Christian Melot

Low back pain in a population of school children

Abstract A study was undertaken to analyse the prevalence of low back pain (LBP) and confounding factors in primary school children in the city of Antwerp. A total of 392 children aged 9 were included in the study. All children completed a validated three-page questionnaire and they all underwent a specific lumbar spine oriented medical examination during their annual routine medical school control. This examination was performed by the city school doctors. The questionnaire was composed of easy “yes/no” questions and visual analogue scales. Statistical analysis was performed using Student’s t-test and chi-squared test at the significance level P < 0.05. The prevalence of LBP was high. No gender difference was found. A total of 142 children (36%) reported having suffered at least one episode of LBP in their lives. Of these, 33 (23%) had sought medical help for LBP from a doctor or physiotherapist. Sixty-four percent of children reporting LBP said that at least one of their parents suffered from or complained of LBP. This was significantly higher than for the children who did not report having suffered LBP. The way in which the school satchel was carried (in the hand, on the back) had no bearing on the incidence of LBP. There was significantly more LBP in children who reported playing video games for more than 2 h per day, but this was not so for television watchers. The visual analogue scales concerning general well-being were all very significantly correlated with self-reported LBP, with children who reported LBP being more tired, less happy, and worse sleepers. Of the 19 clinical parameters taken down during the medical examination, only one was significantly more prevalent in the group of children reporting LBP: pain on palpation at the insertion site on the iliac crest of the ilio-lumbar ligament. From this study we can establish that there are few clinical signs that can help to single out school children with LBP.

Weaning from mechanical ventilation

Weaning covers the entire process of liberating the patient from mechanical support and from the endotracheal tube. Many controversial questions remain concerning the best methods for conducting this process. An International Consensus Conference was held in April 2005 to provide recommendations regarding the management of this process. An 11-member international jury answered five pre-defined questions. 1) What is known about the epidemiology of weaning problems? 2) What is the pathophysiology of weaning failure? 3) What is the usual process of initial weaning from the ventilator? 4) Is there a role for different ventilator modes in more difficult weaning? 5) How should patients with prolonged weaning failure be managed? The main recommendations were as follows. 1) Patients should be categorised into three groups based on the difficulty and duration of the weaning process. 2) Weaning should be considered as early as possible. 3) A spontaneous breathing trial is the major diagnostic test to determine whether patients can be successfully extubated. 4) The initial trial should last 30 min and consist of either T-tube breathing or low levels of pressure support. 5) Pressure support or assist–control ventilation modes should be favoured in patients failing an initial trial/trials. 6) Noninvasive ventilation techniques should be considered in selected patients to shorten the duration of intubation but should not be routinely used as a tool for extubation failure.

High-Altitude Pulmonary Edema Is Initially Caused by an Increase in Capillary Pressure

BackgroundHigh-altitude pulmonary edema (HAPE) is characterized by severe pulmonary hypertension and bronchoalveolar lavage fluid changes indicative of inflammation. It is not known, however, whether the primary event is an increase in pressure or an increase in permeability of the pulmonary capillaries. Methods and ResultsWe studied pulmonary hemodynamics, including capillary pressure determined by the occlusion method, and capillary permeability evaluated by the pulmonary transvascular escape of 67Ga-labeled transferrin, in 16 subjects with a previous HAPE and in 14 control subjects, first at low altitude (490 m) and then within the first 48 hours of ascent to a high-altitude laboratory (4559 m). The HAPE-susceptible subjects, compared with the control subjects, had an enhanced pulmonary vasoreactivity to inspiratory hypoxia at low altitude and higher mean pulmonary artery pressures (37±2 versus 26±1 mm Hg, P <0.001) and pulmonary capillary pressures (19±1 versus 13±1 mm Hg, P <0.001) at high altitude. Nine of the susceptible subjects developed HAPE. All of them had a pulmonary capillary pressure >19 mm Hg (range 20 to 26 mm Hg), whereas all 7 susceptible subjects without HAPE had a pulmonary capillary pressure <19 mm Hg (range 14 to 18 mm Hg). The pulmonary transcapillary escape of radiolabeled transferrin increased slightly from low to high altitude in the HAPE-susceptible subjects but remained within the limits of normal and did not differ significantly from the control subjects. ConclusionsHAPE is initially caused by an increase in pulmonary capillary pressure.

