Oxygen delivery and monitoring in neonatal intensive care units in Mexico in 2011 and in 2023: an observational longitudinal study

Factors which are likely to have contributed to these findings included overcrowded units which would worsen cots: staff ratios. In 2011, the number of qualified and specialist nurses was also below recommended levels, and half of the nurses interviewed had received less than two hours of formal training in neonatal care in the previous year.

Low nurse: baby ratios in NICUs are not limited to low resource settings and have been reported in the United Kingdom [21] and the United States of America [22], for example. Low numbers of nurses and inadequate training are recognised bottlenecks in the delivery of neonatal care in low resource settings [23]. Under staffing has been associated with delayed or missed care practices [21], higher rates of nosocomial infection [22], inpatient mortality [24] and poorer patient care and counselling of parents [22]. Given the variation in case mix between level II and level III NICUs, as well as within level III units, there is considerable debate concerning optimal staffing levels and the skills mix required [21]. Overcrowding, as is often the case in low- and middle-income settings, increases demands on nursing staff and can also increase infection rates [25]. In low resource settings recruiting and retaining nursing staff is challenging, particularly in rural areas, which is compounded by a lack of competency-based training and refresher training, and low motivation [23]. In our study the number of graduate nurses was lower in 2023 than in 2011 in a significant proportion of NICUs. Although reasons for this were not explored, poor remuneration and hospital policies to rotate staff to different services, such as pediatric emergency care, may have been contributory factors.

In our study, less than one in three nurses knew that ROP was a potential complication of preterm birth. Similar findings have been reported from other low resource settings [20, 26]. For example, in a study in a government hospital in Kerala, India, only 48% of nurses had a diploma in nursing; >50% had up to 5 years of experience in paediatric care and 73% also worked in other areas in the hospital. Half of the nurses had some knowledge of ROP but only a quarter had a good level of knowledge and were able to identify optimal oxygen target saturations to prevent it [27].

In our study, lack of equipment limited the ability of staff to adequately deliver and monitor supplemental oxygen, a frequent finding in NICUs in low- and middle-income countries [20, 28, 29]. In addition, most units did not have written protocols on oxygen delivery. In 2023 the availability of equipment to deliver and monitor oxygen was worse than in 2011 in almost 40% of the units revisited.

Improving the quality of neonatal care is challenging in low- and middle-income countries, where there is less emphasis on teamwork and where perinatal services are less well organized than in high income countries. [30] However, several quality improvement initiatives have demonstrated that packages of evidence-based practices delivered primarily by nurses can reduce neonatal mortality, [31] improve the outcomes of neonatal care, [32] lead to a more rational use of supplemental oxygen, [28, 33] and less exposure to hyper- or hypoxia [34]. An initiative in Lima, Peru, which entailed workshops for neonatal nurses on oxygen management, led to a lower incidence of treatment requiring ROP in three of the six NICUs included [11]. Training nurses in the optimal use of oxygen in Mexico City also led to a reduction in aggressive ROP (personal communication).

ROP has a multifactorial etiology and although there has rightly been a focus on oxygen management, other aspects of perinatal care are also important. These include provision of antenatal steroids when preterm delivery is threatened; [35] prevention of hypothermia in labour wards, control of sepsis and improved nutrition including the provision of mothers’ breast milk, [36] reducing pain, and providing supportive care, including kangaroo care. Oral caffeine, which is usually given to prevent or treat apnea of prematurity, is one of the few therapies shown in high quality randomized controlled trails (RCTs) to reduce the incidence of severe ROP [37].

Some of the changes between 2011 and 2023 regarding staffing levels and equipment, and therefore oxygen management, are likely to reflect political and regulatory changes in Mexico during the intervening period. In 2003, Mexico instituted a national health insurance plan, Seguro Popular, which provided access to a package of comprehensive health services with financial protection for more than 50 million people [38]. Neonatal care was included, and by 2011, the infant mortality rate had declined to 15/1000 live births. By 2012, Mexico was on track to achieve universal health coverage [39]. However, in 2019, the new government cancelled Seguro Popular as part of an anti-corruption campaign, which led to sudden and drastic cuts of 30–40% in spending on government health services. The cuts included terminating all contracts with third parties, such as contracting agencies which provided staff to government facilities, and the suspension of payments to non-governmental organizations to provide services, such as HIV testing and management. Time will tell if the cuts lead to reforms that strengthen the health system, including the care of newborns.

Limitations of this study include the selection of large NICUs located in the most densely populated capitals of the country, potentially limiting generalizability of the findings to smaller NICUs and less populated states. In addition, nurses’ knowledge of oxygen management and ROP was not assessed in 2023.