The surgical intensive care unit: current concepts in infection

Gaps and opportunities in sepsis translational research

Infection initiates sepsis, but the clinical disease arises through the innate immune response of the host. A rapidly evolving understanding of the biology of that response has not been paralleled by the development of successful new treatment. The COVID-19 pandemic has begun to change this revealing the promise of distinct therapeutic approaches and the feasibility of new approaches to evaluate them. We review the history of mediator-targeted therapy for sepsis and explore the conceptual, biological, technological, and organizational challenges that must be addressed to enable the development of effective treatments for a leading cause of global morbidity and mortality.

Card9 protects fungal peritonitis through regulating Malt1-mediated activation of autophagy in macrophage

Fungal peritonitis is an inflammatory condition of the peritoneum which occurs secondary to peritoneal dialysis. Most cases of peritonitis are caused by microbial invasion into the peritoneal cavity, resulting in high morbidity and mortality. Unlike bacterial peritonitis, little is known on fungal peritonitis. Card9, an adapter protein, plays a critical role in anti-fungal immunity. In this study, by using zymosan-induced peritonitis and C. albicans-induced peritonitis mouse model, we demonstrated that fungal peritonitis was exacerbated in Card9^-/- mice, compared with WT mice. Next, we found the autophagy activation of peritonealmacrophages was impaired in Card9^-/- peritonitis mice. The autophagy agonist, MG132, ameliorated peritonitis in Card9^-/- mice. The result of microarray analysis indicates Malt1 was significantly decreased in Card9^-/- peritonitis mice. Furthermore, we demonstrated that Malt1 interacts with P62 and mediates the function of P62 to clear ubiquitinated proteins. After overexpression of Malt1, impaired autophagy activation caused by Card9 deficient was significantly rescued. Together, our results indicate that Card9 protects fungal peritonitis by regulating Malt1-mediated autophagy in macrophages. Our research provides a new idea for the pathogenesis of fungal peritonitis, which is of great significance for the clinical treatment of fungal peritonitis.

Identification of methicillin-resistant strains of Staphylococcus aureus isolated from humans and food sources by use mecA 1 and mecA 2 genes in Pulsed-field gel electrophoresis technique

Staphylococcus aureus causes mastitis in dairy cows, lambs, goats, and skin disorders in pigs and other animals. S. aureus causes localized purulent infections that affect soft tissues, bones, and other organs in humans. Using restriction patterns, the researchers want to isolate and identify methicillin-resistant Staphylococcus aureus (MRSA) strains from cattle and humans. They also hope to assess their genetic relatedness by comparing the mecA1 and mecA2 gene sequence discrepancies. Animals (223 strains) and people have been used to acquire S. aureus strains for study (83). The E-test was used to assess whether or not the bacteria were resistant to methicillin. The mecA1 and mecA2 genes were identified by using pulsed-field gel electrophoresis (PFGE) to analyze DNA restriction patterns. The results were shown. S. aureus strains from animals and men were resistant to methicillin in 32 (14.34 %) and 53 (63.8 %), respectively. PFGE was used to determine the differences between human and veterinary pathology strains. Two strains of bacteria collected from animals were discovered to be identical; nevertheless, microorganisms recovered from humans were found to be significantly similar to the bacteria recovered from animals. Both human and veterinary pathology were implicated in the development of methicillin resistance. The MRSA strains found in humans were much more significant than those found in animals. The strains recovered from animals exhibited a high degree of genetic heterogeneity. Still, the enormous number of indistinguishable bacteria in humans leads one to believe that a dominant clone is present. When it comes to the molecular characterization of MRSA isolates, PFGE might be regarded as the gold standard. Keywords. Animals, Human, MRSA, PFGE, Staphylococcus, mecA genes

