Intensive care unit models: Do you want them to be open or closed? A critical review
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/0028-3886.198205
Source of Support: None, Conflict of Interest: None
Intensive care is a specialized branch of medicine dealing with the diagnosis, management, and follow up of critically ill or critically injured patients. It requires input from other branches of medicine on various issues. A critical care specialist has expertise in managing such patients round the clock. Based on his freedom to take decisions in the intensive care unit (ICU), different types of ICUs – open, closed, or semi-closed – have been defined. There is no doubt that all critical patients should be evaluated by an intensivist. Therefore, it is argued that a closed ICU model would be the ideal model. However, this may not always be feasible and other models may be more useful in resource-limited countries. In this review, we compare the different formats of ICU functioning and their suitability in different hospitals.
Keywords: Closed ICU, hospital stay, intensive care unit, mortality, open ICU, semi-closed ICU
Over the past few years, there has been a tremendous advancement in the knowledge, technology, and skills required to treat critically ill patients. An intensive care unit (ICU) is a highly specified and sophisticated area of the hospital, which is specifically designed, staffed, located, furnished, equipped, and dedicated to the management of critically ill patients with serious injuries or complications. The emergence of critical care as a distinct speciality and an increase in the number of doctors being trained in critical care medicine has resulted in a change in the staffing and organizational model of ICU. This has also started a tug-of-war between physicians and intensivists over the care of ICU patients. In the present article, we discuss the pros and cons of various organizational structures of ICUs.
Perhaps the earliest use of critical care protocol to treat patients was made by Florence Nightingale during the Crimean War in the 1850s. She triaged wounded soldiers depending on the severity of their injuries and monitored the sickest soldiers more regularly. This resulted in a sharp decline in the mortality rate. In 1926, the pioneer neurosurgeon, Walter Dandy, established the world's first hospital ICU in Boston with just 3 beds. The field of critical care medicine then took a giant leap in the 1950s during the poliomyelitis outbreak in Denmark. Bjorn Ibsen, an anesthetist, suggested that the polio afflicted patients could be supported through their illness by inserting a tracheostomy tube, manually clearing their secretions, and ventilating them with an oxygen/nitrogen mixer using positive pressure, which resulted in a reduction in mortality from polio from 80% to 25%. Ibsen went on to open the first ICU in 1953, which was replicated around the world, and the branch of critical care medicine was established. In 1958, Dr Max Harry Weil and Dr Hebert Shubin opened a 4-bedded shock ward in Los Angeles County – University of Southern California Medical Center, Los Angeles, USA, to improve the recognition and treatment of serious complications in critically ill patients.
The first ICU in India was actually a coronary care unit, started in 1968 at the King Edward VII Memorial Hospital, Mumbai, followed by another one at the Breach Candy Hospital. Since then, intensive care has grown into a specialty in its own right.
Today, the ICUs comprise up to 10% of all hospital beds and consume as much as 25–30% of hospital resources. In India, critical care beds account for 5–8% of the total bed strength in large public teaching hospitals.
There has been a debate on the role of “intensivists” in the management of critically ill patients and their impact on patient outcomes. Many of the initial critical care units were staffed by physicians whose primary specialties were anesthesiology or internal medicine. Over the past few years, critical care medicine has become a full subspecialty and can no longer be regarded just as a part of anaesthesia, medicine, surgery, or any other speciality. The understanding of physiology in critically ill patients and evidence-based practice is essential in the management of ICU patients. In the ICU, the 9 physiological systems that are monitored include the cardiovascular, central nervous, endocrine, gastrointestinal/nutrition, hematology, microbiology/sepsis, periphery/skin, renal/metabolic, and respiratory systems. An intensivist is usually a physican trained to do this and has undergone primary training in medicine, surgery, anesthesiology, or pediatrics followed by 2–3 years of critical care medicine training. In India, according to the Indian Society of Critical Care Medicine (ISCCM), an intensivist should have a postgraduate qualification in internal medicine, anesthesia, pulmonary medicine, or surgery and either an additional qualification in intensive care, or at least an year training in a reputed ICU abroad.
Based on the extent of involvement and supervision by critical care physicians, ICUs function on 6 different models.
