Search PubMed⌕ Search

Biomedical subjects

A Bouchama

Publications and source records attributed to A Bouchama.

At least 19 recordsLinked to original sources
PubMed2001

Acid-base alterations in heatstroke.

OBJECTIVE: To analyze the acid-base balance during heatstroke. DESIGN: Retrospective study. SETTING: Heatstroke Center, Makkah, Saudi Arabia. PATIENTS: Hundred nine consecutive heatstroke patients (mean age 55 +/- 12 years) with rectal temperature from 40 to 43.4 degrees C following exposure to hot weather. INTERVENTION: Arterial blood gases collected prospectively and analyzed using 95% confidence limits established by controlled experimental studies. Severity of heatstroke on admission assessed by Simplified Acute Physiology Score and Organ System Failure score. RESULTS: Metabolic acidosis was the predominant acid-base change followed by respiratory alkalosis (81 and 55% of the patients, respectively). The prevalence of metabolic acidosis (but not respiratory alkalosis) was significantly associated with the degree of hyperthermia: 63, 95 and 100% at 41, 42 and 43 degrees C, respectively (p < 0.0001). Patients with metabolic acidosis had a large anion gap (24 +/- 5). Arterial partial pressure of oxygen (PaO2), systolic blood pressure and Organ System Failure score were similar with or without metabolic acidosis. Although the acute physiology score was higher in patients with, than without, metabolic acidosis (15.7 +/- 3.7 vs 9.8 +/- 4.4, p < 0.001), there was no significant difference in neurologic morbidity and mortality (7.9 vs 1.1%, 5.6 vs 0%, p = 0.776 and 0.581, respectively). CONCLUSION: We conclude that metabolic acidosis is the predominant response in heatstroke.

Acid-Base Imbalance↗
PubMed2000

Differential effects of in vitro and in vivo hyperthermia on the production of interleukin-10.

OBJECTIVE: To determine whether hyperthermia activates an anti-inflammatory response. DESIGN: A prospective study. SETTING: Heatstroke Center, Makkah, and King Faisal Specialist Hospital, Riyadh, Saudi Arabia. PATIENTS: Twenty-five heatstroke patients pre-cooling (rectal temperature 42.4 +/- 0.8 degrees C) (group 1) and 13 normothermic heat-stressed subjects were studied (group 2). Twelve of the 25 heatstroke patients were also studied post-cooling (group 3). Mononuclear cells from six healthy blood donors resting at 24 degrees C were used for in vitro study. INTERVENTIONS: Mononuclear cells were cultured at a concentration of 1 x 10(6)/ml without and with lipopolysaccharide (LPS) added at concentration of 10, 100, and 1000 ng/ml. The cells were incubated for 24 h at 37, 39, 41, and 43 degrees C. ELISA was used to measure IL-10 in the supernatant and plasma from heatstroke and heat-stressed subjects. RESULTS: All patients in group 1, 40% of group 2, and 37% of group 3, showed elevation of IL-10 (1289 +/- 2519, 248 +/- 393, and 172 +/- 226 pg/ml, respectively) compared with normal control levels, (< 100 pg/ml) P < 0.05. IL-10 level on admission did not correlate with degree of hyperthermia. During 24 h incubation at 37 degrees C without LPS, no IL-10 was detected, whereas with 10 ng/ml LPS, monocytes released 658 +/- 291 pg IL-10/10(6) cells. At 39 degrees C and 41 degrees C IL-10 release was decreased to 225 +/- 114, and 245 +/- 90 pg/10(6) cells, respectively; and was completely inhibited at 43 degrees C (67 +/- 10 pg/10(6) cells), P < 0.0001. CONCLUSION: Heat-stress with and without hyperthermia is associated with anti-inflammatory response in vivo. However, it does not seem to be the direct effect of heat on monocytes, suggesting that other environmental or genetic factors may be involved.

Analysis of Variance↗
PubMed1999

Hematopoietic colony-stimulating factors for neutropenic patients in the ICU.