Nafcillin Resistant Staphylococcus Aureus A Possible Community Origin

An increased incidence in nafcillin (semisynthetic penicillins) resistantStaphylococcus aureus(SR-SA), which peaked in January 1980, was noted in Columbus Children's Hospital (CCH), Columbus, Ohio. To investigate the source of this outbreak, we reviewed the susceptibility patterns ofS. aureusstrains isolated at CCH for a 12-month period (July 1979 to June 1980). A total of 773 isolates from 706 patients were investigated with a total of 40 patients colonized or infected with SR-SA, approximately 25% of which were diagnosed in the ambulatory clinics. These patients did not have any apparent previous contact with the inpatient unit or inpatient personnel. Eight nosocomial infections were also uncovered. The first appeared in December 1979. Our studies suggested that some SR-SA isolates may have originated in the community and these organisms may not be exclusive to the hospital environment, as was felt to be the case previously. We also determined that the baseline incidence for our hospital of SR-SA was approximately 2% of total S.aureusisolates. Only 35% of the SR-SA demonstrated resistance to multiple antibiotics. This report indicates that community and nosocomial 5.aureusisolates should be monitored for nafcillin resistance. Vancomycin susceptibility should be tested on all isolates and reported for SR-SA in life-threatening infections.

Asymptomatic omental granuloma following spillage of gallstones during laparoscopic cholecystectomy protects patients and influences surgeons' decisions: a review

Spillage of gallstones in the peritoneal cavity during laparoscopic cholecystectomy (LC) occurs at rates varying from 5.7% to 16%. These gallstones often cannot be retrieved and can cause early and late abscesses at rates ranging from 0.08% to 1.4%. The case of an 86-year-old woman with colon cancer is described because during an elective right hemicolectomy a granuloma of the omentum with retained gallstones from LC performed 8 years earlier was unexpectedly found. Importantly, the gallstones were found high up in the abdominal cavity. Moreover, this report reaffirms the excellent response of the peritoneal cavity defence mechanisms for protecting patients against gallstones through asymptomatic omental granuloma. Current data indicate that every effort should be made to retrieve spilled gallstones, but routine conversion to an open cholecystectomy is not recommended. Identifying factors that impair host defence mechanisms should help surgeons' decision-making.

Intra-abdominal infections

Intra-abdominal infections in the hospitalized patient differ from those arising in the community in their clinical presentation, sites of involvement, and characteristic microbiology. They are also associated with greater morbidity and mortality. New onset organ dysfunction, more than acute abdominal pain and tenderness, is the predominant clinical manifestation. Successful management depends on aggressive resuscitation and hemodynamic support, administration of adequate antimicrobial therapy, and the timely use of source control measures appropriate to the clinical situation.

Pathophysiology of septic encephalopathy: a review

OBJECTIVES

Encephalopathy is a common complication of sepsis. This review describes the different pathologic mechanisms that may be involved in its etiology.

DATA SOURCES

The studies described here were derived from the database PubMed (http:¿¿www.nlm.nih.gov) and from references identified in the bibliographies of pertinent articles and books. The citations are largely confined to English language articles between 1966 and 1998. Older publications were used if they were of historical significance.

STUDY SELECTION

All investigations in which any aspect of septic encephalopathy was reported were included. This selection encompasses clinical, animal, and in vitro cell culture work.

DATA EXTRACTION

The literature cited was published in peer-reviewed clinical or basic science journals or in books.

DATA SYNTHESIS

Contradictions between the results of published studies are discussed.

CONCLUSIONS

The most immediate and serious complication of septic encephalopathy is impaired consciousness, for which the patient may require ventilation. The etiology of septic encephalopathy involves reduced cerebral blood flow and oxygen extraction by the brain, cerebral edema, and disruption of the blood-brain barrier that may arise from the action of inflammatory mediators on the cerebrovascular endothelium, abnormal neurotransmitter composition of the reticular activating system, impaired astrocyte function, and neuronal degeneration. Currently, there is no treatment.

