CHD is one of the most common congenital structural deformities, and approximately 2–3% of newborns suffer from CHD Reference Hoffman and Kaplan1 . Some infants with non-restricted ventricular septal defect and moderate-to-severe pulmonary hypertension require early medical intervention. Traditional surgical correction is the most important method for treating this type of VSD. Reference Eskedal, Hagemo, Eskild, Aamodt, Seiler and Thaulow2 With the continuous improvement of medical standards and surgical techniques, these patients’ post-operative survival rate has improved significantly. Due to preoperative nutritional status and poor health, perioperative surgical trauma, and myocardial ischaemia–reperfusion injury, patients are prone to various complications after surgery. Amongst these related complications, post-operative pneumonia and gastrointestinal insufficiency are amongst the most common complications, which seriously affect the post-operative recovery of these patients. Reference He, Chen and Li3,Reference Shaath, Jijeh, Faruqui, Bullard, Mehmood and Kabbani4
Numerous studies had shown that oral care could effectively reduce the incidence of pneumonia in critically ill patients and reduce the use of mechanical ventilation after surgery. Reference Fernandez Rodriguez, Peña Gonzalez, Calvo, Chaves Sanchez, Pallas Alonso and de Alba Romero5–Reference Cutler and Sluman8 Prior studies had shown that using breast milk for oral care in infants was more effective in preventing ventilator-associated pneumonia than traditional oral care solutions such as physiological saline or sterile water. Reference Brandtzaeg9 However, few reports described the use of breast milk for oral care in infants who underwent surgical correction of VSD. This study aimed to explore the clinical effect of employing breast milk oral care for infants who underwent surgical correction of VSD.
Methods
Research object
This present study was approved by the ethics committee of our hospital. All parents of infants signed the informed consent form before participating in the study. This study was a prospective randomised controlled study conducted by a provincial hospital in Fujian Province, China. Calculation of the sample size was based on the incidence of post-operative complications in the two groups of patients in the preliminary experiment. Assuming that the difference between the two independent populations was 10%, α = 0.05, β = 0.2, the calculated result of each group was 25 patients. Assuming a 10% dropout rate, the total sample size required in this study was 56 cases (28 cases per group).
The clinical data of 56 infants with non-restricted VSD who underwent surgical correction under cardiopulmonary bypass in our hospital between January, 2020 and July, 2020 were collected. The patients were randomly divided into an intervention group (breast milk oral care group) or a control group (physiological saline oral care) according to the method of computer-generated random numbers. When the patients participated in this study, the researchers randomised the grouping in a double-blind manner and collected relevant data. The ICU physicians, caregivers, and statisticians did not know the patients’ grouping. The inclusion criteria were the following: infants underwent surgical correction of non-restricted VSD under cardiopulmonary bypass and completed the operation; the uncuffed tracheal intubation was used; post-operative haemodynamics was stable; and echocardiography confirmed satisfactory corrected results of cardiac malformations. The exclusion criteria were as follows: (1) infants with severe liver and kidney dysfunction; (2) complications with gastrointestinal deformities or other organ deformities; and (3) infants whose family members refused to participate in this study.
Intervention method
A unified professional nursing team performs oral care. In the breast milk oral care group, the secretions in the oral cavity and subglottis of the infants were exhausted by using a negative pressure suction device before oral care. Then, breast milk was used to sequentially scrub the lips, cheeks, gums, hard palate, tongue, sublingual, and endotracheal tube wall of the patients. Each part required at least one cotton swab, each part was wiped for 30 seconds, and patients received oral care q3h. Breast milk was used for oral care for infants who were breastfeeding, and donor milk was used for infants without available breast milk. And breast milk for oral care was used for patients until oral feeding was possible. In the physiological saline oral care group, the same oral cleaning was performed in the intervention group before implementing oral care. Then, physiological saline was used for oral care, and the procedures were the same as in the intervention group.
Data collection and definitions
The general data, including the patients’ age, gender, weight, time of operation, cardiopulmonary bypass time, and time of aortic occlusion, were recorded. The mechanical ventilation duration, the length of post-operative ICU stay, the time of start feeding and total enteral nutrition, and the length of hospital stay in the two groups of patients were collected by a third independent researcher. Post-operative complications, including pneumonia, sepsis, low cardiac output syndrome, arrhythmia, liver insufficiency, renal insufficiency, gastrointestinal bleeding, and poor incision healing, and were also documented.