Open intensive care unit model
This is an ICU in which patients are admitted under the care of an internist, family physician, surgeon, or any other primary attending physician, with the intensivists being available to provide their expertise via elective consultation. Intensivists may play a de facto primary role in the management of some patients, but only within the discretion of the admitting physician, and have no overreaching authority over patient care. The patient's primary physician determines the need for ICU admission and discharge. Although the primary physician may have less expertise in critical care medicine, it is argued that his long relationship with the patient may provide improved patient care and a greater satisfaction. However, the downside is greater variability in practice patterns. Single-organ specialists may not be aware of the overall management plan, resulting in potentially unnecessary or conflicting orders and increased expenses.
Closed intensive care unit model
In a closed model ICU, all patients admitted to the ICU are cared for by an intensivist-led team that is responsible for making clinical decisions. The admissions and discharges are controlled by an on-site ICU physician in most closed ICU models. Because most ICU patients have similar problems, regardless of the reason for their critical illness, it is believed that management by a team of specially qualified intensive care physicians and nurses provides patients with better care and is associated with improved outcomes with a more efficient use of ICU resources.
This involves an open ICU model in which all patients receive mandatory consultation from an intensivist. The internist, family physician, or surgeon remains a co-attending-of-record with the intensivists collaborating in the management of all ICU patients.
Hybrid or transitional intensive care unit or semi-closed intensive care unit model
Hybrid/transitional/semi-closed ICU is one in which critical care team provides direct patient care in collaboration with other 'privileged' physicians, who are also allowed to write orders. In this model, the primary treating physicians are not a part of the ICU team, but remain actively involved in their patients' care. Many surgical and cardiothoracic ICUs maintain this model.
Multiple consultant model
Multiple consultant model is one where multiple specialists are involved in the patient's care (a pulmonologist or intensivist might be consulted for ventilator management, but no one is designated specifically as the consultant intensivist). In some cases, the intensivist may act as the team leader and coordinate between all consultants, providing an integrated approach to the patient and family.
Mixed intensive care unit models
In practice, the above mentioned models overlap to a considerable extent. The level of involvement of the intensivist may vary from daily rounds by an intensivist to the presence of a full-time intensivist in the ICU. [Table 1] highlights the advantages and disadvantages of various ICU models. Because this article primarily caters to neurosurgeons and neurologists, a brief mention may be made regarding the neuro-ICUs.
The neurosciences intensive care unit
Historically, the first neurosciences intensive care unit (NICU) was opened in John Hopkins Hospital in 1932 by Dandy. NICUs may admit both neurological and neurosurgical patients, but some have remained largely neurosurgical or have specifically catered to neuro-trauma patients. The most common diagnosis at admisson include are stroke, head injury, brain tumor, post-hypoxic encephalopathy, neuromuscular respiratory failure, status epilepticus, various neurological infections, and admission for immediate postoperative observation. NICUs can also be open, closed, or semi-closed, as discussed previously. The increasing use of intravenous thrombolysis and endovascular interventions for stroke implies that more and more stroke patients are being treated in the NICU. The advent of closed NICUs required the arrival of another new subspecialist – the neurointensitivist – who was required to assume a primary care role for patients in the ICU, coordinating both neurological and medical management. Further, in NICUs, certain highly specialized monitoring may be required [Table 2]. The neurointensitivist should not only be well-versed in the standard ICU protocols, but also in the specialized neuro-critical monitoring and interventions, as detailed in [Table 2]. All this requires a good knowledge of the interface between the brain and other organ systems in the face of a critical illness. However, neurointensitivists are an extremely rare breed, and currently in USA, there are only 45 centres that have one. In India, to the best of our knowledge, there is no dedicated fellowships in neurocritical care, although there are post- doctoral courses offered in neuroanesthesia.
Several studies have attempted to identify the consequences of these different ICU staffing patterns on patient care.,,,,,, These are summarized in [Table 3]. A critical analysis of these studies is presented below.
