This background review supports the American College of Physicians' clinical practice guideline on risk assessment for postoperative pulmonary complications after noncardiothoracic surgery.

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Preoperative pulmonary risk stratification for noncardiothoracic surgery: Systematic review for the American College of Physicians

Immediate and early trauma deaths are determined by primary brain injuries, or significant blood loss (haemorrhagic shock), while late mortality is caused by secondary brain injuries and host defence failure. First hits (hypoxia, hypotension, organ and soft tissue injuries, fractures), as well as second hits (e.g. ischaemia/reperfusion injuries, compartment syndromes, operative interventions, infections), induce a host defence response. This is characterized by local and systemic release of pro-inflammatory cytokines, arachidonic acid metabolites, proteins of the contact phase and coagulation systems, complement factors and acute phase proteins, as well as hormonal mediators: it is defined as systemic inflammatory response syndrome (SIRS), according to clinical parameters. However, in parallel, anti-inflammatory mediators are produced (compensatory anti-inflammatory response syndrome (CARS). An imbalance of these dual immune responses seems to be responsible for organ dysfunction and increased susceptibility to infections. Endothelial cell damage, accumulation of leukocytes, disseminated intravascular coagulation (DIC) and microcirculatory disturbances lead finally to apoptosis and necrosis of parenchymal cells, with the development of multiple organ dysfunction syndrome (MODS), or multiple organ failure (MOF). Whereas most clinical trials with anti-inflammatory, anti-coagulant, or antioxidant strategies failed, the implementation of pre- and in-hospital trauma protocols and the principle of damage control procedures have reduced post-traumatic complications. However, the development of immunomonitoring will help in the selection of patients at risk of post-traumatic complications and, thereby, the choice of the most appropriate treatment protocols for severely injured patients.

Pathophysiology of polytrauma.

https://academicworks.medicine.hofstra.edu/cgi/viewcontent.cgi?article=1534&context=articles

HMGB1 in Health and Disease

Background: The systemic manifestations of acute pancreatitis are responsible for the majority of pancreatitis-associated morbidity and mortality and are now believed to be due to the actions of specific inflammatory cytokines. This report summarizes what is known about the role of cytokines in the pathogenesis of acute pancreatitis. Methods: Comprehensive literature review of experimental pancreatitis as well as all reports of cytokine involvement during clinical pancreatitis. Results: Several cytokines and other noncytokine inflammatory mediators are produced rapidly during pancreatitis. These mediators arise in many tissues in a predictable fashion independent of the animal model used or the underlying etiology in human disease. Preventing the activities of these mediators has a profound beneficial effect in experimental animals. Conclusions: A few recently described inflammatory mediators are believed to be primarily responsible for the systemic manifestations of acute pancreatitis and its associated distant organ dysfunction. The predictable nature in which they are produced may allow for novel approaches to treating this disease.

The Role of Cytokines in the Pathogenesis of Acute Pancreatitis

The adult respiratory distress syndrome (ARDS) is an important and common medical emergency and is likely to occur in all hospitals dealing in respiratory care. The syndrome occurs from a variety of diffuse pulmonary injuries which are either direct or indirect attacks on the lung parenchyma. Once lung damage occurs, exudation of fluid and loss of surfactant activity leads to impaired gas exchange and reduced pulmonary compliance. The syndrome presents clinically as marked respiratory distress, tachypnea, cyanosis, refractory hypoxemia, high inflation pressure requirements during ventilatory support, diffuse alveolar infiltrates on chest roentgenograms and postmortem pulmonary congestion, hyperemia and hyaline membrane formation. Principles of management include adequate support of oxygen transport, ventilation and circulation employing volume respirators with positive end-expiratory pressure (PEEP). During the support phase, further pulmonary injury in terms of fluid overload, oxygen toxicity or infection, must be prevented or treated. When these principles of management are followed, recovery often occurs in spite of severe pulmonary injury as indicated by the first two illustrative cases.

https://scholarscompass.vcu.edu/cgi/viewcontent.cgi?article=1739&context=mcvq

The Adult Respiratory Distress Syndrome: Clinical Features, Factors Influencing Prognosis and Principles of Management

Elevation of Circulating Interleukin 6 After Surgery: Factors Influencing the Serum Level

Overwhelming surgical stress exceeding a patient’s reserve capacity causes a disruption of homeostasis, leading to various postoperative complications. This study was under-taken to develop a new scoring system, “E-PASS”, standing for the Estimation of Physiologic Ability and Surgical Stress, that predicts the postsurgical risk by quantification of the patient’s reserve and surgical stress. E-PASS comprises the preoperative risk score (PRS), the surgical stress score (SSS), and the comprehensive risk score (CRS) that is determined by both scores. These scores were computed by a multiple regression analysis conducted on 292 consecutive patients who underwent elective common gastrointestinal operations at one hospital between 1992 and 1995 (internal group). The usefulness of the scores was evaluated in 989 consecutive patients who underwent the same surgical procedures during the same period at another hospital (external group). The morbidity and mortality rates increased similarly in both groups as the CRS increased. A marked step-up of both rates was observed at a CRS>1.0, reaching mortality rates of 20% in the internal subjects and 28.5% in the external subjects. These results suggest that the E-PASS scoring system is reproducible, and that it may be useful for surgical decision making. This system requires no special examinations and can be used in every hospital.