LCOS was defined as blood pressure lower than the age-related normal values and central venous oxygen saturation value <30% of the arterial saturation, accompanied by diuresis <1 ml/kg/h and peripheral temperature <32°C, and serum lactate >3 mmol/L. Reference Cavigelli-Brunner, Hug and Dave10 The diagnosis of post-operative pneumonia was based on the criteria established by the Centers for Disease Control and Prevention, with diagnosis aided by chest radiographs, positive sputum cultures, transtracheal fluid, bronchial washings, and clinical findings. Reference Horan, Andrus and Dudeck11 Renal insufficiency was defined as two times the upper limit of normal value of serum creatinine of the same age or two times the basic value of serum creatinine. Reference Goldstein, Giroir and Randolph12 Liver insufficiency was defined as ALT was greater than two times the normal value of the same age, or total bilirubin was greater than 40 mg/L. Reference Goldstein, Giroir and Randolph12
Statistical analysis
SPSS 18.0 software was used for statistical analysis in this study. Continuous data were presented as the mean ± standard deviation and range. These variables were confirmed to be normal distribution by the normal distribution test. Clinical parameters between the two groups were compared with the independent samples t-test. The χ2 or Fisher’s exact test was used for categorical variables. A p-value <0.05 was considered to be significant.
Results
There were no significant differences in age, gender, weight, operation time, cardiopulmonary bypass time, or aortic cross-clamping time between the two groups, which meant that the two groups of patients were homogeneous and comparable (Table 1).
Table 1. Comparison of the general data between the two groups
Compared with the physiological saline oral care group, the mechanical ventilation duration, the length of ICU stay were significantly shorter in the breast milk oral care group. The length of hospital stay in the breast milk oral care group was shorter than that in the physiological saline oral care group, but the difference was not statistically significant. Besides, patients in the breast milk oral care group had a significant time advantage in time to start feeding and total enteral nutrition time. The incidence of post-operative pneumonia in the breast milk oral care group was 3.6%, which was significantly lower than that of the physiological saline oral care group. There were no significant differences in post-operative LCOS, sepsis, arrhythmia, liver insufficiency, renal insufficiency, gastrointestinal bleeding, or poor incision healing between the two groups (Table 2). There was no significant difference in antibiotic use between the two groups.
Table 2. Comparison of the post-operative date between the two groups
Discussion
Some patients with non-restricted VSD require surgical treatment in infancy due to their severe pathophysiology and physical condition. Open heart surgery in these infants should be performed under general anaesthesia, hypothermic status, and cardiopulmonary bypass. Post-operative mechanical ventilation is often needed to assist in improving patients’ circulatory function. However, due to prolonged mechanical ventilation, surgical trauma, and decreased immunity, the possibility of post-operative pneumonia in infants correspondingly increases. Meanwhile, infants’ immune function is low, pulmonary function is not yet fully developed, and a series of pathophysiological changes caused by cardiac malformations may make infants more likely to develop post-operative pneumonia after surgical correction of VSD. Reference Roeleveld, Guijt, Kuijper, Hazekamp, de Wilde and de Jonge13 Once post-operative pneumonia occurs, it aggravates the condition of the patient and increases the difficulty of care, affects the patients’ prognosis, prolongs the length of hospital stay, increases economic pressure, and the psychological burden of the patients’ family. Reference Azab, Sherbiny and Saleh14 Therefore, strengthening post-operative airway management, providing the right nursing intervention, and reducing the incidence of post-operative pneumonia are the critical factors for improving the prognosis of infants undergoing cardiac surgery.
