Association of hemoglobin concentration and mortality in critically ill patients with severe traumatic brain injury

ABSTRACT: INTRODUCTION: The critical care management of traumatic brain injury focuses on preventing secondary ischemic injury. Cerebral oxygen delivery is dependent upon the cerebral perfusion pressure and the oxygen content of blood, which is principally determined by hemoglobin. Despite its importance to the cerebral oxygen delivery, the precise hemoglobin concentration to provide adequate oxygen delivery to injured neuronal tissue in TBI patients is controversial with limited evidence to provide transfusion thresholds. METHODS: We conducted a retrospective cohort study of severe TBI patients, investigating the association between mean 7-day hemoglobin concentration and hospital mortality. Demographic, physiologic, intensive care interventions, clinical outcomes and daily hemoglobin concentrations were recorded for all patients. Patients were all cared for at a tertiary, level 1 trauma center in a mixed medical and surgical intensive unit. Patients were divided into quartiles based on their mean 7-day hemoglobin concentration: < 90 g/L, 90 - 99 g/L, 100 - 109 g/L and > 110 g/L. Multivariable log-binomial regression was used to model the association between mean daily hemoglobin concentration and hospital mortality. RESULTS: Two hundred seventy-three patients with traumatic brain injury were identified and 169 were included in the analysis based on inclusion/exclusion criteria. Of these, 77% of the patients were male, with a mean age of 38 (SD 17) years and a median best GCS of 6 (IQR 5 - 7). One hundred fifteen patients (68%) received a red blood cell (RBC) transfusion. In RBCs administered in the ICU, the median pre-transfusion hemoglobin was 79 g/L (IQR 73 - 85). Thirty-seven patients (22%) died in hospital. Multivariable analysis revealed that mean 7-day hemoglobin concentration < 90 g/L was independently associated with an increased risk of hospital mortality (RR 3.1, 95% CI 1.5 - 6.3, p = 0.03). Other variables associated with increased mortality on multivariable regression were insertion of external ventricular drain, age and decreased GCS. Red blood cell transfusion was not associated with mortality following multivariable adjustment. CONCLUSIONS: A mean 7-day hemoglobin concentration of < 90g/L is associated with increased hospital mortality in patients with severe traumatic brain injury.     

Mortality of elderly patients in Ontario after hospital admission for chronic obstructive pulmonary disease

BACKGROUND:

Chronic obstructive pulmonary disease (COPD) is associated with significant mortality. It is currently the fourth leading cause of death in Canada and the world.

OBJECTIVES:

To describe the mortality of elderly patients in Ontario after hospital admission for COPD.

METHODS:

A retrospective cohort study was conducted using the Discharge Abstract Database from the Canadian Institute for Health Information. Patients aged 65 years and older who were admitted to hospital between 2001 and 2004 with primary discharge diagnoses labelled with International Classification of Diseases, Ninth Revision codes 491, 492 and 496 were included in the study.

RESULTS:

Mortality rates were 8.81, 12.10, 14.53 and 27.72 per 100 COPD hospital admissions at 30, 60, 90 and 365 days after hospital discharge, respectively. Mortality also increased with age, and men had higher rates than women. No significant differences in mortality rates were found between different socioeconomic groups (P>0.05). Patients with shared care of a family physician or general practitioner and a specialist had significantly lower mortality rates than the overall rate (P<0.05), and their rates were approximately one-half the rate of patients with only one physician.

CONCLUSIONS:

Hospitalization with COPD is associated with significant mortality. Patients who were cared for by both a family physician or general practitioner and a specialist had significantly lower mortality rates than those cared for by only one physician, suggesting that continuous and coordinated care results in better survival.     

Midterm review of national health plans: an example from the United Republic of Tanzania

In the health sector, planning and resource allocation at country level are mainly guided by national plans. For each such plan, a midterm review of progress is important for policy-makers since the review can inform the second half of the plan’s implementation and provide a situation analysis on which the subsequent plan can be based. The review should include a comprehensive analysis using recent data – from surveys, facility and administrative databases – and global health estimates. Any midterm analysis of progress is best conducted by a team comprising representatives of government agencies, independent national institutions and global health organizations. Here we present an example of such a review, done in 2013 in the United Republic of Tanzania. Compared to similar countries, the results of this midterm review showed good progress in all health indicators except skilled birth attendance.     

Heart rate variability in the neonate and infant: analytical methods, physiological and clinical observations

Naturally occurring oscillations in heart rate have long been considered to reflect the modulating influences of the autonomic nervous system. Individual reports of heart rate variability in healthy and sick neonates and infants have provided valuable information as to pathophysiological changes in autonomic cardiovascular control. It is evident that prematurity and poor health are reflected in attenuated heart rate variability. However, at present, there are few standard criteria for the analysis of heart rate variability, preventing precise comparisons among the various studies. Until recommendations for standardized analytical methods are made, clinical application of heart rate variability in neonatal and infant prognosis and therapy remains premature.     

Analysis of the DNA adducts of phenyl glycidyl ether in a calf thymus DNA hydrolysate by capillary zone electrophoresis-electrospray mass spectrometry: evidence for phosphate alkylation

Calf thymus DNA was reacted in vitro with phenyl glycidyl ether (PGE) and was hydrolysed enzymatically, to the 5'-monophosphate nucleotides using deoxyribonuclease I (DNA-ase I) and nuclease P1. The adducts were concentrated using solid phase extraction (SPE), on a polystyrene divinylbenzene copolymer in order to remove the unmodified nucleotides. The adducts could be identified using capillary zone electrophoresis- electrospray tandem mass spectrometry (CZE ES-MS/MS), using sample stacking. In addition to the base alkylated 2'-deoxynucleotides present in the DNA-hydrolysate, also phosphate alkylated 2'-deoxynucleotide adducts were identified for TMP and dAMP. An additional adduct, dUMP alkylated on the uridine moiety was found originating from the hydrolytic deamination of dCMP alkylated on N3 of the cytosine moiety. Enzymatic hydrolysis using nuclease P1 was incomplete as shown by the presence of dinucleotides alkylated on the base moiety. They were successfully hydrolysed to the corresponding 2'-deoxynucleotides by snake venom phosphodiesterase (SVP). Data are shown indicating that alkylations on the pyrimidine bases were more resistant to enzymatic hydrolysis with nuclease P1 than the purine alkylated products.      

The generation of encephalitogenic T cell lines from experimental allergic encephalomyelitis-resistant strains of mice

While only a few strains of mice are susceptible to the primary induction or passive transfer of experimental allergic encephalomyelitis (EAE), the basis of EAE resistance remains unclear. In the present studies, we have defined two approaches that allow for the generation of encephalitogenic, myelin basic protein-reactive, T cell lines from EAE-resistant strains of mice. The first approach, based on the putative relevance of apoptosis to autoimmune disease, involves repeat antigenic stimulation of recently initiated T cell lines. The second approach involves the initiation of lymph node cultures in the absence of exogenous splenocytes as antigenic- presenting cells and the use of a higher antigen concentration. Both approaches lead to the generation of encephalitogenic T cell lines from EAE-resistant mouse strains and will be useful for identifying factors relevant to the pathogenesis of EAE.