Nursing theories provide knowledge to the nurses by describing and explaining different phenomena in depth. These theories guide us in our daily nursing practice, while providing care to the patients (Butcher, 2016). They provides us the opportunity to use knowledge in research and practice. Different nursing theorists have worked on issues that are directly related to the nurse-patient relationship and by applying those theories to achieve the goals. This article is a comparison about two nursing theories, assumptions, concepts, analysis and its application in nursing practice.

The scenario which the author has taken to compare with Rogers' and Leddy's theory is about a forty year old female patient, from a remote area admitted in the intensive care unit with the diagnosis of chronic respiratory disease. She was kept on mechanical ventilator to assist her in breathing and to relax her; she was kept on sedatives and relaxants. The family was very anxious about her disease process. The environment of the intensive care unit was also creating anxiety for them. The lights were functioning throughout the day, noise from equipment, alarms, the movement of crash carts disrupting the unit and also influencing patient's health. Doctors round and discussion in the patient's room was also one of the problems.

After two days, she was given wean off trial and she successfully came out of the ventilator. She remained restless throughout that day as she was not oriented to time, place and person. She was over headed with all the disturbances in her surroundings. Her sleep pattern was altered due to unnecessary environmental stimuli, too much light and noise. The outcome was that, the patient again suffered from respiratory issues and was reintubated. This time, she remained on the ventilator for about a week. She developed a hospital acquired infection with Multiple Resistant Staphylococcus Aureas (MRSA) in her blood and pressure ulcers. The author was really disappointed on all these outcomes. The interventions he performed were, that he initially communicated with the family about the patient's condition. The patient's room was kept quiet to make her relax and as she was not on sedatives this time and so she was oriented to the environment. She was also allowed to meet her relatives who also gave her comfort.

During the past two eras, nursing science has moved in the direction of an increased acceptance of the assumption that, humans are unitary beings whose behavior is a reflection of holistic patterning (Leddy, 2004). Rogerian theory defines the human being and the environment as energy fields there by designated the energy as its basic concept (Leddy, 2004). “Science of Unitary Human being model builds on an assumption of the person as a unified energy field that continuously exchanges energy with an environmental energy field” (Hood, 2014, p. 141). Rogers considered that “physical, biological, psychological, social, cultural and spiritual attributes are merged behaviors that reflect the total person as an individual whole” (Hood, 2014, p.141). There are eight concepts in Roger's theory: energy field, openness, pattern, pandimensionality, hemodynamic principles, resonance, helicy, and integrality. Energy field is the central unit of both living and non-living. It provides a way to see people and the environment as “irreducible wholes” (Nursing Theory, 2015). Analysis of qualitative researches done in the science of unitary human being concludes that, understanding of mutual process of human energy and environmental fields is the uniqueness of nursing specific knowledge (Fawcett, 2000). We can never separate an individual from the environment. “The universal concept of open system holds that energy field integral is infinite, open and with one another. Human and environmental field, both are open systems” (Gunther et al., 2010, p.224).

Rogers described three principles of hemodynamic change that are integrality, helicy and resonance (Hood, 2014). These principles postulate the way the life process and predicts its evolving nature. The concept of integrality is that the human energy field and environmental energy field are continuous, they are one and integrated, but unique to each other. The concept of helicy predicts that change occur as a “continuous, innovative, unpredictable, increasing diversity of human and environmental field patterns” (Hood, 2014, p. 142). Concept of resonance explains that human and environmental fields are in a rhythmic arrangement that keeps changing throughout the human environmental process.

The major concepts defined in Rogers' theory are a person explained as a unitary energy field with a unique pattern; Environment described as an energy field in mutual process with the human being; Health is described as an indication of the complexity and innovativeness of patterning of the energy field that is the person. Nursing is described as inter vening to improve pattern manifestations and the environment to achieve maximum health potentials. She has also given the concept of pan dimensionality.

She only believes in relative present or the infinite now. The ideas of past, present and future are of no importance in Rogers' science. According to Rogers' “The postulate of pan dimensionality is a non- linear domain without spatial and temporal attribute, essentially a spaceless and timeless reality” (as cited in Phillips, 2010, p.56). Rogers' theory is emphasizing on holism and the concept of human environment relationships within energy fields that are widely accepted in nursing practice. Roger had tried to view the invisible things and has also given the importance of awareness and experiencing person's wholeness once at all.

