Olfa Turki

Acinetobacter baumannii ventilator-associated pneumonia: epidemiology, clinical characteristics, and prognosis factors

OBJECTIVE The aim of this study was to describe the epidemiological characteristics of Acinetobacter baumannii ventilator-associated pneumonia (VAP) and to identify factors predictive of a poor outcome. METHODS A retrospective study was conducted over 16 months in a Tunisian intensive care unit (ICU). All adult patients with A. baumannii VAP were included. RESULTS Ninety-two patients were included in they study; 41 (44.6%) were admitted because of multiple trauma. The mean age of the patients was 44.5±19.5 years. All patients needed mechanical ventilation on admission. The mean SAPS II score was 39±15. The mean delay before VAP onset was 8.1±4.7 days. On VAP onset, 57 patients (62%) developed septic shock. Only 14.2% of isolated strains were susceptible to imipenem; none were resistant to colistin. The mean duration of mechanical ventilation was 20±11 days. The mean duration of ICU stay was 24.3±18.7 days. ICU mortality was 60.9%. In the multivariate analysis, factors predictive of a poor outcome were previously known hypertension (odds ratio 5.8, 95% confidence interval 1.4-24.9; p=0.018) and VAP-related septic shock (odds ratio 8.5, 95% confidence interval 3-23.7; p<0.001). CONCLUSION A. baumannii VAP is associated with a high mortality. Hemodynamic impairment is predictive of a poor outcome.

Severe scorpion envenomation among children: does hydrocortisone improve outcome? A case-control study

BACKGROUND To analyse the efficacy and safety of systemic infusion of hydrocortisone hemisuccinate in children admitted to the intensive care unit with severe scorpion envenomation, we assessed the impact on mortality and length of hospital stay. METHOD We conducted a pair-wise, case-control study with 1:1 matching, reviewing records over a 13-year period (1990-2002) for the intensive care unit (ICU) of the Habib Bourguiba University Hospital, Sfax, Tunisia. A total of 184 children were included in the study (92 cases and 92 controls); cases received hydrocortisone hemisuccinate during hospitalization and controls received no steroids. Patients were matched according to age (±2 years), severity factors at admission (pulmonary edema and grades of severity of scorpion envenomation) and scorpion antivenom administration. RESULTS Cases and controls did not differ significantly in age (4.9 ± 5.5 years vs 6.2 ± 3.8 years; p > 0.05), mean temperature on admission (37.2 ± 1.2 vs 37.2 ± 1.06; p = 0.99) or presence of systemic inflammatory response syndrome (SIRS) (77 vs 70; p = 0.198). The proportion of patients with pulmonary edema was similar in the two groups (77 vs 71; p > 0.05), and in each group 46 patients (50%) received scorpion antivenom (p > 0.05). The use of mechanical ventilation, ICU length of stay and ICU mortality was not significantly different between the studied groups. CONCLUSION We detected no significant difference between patients receiving steroids and steroid-free patients in terms of mortality and ICU length of stay. The hydrocortisone hemisuccinate regimen described here had a limited effect in critically ill envenomated children and, therefore, we suggest that it should not be recommended.

Acute renal failure and pregnancy: a seventeen-year experience of a Tunisian intensive care unit

Abstract Purpose: To describe the epidemiologic features of acute renal failure related to pregnancy (PRARF) and to evaluate its prognostic impact. Methods: Retrospective study conducted in a Tunisian intensive care unit over a period of 17 years (1995–2011). Women were included if they were more than 20 weeks pregnant and were admitted to the ICU during pregnancy or immediately (<7 d) post partum. PRARF was defined by a serum creatinine level >0.8 mg/dL and was classified as mild (0.9 to 1.4 mg/dL), moderate (1.5 to 2.9 mg/dL) or severe (>3 mg/dL). Results: Five hundred and fifty patients were included. Mean age was 31 ± 6 years. Mean SOFA score was 4 ± 3. PRARF was diagnosed in 313 patients (56.9%). ARF was mild in 215 cases (39.1%), moderate in 65 cases (11.8%) and severe in 33 cases (6%). Main causes leading to this complication were preeclampsia (66.5%) and acute hemorrhage (27.8%). Only two patients (0.4%) developed chronic renal failure and needed long-term dialysis. Patients who developed this complication had higher SOFA score (4.7 ± 3.5 vs. 3.2 ± 2.1; p < 0.001). Thirty-three patients (6%) died in the ICU. The rate of ICU mortality was significantly higher in patients with PRARF (9.3 vs. 1.7%; p < 0.001). Conclusions: PRARF is associated with higher mortality. Thus, appropriate monitoring of pregnancies is needed in order to prevent its onset by an early and prompt management of the underlying risk factors.