Erythropoietin response is blunted in critically ill patients

Objectives: Critically ill patients often develop anaemia which can be related to a number of factors. However, the exact causes of anaemia in many patients remain unexplained. We hypothesized that the relationship between erythropoietin (EPO) and haematocrit may be altered in critically ill patients. Design: Serum concentrations of EPO were serially determined by the ELISA method in 36 critically ill, non-hypoxaemic patients who stayed more than 7 days in the Intensive Care Unit, including 22 patients with sepsis and 14 without. Eighteen ambulatory patients with iron-deficiency anaemia served as a control group. Setting: Two University Hospital Intensive Care Departments. Results: A significant inverse correlation between serum EPO and haematocrit levels was found in the control patients (r = −0.81, p < 0.001), but not in the critically ill patients (r = −0.09, NS), except in a subgroup of non-septic patients without renal failure (r = −0.61, p < 0.01). Conclusions: EPO levels can be inappropriately low in critically ill patients, so that EPO deficiency may contribute to the development of anaemia in these patients. This phenomenon is observed not only in the presence of acute renal failure, but also in the presence of sepsis.

Effects of levosimendan on systemic and regional hemodynamics in septic myocardial depression

We read with interest the contribution by Morelli et al. [1]. However, we find that the manuscript makes a number of omissions and is sometimes quite confusing. We would like to raise the following questions: First, one would like to know when and where the study was conducted. Indeed, this raises the issue of selection criteria. Clearly the patients were not enrolled consecutively, and we suppose that there was some convenience factor in the enrollment. Indeed, the patient population was very homogeneous: their cardiac output values were very close to 4.1 l min–1 m–2 at baseline (with a standard deviation of only 0.2 l min–1 m–2); likewise the standard deviation for mean arterial pressure was less than 3 mmHg, and that for PCO2 gap 1 mmHg (less than the measurement error). There should also be some information about the degree of organ dysfunction in these patients. At least the number of patients treated with extracorporeal renal support should be provided. Second, it is difficult to appreciate whether the baseline measurements were performed on or off dobutamine. The text only mentions in the protocol section that “the dobutamine infusion was stopped for a short time necessary to start the syringe-pumps containing either dobutamine or levosimendan.” If the patients were off dobutamine at baseline, the total lack of effect of dobutamine at 24 h is quite surprising. If the baseline measurements were obtained on dobutamine, the measurements obtained at 24 h on levosimendan would be a comparison of levosimendan (at 24 h) vs. dobutamine (at baseline). If the aim was to study the hemodynamic effects of levosimendan, why was the study not performed over a shorter period of time? It is quite unusual that the patients remained so stable during a 24-h period without any change in lactate level in patients treated with dobutamine. Even patients who do not improve experience a decrease in blood lactate levels over time: we therefore presume that some patients deteriorated substantially. Third, there should be more information about the source of sepsis. It is also surprising that all patients had either a Gram-positive or a Gramnegative culture (Table 1) but never a mixed flora, other micro-organisms than bacteria or negative cultures. Fourth, the statistical analysis is suboptimal: As two groups are compared over time, an analysis of variance should be applied. We would thank the authors for adding this important information to their interesting study. References

Albumin administration improves organ function in critically ill hypoalbuminemic patients: A prospective, randomized, controlled, pilot study*