Methicillin-resistant Staphylococcus aureus infections in 11 dogs

Methicillin-resistant Staphylococcus aureus infection was identified in 11 dogs. The infection was associated with surgical treatment especially orthopaedic surgery. Infection after traumatic wounding, and recurrent pyoderma was also seen. Oral antibiotic treatment improved or resolved the infection in nine of the 11 dogs, although the methicillin-resistant isolates were susceptible to relatively few antibiotics.

Genetic determinants of mortality in acute necrotizing pancreatitis

Acute necrotizing pancreatitis (ANP), which often progresses to infection, sepsis, and multisystem organ failure, runs a course remarkably similar to that seen frequently after severe burns, massive physical trauma, or major surgery. There is extensive evidence that the development of the sepsis response is mediated by immunocytes, particularly activated polymorphonuclear leukocytes (PMNLs) and their secretions (reactive oxygen species, lysosomal hydrolases, cytokines, and so on). Some years ago it was suggested that the high mortality of ANP may be related to an overaggressive immunological defense system of the host rather than to autodigestion of the gland. Recent investigations of the immunoregulatory responses following surgery or other trauma have not only furnished additional support for this concept, but also revealed some genetic factors that may critically influence the outcome of posttraumatic illness including ANP. The prognostic significance of abnormal, early polymorphonuclear leukocyte (PMNL) activation in the development of sepsis, high neutrophil expression of certain receptor molecules, low monocyte and lymphocyte expression of major histocompatibility antigen MHC-class II, and the influence of the genetically encoded TNF and IL-1 secretion on the course of the illness are discussed and related to ANP. Evidence is presented for the potential usefulness of some of these parameters in the prognosis and future treatment of ANP.

Sequential anti-core glycolipid immunoglobulin antibody activities in patients with and without septic shock and their relation to outcome

OBJECTIVE

This study follows the sequential changes in anti-lipopolysaccharide antibodies in infected patients with and without septic shock.

SUMMARY BACKGROUND DATA

A relation between high endogenous levels of anti-LPS antibodies and protection against bacteremia and septic shock in at-risk patient groups has been observed. However, information on the daily follow-up and kinetics of apparition or disappearance of anti-LPS antibody activities and their relations with the protective properties of the different immunoglobulin classes has not been clearly investigated.

METHODS

Two hundred and five septic surgical patients were studied during their stay in the intensive care unit during a period of 3 years. Among these patients, septic shock developed in 54 and 47 died. A sensitive ELISA was used to study circulating IgM and IgG antibodies to the core glycolipid (CGL) region of Salmonella minnesota R595. The activities were measured each day when sepsis occurred and every hour during septic shock.

RESULTS

Anti-CGL IgM activity was found in 32% of the septic patients. This response, however, most often appeared to be transient. A strong correlation was observed between the occurrence of septic shock and the absence of anti-CGL IgM activity on admission to the ICU (p < 0.02). Anti-CGL IgG activity was detected in 82% of the patients and better correlated with outcome for patients with high or rising activities during their hospitalization (p < 0.0005). In patients with septic shock or irreversible organ failure, a fall in the anti-CGL IgG activity was observed before death, suggesting that the IgG antibodies were consumed during this acute event. Therefore, the anti-CGL IgG activity measured by ELISA could be used as a marker of the evolution of the illness.

CONCLUSIONS

Our observations demonstrate the interest to follow-up the evolution of the anti-CGL antibodies during sepsis. The fall of these antibodies during septic shock and in patients who died was an additional argument to perform, as an additive form, passive antibody therapy to decrease lethality in this group of patients.

