The incidence of SCAP has shown an increasing trend over the last decades and it is reported as one of the most common causes of sepsis in hospitalized patients. SCAP is not only associated with high short-term and long-term mortality rates but also imposes a huge burden in clinical settings. Hence, improving the management strategy for SCAP is a key imperative. SCAP usually necessitates ICU admission, mainly because of the need for mechanical ventilation or vasoactive agents. However, ICU admission can cause some complications, such as secondary infection, malnutrition, and ICU syndrome, which can lead to increased expenditure and prolonged LOS in ICU.
HDU, a setting outside of ICU but with critical care, provides a new pattern to manage SCAP patients. As a bridge between the ICU and the normal unit, HDU can allow provision of both close supervision and family company.
In our study, we compared the two management patterns of RICU-HDU-NU and RICU-NU in SCAP patients. We analyzed the clinical data of 87 SCAP patients including 40 in the HDU group and 47 in the normal group.
We found that patients in both two groups showed increase in oxygenation index and reduction in APACHE II and SOFA scores through treatment. There was no significant between-group difference with respect to oxygenation index, APACHE II score and SOFA score at the time of admission or discharge from RICU or the rate of return to ICU within 48 hours. This implied a comparable therapy effect in the two groups. Instead, patients in the HDU group had less sequential noninvasive ventilation period, shorter LOS in hospital and RICU, and lower expenditure. As expected, the RICU-HDU-NU pattern decreased the LOS and expenditure, but it did not decrease the therapy effect, which illustrates that this pattern can be developed for management of SCAP.
Hukins et al presented real-life data on the outcomes of HDU management of patients with respiratory failure at a tertiary care hospital in Australia. They found that use of NIV for treatment of hypoxaemic respiratory failure in HDU is effective in most patients.
The following reasons may explain the comparable outcomes in the two groups: 1) The same medical and nursing team was responsible for both groups to maintain the continuity in therapy, even though there were relatively lesser nurses in the HDU. With the stabilization of the patient’s condition and help of family, a nurse-patient ratio of 1:4 is acceptable. 2) With respect to nosocomial infection, Stenotrophomonas maltophilia and Yeast were the most commonly isolated organisms in the HDU group, which are not among the most common causes of hospital-acquired infection and less likely to be antibiotic-resistant. Nevertheless, Staphylococcus aureus and Acinetobacter aumannii, which are among the top 5 bacteria causing nosocomial infection according to 2021 CHINET data, were the main bacteria in the normal group, which are more likely to develop drug resistance. Thus, it would be easier to treat hospital infection in the HDU group. 3) Transferring the patient out of ICU as soon as possible decreases the LOS in ICU and minimizes the risk of secondary infection; in addition, the presence of family members helps decrease the risk of ICU syndrome. This may be related to the shorter period of sequential NIV and LOS in hospital. Decreased LOS is liable to reduce the expenditure.
In our study, although there was no significant difference with respect to the distribution of causative organisms of hospital-acquired infection, we found that most bacteria in HDU group seemed unfamiliar to normal ICU and may be less likely to be drug-resistant. A larger study in future may show significant difference in bacteria distribution. Moreover, inclusion of drug sensitivity test for all pathogens in future may help characterize the microbial profile in the two groups.
The mortality rate of patients with SCAP in the HDU and normal groups were 5% and 8.5%, respectively, which is lower than that in previous studies[15–16]. This was because we only analyzed the patients who had been transferred out of RICU, regardless of whether they were readmitted to RICU again or not. There were 20 patients who could not be extubated and died in RICU. Inclusion of these cases would increase the mortality rate to approximately 24.3%, which is closer to that reported in the study by Waldens et al.
Our study is of much clinical significance. We highlight a new strategy for management of SCAP which helped achieve good results. The RICU-HDU-NU pattern is worth developing for the treatment of SCAP patients. Moreover, establishing HDU can help ease the bed burden of RICU and nurses and improve the bed rotation rate, an assessment indicator in hospitals. Third, the company of family members in the HDU improves the satisfaction of patients and family members.
Owing to the increasing burden of severe pneumonia due to the COVID-19 pandemic, many countries have started to develop HDU[17–18]. However, the concept of HDU is not widely developed in China, and it is mostly designed for surgical patients. The development of internal medicine HDU lags behind that of surgical HDU[20–21]. Our research may provide a new idea to develop internal medicine HDU in each specialty.
Some limitations of our study should be acknowledged. This was a retrospective, single-center study with a small sample size. Multicenter prospective studies are required to provide more definitive evidence of the benefits of HDU.