Paracetamol therapy and outcome of critically ill patients: a multicenter retrospective observational study

Introduction

In this study, we aimed to examine the association between paracetamol administration in the intensive care unit (ICU) and mortality in critically ill patients.

Methods

We conducted a multicenter retrospective observational study in four ICUs. We obtained information on paracetamol use, body temperature, demographic, clinical and outcome data from each hospital’s clinical information system and admissions and discharges database. We performed statistical analysis to assess the association between paracetamol administration and hospital mortality.

Results

We studied 15,818 patients with 691,348 temperature measurements at 4 ICUs. Of these patients, 10,046 (64%) received at least 1 g of paracetamol. Patients who received paracetamol had lower in-hospital mortality (10% vs. 20%, P <0.001), and survivors were more likely to have received paracetamol (66% vs. 46%; P <0.001). However, patients treated with paracetamol were also more likely to be admitted to the ICU after surgery (70% vs. 51%; P <0.001) and/or after elective surgery (55% vs. 37%; P <0.001). In multivariate logistic regression analysis including a propensity score for paracetamol treatment, we found a significant and independent association between the use of paracetamol and reduced in-hospital mortality (adjusted odds ratio =0.60 (95% confidence interval (CI), 0.53 to 0.68), P <0.001). Cox proportional hazards analysis showed that patients who received paracetamol also had a significantly longer time to death (adjusted hazard ratio =0.51 (95% CI, 0.46 to 0.56), P <0.001). The association between paracetamol and decreased mortality and/or time to death was broadly consistent across surgical and medical patients. It remained present after adjusting for paracetamol administration as a time-dependent variable. However, when such time-dependent analysis was performed, the association of paracetamol with outcome lost statistical significance in the presence of fever and suspected infection and in patients in the lower tertiles of Acute Physiology and Chronic Health Evaluation II scores.

Conclusions

Paracetamol administration is common in the ICU and appears to be independently associated with reduced in-hospital mortality and time to death after adjustment for multiple potential confounders and propensity score. This association, however, was modified by the presence of fever, suspected infection and lesser illness severity and may represent the effect of indication bias.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-0865-1) contains supplementary material, which is available to authorized users.

Using skin for drug delivery and diagnosis in the critically ill

Skin offers easy access, convenience and non-invasiveness for drug delivery and diagnosis. In principle, these advantages of skin appear to be attractive for critically ill patients given potential difficulties that may be associated with oral and parenteral access in these patients. However, the profound changes in skin physiology that can be seen in these patients provide a challenge to reliably deliver drugs or provide diagnostic information. Drug delivery through skin may be used to manage burn injury, wounds, infection, trauma and the multisystem complications that rise from these conditions. Local anaesthetics and analgesics can be delivered through skin and may have wide application in critically ill patients. To ensure accurate information, diagnostic tools require validation in the critically ill patient population as information from other patient populations may not be applicable.

End points for phase II trials in intensive care: recommendations from the Australian and New Zealand Clinical Trials Group consensus panel meeting

BACKGROUND

There is uncertainty about which end points should be used for Phase II trials in critically ill patients.

OBJECTIVE

To systematically evaluate potential end points for Phase II trials in critically ill patients.

DESIGN AND SETTING

A report outlining a process of literature review and recommendations from a consensus meeting conducted on behalf of the Australian and New Zealand Intensive Care Society Clinical Trials Group (ANZICS CTG) in October 2011.

RESULTS AND CONCLUSIONS

The consensus panel concluded that there are no adequately validated end points for Phase II trials in critically ill patients. However, the following were identified as potential Phase II end points: hospital-free days to Day 90, ICU-free days to Day 28, ventilator-free days to Day 28, cardiovascular support-free days to Day 28, and renal replacement therapy-free days to Day 28. We recommend that these end points be evaluated further.

The metabolic syndrome in critically ill patients

Metabolic support in intensive care is a rapidly evolving field with new information being gathered almost on a daily basis. In endocrine practice, over the last 20 years, researchers have focussed on a new entity, termed the "metabolic syndrome". This describes the constellation of abnormalities which include central adiposity, insulin resistance and inflammation. All of these predispose the individual to a greater risk of cardiovascular events. Of interest is the observation that some of the metabolic abnormalities in sepsis and multiple organ dysfunction syndrome of critical illness share several common features with that of the metabolic syndrome. In this chapter we describe the features of the metabolic syndrome as is understood in endocrine parlance, the metabolic abnormalities of critical illness and explore the common threads underlying the pathophysiology and the treatment of the two syndromes. The role of adiponectin in the metabolic abnormalities in both the metabolic syndrome and in sepsis are reviewed. The potential role of the pleiotropic effects of statins in the therapy of sepsis is also discussed.

