# Modern surgical care Modern surgical care The role of surgical critical care, including resuscitation and/ or organ support, must be to work alongside the metabolic e ff ects of injury while the patient is restored to a situation from which homeostatic mechanisms can achieve a return to normality . The systemic e ff ects of injury still impact heavily on survival and complications through loss of muscle mass, sepsis and MODS. In fact, modern treatment of major trauma can now be so successful that the great majority of hospital deaths . in developed countries occur after some days as a result of complex physiological processes, rather than as a direct and rapid consequence of organ damage or blood loss, although it is the initial injury and blood loss that sets the scene for the later systemic e ff ects. Parallel with the catabolic e ff ects introduced above, inflammatory-type processes cause immune suppression. While this inflammation is often initially sterile, the nature of surgery and injury predisposes to infection and sepsis. Impaired immunity as part of the metabolic response failure is a key part of perioperative care and a leading mode of death among our patients. Even in modern trauma systems, MODS carries a mortality of around 25%. As a consequence of modern understanding of the meta bolic response to injury , elective surgical practice now seeks to actively reduce the need for a homeostatic response by mini mising the primary insult via minimal access surger y and by ‘stress-free’ perioperative care or enhanced recovery after sur gery (ERAS). This chapter will review the mediators of the str ess response, the physiological and biochemical pathway changes associated with surgical injury and the changes in body composition that occur following surgical injur y . Empha sis is placed on why knowledge of these events is important to understand the rationale for modern ‘stress-free’ perioperative and critical care. Summary box 1.1 Basic concepts /uni25CF /uni25CF /uni25CF /uni25CF Figure 1.1 Homeostasis is the foundation of normal physiology ‘Stress-free’ perioperative care helps to preserve homeostasis following elective surgery Resuscitation, surgical intervention and critical care can return the severely injured patient to a situation in which homeostasis becomes possible once again The metabolic response to surgery in /f_l uences these processes profoundly, particularly through catabolic effects, MODS and impaired immunity 140 Major trauma 130 Minor trauma 120 110 Normal 100 range 90 Starvation Resting metabolic rate (%) 80 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 Major trauma 25 Minor trauma 20 15 Normal (g N/day) 10 range Nitrogen excretion 5 0 Hypermetabolism and increased nitrogen excretion are closely related to the magnitude of the initial injury and show a graded response. Modern surgical care The role of surgical critical care, including resuscitation and/ or organ support, must be to work alongside the metabolic e ff ects of injury while the patient is restored to a situation from which homeostatic mechanisms can achieve a return to normality . The systemic e ff ects of injury still impact heavily on survival and complications through loss of muscle mass, sepsis and MODS. In fact, modern treatment of major trauma can now be so successful that the great majority of hospital deaths . in developed countries occur after some days as a result of complex physiological processes, rather than as a direct and rapid consequence of organ damage or blood loss, although it is the initial injury and blood loss that sets the scene for the later systemic e ff ects. Parallel with the catabolic e ff ects introduced above, inflammatory-type processes cause immune suppression. While this inflammation is often initially sterile, the nature of surgery and injury predisposes to infection and sepsis. Impaired immunity as part of the metabolic response failure is a key part of perioperative care and a leading mode of death among our patients. Even in modern trauma systems, MODS carries a mortality of around 25%. As a consequence of modern understanding of the meta bolic response to injury , elective surgical practice now seeks to actively reduce the need for a homeostatic response by mini mising the primary insult via minimal access surger y and by ‘stress-free’ perioperative care or enhanced recovery after sur gery (ERAS). This chapter will review the mediators of the str ess response, the physiological and biochemical pathway changes associated with surgical injury and the changes in body composition that occur following surgical injur y . Empha sis is placed on why knowledge of these events is important to understand the rationale for modern ‘stress-free’ perioperative and critical care. Summary box 1.1 Basic concepts /uni25CF /uni25CF /uni25CF /uni25CF Figure 1.1 Homeostasis is the foundation of normal physiology ‘Stress-free’ perioperative care helps to preserve homeostasis following elective surgery Resuscitation, surgical intervention and critical care can return the severely injured patient to a situation in which homeostasis becomes possible once again The metabolic response to surgery in /f_l uences these processes profoundly, particularly through catabolic effects, MODS and impaired immunity 140 Major trauma 130 Minor trauma 120 110 Normal 100 range 90 Starvation Resting metabolic rate (%) 80 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 Major trauma 25 Minor trauma 20 15 Normal (g N/day) 10 range Nitrogen excretion 5 0 Hypermetabolism and increased nitrogen excretion are closely related to the magnitude of the initial injury and show a graded response. Modern surgical care The role of surgical critical care, including resuscitation and/ or organ support, must be to work alongside the metabolic e ff ects of injury while the patient is restored to a situation from which homeostatic mechanisms can achieve a return to normality . The systemic e ff ects of injury still impact heavily on survival and complications through loss of muscle mass, sepsis and MODS. In fact, modern treatment of major trauma can now be so successful that the great majority of hospital deaths . in developed countries occur after some days as a result of complex physiological processes, rather than as a direct and rapid consequence of organ damage or blood loss, although it is the initial injury and blood loss that sets the scene for the later systemic e ff ects. Parallel with the catabolic e ff ects introduced above, inflammatory-type processes cause immune suppression. While this inflammation is often initially sterile, the nature of surgery and injury predisposes to infection and sepsis. Impaired immunity as part of the metabolic response failure is a key part of perioperative care and a leading mode of death among our patients. Even in modern trauma systems, MODS carries a mortality of around 25%. As a consequence of modern understanding of the meta bolic response to injury , elective surgical practice now seeks to actively reduce the need for a homeostatic response by mini mising the primary insult via minimal access surger y and by ‘stress-free’ perioperative care or enhanced recovery after sur gery (ERAS). This chapter will review the mediators of the str ess response, the physiological and biochemical pathway changes associated with surgical injury and the changes in body composition that occur following surgical injur y . Empha sis is placed on why knowledge of these events is important to understand the rationale for modern ‘stress-free’ perioperative and critical care. Summary box 1.1 Basic concepts /uni25CF /uni25CF /uni25CF /uni25CF Figure 1.1 Homeostasis is the foundation of normal physiology ‘Stress-free’ perioperative care helps to preserve homeostasis following elective surgery Resuscitation, surgical intervention and critical care can return the severely injured patient to a situation in which homeostasis becomes possible once again The metabolic response to surgery in /f_l uences these processes profoundly, particularly through catabolic effects, MODS and impaired immunity 140 Major trauma 130 Minor trauma 120 110 Normal 100 range 90 Starvation Resting metabolic rate (%) 80 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 Major trauma 25 Minor trauma 20 15 Normal (g N/day) 10 range Nitrogen excretion 5 0 Hypermetabolism and increased nitrogen excretion are closely related to the magnitude of the initial injury and show a graded response.