The neurological complications of sepsis

Encephalopathy and polyneuropathy occur in 70% of septic patients. The encephalopathy is diffuse, appears early, is often severe, but reverses quickly with successful treatment of the sepsis. The electroencephalogram is a sensitive indicator of the incidence and severity of the encephalopathy, but computed tomograms of the brain and cerebrospinal fluid findings are unremarkable. Critical-illness polyneuropathy develops later and in association with multiple-organ failure. Recovery is more gradual. Difficulty in weaning from the ventilator is an important early manifestation. Electromyography should be routinely performed to establish the diagnosis. The polyneuropathy is a primary axonal degeneration, predominantly of distal motor fibers. A persistent deficit may eventuate in severe cases. Whether muscle is affected as consistently as brain and peripheral nerve, and by the same process, has not been determined. Medications used in critical care units, notably sedatives and neuromuscular blocking agents, often confuse the clinical picture. The neurological pathophysiology is unknown but current evidence suggests that nervous system dysfunction arises through the same mechanisms as for systemic organs in the septic syndrome.

Septic Shock

The incidence of sepsis and septic shock has been increasing dramatically over the past 10 years. Despite advances in antimicrobial therapy, the mortality of septic shock remains very high. We review the clinical manifestations of sepsis and septic shock and describe the cardiovascular manifestations. Pathophysiology of the cardiovascular changes is discussed, and mediators believed to be involved in the pathogenesis are reviewed. Management of septic shock is also discussed, including antimicrobial therapy, supportive care, and adjunctive treatment aimed at affecting the mediators involved in producing the sepsis syndrome.

Monitoring the response to injury

Tissue trauma leads to a severity-dependent activation of plasma and cellular systems. This response can be recorded by determining parameters which represent the activation state of these systems. In severely injured patients with multiple trauma three out of 14 parameters measured at the time of admission proved to be indicators of subsequent septic complications with a high degree of accuracy: Fibrinopeptide A (FPA--the first split product of fibrinogen), the C3 split product C3a, and the elastase-alpha 1 proteinase inhibitor-complex (E alpha 1 PI). In a second series of multiple-injured patients with femoral fractures who did not develop clinical sepsis (N = 25) these parameters were measured continuously to evaluate the influence of injury severity and of therapeutic strategy on the further course. We found a strong correlation between injury severity (ISS) and the degree of activation. The signs of activation decreased rapidly following immediate operative fixation, and remained elevated or even increased after primary femoral traction and secondary stabilization. The operative procedure did not cause any additional activation. Complications such as infection or the formation of haematomas were reflected by raised parameter levels.

The ecology and immunology of the gastrointestinal tract in health and critical illness

Interactions between the indigenous flora of the gastrointestinal tract and immunologically competent cells in the gut mucosa, gut-associated lymphoid tissues and liver play an important role in normal immune homeostasis. The microbial flora of the normal gut is complex, yet remarkably constant over time. The relative sterility of the upper gut is maintained by multiple factors including gastric acid, bile salts, normal motility and mucosal IgA, while the lower gut is densely colonized with a complex flora. An intact Gram-negative flora is a prerequisite for normal immunological maturation. On the other hand, overgrowth of the gut, particularly by Gram-negative bacteria or fungi, facilitates the translocation of bacteria into the host, and results in suppression of T-cell responses and altered hepatic Kupffer cell function. Bacterial overgrowth and the consequences of the interactions of this potentially pathogenic flora with the gut immune system may contribute to the septic state in critical illness, and to the syndrome of multiple organ failure.

Sepsis. What it is and how to recognize it

Sepsis, shock, and resuscitation may result in various degrees of ischemia-perfusion injury that may produce widespread organ dysfunction through complex interactions and activation of host immunoinflammatory processes. As the pathophysiologic mechanisms of the inflammatory response are better defined, we may be able to modulate the generalized inflammatory state we know as sepsis and prevent the development of multiple organ failure syndrome. At present, however, the mainstay of therapy remains prompt resuscitation to eliminate regions of hypoperfusion and to limit as much as possible those factors that predispose to further organ injury while the source of inflammatory stimulation is being identified and controlled.