The predictive ability of a weighted systemic inflammatory response syndrome score for microbiologically confirmed infection in hospitalised patients with suspected sepsis

BACKGROUND

The systemic inflammatory response syndrome (SIRS) concept lacks sensitivity and specificity for guiding clinical practice and sepsis research.

OBJECTIVE

To assess the performance of a weighted SIRS score, with emphasis on white cell count and temperature criteria in predicting microbiologically confirmed infection.

DESIGN AND SETTING

Prospective cohort study at Princess Alexandra Hospital, a tertiary teaching hospital in Queensland, Australia.

PARTICIPANTS

Patients aged 18 years or older who were hospitalised with suspected infection and started on antimicrobial therapy.

MAIN OUTCOME MEASURES

The utility of each SIRS criterion, the 1992 consensus conference recommendation (≤ 2 SIRS criteria) and a weighted SIRS score in predicting microbiologically confirmed infection were compared.

RESULTS

2085 patients were included in the analysis. All criteria performed poorly, with low sensitivities (27.3%-70.6%), low specificities (37.5%-77.5%), low positive predictive values (61.5%-65.3%), low negative predictive values (39.8%-45.1%), and likelihood ratios close to 1.0. Both SIRS and weighted SIRS scores did not perform better than clinicians' suspicion for infection.

CONCLUSIONS

Both SIRS and weighted SIRS score had low predictive ability for microbiologically confirmed infection. A more robust conceptual framework incorporating clinical, biochemical and immunological markers must be formulated and validated to better guide clinical practice and research. Clinicians' suspicions may be as good as any scoring system at identifying patients with infection and sepsis.

A Canadian Critical Care Trials Group project in collaboration with the international forum for acute care trialists - Collaborative H1N1 Adjuvant Treatment pilot trial (CHAT): study protocol and design of a randomized controlled trial

BACKGROUND

Swine origin influenza A/H1N1 infection (H1N1) emerged in early 2009 and rapidly spread to humans. For most infected individuals, symptoms were mild and self-limited; however, a small number developed a more severe clinical syndrome characterized by profound respiratory failure with hospital mortality ranging from 10 to 30%. While supportive care and neuraminidase inhibitors are the main treatment for influenza, data from observational and interventional studies suggest that the course of influenza can be favorably influenced by agents not classically considered as influenza treatments. Multiple observational studies have suggested that HMGCoA reductase inhibitors (statins) can exert a class effect in attenuating inflammation. The Collaborative H1N1 Adjuvant Treatment (CHAT) Pilot Trial sought to investigate the feasibility of conducting a trial during a global pandemic in critically ill patients with H1N1 with the goal of informing the design of a larger trial powered to determine impact of statins on important outcomes.

METHODS/DESIGN

A multi-national, pilot randomized controlled trial (RCT) of once daily enteral rosuvastatin versus matched placebo administered for 14 days for the treatment of critically ill patients with suspected, probable or confirmed H1N1 infection. We propose to randomize 80 critically ill adults with a moderate to high index of suspicion for H1N1 infection who require mechanical ventilation and have received antiviral therapy for ≤ 72 hours. Site investigators, research coordinators and clinical pharmacists will be blinded to treatment assignment. Only research pharmacy staff will be aware of treatment assignment. We propose several approaches to informed consent including a priori consent from the substitute decision maker (SDM), waived and deferred consent. The primary outcome of the CHAT trial is the proportion of eligible patients enrolled in the study. Secondary outcomes will evaluate adherence to medication administration regimens, the proportion of primary and secondary endpoints collected, the number of patients receiving open-label statins, consent withdrawals and the effect of approved consent models on recruitment rates.

DISCUSSION

Several aspects of study design including the need to include central randomization, preserve allocation concealment, ensure study blinding compare to a matched placebo and the use novel consent models pose challenges to investigators conducting pandemic research. Moreover, study implementation requires that trial design be pragmatic and initiated in a short time period amidst uncertainty regarding the scope and duration of the pandemic.

TRIAL REGISTRATION NUMBER

ISRCTN45190901.

Antibiotic dosing in the 'at risk' critically ill patient: Linking pathophysiology with pharmacokinetics/pharmacodynamics in sepsis and trauma patients

Background

Critical illness, mediated by trauma or sepsis, can lead to physiological changes that alter the pharmacokinetics of antibiotics and may result in sub-therapeutic concentrations at the sites of infection. The first aim of this project is to identify the clinical characteristics of critically ill patients with significant trauma that have been recently admitted to ICU that may predict the dosing requirements for the antibiotic, cefazolin. The second aim of this is to identify the clinical characteristics of critically ill patients with sepsis that may predict the dosing requirements for the combination antibiotic, piperacillin-tazobactam.