OBJECTIVE: To assess whether adjunct hematopoietic colony-stimulating factor (H-CSF) accelerates neutrophil recovery and improves survival. DESIGN: A retrospective study. SETTING: Medical/surgical intensive care unit (ICU). PATIENTS: 30 neutropenic patients admitted to the ICU and treated with H-CSF. Controls were the preceding 30 neutropenic patients not treated with H-CSF. MEASUREMENTS AND RESULTS: Patient admission characteristics were reviewed. Endpoints were neutrophil recovery ( > 1.0 x 10(9)/l), length of ICU stay and survival. Depth and duration of neutropenia (0.267 +/- 0.04 x 10(9)/l for 12 +/- 1.7 days vs 0.293 +/- 0.05 x 10(9)/l for 15 +/- 1.9 days; p = 0.67 and 0.21), and the Acute Physiology and Chronic Health Evaluation II and organ system failure scores were similar. Systemic candidiasis was lower in the H-CSF group (20 vs 3 %; p > 0.05). In 11 (36.6 %) and 10 (33.3 %) patients neutrophil count recovered ( > 1.0 x 10(9)/l); H-CSF did not reduce the duration of neutropenia (7.8 +/- 1.4 vs 5.7 +/- 1.3 days; p = 0. 28), the length of ICU stay (7.8 +/- 1.1 vs 8.9 +/- 1.5 days; p = 0. 55) or improve survival (23 vs 10 %; p = 0.168). CONCLUSION: H-CSF for treatment of neutropenia in patients admitted to the ICU did not accelerate neutrophil recovery or improve survival.

APACHE↗
PubMed1998

Lymphocyte subsets and adhesion molecules expression in heatstroke and heat stress.

We examined the specificity of the recently reported alterations in circulating lymphocytes in heatstroke by determining lymphocyte subsets in 14 consecutive heatstroke patients before and after cooling and in 7 heat-stressed controls using single- or two-color immunofluorescence flow cytometry. The relationship with catecholamine levels was also studied. In heatstroke, percentages of T (CD3(+)/CD19(-)), T-helper (CD4(+)/CD8(-)), T-inactive [CD3(+)/human leukocyte antigen-DR-], CD11a+, CD11c+, and CD44(+) lymphocytes were significantly decreased, whereas percentages of T-suppressor-cytotoxic (CD8(+)/CD4(-)), natural killer (NK; CD3(-)/CD16(+) or CD56(+)), CD3(+)/CD16(+) or CD56(+), and CD54(+) lymphocytes were significantly increased, compared with 11 normal controls. The changes in the absolute numbers of lymphocyte subsets were in the same direction and were significant for T-helper, T-suppressor-cytotoxic, NK, CD3(+)/CD16(+) or CD56(+), and CD11c+ lymphocytes. Milder but significant changes in percentages of T-helper, T-suppressor-cytotoxic, CD11c+, and CD44(+) lymphocytes were seen in heat stress. Cooling was associated with partial or complete normalization, further derangement (CD11a+, CD11c+), or overcorrection (NK, T-suppressor-cytotoxic, CD11b+) of abnormal percentages of lymphocyte subsets. Norepinephrine levels were significantly elevated in heatstroke (4.7-fold) and heat stress (3.2-fold), but did not significantly correlate with lymphocyte subsets. We conclude that heatstroke is associated with significant changes in percentages and in absolute numbers of a wide range of circulating lymphocyte subsets that are not related to elevated catecholamine levels or totally normalized by cooling. Similar, albeit milder, changes are seen in heat stress, suggesting that the two syndromes represent a continuum.

Antigens, CD↗
PubMed1997

Concentrations of soluble tumor necrosis factor and interleukin-6 receptors in heatstroke and heatstress.