Leddy's Human Energy Model (HEM) was influenced by Roger's science of unitary human being, and other philosophies. The major assumption of this model is divided into three aspects of universal essence: matter, information and energy. Model Leddy (as cited in Hood, 2014, p.146) proposes that the “purpose of nursing is to facilitate the harmonious pattern of the essence fields of both the client and nurse”.

Leddy (2004) has used five key concepts in her model that are, Self-organization which is the pattern and its manifestation to define the structure of human being, Energy field which is the dynamic web of energy interactions, Awareness, an energy that links human beings and the environment, Energy that is manifested by movement and change, and the last concept is pattern which is a web of relationships. Leddy (2004) has derived three theories from her model: the theory of healthiness, the theory of participation and the theory of energetic patterning. She has also made certain instruments to be used in research those are Leddy healthiness scale (1996) and the person–environment participation scale (1995).

The major concepts of Leddy's theory are Person, which is explained as a unitary, self-organized field of matter, energy and information that constantly interacts with an environment universal essence field. Another concept is Environment which is a dynamic, ordered, connected web in the continuous transformation of energy matter, and information with the human being. The other concept is a health which is defined as the rhythmic pattern of harmony/dissonance of the whole. The last concept is nursing which is knowledge based consciousness involved in a mutual, connected and goal directed relationship with the client.

The purpose of selecting these particular theories is that, they both depict about the human-environment relationship. Roger has the concept of unitary human being and the environment viewing them as an integral part of life. Clear explanation of energy fields and the relationship of these energy fields with the nursing knowledge and practice is explicitly defined. Susan Leddy's human energy model is selected because it is also influenced by the Roger's theory. It focuses on facilitating the nurse-patient relationship. She has also derived three different theories from her model. The theory of healthiness, the theory of participation and the theory of energetic patterning, where all the three pointed about the humanenvironment mutual processes. The relationship of these two theories very well fits with the author’s my selected clinical scenario.

The above mentioned scenario explains about the patient -environment relationship which is also the main theme of Rogers and Leddy's theory. This scenario also discusses about the role of nurse in improving the patient's condition by manipulating the environment, making it suitable for the patient. Roger's science of Unitary human being defines a person as a unitary energy field with a unique pattern while Leddy's human energy model defines a person as a selforganized field of matter, and information, that constantly interacts with an environment. Both the theorists have talked about the person as a whole, but had seen through different perspectives. Roger viewed environment as the mutual process between energy field and human being, while Susan Leddy viewed the environment as a continuous web for the transformation of energy with the person.

Keeping the above scenario in this place, the patient should be viewed as a whole and inseparable one from the environment. Physical and psychosocial attributes also plays an important role in molding the behavior of the patient. Light, noise and ventilation problems in the above scenario are the physical components that are increasing disruptions for the patient. Rogers,1992 (as cited in Hood, 2014, p.141) views caring in nursing “as simply a way of using knowledge” while Leddy, 1998 (as cited in Hood, 2014, p.146) said that “Knowledge- based consciousness in a goal directed relationship with the client is the basis for Nursing”.

Both the theorists have talked about basis of nursing as knowledge, but the approaches are different because Roger's theory explains about caring, while Leddy's model talked about the goal directed and the consciousness in nursing. This model also explains about the mutual relationship and connectedness of human beings with their environment and with the other human beings. Leddy (2004) describes the nurse–patient relationship as a commitment characterized by intentionality, authenticity, mutual trust, respect and a honest sense of connection. All these characteristics are essential to build a good rapport and trustworthy relationship.

Health is another main concept which has been given by both the theorists. Roger's sciences of unitary human being believe that health is “An indication of the complexity and innovativeness of patterning of the energy field. All manifestations of patterning that emerged out of the human environment relationships are continuously innovative” (Hood, 2014, p. 141). Roger believes that nurses should address health promotion with the patients because disease process is the main manifestation of human environment mutual process. On the other hand, Leddy's model (2004) believes that “the facilitation of harmonious health patterning for both client and nurse is the main purpose of nursing” (p.146).

During patient care, a nurse should focus on the physiological needs which enhance the patient is wellbeing and promote quick recovery. In the above clinical scenario, the patient was in critical care area, where the patient was exposed to unnecessary environmental stimuli. The exposure of extreme noise and light disturbs the patient's sleeping pattern and increases anxiety among the patient and the family members. One of the theories that were derived from Leddy's model was the theory of healthiness that talks about the above situation. According to Leddy 2004 (as cited in Leddy & Pepper 2006), Healthiness is a process characterized by purpose, connections, and power to attain goal. It influences the ongoing pattern which is reflected in health.

