Nosocomial infections in the surgical intensive care unit: an observational retrospective study from a large tertiary hospital in Palestine

Nosocomial infections can spread in a variety of medical settings, including wards, surgical rooms, nursing homes, and others. There are numerous mechanisms by which infection occurs in the healthcare setting. In addition to contaminated tools and equipment, bedding, or aerosols, healthcare personnel can also spread illness [20]. The main objective of our study was to assess the incidence of nosocomial infections in SICU patients between 2020 and 2021.

The incidence of infections during stays in the ICU in Jenin, another West Bank district, in 2020 was 55% [21], while in Iran, it was 51.4% [22]. Both results were higher than the rate in our study, which included 352 patients, of whom 95 had either suspected or confirmed infections (26.9%) after staying in the ICU for more than 48 h. The incidence of nosocomial infections in our hospital was somewhat lower than the incidence found in India (33.3%) [8] and Boston City Hospital (31%) [8]. The overall mortality rate in our study was 34.4% in comparison with a study conducted in Libya in which the overall mortality rate was 29% [23] and a Chinese study in which the overall mortality rate was 23.6% [24]. The discrepancy between the values mentioned above is not inconceivable; many aspects must be considered, including patient demographics, ICU environment, admission diagnoses, type of surgery, and length of stay. Regarding suspected nosocomial infections, the uncertainty linked with early infection detection in critically ill individuals is well acknowledged because patients may display infection-related signs and symptoms due to noninfectious causes such as aspiration, venous thrombosis, and pancreatitis, for which even experienced intensivists struggle to appropriately identify infected patients who may benefit from early empiric therapy. Obviously, not all patients suspected of having infections are alike, and traditional objective measures of illness such as fever and leukocytosis cannot effectively distinguish between infected and uninfected patients. Therefore, improved diagnostic tools are necessary for rapid detection and differentiation of infectious from noninfectious causes [25]. Furthermore, in the intensive care unit, patients who are suspected of having an infection may not require antibiotics unless the infection is confirmed using a combination of laboratory, radiologic, and microbiological data, even if they are not in septic shock [25]. This approach can eliminate the reporting of nosocomial infections and the corresponding overuse of unnecessary antibiotics, as well as reduce collateral damage due to the emergence of multidrug-resistant organisms.

Pneumonia represented the highest percentage of all known sources of nosocomial infections in our study (36.8%), followed by skin and soft tissue infections (35.8%) and urinary tract infections (33.7%). However, the results of Baviskar et al. were not consistent with our study, as the most predominant cause of nosocomial infections in the study’s hospital ICU in India was skin and soft tissue infection (36.6%), followed by respiratory infections (24.4%) and genitourinary infections (23.4%) [8]. Pneumonia and UTIs were the most prevalent nosocomial infections in Gaza and Jenin, respectively [26]. Ventilator-associated pneumonia (VAP) and catheter-associated UTI were the predominant causes of infection in other countries [27].

The use of invasive medical devices is observed as a potential source of infection, especially in critically ill patients. By breaking down protective epithelial and mucosal barriers and favoring the growth and colonization of microorganisms in the different forms of foreign bodies introduced to the patient, the risk of device-associated infections is pertinent [28, 29]. The devices most frequently used in our SICU were endotracheal tubes (83.2%), urinary catheters (64.2%), and central lines (43.2%). A similar study of one-year duration in Libya showed comparable percentages of device-associated nosocomial infections, where endotracheal tubes (39.2%) and urinary catheters (19%) were considered the most common site of infection.

A great number of studies have reported the superiority of gram-negative organisms as a cause of NIs compared to gram-positive microorganisms [30]. In our study, 115 growths of the culture-confirmed infections were of gram-negative microorganisms, and 82 samples showed growths of gram-positive microorganisms. P. aeruginosa and A. baumannii were the microorganisms most commonly isolated in patients with nosocomial infections in the SICU, each comprising approximately 25 and 24 positive cultures, respectively, followed by E. coli. The most commonly remorted gram-positive organisms were S. epidermidis (17.9%) and VRE (17.7%). The results of our study were consistent with a 2-year prospective study carried out in the 15-bed ICU of Farawaniya Hospital in Kuwait, which showed that 68% of culture-confirmed pathogens were gram-negative species, 27% were gram-positive and 5% were fungi. The most prevalent organisms were P. aeruginosa (20, 17%), followed by A. baumannii (15, 13%), Klebsiella spp. (13, 11%) and E. coli (10, 8%) [31]. A. baumannii and P. aeruginosa are very often the cause of nosocomial infections in various hospital ICUs in different countries [32].