In a systemic review Pronovost et al., concluded that high-intensity staffing (mandatory intensivist consultation or a closed ICU) was associated with a lower ICU mortality rate in 93% of studies with a reduced length of stay in the ICU. It is generally agreed that intensivists can better manage critically ill patients because of a better understanding and management of ICU pathology, better use of evidence-based medicine, increased usage of protocols, and better ventilation management. As a result, various bodies have recommended that all patients in adult or pediatric general medical and/or surgical ICUs and NICUs should be managed or co-managed by an intensivist. There are, however, some problems with the definitiveness of the statement that ICUs should always function on a closed basis. First is the level of evidence. Most studies have used historical controls or before–after study designs and are limited to specific ICUs (for example, medical or surgical) in 1 or 2 centers. It is difficult to compare the outcome of ICUs in two time periods as advances in medicine over a time period could be responsible for better outcome in the closed ICU model. Further, cross-sectional studies are well-known for confounding factors due to variations in the illness severity. However, randomized controlled trials (RCTs) are difficult to perform in this scenario because of obvious logistic problems. Levy et al., compared the hospital mortality between patients cared entirely by critical care physicians and those cared entirely by non-critical care physicians and concluded that odds for in-hospital mortality were higher for patients managed by critical care physicians. This study, thus, casts doubt on an established recommendation. Interestingly, among the 123 ICUs included in the study, only 23 ICUs were functioning on a closed basis.
On the contrary, Kim et al., found that the lowest odds of death within 30 days were in ICUs that had high-intensity physician staffing and multidisciplinary care teams. Similarly, in a study published in 2011, mortality decreased from 25.7% to 15.8% in high risk surgical patients when the format of ICU was changed from open to closed. However, a recent 2015 international multicenter observational study showed different results. Based on post hoc analysis of data from the the Extended Prevalence of Infection in the ICU Study (EPIC II) study, which was an international 1-day point prevalence study of all patients admitted in over 1265 ICUs in 75 countries, the authors found that a high nurse: patient ratio was independently associated with a lower risk of in-hospital death. In addition, availability of an in-house intensivist 24 hours a day was associated with a trend toward a reduced risk of in-hospital death. However, the ICU format (open vs. closed) did not influence the adjusted risk of in-hospital death. Thus, there is an uncertainty regarding the contention that closed ICU models have lower mortality and in-hospital stay rates. However, the authors postulated that most of the ICUs in this study were of the closed type and the relatively small number of open ICUs may not have been sufficient to demonstrate possible differences in outcome according to the ICU format. The conflicting results and the lack of randomized control trials imply that the last word on this subject is yet to be stated.
Logistics of closed intensive care unit
The second issue is that of logistics. To provide services for a single ICU with 24 X 7 coverage, five full-time equivalent (FTE) intensivists are required. In the United States, in the 2011–2012 academic year, 1957 trainees were enrolled in the adult critical care medicine fellowships (surgery, anesthesia, medical critical care, and pulmonary/critical care), which is grossly inadequate. The situation is worse in India with a much larger population when compared to USA with a total of 13 DM critical care and 17 FNB critical care seats annually. It is impossible to provide a comprehensive critical care management in our country with such a small number of critical care specialists, and thus it is impossible to follow the closed model in most of the places, although the Indian Society of Critical Care Medicine (ISCCM) discourages adoption or continuance of open ICUs.
In the USA, a survey conducted by the task force of the Society of Critical Care Medicine in 2007 revealed that intensivists provided clinical care in 60% of surveyed ICUs, with an average of 12.7 staff members identified by the ICU director as intensivists. This implies that, even in a resource-rich setting, almost half of the ICU patients could not be treated by intensivists. Hence, a 24 hour-a-day coverage by an intensivist is a feat that is unrealistic for most hospitals due to perceived costs and the scarcity of intensivists. To the best of our knowledge and literature search, no such data is available from our country, although it is likely that the situation could only be worse. Most of the ICUs in India are, therefore, handled by anesthetists, physicians, or pediatricians. Even within an institute, different models are at work in different ICUs. In our institute, which is a tertiary care super-speciality teaching hospital, there are 7 ICUs which work on different models (1 closed, 3 semi-closed, and 3 open).
Burnout is a psychological term for the experience of long-term exhaustion and diminished interest (depersonalization or cynicism), usually in the work context. Burnout syndrome (BOS) was identified in the early 1970s in human service professionals, most notably in healthcare workers. The most well-studied measurement of burnout in the literature is the Maslach Burnout Inventory (MBI), which is a 22-item questionnaire that has a high reliability and validity. Higher levels of severe BOS are found in oncologists, anesthesiologists, physicians caring for patients with AIDS, and physicians working in emergency departments. Based on the most recent studies, severe burnout syndrome is present in approximately 50% of critical care physicians, and in one-third of critical care nurses. Burnout ultimately leads to unsatisfactory patient care and higher attrition rates resulting in depletion of an already scarce workforce.
