Statistics review 4: sample size calculations.


:The present review introduces the notion of statistical power and the hazard of under-powered studies. The problem of how to calculate an ideal sample size is also discussed within the context of factors that affect power, and specific methods for the calculation of sample size are presented for two common scenarios, along with extensions to the simplest case.


Crit Care


Whitley E,Ball J





Has Abstract


2002-08-01 00:00:00












  • Estimation of the diaphragm neuromuscular efficiency index in mechanically ventilated critically ill patients.

    abstract:BACKGROUND:Diaphragm dysfunction develops frequently in ventilated intensive care unit (ICU) patients. Both disuse atrophy (ventilator over-assist) and high respiratory muscle effort (ventilator under-assist) seem to be involved. A strong rationale exists to monitor diaphragm effort and titrate support to maintain resp...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Jansen D,Jonkman AH,Roesthuis L,Gadgil S,van der Hoeven JG,Scheffer GJ,Girbes A,Doorduin J,Sinderby CS,Heunks LMA

    更新日期:2018-09-27 00:00:00

  • Variation in the PaO2/FiO2 ratio with FiO2: mathematical and experimental description, and clinical relevance.

    abstract:INTRODUCTION:Previous studies have shown through theoretical analyses that the ratio of the partial pressure of oxygen in arterial blood (PaO2) to the inspired oxygen fraction (FiO2) varies with the FiO2 level. The aim of the present study was to evaluate the relevance of this variation both theoretically and experimen...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Karbing DS,Kjaergaard S,Smith BW,Espersen K,Allerød C,Andreassen S,Rees SE

    更新日期:2007-01-01 00:00:00

  • Recognition of hypovolemic shock: using base deficit to think outside of the ATLS box.

    abstract::Base deficit has frequently been utilized as an informal adjunct in the initial evaluation of trauma patients to assess the extent of their physiologic derangements. However, the current Advanced Trauma Life Support (ATLS) classification system for hypovolemic shock does not include base-deficit measurements and relie...

    journal_title:Critical care (London, England)

    pub_type: 评论,杂志文章


    authors: Privette AR,Dicker RA

    更新日期:2013-03-13 00:00:00

  • Clinical manifestations of disordered microcirculatory perfusion in severe sepsis.

    abstract::Microcirculatory dysfunction plays a pivotal role in the development of the clinical manifestations of severe sepsis. Prior to the advent of new imaging technologies, clinicians had been limited in their ability to assess the microcirculation at the bedside. Clinical evidence of microcirculatory perfusion has historic...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章,评审


    authors: Trzeciak S,Rivers EP

    更新日期:2005-01-01 00:00:00

  • The benefit of specialized team approaches in patients with acute kidney injury undergoing continuous renal replacement therapy: propensity score matched analysis.

    abstract:INTRODUCTION:Continuous renal replacement therapy (CRRT) has been widely used in critically ill acute kidney injury (AKI) patients. Moreover, some centers operate a specialized CRRT team (SCT) composed of physicians and nurses, but few studies have yet determined the superiority of SCT control. METHODS:A total of 334 ...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Oh HJ,Lee MJ,Kim CH,Kim DY,Lee HS,Park JT,Na S,Han SH,Kang SW,Koh SO,Yoo TH

    更新日期:2014-08-13 00:00:00

  • Rapid response systems: are they really effective?

    abstract::This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2015 and co-published as a series in Critical Care. Other articles in the series can be found online at Further information about the Annual Update in Intensive Care a...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章,评审


    authors: Sandroni C,D'Arrigo S,Antonelli M

    更新日期:2015-03-16 00:00:00

  • Microcirculatory perfusion disturbances in septic shock: results from the ProCESS trial.

    abstract:BACKGROUND:We sought to determine the effects of alternative resuscitation strategies on microcirculatory perfusion and examine any association between microcirculatory perfusion and mortality in sepsis. METHODS:This was a prospective, formally designed substudy of participants in the Protocolized Care in Early Septic...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章,多中心研究,随机对照试验


    authors: Massey MJ,Hou PC,Filbin M,Wang H,Ngo L,Huang DT,Aird WC,Novack V,Trzeciak S,Yealy DM,Kellum JA,Angus DC,Shapiro NI,ProCESS investigators.

