with the development of new technologies and drugs , health care is becoming increasingly complex and expensive . governments and health care providers around the world devote a large proportion of their budgets to maintaining quality of care . growing concern over patient care and safety has prompted initiatives such as the 5 million lives campaign , a voluntary initiative to protect patients from 5 million incidents of medical harm between december 2006 and december 2008 . with the dawn of a new era focusing on quality and patient safety , the responsibility for overseeing quality this is the mainstay of quality , and therefore indicators ( units of measurement ) must be identified for each management situation . however , these indicators must be well understood and must focus on the primary outcomes of interest . if one evaluates the wrong factors along the way , then unexpected and misleading results may emerge . we therefore structured this review of last year 's critical care papers related to intensive care unit ( icu ) management , dividing them into the primary categories of structure and processes , naturally leading on to outcomes , including cost issues . structure includes the physical aspects of the icu , biomedical equipment ( beds , monitors , ventilators and other devices ) and how the multidisciplinary team is organized . organization includes both quantity and quality of staffing , and the leadership taken by the icu medical team regarding medical decisions ( for instance , open versus closed units ) . manpower ( staffing level ) appears to be a fundamental component , as indicated by hugonnet and colleagues . in their prospective cohort study , the fourth quartile of nurse - to - patient ratio ( > 2.2 ) was associated with lower risk for late - onset ventilator - associated pneumonia ( hazard ratio = 0.42 , 95% confidence interval = 0.18 to 0.99 ) . this observation is consistent with various adverse factors associated with reduced staffing that can lead to inadequate care in ventilated patients : multiple opportunities for cross - contamination , increased workload , low compliance with hand hygiene recommendations and a stressful environment . during the period of study , the median nurse - to - patient ratio was 1.9 ( interquartile range 1.8 to 2.2 ) . in general , the ideal nurse - to - patient ratio is difficult to estimate , given the heterogeneity of data reported in the literature [ 6 - 8 ] and wide variation in local policies and practices . there is a growing need for further research specifically examining relationships between staffing models and outcomes . an interesting safety issue in icu care was the focus of a study by van lieshout and colleagues , namely the impact of electromagnetic interference by next - generation mobile phones on critical care medical equipment . episodes of electromagnetic interference were identified in 43% of 61 critical care medical devices , and 33% of these episodes were classified as hazardous ( total switch off and restart of a mechanical ventilator , complete stop of syringe pumps without alarm , and incorrect pulsing by external pacemaker ) . van lieshout and colleagues recommend a policy of keeping mobile phones at least 1 m from the critical care bedside , combined with easily accessed areas in which mobile phone use is unrestricted . processes may be understood as specific approaches to the delivery of health care , and these areas are important targets for quality improvement in the icu . approaches to process improvement include ( but are not limited to ) use of protocols and care bundles , and capacity optimization . issues related to rationing of icu care are gaining attention in the literature [ 10 - 12 ] . rationing may be defined as allocation of health care resources in the face of limited availability , which necessarily means that beneficial interventions are withheld from some individuals . some studies conducted in icus have documented high rates of refusal to admit because of lack of available beds . this is a discussion that leads to numerous ethical conflicts and to a need to identify ways to optimize icu capacity . in a retrospective study conducted at erasmus university medical center , the netherlands , van houdenhoven and coworkers   created and validated three models that incorporate characteristics of individual patients who underwent oesophagectomy for cancer to predict length of stay ( los ) in the icu . the authors concluded that it is possible to predict los and optimize icu occupancy , yielding more efficient use of icu beds and better quality of care as a result of fewer cancellations of surgical procedures . however , the best model used data acquired during the first 72 hours of icu admission , which limits its use before procedures have been applied . evidence - based protocols are known to minimize errors and adverse effects , but even simple procedures , such as taking a conservative approach to red blood cell ( rbc ) transfusions , are difficult to implement and strongly influenced by physicians ' personal convictions . understanding the adverse effects of a procedure may be important in justifying unit protocols that restrict its use . a secondary analysis of a multicentre , prospective cohort of critically ill patients   indicated that rbc transfusion is associated with an increased risk for developing acute respiratory distress syndrome ( ards ) , with a dose - response relationship . among 4,730 patients without ards at admission , 246 ( 5.2% ) developed ards in the icu . on average , patients developing ards received significantly more blood than did control patients ( 3.8 units versus 1.8 units per patients transfused ; p < 0.0001 ) , and there was a significant association between rbc transfusion and ards development ( adjusted odds ratio = 2.8 ) , with a clear dose - response relationship . the likely cause and effect relationship between rbc transfusion and ards is supported by the tricc ( transfusion requirements in critical care ) study , which compared a conservative ( 7 g / dl ) versus a liberal ( 10 g / dl ) transfusion threshold . this study identified a 7.7% incidence of ards with the conservative threshold versus 11.4% with the liberal threshold ( p = 0.06 ) . the final point in the quality improvement process is to describe the results , in terms of the primary outcomes . there are many important outcomes critical care , including mortality and los , but other factors are receiving research