Planned reoperations and open management in critical intra-abdominal infections: prospective experience in 52 cases

Open management and "planned relaparotomies" in the treatment of critical abdominal infections have recently generated interest and hope. Most studies which examine the value of these therapeutic modalities are retrospective and include poorly stratified groups of patients. Since 1985, we have consistently applied these aggressive methods of treatment in all patients presenting with intra-abdominal infections belonging to the following groups: I) diffuse postoperative peritonitis (29 cases); II) diffuse fecal peritonitis (14 cases); and III) infected pancreatic necrosis (9 cases). The overall mortality rate was 44%; it was 55%, 14% and 56%, respectively, in the 3 groups. The abdomen was closed between reoperations in 21 patients who required an average of 1.7 relaparotomies; the mortality in this group was 24%. Thirty-one patients, who required an average of 3.8 relaparotomies, were managed with the open method resulting in a mortality of 58%. Multiple organ failure was the cause of death in 87% of the patients. We conclude that "planned relaparotomies" may have been beneficial in group II. The value of open management in patients belonging to groups I and III remains unproven. The mechanical-surgical answers to severe forms of peritonitis may have reached their limit.

Laboratory models of sepsis and septic shock

That there are so many models of sepsis and septic shock is tacit evidence that none of them are perfect. Although sepsis presents in many forms clinically, most clinicians would probably agree that virtually all severely septic patients manifest respiratory failure and ventilator dependence. Furthermore, failure of organs other than the lungs typically occurs days to weeks after the onset of the septic process. Although early deaths occur commonly in some situations (e.g., meningococcemia, pneumococcal bacteremia in asplenic individuals, Gram-negative bacteremia in the setting of profound granulocytopenia), most deaths due to sepsis occur after a protracted course in an intensive care unit. Thus, for certain important experiments, there is a need for an animal model of severe chronic sepsis characterized by these features: persistent hypermetabolism, low systemic vascular resistance, respiratory failure severe enough to require mechanical ventilation, late (nonpulmonary) organ system failure, and death. Obviously, creation of such a model will require a major commitment of resources, because it will require, in essence, the creation of an animal intensive care unit. Nevertheless, we believe that progress in sepsis-related research would be substantially facilitated were such a model available. Even without such a model, progress will continue in this field. A wide variety of good animal models are already available to investigators. In the next decade, as new methods, such as the powerful tools of molecular biology, are applied to problems related to the sepsis syndrome, these models will be invaluable in improving our understanding of pathophysiology and in developing new and more effective approaches toward therapy.

Diagnostic and therapeutic challenges of intraabdominal infections

With the advances that are being made in many areas of medicine, the surgeon must be familiar with infectious diseases of the peritoneal cavity, which have increased in scope and complexity. In addition to the surgical management of secondary peritonitis resulting from perforation of the gastrointestinal tract, the practicing surgeon may be called on to manage patients with cirrhosis with infected ascitic fluid as well as patients undergoing peritoneal dialysis with infected dialysis fluid. In addition, there is increasing recognition of a group of patients with persistent intraabdominal sepsis or tertiary peritonitis in whom infection is associated with multiple systems organ failure and general depression of the immune system. This article endeavors to present an overview of the diagnostic and therapeutic approaches to these disease entities.

Pulmonary macrophage antimicrobial activity in canine endotoxin shock and lung injury

Bacterial sepsis and pneumonia are common complications of lung injury and predispose the host to a poor resolution. We studied the functional integrity of pulmonary macrophages derived from minced lung preparations in a canine model of endotoxin-induced shock with acute lung injury. Dogs given 2 mg/kg of Escherichia coli endotoxin 055:B5 developed classic shock symptoms with concomitant acute lung injury; control animals given saline showed no physiological or pathological abnormalities. Compared to previous work with this canine model, the lung injury in this extended time period (6 h) had progressed to include alveolar edema. Six hours after endotoxin infusion, the left lung was lavaged, perfused, and the resulting lung minced for isolation of pulmonary macrophages. The endotoxic-model pulmonary macrophages showed several significant functional differences from controls. Although they elicited greater production of H2O2 (p less than 0.05), both phagocytosis of radiolabeled Staphylococcus aureus and E. coli (p less than 0.05) and bactericidal activity (p less than 0.05) were diminished compared to controls. Compared to alterations previously described in alveolar macrophages, these cells produced less H2O2 and demonstrated abnormal bacterial killing at all time points. These observations suggest that the functional alterations of pulmonary macrophages that follow acute lung injury contribute to the ineffective cell-mediated antimicrobial response. These derangements may promote an increased risk of nosocomial pneumonia, the high mortality often observed subsequent to pneumonia, or the propagation of acute lung injury that facilitates respiratory failure.