OBJECTIVE: Increased proinflammatory cytokine concentrations have been implicated in the pathogenesis of heatstroke. Soluble cytokine receptors can modulate circulating cytokine activities. We examined the possible role of soluble tumor necrosis factor receptors (sTNFR 60, sTNFR 80) and interleukin-6 receptor (sIL-6R) in heatstroke by determining their concentrations before and after cooling, as well as in heatstressed controls. DESIGN: Prospective controlled study. SETTING: Heatstroke Center, Makkah, Saudi Arabia (1993 pilgrimage). PATIENTS: Twenty-five consecutive heatstroke patients before and after cooling, 14 heatstressed controls (HSC), and 13 normal controls (NC). MEASUREMENTS AND MAIN RESULTS: Concentrations of sTNFR 60, sTNFR 80, and sIL-6R, as well as their ligands, were measured using commercially available enzyme-linked immunosorbent assay kits. Mean sTNFR 60 concentration was increased in heatstroke (p <.0001, vs. NC; p < .0001, vs. HSC) and in HSC (p = .004, vs. NC). Mean sTNFR 80 concentration was increased in heatstroke and decreased in HSC (p = .01, heatstroke vs. HSC). Mean sIL-6R concentration was decreased in heatstroke and increased in HSC (p = .04, heatstroke vs. NC; p = .001, heatstroke vs. HSC). IL-6 was undetectable in NC and mean IL-6 concentration was more increased in heatstroke than in HSC (p = .001). Rectal temperature and creatinine concentrations correlated significantly with sTNFR 60, sTNFR 80, sIL-6R, and IL-6 concentrations. After cooling, mean concentrations of sIL-6R and sTNFR 80 increased significantly, whereas the mean sTNFR 60 concentration did not change. Residual neurologic deficits were associated with higher precooling IL-6 (p = .002) and postcooling sTNFRs (p < .0001) concentrations. CONCLUSIONS: Significant changes in cytokine receptor concentrations are associated with heatstress. In heatstroke, the changes are more pronounced, and for some cytokine receptors, the changes are in the opposite direction (compared with changes in heatstress). Concentrations of IL-6 and sTNFRs correlate with hyperthermia and outcome. Cooling did not normalize sTNFR concentrations, suggesting failure to control the inflammatory response.

Adult↗
PubMed1996

Evidence for endothelial cell activation/injury in heatstroke.

OBJECTIVES: We treated the hypothesis that heatstroke is associated with endothelial cell activation/injury and examined the possibility that the markers of endothelial cell activation/injury may be associated with its severity and complications such as disseminated intravascular coagulation, lung injury, and renal dysfunction. DESIGN: Prospective analyses. SETTING: Heatstroke Center in Makkah, Saudi Arabia. PATIENTS: Twenty-two adult patients with heatstroke. INTERVENTIONS: The plasma concentration of endothelin, circulating intercellular adhesion molecule-1 (ICAM-1), and von Willebrand factor-antigen values were measured, respectively, by radioimmunoassay, enzyme-linked immunosorbent assay, and rocket electroimmunoassay, in heatstroke patients on admission (precooling) and after complete cooling (postcooling), and in ten normal control patients. MEASUREMENTS AND MAIN RESULTS: Precooling heatstroke patients (rectal temperature 40.9 +/- 1.1 [SD] degrees C) had increased circulating concentrations of endothelin, c-ICAM-1, and von Willebrand factor-antigen in 100%, 80%, and 77% of patients to 126.4 +/- 11.2 pmol/L, 523.1 +/- 154.4 ng/mL, and 3.85 +/- 2.3 U/mL, respectively (control values: 13.7 +/- 4.2 pmol/L [p < .001]; 247.4 +/- 68.2 ng/ml [p < .001]; and < 1.5 U/mL, respectively). There was a significant (r2 = .68, p < .01) correlation between circulating ICAM-1 and endothelin concentrations. Plasma endothelin concentration correlated negatively with temperature (r2 = .35, p < .05). Mean endothelin concentration was similar in patients with or without renal dysfunction, and mean von Willebrand factor-antigen concentration was similar in patients with or without lung injury or disseminated intravascular coagulation. There were no significant correlations between circulating ICAM-1, endothelin, or von Willebrand factor-antigen concentration and the Simplified Acute Physiology core. After cooling, mean circulating ICAM-1 and endothelin concentrations decreased significantly to 400 +/- 109 ng/mL and 93 +/- 38.5 pmol/L, respectively, whereas the mean von Willebrand factor-antigen concentration increased to 5.55 +/- 2.18 U/mL (p > .05). CONCLUSIONS: Our findings of increased circulating concentrations of circulating ICAM-1, endothelin, and von Willebrand factor-antigen are consistent with the hypothesis that heatstroke is associated with endothelial cell activation/injury. Whether the endothelial cell activation/injury is implicated in the pathophysiology of this disorder merits further studies.