attention . these include quality of life ( qol ) outcomes after icu discharge ( including functional and psychosocial recovery )   and cost . indeed , the concept of value is related to providing the best possible quality at the lowest possible cost . therefore , when two icus provide the same level of care , the most valuable one is that which is least expensive . modelling mortality has been used for many years in critical care [ 20 - 23 ] for benchmarking , process improvement and standardizing illness severity in clinical studies . an interesting report by hofhuis and colleagues   explored the influence of qol before icu admission , assessed using the 36-item short form questionnaire , in terms of predicting mortality . those investigators followed a prospective cohort in a university - affiliated teaching hospital and compared the ability of 36-item short form components to predict 6-month mortality as compared with that of the acute physiology and chronic health evaluation ( apache ) ii scoring system . the authors concluded that pre - admission health - related qol in critically ill patients is as good as apache ii scores in predicting 6-month mortality . the models studied were more specific ( 81% to 84% ) than sensitive ( 44% to 56% ) , similar to other validated scoring systems . however , the models did not meet standard thresholds for discrimination , because all areas under the receiver operating characteristic curves were under 0.80 . several limitations were noted : the apache ii system was intended for use in predicting inhospital mortality and not long - term mortality , and only patients with an icu stay longer than 48 hours were included . finally , it is unclear how accurate proxy assessments of pre - admission health - related qol are , especially for items relating to mental health function . whether advances in acute care can be translated into long - term benefits remains unclear , especially in chronically critically ill patients . in a retrospective observational study conducted in germany , hartl and colleagues   analyzed changes in acute and long - term mortality in surgical patients with an icu stay longer than 28 days . the overall icu survival rate was 54% , with survival rates at 1 , 3 and 5 years of 62% , 45% and 37% , respectively , among icu survivors . this study showed that acute mortality is determined by disease severity during the icu stay and by pre - existing illnesses , whereas long - term survival mostly depends on underlying disease . interestingly , the authors were also able to demonstrate that both acute and long - term outcomes in this specific population did not differ over 2 decades in their institution , which is in contrast to several other studies that showed improved outcomes over time in populations of patients with severe sepsis . prolonged mechanical ventilation ( pmv ) is an important outcome in critical care because of the associated resource utilization . however , clear definitions for pmv and chronic critical illness have been lacking in the literature . in a prospective cohort of 817 patients mechanically ventilated for 48 hours or more , of whom 293 were pmv patients , cox and coworkers   compared 1-year health outcomes ( survival , functional status , qol and hospital costs ) between two common pmv definitions . these definitions were ventilation for  21 days in total , with ventilation discontinued for no more than 48 hours ; and diagnosis - related group 541 and 542 , involving mechanical ventilation for more than 96 hours and a tracheostomy . they also compared outcomes between pmv patients and those ventilated for shorter periods of time . the investigators found that pmv defined as mechanical ventilation for  21 days more specifically identified those who are outliers in terms of resource consumption from among ventilated patients . one - year mortality in patients ventilated for longer than 21 days was similar to that in patients receiving mechanical ventilation for shorter periods . between the two pmv definitions , the one using diagnosis - related group 541/542 selects those patients who have lower illness severity , lower mortality and lower hospital costs , as compared with the definition involving  21 days of mechanical ventilation . patients who survive critical illness often report poor qol and exhibit symptoms of post - traumatic stress disorder ( ptsd ) . studies conducted in long - term survivors of icu treatment identified clear and vivid recall of various categories of traumatic memory , such as nightmares , anxiety , respiratory distress , or pain , with little or no recall of factual events . a high number of these traumatic memories from the icu have been shown to be a significant risk factor for later development of ptsd in long - term survivors . the relationship between critical illness and ptsd has been assessed in few studies over the past decade , with reported prevalence rates ranging from 5% to 63% . the highest prevalence rates were reported in small studies , and loss to follow up ranged from 10% to 70% . in a cohort of 100 patients with secondary peritonitis , of whom 61 were admitted to the icu , the overall prevalence of long - term ptsd using post - traumatic stress syndrome-10 questionnaires was 24% . icu admission per se was significantly associated with ptsd after controlling for other factors related to ptsd ( age , sex and apache ii score ) . older age and male sex were associated with a lower incidence of ptsd , whereas higher apache ii score , mechanical ventilation   and administration of higher doses of lorazepam   were associated with a greater incidence . although the latter could either indicate causation or simply be a marker for acute anxiety , long - term follow up of a randomized study of daily interruption to sedation   indicated that this strategy may decrease ptsd symptoms . in an era in which mental health professionals are beginning to recognize the significant costs   associated with this psychiatric syndrome , understanding the relationship between critical illness and ptsd some failed to identify any such relationship , but others  such as a retrospective cohort study from the netherlands    found important associations . they studied mortality among 4,605 patients with severe sepsis admitted to 28 different icus , and they found that a higher annual volume is associated with lower in - hospital mortality in this group of patients ( odds ratio = 0.970 , 95% confidence interval = 0.943 