Objective:To test the hypothesis that administration of albumin to correct hypoalbuminemia might have beneficial effects on organ function in a mixed population of critically ill patients. Design:Prospective, controlled, randomized study. Setting:Thirty-one-bed, mixed medicosurgical department of intensive care. Patients:All adult patients with a serum albumin concentration ≤30 g/L were assessed for eligibility. Principal exclusion criteria were expected length of stay <72 hrs, life expectancy <3 months or a do-not-resuscitate order, albumin administration in the preceding 24 hrs, or evidence of fluid overload. Interventions:The 100 patients were randomized to receive 300 mL of 20% albumin solution on the first day, then 200 mL/day provided their serum albumin concentration was <31 g/dL (albumin group), or to receive no albumin (control group). Measurements and Main Results:The primary outcome was the effect of albumin administration on organ function as assessed by a delta Sequential Organ Failure Assessment score from day 1 to day 7 (or the day of intensive care discharge or death, whichever came first). The two groups of 50 patients were comparable at baseline for age, gender, albumin concentration, and Acute Physiology and Chronic Health Evaluation II score. Albumin concentration did not change over time in the control group but increased consistently in the albumin group (p < .001). Organ function improved more in the albumin than in the control group (p = .026), mainly due to a difference in respiratory, cardiovascular, and central nervous system components of the Sequential Organ Failure Assessment score. Diuretic use was identical in both groups, but mean fluid gain was almost three times higher in the control group (1679 ± 1156 vs. 658 ± 1101 mL, p = .04). Median daily calorie intake was higher in the albumin than in the control group (1122 [935–1158] vs. 760 [571–1077] kcal, p = .05). Conclusions:Albumin administration may improve organ function in hypoalbuminemic critically ill patients. It results in a less positive fluid balance and a better tolerance to enteral feeding.

Sociocultural factors and back pain. A population-based study in Belgian adults.

A population-based survey of approximately 4000 adults in Belgium, a bi-cultural country with a uniform health care system, explored the relationships of socio-cultural and employment factors to the reported experience of low back pain (LBP). Predictors of 1) history of LBP, 2) first LBP, and 3) daily LBP were examined by multiple logistic regression analysis. Thirty-three percent of the population had current LBP, including 5% experiencing their first episode; 26% had past but not current LBP, and 41% had never had LBP. Increasing age (OR > 2.0, P = .000) and female gender (OR 2.16, P = .000) were associated with history of LBP; only gender (OR 1.40, P = .02) was associated with first episode; neither was associated with daily LBP. Language was associated with history (OR 1.80, P = .000) and first occurrence (OR 1.77, P = .000) but not daily LBP. Among those employed, work dissatisfaction was associated with history of LBP (OR > 2.4, P = .02) and daily LBP (OR 3.85, P = .02), but not with first episode. The results suggest that sociocultural factors influence the expression of LBP, but not the risk of chronicity once LBP is reported, and that work satisfaction may not be causally related to LBP, but may intervene along with type of occupation in the possibility of continuing employment once LBP is present. Prospective studies are needed to confirm these results and elucidate causal relationships.

Time course of hemoglobin concentrations in nonbleeding intensive care unit patients

ObjectivesTo evaluate the time course of hemoglobin concentrations in nonbleeding intensive care unit patients. DesignProspective, observational study. SettingMultidisciplinary (medicosurgical) department of intensive care. PatientsNinety-one patients with no evidence of recent or active blood loss, no history of hematologic disease or chronic renal failure, and no need for extracorporeal epuration techniques. InterventionsNone. Measurements and Main ResultsData collection included primary diagnoses, Acute Physiology and Chronic Health Evaluation II and sepsis-related organ failure assessment scores, signs of sepsis, 24-hr fluid balance, and hemoglobin concentrations. For the entire intensive care unit stay, the fall in hemoglobin concentrations (calculated from the mean of individual slopes of hemoglobin concentrations over time) averaged 0.52 ± 0.69 g/dL/day. For the 33 patients who stayed in the intensive care unit for >3 days, this decline was larger for the first 3 days than for subsequent days (0.66 ± 0.84 g/dL/day vs. 0.12 ± 0.29 g/dL/day;p < .01). After the third intensive care unit day, the change in hemoglobin concentrations was inversely related to the severity of the disease, as reflected by the Acute Physiology and Chronic Health Evaluation II and the sepsis-related organ failure assessment scores. Hemoglobin concentrations decreased by 0.44 ± 0.70 g/dL/day in the nonseptic and 0.68 ± 0.66 g/dL/day in the septic patients (p = .13). After the third intensive care unit day, hemoglobin concentrations continued to decrease in the septic patients but not in the nonseptic patients (−0.29 ± 0.19 vs. 0.006 ± 0.3 g/dL/day;p = .0016). The fall in hemoglobin concentrations was not significantly related to the fluid balance. The volume of blood drawn daily for laboratory studies was 40.3 ± 15.4 mL: 49.0 ± 11.3 mL in the septic patients and 36.7 ± 14.9 mL in the nonseptic patients (p = .04). ConclusionsHemoglobin concentrations typically decline by >0.5 g/dL/day during the first days of intensive care unit stay in nonbleeding patients. Beyond the third day, hemoglobin concentrations can remain relatively constant in nonseptic patients but continue to decrease in septic patients, as well as patients with high sepsis-related organ failure assessment or Acute Physiology and Chronic Health Evaluation II scores. These observations may help in the interpretation of hemoglobin concentrations in critically ill patients.