Adult↗
PubMed1996

Respiratory arrest: a complication of Arnold-Chiari malformation in adults.

We describe the cases of 2 adult patients who developed respiratory arrest and were found to have Arnold-Chiari malformation on magnetic resonance imaging. Following posterior fossa decompression both patients improved, though one of them subsequently died during sleep. Imaging of the craniocervical junction should be part of the workup of patients with unexplained apneic episodes.

Adult↗
PubMed1996

Activation of coagulation and fibrinolysis in heatstroke.

Hemorrhagic diathesis and widespread microthrombosis are common in heatstroke. To assess the early stages of coagulopathy in heatstroke, thrombin-antithrombin III (TAT), fibrin monomers, plasmin-alpha 2-antiplasmin (PAP), plasminogen and D-Dimer were measured in 16 heatstroke patients (means +/- SE rectal temperature 42.3 +/- 0.2 degrees C) pre- and postcooling and compared with 8 heatstressed and 23 normal controls. Comparing heatstroke patients with normal controls, TAT, fibrin monomers, PAP and D-Dimer were elevated to (median (range)) 16.5 (4-1000) versus 3.5 (2-7.2) micrograms/l p < 0.001, 16 (4-113) versus 2 (2-9) nM p < 0.001; 3300 (1000-36500) versus 255 (136-462) micrograms/l p < 0.001 and 0.72 (0.22-64.8) versus 0.15 (0.05-0.25) microgram/ml p < 0.01 respectively. Plasminogen decreased to 81% (34-106); PAP, TAT and D-Dimer correlated significantly with hyperthermia (r = 0.577, p = 0.02; r = 0.635, p = 0.01; r = 0.76, p = 0.003). Postcooling PAP decreased to 545 (260-850) micrograms/l p < 0.005, TAT 10 (6-70) micrograms/l, and fibrin monomers 22 (18-86) nM remained unchanged. Heatstressed controls showed mild but significant increase in all markers. Activation of coagulation and fibrinolysis occurs early and is profound and sustained in heatstroke. Cooling seems to attenuate the activation of fibrinolysis only, however, this requires confirmation in a larger study population.

Aged↗
PubMed1995

Open lung biopsy provides a higher and more specific diagnostic yield compared to broncho-alveolar lavage in immunocompromised patients. Fungal Study Group.

In order to examine the feasibility and safety of undertaking a larger prospective study to compare the diagnostic yield from concurrent open lung biopsy (OLB) and bronchoalveolar lavage (BAL) in febrile neutropenic patients with pulmonary infiltrates and the impact of such knowledge on clinical outcome, a pilot exploratory study was performed. 13 immunocompromised patients (mainly with haematological malignancy or bone marrow transplantation recipients) were investigated. At least one diagnostic finding in 12 of 13 patients was provided by OLB compared to 4 of 13 patients by BAL. BAL provided 7 specific diagnoses (pneumocystis 1, fungal infection 3, bacterial pneumonia 1, pulmonary haemorrhage 2) whilst OLB provided 12 specific diagnosis (CMV 2, pneumocystis 3, fungal infection 1, bacterial pneumonia 1, pulmonary haemorrhage 4, pulmonary embolism 1). Five patients with nonspecific interstitial/alveolar inflammation were diagnosed only by OLB. The concordance that the exact same specific diagnoses present in the OLB were found in the BAL was zero. There were 2 minor complications (1 wound infection by OLB, 1 moderate haemorrhage by BAL). Mortality at 28 days was 8 of 13 patients which in no case was related to either procedure. We suggest that OLB is a safe procedure in such patients, provides superior and more complete diagnostic information compared to BAL and a larger controlled study to investigate the impact of early OLB on the outcome of these patients appears to be justified.

Adolescent↗