Methods/Design

This is an observational pharmacokinetic study of patients with trauma (cefazolin) or with sepsis (piperacillin-tazobactam). Participants will have samples from blood and urine, collected at different intervals. Patients will also have a microdialysis catheter inserted into subcutaneous tissue to measure interstitial fluid penetration of the antibiotic. Participants will be administered sinistrin, indocyanine green and sodium bromide as well as have cardiac output monitoring performed and tetrapolar bioimpedance to determine physiological changes resulting from pathology. Analysis of samples will be performed using validated liquid chromatography tandem mass-spectrometry. Pharmacokinetic analysis will be performed using non-linear mixed effects modeling to determine individual and population pharmacokinetic parameters of antibiotics.

Discussion

The study will describe cefazolin and piperacillin-tazobactam concentrations in plasma and the interstitial fluid of tissues in trauma and sepsis patients respectively. The results of this study will guide clinicians to effectively dose these antibiotics in order to maximize the concentration of antibiotics in the interstitial fluid of tissues.

Acute fluid shifts influence the assessment of serum vitamin D status in critically ill patients

Introduction

Recent reports have highlighted the prevalence of vitamin D deficiency and suggested an association with excess mortality in critically ill patients. Serum vitamin D concentrations in these studies were measured following resuscitation. It is unclear whether aggressive fluid resuscitation independently influences serum vitamin D.

Methods

Nineteen patients undergoing cardiopulmonary bypass were studied. Serum 25(OH)D₃, 1α,25(OH)₂D₃, parathyroid hormone, C-reactive protein (CRP), and ionised calcium were measured at five defined timepoints: T1 - baseline, T2 - 5 minutes after onset of cardiopulmonary bypass (CPB) (time of maximal fluid effect), T3 - on return to the intensive care unit, T4 - 24 hrs after surgery and T5 - 5 days after surgery. Linear mixed models were used to compare measures at T2-T5 with baseline measures.

Results

Acute fluid loading resulted in a 35% reduction in 25(OH)D₃ (59 ± 16 to 38 ± 14 nmol/L, P < 0.0001) and a 45% reduction in 1α,25(OH)₂D₃ (99 ± 40 to 54 ± 22 pmol/L P < 0.0001) and i(Ca) (P < 0.01), with elevation in parathyroid hormone (P < 0.0001). Serum 25(OH)D₃ returned to baseline only at T5 while 1α,25(OH)₂D₃ demonstrated an overshoot above baseline at T5 (P < 0.0001). There was a delayed rise in CRP at T4 and T5; this was not associated with a reduction in vitamin D levels at these time points.

Conclusions

Hemodilution significantly lowers serum 25(OH)D₃ and 1α,25(OH)₂D₃, which may take up to 24 hours to resolve. Moreover, delayed overshoot of 1α,25(OH)₂D₃ needs consideration. We urge caution in interpreting serum vitamin D in critically ill patients in the context of major resuscitation, and would advocate repeating the measurement once the effects of the resuscitation have abated.

Plasma protein C levels in immunocompromised septic patients are significantly lower than immunocompetent septic patients: a prospective cohort study

Introduction

Activated Protein C [APC] improves outcome in immunocompetent patients with severe sepsis particularly in those who are perceived to have high mortality risk. Before embarking on a trial of APC administration in immunocompromised septic patients, a preliminary study on plasma levels of protein C in this cohort is essential.

Objective

To assess serum Protein C concentrations in immunocompromised patients as compared to immunocompetent patients during sepsis, severe sepsis, septic shock and recovery.

Methods

Prospective cohort study in a tertiary hospital. Patients satisfying inclusion criteria were enrolled after informed consent. Clinical variables were noted with sample collection when patients met criteria for sepsis, severe sepsis, septic shock and recovery. Protein C levels were measured using monoclonal antibody based fluorescence immunoassay.

Results

Thirty one patients participated in this study (22 immunocompromised, 9 immunocompetent). Protein C levels were found to be significantly lower in the immunocompromised group compared to the immunocompetent group, particularly observed in severe sepsis [2.27 (95% CI: 1.63-2.9) vs 4.19 (95% CI: 2.87-5.52) mcg/ml] (p = 0.01) and sepsis [2.59 (95% CI: 1.98-3.21) vs 3.64 (95% CI: 2.83-4.45) mcg/ml] (p = 0.03). SOFA scores were similar in both the groups across sepsis, severe sepsis and septic shock categories. Protein C levels improved significantly in recovery (p = 0.001) irrespective of immune status.