The theorist has also given Leddy Healthiness Scale (LHS) in 1996, which include items that measure meaningfulness, connections, ends, capability, control, choice, challenge, capacity, and confidence. This scale can be used in the above case scenario by identifying the positive and negative relationships between noise, light and cleanliness with the patient's illness and recovery. On the other hand, Roger has not given the concept of healthiness in the same context as Leddy (2004), but she has talked about “health as an index of field patterning” (p.141). She believes that health and illness are inseparable and is a part of the same continuum.

The three main hemodynamic principles about which Roger had talked about are integrality, helicy and resonance. Understanding of these principles is very necessary when applying Rogers' theory in practice. The principle of integrality focuses on human and environmental energy field, which are continuous in nature. Applying this principle in the scenario, the environmental stimuli has a direct impact on the patient's health and they are positively directed towards the patient’s recovery. Another principle is helicy, which says that human field becomes diverse with time. With the age, as the behavior of the person changes, it may reoccur but at a complex level. This principle is not very much related with the scenario because it talks about the life process. The third principle is resonance. According to Rogers (as cited in Leddy & Pepper, 2006, p.124) “Change in life occurs from lower to higher frequency patterning which is best represented by our sleep-wake cycles”.

In contrast to Roger, Leddy has given five key concepts in her model that were discussed in the overview of Susan's model. According to Leddy, 2004 the main theme of all five concepts is that “Humans have an awareness that enables the development of self-identity, the construction of meaning, and the capability to influence change by making choices” (as cited in Leddy & Pepper, 2006, p. 129). Although, both the theorists have given more or less same concepts, but Rogers theory is more focused on openness of human and environmental energy field and it has explicitly defined key concepts, nursing paradigms and principles in her theory. Susan's model is quite new in nursing field and so more work and researches can be done to improve it.

The potential outcomes of the above clinical scenario were that the patient was reintubated because of the increased environmental stimuli in the critical care area. She also got pressure ulcers and blood stream infection due to prolonged stay in the hospital. She was not oriented to the environment after getting weaned off and family members were anxious throughout the patient's stay in ICU. By applying Roger's environmental theory here, the author relates the patient with her environment in an energy field. Roger said that human beings and environment are inseparable and by using a Rogerian framework he focussed on the role of nurse pattern manifestation on the patient. Roger had also given the steps of the nursing process that includes assessment, voluntary mutual patterning and evaluation. Relating assessment with the author’s scenario, the patient is physiological and emotional needs should have accessed.

When the patients are on mechanical ventilator, the physical needs are usually ignored. It mainly focus on medication needs and ventilator needs, but forgets the importance of maintaining the noise level, lights and cleanliness needs which are directly related to the disease and recovery process of the patient. Being a Roger’s nurse, the author can empower the patient by participating her in the process of change when she got out of ventilator and tried to communicate with her by orienting her and bringing family members for her comfort. Cleanliness is also one part of environment, on which Roger has not talked upon directly in her theory, but by applying her theory, the whole environment should be focused and kept with the patient as both are seen unitary with each other in her perspective.

Applying Susan Leddy Human Energy Model can facilitate the patient for harmony in her health patterns, which is the purpose of nursing. When patient was weaned off first time the author has thought of making her comfortable by decreasing the noise levels, setting alarms in the cardiac monitor and not opening the patient's door unnecessarily, which think this could have brought harmony in the patients' health and she might have saved from getting reintubated. Also, when the patient is conscious, choices should be given, which influences her health and healing and promote a trustworthy and respectful nurse-patient relationship.

Both the theorists have focused on the human environment relationship, but they have used different approaches to explain their theories. The author thought that she could have done interventions based on the theorist to obtain the possibly pleased outcome, but Rogers theory is more open and focused on energy field considering human being and environment in it. The principles and concepts also discussed about the nurse-patient relationship and how it can be a committed along with a trustworthy relationship.

Although there is a thread between both the theorist, but Rogers theory provide a framework for nursing study and research that can be used to improve nursing education, practice and research in the future. On the other hand, the Susan conceptual framework can potentially be useful for research only because it is based on instruments and research guidelines. This model is a bit newer and unique model in nursing field and it separates the traditional approach to a new and faster approach. This model can be used for research on different nursing modalities such as relaxation techniques, imagery, exercise and nutritional counseling. Many nursing theorists have worked on Roger's conceptual model, but Susan Leddy's model is very new and a lot can be done to improve it and it can be applied in research and clinical practice.