Estimation of Physiologic Ability and Surgical Stress (E-PASS) as a new prediction scoring system for postoperative morbidity and mortality following elective gastrointestinal surgery

Objectives Progression from systemic inflammatory response syndrome (SIRS) to sepsis, severe sepsis, and septic shock has been demonstrated in a variety of patients. However, the presence of SIRS alone was not helpful in predicting the development of multiple organ dysfunction syndrome (MODS) since SIRS includes many nonprogressive conditions. This study was conducted to investigate the clinical significance of SIRS in postoperative patients. Design Retrospective study. Setting The surgical department of a university hospital. Patients Two hundred ninety-two consecutive patients who received elective common gastrointestinal surgery (esophagectomy, pancreatoduodenectomy, hepatectomy, gastrectomy, colorectal resection, and laparoscopic cholecystectomy) between 1992 and 1995. Interventions Patients were analyzed for preoperative physiologic status, surgical stress parameters, and postoperative status of SIRS, complications, and end-organ dysfunction. Measurements and main results Duration of SIRS or positive criteria's number of SIRS after surgery significantly correlated with surgical stress parameters (blood loss/body weight and operation time) and peak serum C-reactive protein concentrations. SIRS that continued or reappeared after postoperative day 3 was an early sign of postoperative complications. SIRS continuing consecutively for 2 days after postoperative day 3 had a 70.6% positive predictive value and a 92.5% negative predictive value for postoperative complications. Septic complications and prolongation of SIRS were associated with MODS. Five of six patients who met the SIRS criteria for >30 days developed severe MODS, and three of them died. Conclusions SIRS is a useful criterion for the recognition of postoperative complications and end-organ dysfunctions. Early recovery from SIRS may arrest the progression of organ dysfunction.

Systemic inflammatory response syndrome and organ dysfunction following gastrointestinal surgery.

The dynamic aspects of circulating cytokines and cytokine modulators and their relationship with development of multiple organ failure (MOF) in patients with acute pancreatitis were analyzed. All cytokine and C-reactive protein levels in the circulation were higher than those in the MOF group. In particular, plasma concentrations of soluble tumor necrosis factor receptors (sTNF-RI and sTNF-RII) were significantly higher in patients with MOF than in those without even at admission. Furthermore, plasma concentrations of sTNF-Rs and interleukin-1 (IL-1) receptor antagonist (IL-1ra) were much higher than those of their counterparts, TNFalpha and IL-beta, respectively. These results suggest that the plasma concentrations of sTNF-Rs are useful predictors for the development of MOF, and actions of TNF-alpha and IL-1beta could be regulated by their modulators (soluble receptor and receptor antagonist, respectively) in the pathologic condition of severe acute pancreatitis.

Relationship Between Plasma Cytokine Concentration and Multiple Organ Failure in Patients with Acute Pancreatitis

We previously reported generating a scoring system termed E-PASS that predicted postsurgical risk. This study was undertaken to evaluate the usefulness of this system. A consecutive series of 902 patients who underwent elective gastrointestinal operations in six national hospitals in Japan were prospectively assessed for a comprehensive risk score (CRS) of the E-PASS, which was compared with their postoperative course. The postoperative morbidity rates linearly increased as the CRS increased. The postoperative mortality rate was only 0.13%, when the CRS was below 0.5; however, it increased to 9.7% when the CRS ranged from 0.5 to or =1.0. The CRS correlated significantly with the severity of postoperative complications (rs = 0.527, P or =0.5 was compared among the hospitals, it was related to the hospital volume of operations, being 44.2% at the volume of or =200 cases. These results suggest that E-PASS may be useful for predicting postsurgical risk, estimating medical expense, and comparing surgical quality.

Evaluation of an Estimation of Physiologic Ability and Surgical Stress (E-PASS) scoring system to predict postoperative risk: a multicenter prospective study.

Satoshi Ikei

Papers

Elevation of Circulating Interleukin 6 After Surgery: Factors Influencing the Serum Level

Estimation of Physiologic Ability and Surgical Stress (E-PASS) as a new prediction scoring system for postoperative morbidity and mortality following elective gastrointestinal surgery

Systemic inflammatory response syndrome and organ dysfunction following gastrointestinal surgery.

Relationship Between Plasma Cytokine Concentration and Multiple Organ Failure in Patients with Acute Pancreatitis

Evaluation of an Estimation of Physiologic Ability and Surgical Stress (E-PASS) scoring system to predict postoperative risk: a multicenter prospective study.