    更新日期:2018-11-20 00:00:00

  • Long term effect of a medical emergency team on cardiac arrests in a teaching hospital.

    abstract:INTRODUCTION:It is unknown whether the reported short-term reduction in cardiac arrests associated with the introduction of the medical emergency team (MET) system can be sustained. METHOD:We conducted a prospective, controlled before-and-after examination of the effect of a MET system on the long-term incidence of ca...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Jones D,Bellomo R,Bates S,Warrillow S,Goldsmith D,Hart G,Opdam H,Gutteridge G

    更新日期:2005-01-01 00:00:00

  • Prevalence of iron deficiency on ICU discharge and its relation with fatigue: a multicenter prospective study.

    abstract:INTRODUCTION:Prevalence of iron deficiency (ID) at intensive care (ICU) admission is around 25 to 40%. Blood losses are important during ICU stay, leading to iron losses, but prevalence of ID at ICU discharge is unknown. ID has been associated with fatigue and muscular weakness, and may thus impair post-ICU rehabilitat...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章,多中心研究


    authors: Lasocki S,Chudeau N,Papet T,Tartiere D,Roquilly A,Carlier L,Mimoz O,Seguin P,Malledant Y,Asehnoune K,Hamel JF,AtlanREA group.

    更新日期:2014-09-30 00:00:00

  • A systematic review of biomarkers multivariately associated with acute respiratory distress syndrome development and mortality.

    abstract:BACKGROUND:Heterogeneity of acute respiratory distress syndrome (ARDS) could be reduced by identification of biomarker-based phenotypes. The set of ARDS biomarkers to prospectively define these phenotypes remains to be established. OBJECTIVE:To provide an overview of the biomarkers that were multivariately associated ...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: van der Zee P,Rietdijk W,Somhorst P,Endeman H,Gommers D

    更新日期:2020-05-24 00:00:00

  • Unraveling the role of high mobility group box protein 1 in severe trauma.

    abstract::High mobility group box protein 1 (HMGB1) has been shown to participate in acute inflammatory reactions, including acute lung injury and sepsis. There is also evidence that circulating levels of HMGB1 are increased after severe trauma and are associated with clinically important outcome parameters, including mortality...

    journal_title:Critical care (London, England)

    pub_type: 评论,杂志文章


    authors: Abraham E

    更新日期:2009-01-01 00:00:00

  • Success and complications by team composition for prehospital paediatric intubation: a systematic review and meta-analysis.

    abstract:BACKGROUND:Clinical team composition for prehospital paediatric intubation may affect success and complication rates. We performed a systematic review and meta-analysis to determine the success and complication rates by type of clinical team. METHODS:We searched MEDLINE, EMBASE, and CINAHL for interventional and obser...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章,meta分析


    authors: Garner AA,Bennett N,Weatherall A,Lee A

    更新日期:2020-04-15 00:00:00

  • Successful treatment of severe sepsis and diarrhea after vagotomy utilizing fecal microbiota transplantation: a case report.

    abstract:INTRODUCTION:Dysbiosis of intestinal microbiota likely plays an important role in the development of gut-derived infections, making it a potential therapeutic target against sepsis. However, experience with fecal microbiota transplantation (FMT) in the treatment of sepsis and knowledge of the underlying mechanisms are ...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Li Q,Wang C,Tang C,He Q,Zhao X,Li N,Li J

    更新日期:2015-02-09 00:00:00

  • Microcirculatory perfusion disturbances following cardiac surgery with cardiopulmonary bypass are associated with in vitro endothelial hyperpermeability and increased angiopoietin-2 levels.

    abstract:BACKGROUND:Endothelial hyperpermeability following cardiopulmonary bypass (CPB) contributes to microcirculatory perfusion disturbances and postoperative complications after cardiac surgery. We investigated the postoperative course of renal and pulmonary endothelial barrier function and the association with microcircula...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Dekker NAM,van Leeuwen ALI,van Strien WWJ,Majolée J,Szulcek R,Vonk ABA,Hordijk PL,Boer C,van den Brom CE

    更新日期:2019-04-11 00:00:00

  • Clinical review: What are the best hemodynamic targets for noncardiac surgical patients?