In our study, vancomycin (50, 52.6%), piperacillin/tazobactam (26, 27.4%), and meropenem (35, 36.8%) were the three drugs prescribed most frequently. In January 2005, a Turkish study showed that the most commonly used antibiotics were piperacillin/tazobactam, amikacin, and meropenem [33]. The prevalence of illness and death brought on by bacterial infections has significantly decreased because of the appropriate use of antibiotics. Nevertheless, the inappropriate utilization of these drugs has generated selective pressure and given rise to antibiotic resistance. Proper management of antibiotics in ICUs involves swift detection and effective treatment of bacterial infections in critically ill patients, as well as enhancing our capacity to prevent the administration of unnecessary broad-spectrum antibiotics, decreasing the length of their use, and limiting the number of patients who receive unnecessary antibiotic treatment [34, 35].

Fungi are not considered a familiar cause of nosocomial infections, but in our study, five strains of 39 fungi were isolated from patients in the SICU. The most frequently occurring Candida species was C. albicans (17), followed by C. parapsilosis (13), C. glabrata (7), C. tropicalis (1), and C. krusei (1). In January 2021, a study in China described eight species of Candida in 89 patients who acquired infections during their stay in a hospital ICU, of which six were attributed to C. albicans and two to C. tropicalis [24].

Healthcare-associated infections are known to prolong length of stay (LOS). Our study’s median duration of stay was 18.5 days. Meanwhile, in an Indian study, the average stay in the SICU was longer and equalled 14.4 days [24]. Extending the LOS by one day has been linked to the likelihood of raising the potential of acquiring an infection by 1.37%, while being infected also leads to an increase in LOS by 9.32 days. This leads to increased antibiotic use and promotes the development of antibiotic resistance, contributing to an increased financial burden on both the patient and the hospital [36].

In the ICU, patients are susceptible to hospital-acquired infections (HAIs), which can result in heightened morbidity and mortality. There is an increasing emphasis on the prevention of HAIs, and the implementation of infection control techniques is vital for addressing this concern. In recent times, various healthcare settings have witnessed progress in measures aimed at preventing infections. These measures encompass a focus on monitoring hand hygiene, revising isolation precautions, adopting novel approaches for environmental cleaning, implementing decontamination bathing, initiating antimicrobial stewardship programs, utilizing daily reassessment-intervention bundles, identifying and mitigating risk factors, as well as maintaining staff education initiatives and conducting active surveillance testing [37]. These efforts play a pivotal role in diminishing the occurrence of nosocomial infections [38, 39]. As demonstrated by several studies, strict adherence to meticulous infection control measures, particularly focusing on hand hygiene and robust implementation of evidence-based preventive techniques for ventilator-associated pneumonia and bloodstream infections, holds paramount importance in the reduction of NIs [40,41,42,43,44,45]. Our surgical ICU, situated within a bustling 6-bed unit at a tertiary care teaching hospital in the public sector, occupies a relatively compact space that lacks sufficient separation between the beds. Furthermore, our institution functions as an academic center with diverse medical and nursing specialties conducting clinical rotations throughout the year. These factors, indeed, have the potential to elevate the risk of NIs. Additionally, various investigations have unveiled that the utilization of invasive devices such as central venous or urinary catheters, intubation, tracheostomy, and mechanical ventilation, serves as a significant predisposing factor for infections [46, 47]. Therefore, the implementation of published and evidence-based infection control protocols is anticipated to substantially decrease the likelihood of pathogen transmission and the overall incidence of nosocomial infections.

Strengths and limitations

Although this paper is one of the few studies conducted in Palestine that elucidate nosocomial infections in surgical ICUs, our research has several limitations. First, the data we collected were obtained from a single center and may not be generalizable to other centers. Second, our study was retrospective, and we were unable to identify the surveillance criteria necessary for identifying device-related infections, central line–associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), ventilator-associated events (VAEs) and surgical site infections (SSIs), in addition to not representing the microbiological profile based on the isolation site.