Conclusion

Protein C levels were significantly lower in immunocompromised patients when compared to immunocompetent patients in severe sepsis and sepsis categories. Our study suggests a plausible role for APC in severely septic immunocompromised patients which need further elucidation.

Antibiotic resistance--what's dosing got to do with it?

OBJECTIVE

This review seeks to identify original research articles that link antibiotic dosing and the development of antibiotic resistance for different antibiotic classes. Using this data, we seek to apply pharmacodynamic principles to assist clinical practice for suppressing the emergence of resistance. Concepts such as mutant selection window and mutant prevention concentration will be discussed.

DATA SOURCES

PubMed, EMBASE, and the Cochrane Controlled Trial Register.

STUDY SELECTION

All articles that related antibiotic doses and exposure to the formation of antibiotic resistance were reviewed.

DATA SYNTHESIS

The escalation of antibiotic resistance continues worldwide, most prominently in patients in intensive care units. Data are emerging from in vitro and in vivo studies that suggest that inappropriately low antibiotic dosing may be contributing to the increasing rate of antibiotic resistance. Fluoroquinolones have widely been researched and publications on other antibiotic classes are emerging. Developing dosing regimens that adhere to pharmacodynamic principles and maximize antibiotic exposure is essential to reduce the increasing rate of antibiotic resistance.

CONCLUSIONS

Antibiotic dosing must aim to address not only the bacteria isolated, but also the most resistant subpopulation in the colony, to prevent the advent of further resistant infections because of the inadvertent selection pressure of current dosing regimens. This may be achieved by maximizing antibiotic exposure by administering the highest recommended dose to the patient.

Malaria deaths as sentinel events to monitor healthcare delivery and antimalarial drug safety

OBJECTIVES

To identify case management, health system and antimalarial drug factors contributing to malaria deaths.

METHOD

We investigated malaria-related deaths in South Africa's three malaria endemic provinces from January 2002 to July 2004. Data from healthcare facility records and a semi-structured interview with patients' contacts were reviewed by an expert panel, which sought to reach consensus on factors contributing to the death. This included possible health system failures, adverse reactions to antimalarials, inappropriate medicine use and failing to respond to treatment.

RESULTS

Approximately 177 of 197 cases met inclusion criteria for the study. Delay in seeking formal health care was significantly longer for patients who sought traditional health care [median 4; inter-quartile range (IQR) 3-7 days] than for patients who did not (median 3; IQR 1-5 days; P = 0.033). Patients with confirmed or suspected HIV/AIDS were significantly more likely to use traditional approaches (25%) than those with other comorbidities (0%; P = 0.002). Malaria was neither suspected nor tested for at a primary care facility in 23% of cases with adequate records. Initial hospital assessment was considered inadequate in 74% of cases admitted to hospital and in-patient monitoring and management was adequate in only 27%. There were 32 suspected adverse reactions to antimalarial therapy.

CONCLUSION

A confidential enquiry into malaria-related deaths is a useful tool for identifying preventable factors, health system failures and adverse events affecting malaria case management.

Establishing a workplace antiretroviral therapy programme in South Africa

Ways to expand access to antiretroviral treatment (ART) in low income settings are being sought. We describe an HIV care programme including ART in an industrial setting in South Africa. The programme uses guidelines derived from local and international best practice. The training component aims to build capacity among health care staff. Nurses and doctors are supported by experienced HIV clinicians through telephone consultation and site visits. Patients undergo a three-stage counselling procedure prior to starting ART. Drug regimens and monitoring are standardised and prophylaxis against opportunistic infections (isoniazid and cotrimoxazole) is offered routinely. Laboratory and pharmacy services, using named-patient dispensing, are centralized. The programme is designed to ensure that data on clinical and economic outcomes will be available for programme evaluation. Between November 2002-December 2004, ART delivery has been established at 70 ART workplace ART sites. The sites range from 200 to 12000 employees, and from small occupational health clinics and general practitioner rooms to larger hospital clinics. During this period, 2456 patients began ART. Of those on treatment for at least three months, 1728 (78%) have been retained on the programme and only 38 (1.7%) patients have failed the first-line ART regimen. This model for delivery of ART is feasible and successful in an industrial setting. The model may be generalizable to other employment health services in settings of high HIV prevalence, and as a model for implementing ART in other types of health-care settings.