Post-operative pneumonia is a severe complication that can increase patient mortality. Reference Chastre, Luyt, Trouillet and Combes15 Studies have found that ventilator-associated pneumonia was primarily attributable to reduce the saliva in the oral cavity and dry oral mucosa during ventilator-assisted breathing, which led to a decrease in oral self-cleaning ability and caused a large number of pathogenic bacteria in the oropharynx to multiply and followed the intubation translocation. Reference Tan, Zhang and Zhang16–Reference Ma, Yang, Li, Zhang and Kang18 Therefore, strengthening oral hygiene care might play an important role in preventing and treating post-operative pneumonia. At present, physiological saline, sterile water, and sodium bicarbonate for oral care are routinely used clinically, but there are still some disadvantages to these practices. Reference Ahn, Jun, Kim and Sohn19
Breast milk contains many biologically active substances, including various immunoglobulins and cytokines, which provide health protection at various developmental stages in infants. Reference Lee, Kurtin and Wight20 Amongst these substances, lactoferrin and secretory immunoglobulin A are present in large amounts in breast milk and have bacteriostatic, antibacterial, antiviral, anti-inflammatory, and immunomodulatory effects. Breast milk can inhibit pathogenic bacteria’s attachment to the oral mucosa and gastrointestinal mucosa to protect mucosal integrity and prevent infection. Breast milk also contains various beneficial bacterial strains, such as Bifidobacterium, which can be colonised in the baby’s mouth to prevent pathogenic bacteria from colonising the gastrointestinal tract and respiratory tract mucosa. Therefore, breast milk can be used in oral care to avoid the invasion of respiratory pathogens, causing pneumonia. Reference Meier, Patel and Esquerra-Zwiers21,Reference Rodriguez, Meier, Groer, Zeller, Engstrom and Fogg22 Studies have shown that using breast milk for oral care could reduce the occurrence of ventilator-associated pneumonia. Thibeau and his colleagues discussed the impact of using breast milk for oral care on preventing ventilator-associated pneumonia, and the results showed that this method was safe and effective. Reference Thibeau and Boudreaux23 Sohn and other studies had also shown that using breast milk for oral care could change the type of oral colonisation bacteria and effectively reduce pneumonia. Reference Sohn, Kalanetra, Mills and Underwood24 The results of this study also showed that compared with physiological saline oral care, the incidence of post-operative pneumonia in the breast milk oral care group was significantly lower. Therefore, the corresponding mechanical ventilation duration, the length of ICU, and hospital stay were shorter. These results were consistent with the findings of other studies and suggested that breast milk oral care was effective in infants after cardiac surgery.
Using breast milk for oral care, while using the specific ingredients of breast milk to clean the oral cavity, a small amount of breast milk could also stimulate the development of oral taste and the secretion of digestive enzymes in the gastrointestinal tract, promoting the early establishment of gastric kinetics and the production of various digestive enzymes. Such results might improve digestion and absorption compliance, reduce the incidence of feeding intolerance, and restore gastrointestinal function in a shorter time. Reference Fucile, Milutinov, Timmons and Dow25 The results of this study also showed that breast milk oral care was conducive to the recovery of gastrointestinal function earlier. The time of starting feeding in the breast milk oral care group was significantly earlier than that of the physiological saline oral care group, and early total enteral nutrition was easy to achieve. All of these factors might lead to a positive effect on the patients’ post-operative recovery.
Some key points still needed to be considered when performing breast milk oral care, which were stated as follows: (1) Breast milk should be confirmed to be clean and hygienic. A professional nursing team should provide health guidance to family members, guide the infant’s mother to milk correctly, ensure breast milk hygiene during milking and transportation, and pasteurise breast milk for half an hour before oral care. (2) The nurses should perform hand hygiene during oral care to avoid cross-infection. (3) During the process of oral care, the infant should be raised on the side of the head to avoid accidental aspiration caused by excessive dampness of the cotton swab. A cotton swab was used for each part each time to prevent cross-infection. 4) The nurses should pay attention to the oral conditions, vital signs, and fixed scales of the infant’s tracheal intubation to avoid endotracheal intubation displacement.
Limitations
There were several limitations to this study. This study was a single-centre study with a small sample size, which might result in a deviation of the result. The part of indicators selected in this study was subjective, which might also affect the accuracy of the results. Different treatments for VSD, such as transcatheter device closure, transthoracic device closure, and surgical repair, might lead to different clinical results, so intervention measures in this study might have different results amongst these three treatments, which needed a further demonstration. The research object of this study was limited to infants with non-restricted VSD, and the results of the study might be different from patients with other types of CHD. Research with larger sample sizes, at multiple centres and more extended periods, needs to be conducted in the future to confirm our results.
Conclusion
Using breast milk for oral care in infants who underwent surgical correction of non-restricted VSD is a simple, safe, and effective treatment. Compared with using physiological saline for oral care, employing breast milk for oral care can reduce the incidence of post-operative pneumonia and can promote the recovery of gastrointestinal function, thereby speeding the recovery of these infants. This approach is worthy of clinical application.
Acknowledgements
We highly acknowledge the contribution by the participants: Yi-Rong Zheng, Jing Wang, Ling-Shan Yu, Qiu-Yu Chen, Li-Li Chen, Ya-Li Huang.
Consent for publication
Not applicable.
Funding
This study was supported by the National Key Research and Development Program of China (grant no. 2016YFC1301900).
Conflicts of interest
Conflicts of interest None.
Author contributions
X-rY and QC designed the study, performed the statistical analysis, participated in the operation, and drafted the manuscript. Y-qL, J-fL, and Z-cW collected the clinical data. HC provided the financial support. All authors read and approved the final manuscript.
Ethical standards
The present study was approved by the ethics committee of Fujian Maternity and Child Health Hospital, China and adhered to the tenets of the Declaration of Helsinki.