Value of Serum Cholinesterase Activity in the Diagnosis of Septic Shock Due to Bacterial Infections.

Background: We aimed to investigate whether serum cholinesterase (SChE) activity can be helpful for the diagnosis of septic shock and to evaluate its usefulness in comparison with procalcitonin (PCT) and C-reactive protein (CRP). Methods: A prospective single-blinded study conducted in an intensive care unit of university hospital. Patients were classified as having cardiogenic shock, septic shock, or hemorrhagic shock. We also included a control group without neither hemodynamic instability nor sepsis. For all included patients, SChE, PCT, and CRP were simultaneously sampled. Results: The comparison of sepsis markers between all groups showed that the mean values of PCT and CRP were significantly higher in patients with septic shock. However, SChE activity was significantly lower in this group. The SChE activity was found to be more accurate than PCT and CRP for the diagnosis of septic shock. In fact, an SChE activity ≤ 4000 UI/L predicted the diagnosis of septic shock with a sensitivity of 78%, a specificity of 89%, a predictive negative value of 97%, and a predictive positive value of 65%. However, the prognostic value of SChE activity was poor in multivariate analysis. Conclusion: The SChE activity level was significantly decreased in patients with septic shock. However, its prognostic value is poor. Our results suggest that SChE activity is useful for the diagnosis of septic shock. Further studies are warranted to confirm our findings.

Impact of acetazolamide use in severe exacerbation of chronic obstructive pulmonary disease requiring invasive mechanical ventilation.

Purpose: To analyse the impact of acetazolamide (ACET) use in severe acute decompensation of chronic obstructive pulmonary disease requiring mechanical ventilation and intensive care unit (ICU) admission . Patients and Methods: Retrospective pair-wise, case-control study with 1:1 matching. Patients were defined as cases when they had received acetazolamide (500 mg per day) and as controls when they did not received it. Patients were matched according to age , severity on admission (pH, PaO 2 /FiO 2 ratio) and SAPSII score. Our primary endpoint was the effect of ACET (500 mg per day) on the duration of mechanical ventilation. Our secondary endpoints were the effect of ACET on arterial blood gas parameters, ICU length of stay (LOS) and ICU mortality. Results: Seventy-two patients were included and equally distributed between the two studied groups. There were 66 males (92%). The mean age (± SD) was 69.7 ± 7.4 years ranging from 53 to 81 years . There were no differences between baseline characteristics of the two groups. Concomitant drugs used were also not significantly different between two groups. Mean duration of mechanical ventilation was not significantly different between ACET(+) and ACET(-) patients (10.6 ± 7.8 days and 9.6 ± 7.6 days, respectively; P = 0.61). Cases had a significantly decreased serum bicarbonate, arterial blood pH, and PaCO 2 levels . We did not found any significant difference between the two studied groups in terms of ICU LOS. ICU mortality was also comparable between ACET(+) and ACET(-) groups (38% and 52%, respectively; P = 0.23). Conclusion: Although our study some limitations, it suggests that the use of insufficient acetazolamide dosage (500 mg/d) ACET (500 mg per day) has no significant effect on the duration of mechanical ventilation in critically ill COPD patients requiring invasive mechanical ventilation. Our results should be confirmed or infirmed by further studies.