In a closed ICU model, the primary clinical duties of the intensivists consist of caring for patients in the ICU with no outpatient responsibilities. This concept of a truly 'closed' critical care area has been challenged in recent years to enable access for patients outside the unit to intensive care processes and personnel. 'Critical care without walls' is the theory applied to this idea, whereby intensivists and critical care nurses offer their help and expertise to those who are acutely unwell in the ward. In the existing setting of mismatch between the intensivist supply and demand, this concept appears too ambitious, However, a new development has occurred, at least in the West. Here the growing intensivist shortage has coincided with the appearance of hospitalists, (physicians who focus on the care of hospitalized medical patients) on the healthcare landscape. Eighty-five percent of practicing hospitalists are internists, who have historically been well trained to manage acutely ill hospitalized patients. With their consistent presence in the hospital (many programs provide 24 × 7 in-house coverage), hospitalists see patients several times a day, if necessary, and can respond to their acute needs in real time. Enhancing hospitalists' skills to provide critical care services by providing them with limited, competency-based critical care training can go a long way in reducing the shortage of intensivists. Taniguchi and Okajima compared the open versus semi-closed ICUs and found that mortality of ICU patients was 9.9% in the open group and 6.6% in the semi-closed group (P = 0.05). The average length of hospital stay was 4.9 days in the open group and 4.8 days in the semi-closed group.
It is clear that both open and closed ICU models have their own advantages and disadvantages. A closed ICU system may be ideal, but is probably not feasible at present, and with an ageing population and increasing requirement of intensivists, probably not achievable in the near future. With the continued rising costs of healthcare and the persistent short supply of intensivists, the semi-closed ICU model may make more sense to hospitals because the primary physician, under the guidance of the intensivist, can also help manage the patient when the intensivist is not immediately available. Further, protocol-driven care has been shown to be very effective in improving various aspects of patient care in the ICU setting. Brook et al., demonstrated that nursing-implemented sedation protocols not only deliver optimal sedation but can also decrease a patient's duration on mechanical ventilation. Similar protocols for management of anemia, acute respiratory distress syndrome/acute lung injury (ARDS/ALI), and weaning off from mechanical ventilation can be implemented by residents or nursing staff, and thus positively influence the patient outcome in semi-closed units. Leape et al., showed that ICUs can reduce the rate of preventable adverse drug events by 66% in the presence of a clinical pharmacist.
Protocol driven discharge and weaning
The discharge and weaning criteria may differ in various ICUs. For example, in NICUs, for shifting patients to a step down care, besides the common requirement of stable metabolic, hemodynamic, and respiratory profiles and requirement of respiratory therapies (e.g., suction) every 4 hours or less, other considerations such as a stable neurological status for at least 24 hours and absence of seizures may be important. Similarly, airway and pulmonary management of the patient with neurological disease is associated with many challenges. The managing intensivist should be well versed with the patient's neurological condition and its pathogenesis. These will have huge implications for the management of the airway and respiratory status. Although specific guidelines have been developed for weaning and discontinuation of ventilatory support, developing specific extubation criteria for the neurological patient has proven to be problematic. The patients' respiratory muscle strength and their ability to maintain oxygenation with decreasing ventilatory support have received maximum attention., The most consistent airway parameters associated with extubation success were the presence of a spontaneous cough and a required suctioning frequency of >2 hours. For extubation, it is reasonable to incorporate the same pulmonary function tests that are used during intubation.
Thus, a protocol driven semi-closed ICU may be a solution for resource-limited countries like India.
Critical care medicine is one of the fastest growing specialities in medicine. There is no doubt that all critical patients should be evaluated by an intensivist, and possibly a closed ICU model is the ideal model. Still this is not achievable even in the near future in ICUs across India or even in a resource-rich country such as USA. What is more important is to reduce mortality and ICU stay in a cost effective manner. This can be achieved in semi-closed ICU with appropriate well-written protocols for various procedures. The recent post hoc analysis of the EPIC II study also shows that providing a better nurse-patient ratio and round-the-clock availability of an in-house intensivist goes a long way in reducing the mortality rates and hospital stay duration irrespective of the format of ICU. Finally, ICU management is a team effort. It is important to create an environment where opinions of all members of the team are respected with a common goal to reduce ICU-related mortality in a cost effective manner.
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Conflicts of interest
There are no conflicts of interest.
[Table 1], [Table 2], [Table 3]