to 0.997 ; p = 0.029 ) ; the upper quartile of sepsis admissions was 96 patients / year and , compared with the lower quartile ( 38 patients / year ) , the absolute risk for inhospital mortality was 3% to 4% lower . interestingly , this study also demonstrated a higher risk for in - hospital mortality when step - down units were present in hospitals ; this finding warrants further study . adequate structure   and staffing levels [ 4 - 8 ] , and well established and understood processes   that are associated with higher volumes of specific patient types may reduce icu and in - hospital mortality . another approach to improving quality of care is to reduce missed diagnoses by analyzing discrepancies between pre - mortem and post - mortem diagnoses . a retrospective review of medical records and autopsy reports in critically ill cancer patients was undertaken in an oncologic icu in the usa . missed diagnoses with potential impact on treatment and survival were noted in 26% of autopsies . most discrepancies were due to opportunistic infections ( viral , bacterial , fungal and parasitic ) and cardiopulmonary complications . lung infections were the most prevalent , followed by central nervous system , gastrointestinal and disseminated infectious disease . ischaemic cardiomyopathy , thrombotic endocarditis , congestive heart failure and pulmonary embolism were identified as cardiopulmonary missed diagnoses . another study enrolling critically ill patients   found that post - mortem findings were in complete agreement with pre - mortem diagnoses in fewer than half of cases ( n = 17 [ 45% ] ) . myocardial infarction , carcinoma and pulmonary embolism represented the most frequently missed diagnoses , which is clearly different from the former study and probably highlights differences between the two populations . these findings further confirm the importance of the post - mortem examination in determining an accurate cause of death and in continuously improving and renewing the search for alternative diagnostic hypotheses during the course of critical illness , especially in immunosuppressed patients . it may be influenced by los , severity of illness , presence of sepsis , ventilator - associated pneumonia , the level of hospital care , drug costs and staffing levels . several studies have shown that severity of illness has a large impact on icu costs [ 46 - 50 ] . a german national prevalence study examining the costs of critical care   revealed that , in the studied population , 10% of all patients consumed about 19% of total resources . in all levels of hospital care , the most expensive patients were those who required mechanical ventilation , those with greater severity of illness and/or severe sepsis , those admitted for emergency surgical procedures and nonsurvivors . ventilator - associated pneumonia probably also influences costs , because it is associated with increased duration of mechanical ventilation ( by 5 to 7 days ) and longer hospital los . hospital costs in patients receiving pmv are substantially higher than in patients ventilated for shorter periods , and up to 41% of pmv patients receive potentially ineffective care . staffing levels contribute to a major proportion of icu costs ( 56.1% on average overall ) . neverthless , there is growing evidence that high workload and low staffing level increases the risk for negative patient outcomes such as death and nosocomial infection [ 4 - 8 ] . thus , finding an adequate staff - to - patient ratio that neither increases costs nor decreases quality of assistance and patient safety is the answer to this cost - effectiveness question . new and expensive drugs also have a major impact on icu costs , but they are often not adequately evaluated for cost - effectiveness . a prospective observational study was conducted in france to evaluate the cost - effectiveness of recombinant human activated protein c ( rhapc ) in severe sepsis and multiple organ failure . they used propensity scores to match patients before and after rhapc was licensed for use in france , thus avoiding selection bias from the original randomized controlled trial . the study concluded that there was a 74% probability that the use of rhapc would be cost - effective if there were willingness to pay  50,000 per life - year gained and a 64.3% probability if there were willingness to pay  50,000 per quality - adjusted life - year gained . an important difference between this study and other studies examining the cost - effectiveness of rhapc   is that they did not demonstrate as large an effect size in their actual practice population as was seen in the prowess ( recombinant human activated protein c worldwide evaluation in severe sepsis ) trial . last year 's critical care papers dealt with several aspects of icu management , including quality , safety and cost management . rational use of drugs , optimization of icu capacity , mechanical ventilation and its complications , and adequate staffing levels are important factors that should be highlighted in efforts to improve the quality of care delivered to patients during an icu stay and after discharge . managing costs and providing high quality of care simultaneously are emerging challenges that must be understood and met . apache : acute physiology and chronic health evaluation ; ards : acute respiratory distress syndrome ; icu : intensive care unit ; los : length of stay ; pmv : prolonged mechanical ventilation ; ptsd : post - traumatic stress disorder ; qol : quality of life ; rbc : red blood cell ; rhapc : recombinant human activated protein c.
with the development of new technologies and drugs , health care is becoming increasisngly complex and expensive . 
 governments and health care providers around the world devote a large proportion of their budgets to maintaining quality of care . during 2007 , 
 critical care published several papers that highlight important aspects of critical care management , which can be subdivided into structure , processes and outcomes , including costs . 
 great emphasis was given to quality of life after intensive care unit stay , especially the impact of post - traumatic stress disorder . 
 significant attention was also given to staffing level , optimization of intensive care unit capacity , and drug cost - effectiveness , particularly that of recombinant human activated protein c. managing costs and providing high - quality care simultaneously are emerging challenges that we must understand and meet .