Triple regimen of selective decontamination of the digestive tract, systemic cefotaxime, and microbiological surveillance for prevention of acquired infection in intensive care

All 324 patients admitted over sixteen months to a general intensive therapy unit (ITU) were prospectively studied to assess the effect of a novel prophylactic antibiotic regimen on the incidence of acquired infection. Consecutive control (161 patients) and test (163 patients) groups were analyzed. In the control group, antibiotic administration was determined by clinical and microbiological evidence of infection. In the test group, treatment consisted of a triple regimen of selective decontamination of the digestive tract (polymyxin E, tobramycin, and amphotericin B) administered throughout the ITU stay, systemic cefotaxime administered for the initial four days, and regular microbiological screening of multiple sites. The test group showed a striking and consistent reduction in colonisation of the digestive tract with aerobic gram-negative bacilli, and there was a substantial reduction in the incidence of acquired infection (24% to 10%). Mortality in certain categories of patients was also reduced. There is now a considerable body of evidence to justify the more widespread use of this selective parenteral and enteral anti-sepsis regimen (SPEAR) in general intensive care practice.

Clinical pharmacological and therapeutic considerations in general intensive care. A review

The application of clinical pharmacological concepts and therapeutic standards in intensive care settings presents particularly difficult problems due to the lack of adequately controlled background information and the highly variable and rapidly evolving clinical conditions where drugs must be administered and their impact evaluated. In this review, an attempt has been made to discuss the available knowledge within the framework of a problem-oriented approach, which appears to provide a more clinically useful insight than a drug-centred review. Following a brief discussion of the scanty data and the most interesting models to which reference can be made from a pharmacokinetic point of view (the burn patient being taken as an example), the review concentrates on the main general intervention strategies in intensive care patients. These are based mainly on non-pharmacological measures (correction of fluid and electrolyte balance, total parenteral nutrition, enteral nutrition, oxygenation and ventilatory management) and are discussed with respect to the specific challenge they present in various clinical conditions and organ failure situations. In addition, 4 major selected clinical conditions where general management criteria and careful use of prophylactic and therapeutic drug treatments must interact to cope with the variety of presentations and problems are reviewed. These include: acute cerebral damage; anti-infective prophylaxis and therapy; cardiovascular emergencies; and problems of haemostasis. Each problem is analysed in such a way as to frame the pharmacological intervention in its broader context of the underlying (established or hypothesised) pathophysiology, with special attention being paid to those methodological issues which allow an appreciation of the degree of reliability of the data and the recommendations which appear to be practiced (often haphazardly) in intensive care units. The thorough review of the published literature provided (up to mid-1986) clearly shows that in this field the quality of randomised controlled and epidemiological studies is rather unsatisfactory. It would be highly beneficial to research and to clinical care if larger multicentric protocols and prospective epidemiological comparative investigations could be carried out to investigate more timely and adequately the variables which determine drug action, and the final outcome in the many subgroups of patients which must be considered in a proper stratification of intensive care unit populations.