    abstract::Perioperative hemodynamic optimization, or goal-directed therapy (GDT), has been show to significantly decrease complications and risk of death in high-risk patients undergoing noncardiac surgery. An important aim of GDT is to prevent an imbalance between oxygen delivery and oxygen consumption in order to avoid the de...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章,评审


    authors: Lobo SM,de Oliveira NE

    更新日期:2013-03-19 00:00:00

  • Measuring the anticoagulant effect of low molecular weight heparins in the critically ill.

    abstract::Antithrombotic prophylaxis in critically ill patients frequently fails. Venous thromboembolism is associated with adverse clinical outcomes, including a prolonged intensive care unit stay and death. A potential mechanism by which critically ill patients may be predisposed to antithrombotic failure is the inability to ...

    journal_title:Critical care (London, England)

    pub_type: 评论,杂志文章,评审


    authors: Crowther M,Lim W

    更新日期:2006-01-01 00:00:00

  • Significance of lipopolysaccharide-binding protein (an acute phase protein) in monitoring critically ill patients.

    abstract:INTRODUCTION:The present study was conducted to assess the value of serum concentration of lipopolysaccharide-binding protein (LBP) in patients with systemic inflammatory response syndrome (SIRS), sepsis and septic shock with respect to its ability to differentiate between infectious and noninfectious etiologies in SIR...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Prucha M,Herold I,Zazula R,Dubska L,Dostal M,Hildebrand T,Hyanek J

    更新日期:2003-12-01 00:00:00

  • Artificial neural networks as prediction tools in the critically ill.

    abstract::The past 25 years have witnessed the development of improved tools with which to predict short-term and long-term outcomes after critical illness. The general paradigm for constructing the best known tools has been the logistic regression model. Recently, a variety of alternative tools, such as artificial neural netwo...

    journal_title:Critical care (London, England)

    pub_type: 评论,杂志文章


    authors: Clermont G

    更新日期:2005-04-01 00:00:00

  • Antibiotic therapeutic drug monitoring in intensive care patients treated with different modalities of extracorporeal membrane oxygenation (ECMO) and renal replacement therapy: a prospective, observational single-center study.

    abstract:BACKGROUND:Effective antimicrobial treatment is key to reduce mortality associated with bacterial sepsis in patients on intensive care units (ICUs). Dose adjustments are often necessary to account for pathophysiological changes or renal replacement therapy. Extracorporeal membrane oxygenation (ECMO) is increasingly bei...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Kühn D,Metz C,Seiler F,Wehrfritz H,Roth S,Alqudrah M,Becker A,Bracht H,Wagenpfeil S,Hoffmann M,Bals R,Hübner U,Geisel J,Lepper PM,Becker SL

    更新日期:2020-11-25 00:00:00

  • Intra-abdominal hypertension in patients with severe acute pancreatitis.

    abstract:INTRODUCTION:Abdominal compartment syndrome has been described in patients with severe acute pancreatitis, but its clinical impact remains unclear. We therefore studied patient factors associated with the development of intra-abdominal hypertension (IAH), the incidence of organ failure associated with IAH, and the effe...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: De Waele JJ,Hoste E,Blot SI,Decruyenaere J,Colardyn F

    更新日期:2005-08-01 00:00:00

  • Decreased CX3CR1 messenger RNA expression is an independent molecular biomarker of early and late mortality in critically ill patients.

    abstract:BACKGROUND:Chemokine (C-X3-C motif) receptor 1 (CX3CR1) was identified as the most differentially expressed gene between survivors and non-survivors in two independent cohorts of septic shock patients and was proposed as a marker of sepsis-induced immunosuppression. Whether such a biomarker is associated with mortality...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Friggeri A,Cazalis MA,Pachot A,Cour M,Argaud L,Allaouchiche B,Floccard B,Schmitt Z,Martin O,Rimmelé T,Fontaine-Kesteloot O,Page M,Piriou V,Bohé J,Monneret G,Morisset S,Textoris J,Vallin H,Blein S,Maucort-Boulch D,

    更新日期:2016-06-30 00:00:00

  • Association between kidney intracapsular pressure and ultrasound elastography.

    abstract:BACKGROUND:Kidney congestion is a common pathophysiologic pathway of acute kidney injury (AKI) in sepsis and heart failure. There is no noninvasive tool to measure kidney intracapsular pressure (KIP) directly. METHODS:We evaluated the correlation of KIP with kidney elasticity measured by ultrasound surface wave elasto...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Kashani KB,Mao SA,Safadi S,Amiot BP,Glorioso JM,Lieske JC,Nyberg SL,Zhang X