Transpulmonary thermodilution for the assessment of hemodynamic patterns in patients with severe scorpion envenomation

Dear Editor, Scorpion envenomation still remains a public health problem worldwide [1]. In North African countries, cardiogenic shock and/or acute pulmonary edema represent the main leading cause for intensive care unit (ICU) admission [2]. Thus, monitoring severely envenomed patients may be required. Transpulmonary thermodilution (TPT) may be helpful in this group of patients to guide therapeutic management. From 1 January 2012 to 31 December 2013, we prospectively included three consecutive patients stung by an Androctonus australis scorpion. All included patients were hypotensive and had acute pulmonary edema. Upon their admission, they were equipped with a venous catheter inserted in the superior vena cava territory. An arterial catheter (Pulsion Medical Systems) was placed in the femoral site and connected to a PiCCO device. All the measures were indexed for ideal body weight and were performed before and 1 h after dobutamine infusion (5–10 lg/kg/min). All our patients were young (aged 18–23 years) and had no previous medical history. All of them received antivenom and required mechanical ventilation. Baseline hemodynamic parameters showed decreased indexed cardiac output (CI), indexed stroke volume (SVI) and cardiac function index (CFI). Indexed global end diastolic volume (GEDVI) was also decreased whereas systemic vascular resistance (SVRI) was increased in all cases. EVLWI was increased in all our patients (Table 1). Dobutamine infusion induced an increase of CI, SVI and CFI whereas GEDVI remained unchanged. EVLWI was decreased in all cases under 10 ml/kg (Table 1). Tissue oxygenation also improved as base-excess decreased from -6 to -2 mEq/1 in patient (1), from -4 to -2 mEq/l in patient (2) and from -5 to -2 mEq/L in patient (3). All our patients survived. Our results confirm the cardiac dysfunction in severely envenomed patients, such as CI, SVI and CFI, were markedly decreased on admission and significantly increased after dobutamine infusion. Jabot et al. [3] reported that a CFI lower than 4.1 allowed diagnosing a Left Ventricular Ejection Fraction \45 % with a sensitivity of 89 % and a specificity of 67 %. Three leading mechanisms can

Incidence, mechanisms and impact outcome of hyperglycaemia in severe scorpion-envenomed patients

Hyperglycaemia is often observed in severe scorpion-envenomed patients. It is due to a severe autonomic storm with a massive release of catecholamines, increased glucagon levels, cortisol levels, and either decreased insulin levels or insulin resistance. The presence of hyperglycaemia is an indicator of severity in this specific condition. Indeed, hyperglycaemia was associated with the severity of clinical manifestations of severe scorpion envenomation requiring intensive care unit (ICU) admission. In fact, the presence of hyperglycaemia was associated with the presence of respiratory failure, pulmonary oedema, haemodynamic instability, neurological failure, multisystem organ failure, and an increased mortality and ICU length of stay. As a consequence, we think the presence of hyperglycaemia in scorpion-envenomed patients at the emergency department prompts searching for presence of systemic manifestations or cardiorespiratory manifestations. As a consequence, the presence of hyperglycaemia can help screen severe patients at the emergency department. The current management of severe scorpion envenomation involves the admission and close surveillance in the ICU, where vital signs and continuous monitoring enable early initiation of therapy for life-threatening complications. The use of antivenom for scorpion stings remains controversial. All patients with pulmonary oedema should receive prazosin and possibly dobutamine, according the scorpion’s species. Mechanical ventilation is usually used in severe cases. Insulin should be reserved for severe cases with confirmed excessive hyperglycaemia (>10 mmol/l).

Evidence of Direct Toxicological Effects of Scorpion Venom on Central Nervous System in Tunisian Children

Background Severe scorpion envenomation can lead to severe neurological manifestations, which are an indicator of the severity of the scorpion sting. The direct action of scorpion venom on the central nervous system can explain partly these neurological disorders. Methods and Findings We report a case of severe scorpion envenomation in 16-month-old boy with no pathological history admitted in ICU for severe scorpion envenomation. The result of cerebral MRI agrees with the hypothesis of direct action of scorpion venom on the central nervous system. Patient had improved; however, he has kept as neurological sequelae language disorders and blindness. The boy was discharged 21 days after ICU admission. Conclusion Our observation confirms that severe scorpion envenomation can be complicated by severe neurological manifestations. Although one case report is not enough to conclude such important hypothesis regarding the direct effect of scorpion venom on central nervous system (especially that the age of patient is more than one year), our case agrees with this hypothesis.