Hospital acquired infections surveillance and control in intensive care services. Results of an incidence study

Hospital acquired infections (HAI) continue to constitute a major health problem for hospital patients. Such a problem is particularly relevant in Intensive Care Wards. Here infections appear to be directly or indirectly related to the patients' death, and the patients, of course, represent a selected group of the most susceptible hosts in the whole hospital due to their immunosuppressed states, underlying diseases and the numerous and highly invasive diagnostic and therapeutic procedures to which they are submitted. This paper reports the results of a one-year surveillance incidence study carried out in four Intensive Care Wards at Padua Hospital by means of a daily visits to the wards and careful collection of the patients' data in a computerized sheet. Two-hundred-thirty-one of the 859 patients considered developed one or more HAI (HAI percentage 26.9%) for a total of 382 HAIs (Infections ratio 44.5%). Nosocomial pneumonias were the most frequent infections detected, whereas urinary tract infections, bacteremias and wound infections were less common in such patients. The study also confirmed the importance of invasive procedures and surgical operations in the predisposition to HAIs. In particular, the importance of the urinary catheter and of tracheal intubation was outlined. In addition, HAI appeared to be related to the duration of hospitalization and to the severity of the patients' illness. HAIs (especially nosocomial pneumonias) were also closely related to the patients' death. Pseudomonas aeruginosa, S. aureus, Acinetobacter and Streptococcus D were the most frequently isolated agents in the infected patients. Gram-negative agents accounted for 57% of all agents isolated and were particularly frequent in both pneumonias and urinary tract infections.(ABSTRACT TRUNCATED AT 250 WORDS)

Postoperative intra-abdominal sepsis

Postoperative intra-abdominal sepsis carries a high mortality. Diagnosis by clinical examination is often difficult, and imaging techniques may be helpful. Diagnostic laparotomy should be considered early, even in the absence of localizing signs. The use of aggressive surgical techniques may improve prognosis. The timing of surgical intervention is as important as the technique. Early diagnosis and treatment is particularly crucial in critically ill patients.

Mortality associated with multiple organ system failure and sepsis in pediatric intensive care unit

Seven hundred twenty-six patients from five pediatric intensive care units were studied to determine the association of multiple organ system failure (MOSF) with mortality and to test the hypothesis that MOSF associated with sepsis has a higher mortality rate than MOSF without sepsis. There were 177 (24%) patients with MOSF and 83 (11%) nonsurvivors of MOSF. The mortality rates for two, three, or four or more failed organ systems were 26%, 62%, and 88%, respectively (P less than 0.001). Eighty-four (47%) patients with MOSF had associated sepsis. Sepsis (both bacteremia and clinical sepsis syndrome) did not significantly increase mortality rates in the groups with organ system failure. Mortality rates for patients with sepsis before or within 24 hours of development of MOSF (early sepsis) did not differ from mortality rates for those patients with onset of sepsis more than 24 hours after developing MOSF (late sepsis, 53% vs 33%, P = NS). We conclude that underlying pathophysiologic mechanisms of MOSF other than sepsis are as important as sepsis in critically ill pediatric patients.

Early evaluation of coagulase negative staphylococcus in blood samples of intensive care unit patients. A clinically uncertain judgement

Of 2160 intensive care unit patients, 36 patients with positive blood cultures had coagulase-negative staphylococcus in one blood bottle, whereas the organism was present in two or more bottles in 38 cases. The groups were not significantly different in 27 clinical variables, obtained at the time of their first positive blood culture. There was also no significant difference in the antimicrobial sensitivities. No initial clinical data supported the classification of coagulase-negative staphylococcus as either pathogen or contaminant. When the 74 patients with blood culture positive coagulase-negative staphylococcus were compared with three "control groups" ("absent septicemia," "probable septicemia" and "proven septicemia") they were not different from those with "probable septicemia." A discriminant analysis was performed comparing patients with "absent septicemia" and with "proven septicemia" in an attempt to classify patients with isolates of coagulase-negative staphylococcus in one of these groups at an early stage. Patients with two or more positive blood cultures were not statistically classified more frequently as septicemic than patients with one blood bottle positive for this organism. However, patients categorized as septicemic had a significantly higher mortality (59%) than those classified as non-septicemic (35%) (p less than 0.05).