Beta-blockers cause paracentesis-induced circulatory dysfunction in patients with cirrhosis and refractory ascites: A cross-over study

BACKGROUND & AIMS In patients with cirrhosis and refractory ascites the role of beta-blockers in the development of paracentesis-induced circulatory dysfunction (PICD) is unknown. The aim of this study was to investigate the incidence of PICD before and after discontinuation of beta-blockers in patients with cirrhosis and refractory ascites. A self control cross-over study was performed. METHODS Patients with cirrhosis and refractory ascites treated with beta-blockers were selected. Heart rate, arterial pressure, and plasma renin concentrations (PRC) were collected before, immediately after and 1 week after large-volume paracentesis associated with intravenous albumin administration. Beta-blocker therapy was progressively discontinued after complete endoscopic eradication of varices. The clinical and biological evaluation was then repeated. The presence of PICD was defined as an increase in PRC of at least 50% above baseline 1 week after paracentesis. RESULTS Ten patients were included (nine men, mean age 59.1 ± 10.7 years old). The MELD score was 17.7 ± 4.4 and eight patients were Child-Pugh C. When patients were given beta-blockers, the heart rate did not change immediately after paracentesis while mean arterial pressure significantly decreased; PICD developed in eight patients. After beta-blockers were discontinued, the heart rate significantly increased immediately after paracentesis and mean arterial pressure significantly decreased; PICD only developed in one patient; the difference in the incidence of PICD was significant when these same patients were treated with beta-blockers. CONCLUSIONS The use of beta-blockers may be associated with a high risk of PICD in patients with cirrhosis and refractory ascites.

Development of ionized hypomagnesemia is associated with higher mortality rates.

ObjectivePrevious studies have shown a wide variation in the prevalence of total serum hypomagnesemia in intensive are unit (ICU) patients and in associated mortality rates. As the ionized part of magnesium is the active portion, we sought to define the prevalence of ionized hypomagnesemia in critically ill patients and to evaluate its relationship with organ dysfunction, length of stay, and mortality. DesignProspective observational study. SettingA 31-bed, medical-surgical, university hospital ICU. PatientsA total of 446 consecutive patients admitted to the ICU over a 3-month period. InterventionsNone. Measurements and Main ResultsThe ionized magnesium level (normal value, 0.42–0.59 mmol/L) was measured at admission and then every day until discharge from the ICU. At admission, 18% of patients had ionized hypomagnesemia, 68% had normal ionized magnesium levels, and 14% had ionized hypermagnesemia. There was no significant difference in the length of stay or in the mortality rate between these three groups of patients. Hypomagnesemic patients more frequently had total and ionized hypocalcemia, hypokalemia, and hypoproteinemia. A total of 23 patients developed ionized hypomagnesemia during their ICU stay; these patients had higher Acute Physiology And Chronic Health Evaluation II (14.9 ± 5.4 vs. 11.0 ± 6.2) and Sequential Organ Failure Assessment (SOFA; 7.1 ± 5.4 vs. 3.9 ± 2.8) scores at admission (p < .01 for both), a higher maximum SOFA score during their ICU stay (10.0 ± 5.6 vs. 4.4 ± 3.2, p < .01), a higher prevalence of severe sepsis and septic shock (57 vs. 11%, p < .01), a longer ICU stay (15.4 ± 15.5 vs. 2.8 ± 4.7 days, p < .01), and a higher mortality rate (35% vs. 12%, p < .01) than the other patients. The major risk factors for developing hypomagnesemia during the ICU stay were a prolonged ICU stay, treatment with diuretics, and sepsis. ConclusionDevelopment of ionized hypomagnesemia during an ICU stay is associated with a worse prognosis. It is often associated with the use of diuretics and the development of sepsis. Monitoring of ionized magnesium levels may have prognostic, and perhaps therapeutic, implications.