypotheses, lack of power calculations, definitional issues, potential conflicts of interest; concluded no reliable supporting evidence exists [29].

• Simpson et al. 2018 found no change in human milk microbiome composition when 415 breastfeeding women were randomized to receive probiotics or placebo [30].

“Avoid the use of nipple shields. Available evidence does not support the use of nipple shields. Neither safety nor effectiveness has been demonstrated. Nipple shields … result in inadequate breast milk extraction [McKenchie & Eglash 2010]” [1, p. 367]. Level of Evidence 3. Strength of recommendation C.

• A 2015 systematic review and 2021 review conclude that nipple shield use substantially benefits breastfeeding when problems emerge, in measurable outcomes and in reports by mothers [20, 31].

• A 2021 study randomized nipple shield use in 20 mothers with nipple pain compared to 28 without, finding nipple shields improved maternal comfort; did not impact milk removal or sucking strength in the pain group [32].

• Nipple shield use often masks failure to address underlying problems of positional instability or conditioned dialling up at the breast [6] but may be effective adjunct support for nipple pain and damage, concurrent with fit and hold repair.

“It should be noted that ultrasound studies documenting a small number of orifices approaching the nipple [Ramsay 2005] reflect limitations of radiographic images as compared with histological anatomy” [1, p. 363]

• Ramsay et al. showed dense glandular and duct tissue within a 3 cm radius of the base of nipple, and on average 9 main ducts (range 4–18) [33].

• Histological studies which reveal more nipple duct orifices than demonstrated in Ramsay et al’s ultrasound study not cited.

• Purported limitations of Ramsay et al’s ultrasound studies relative to histology not clarified.