    更新日期:2017-10-19 00:00:00

  • Treatment of central line-associated bloodstream infections.

    abstract:: ...

    journal_title:Critical care (London, England)

    pub_type: 社论


    authors: Guenezan J,Drugeon B,Marjanovic N,Mimoz O

    更新日期:2018-11-16 00:00:00

  • Bench-to-bedside review: fulfilling promises of the Human Genome Project.

    abstract::Since most common diseases have been shown to be influenced by inherited variations in our genes, completion of the Human Genome Project and mapping of the human genome single-nucleotide polymorphisms will have a tremendous impact on our approach to medicine. New developments in genotyping techniques and bioinformatic...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章,评审


    authors: Chiche JD,Cariou A,Mira JP

    更新日期:2002-06-01 00:00:00

  • Antimicrobial resistance and patient outcomes: the hazards of adjustment.

    abstract::Outcomes studies of infections with resistant bacteria often do not account appropriately for intermediate variables--events in the causal pathway between the exposure and the outcome--when controlling for confounders. We discuss how failure to distinguish between confounders and intermediate variables can bias the an...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章,评审


    authors: Schwaber MJ,Carmeli Y

    更新日期:2006-01-01 00:00:00

  • Decompressive craniectomy for acute ischemic stroke.

    abstract::Malignant stroke occurs in a subgroup of patients suffering from ischemic cerebral infarction and is characterized by neurological deterioration due to progressive edema, raised intracranial pressure, and cerebral herniation. Decompressive craniectomy (DC) is a surgical technique aiming to open the "closed box" repres...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章,评审


    authors: Beez T,Munoz-Bendix C,Steiger HJ,Beseoglu K

    更新日期:2019-06-07 00:00:00

  • Recorded time periods of bispectral index values equal to zero predict neurological outcome after out-of-hospital cardiac arrest.

    abstract:BACKGROUND:Prognostication in out-of-hospital cardiac arrest (OHCA) survivors is often difficult. Recent studies have shown the predictive ability of bispectral index (BIS) monitoring to assist with early neuroprognostication. The aim of this study was to investigate whether characteristics of BIS values equal to zero ...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Eertmans W,Genbrugge C,Haesevoets G,Dens J,Boer W,Jans F,De Deyne C

    更新日期:2017-08-22 00:00:00

  • Effects of dopexamine on the intestinal microvascular blood flow and leukocyte activation in a sepsis model in rats.

    abstract:INTRODUCTION:The administration of dopexamine may constitute a therapeutical option to improve hepatosplanchnic perfusion in sepsis. In order to verify this hypothesis, we administered dopexamine in an experimental sepsis model in rats. METHODS:This prospective, randomized, controlled laboratory study was conducted in...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Birnbaum J,Klotz E,Spies CD,Lorenz B,Stuebs P,Hein OV,Grundling M,Pavlovic D,Usichenko T,Wendt M,Kox WJ,Lehmann C

    更新日期:2006-01-01 00:00:00

  • Clinical risk conditions for acute lung injury in the intensive care unit and hospital ward: a prospective observational study.

    abstract:BACKGROUND:Little is known about the development of acute lung injury outside the intensive care unit. We set out to document the following: the association between predefined clinical conditions and the development of acute lung injury by using the American-European consensus definition; the frequency of lung injury d...

    journal_title:Critical care (London, England)

    pub_type: 杂志文章


    authors: Ferguson ND,Frutos-Vivar F,Esteban A,Gordo F,Honrubia T,Peñuelas O,Algora A,García G,Bustos A,Rodríguez I

    更新日期:2007-01-01 00:00:00

  • Preserving spontaneous breathing during mechanical ventilatory support: an old yet fascinating story.

    abstract::Facilitation of early spontaneous breathing activity is the most important measure to shorten weaning and avoid ventilator-induced lung injury and diaphragmatic injury in mechanically ventilated patients. However, the optimal degree of spontaneous muscle activity and ventilator support remains to be determined. Furthe...

    journal_title:Critical care (London, England)

    pub_type: 评论,杂志文章


    authors: Calzia E,Dembinski R

    更新日期:2013-11-19 00:00:00