Minimum effective volume of 0.5% bupivacaine with epinephrine in ultrasound-guided interscalene brachial plexus block.

BACKGROUND: The use of ultrasound (US) in regional anaesthesia enables a reduction in the local anaesthetic volume. The present study aimed to determine the minimum effective volume (MEV(90)) of 0.5% bupivacaine with epinephrine for interscalene brachial plexus block (ISBPB). METHODS: The volume of the anaesthetic was determined using a step-up/step-down method and was based on the outcome of the preceding block. A positive or negative block resulted in a 1 ml reduction or increase in volume, respectively. The success of the block was defined as the presence of motor block in three muscle groups and the absence of thermal and pain sensations in three dermatomes within 30 min of the injection. Diaphragmatic paralysis and analgesia were assessed at 30 min, 4, and 6 h. RESULTS: The MEV(90) for US-guided brachial plexus block under the conditions of the present study was 0.95 ml [R(2): 0.97, 95% confidence interval (CI): 0.6-1.22 ml]. The estimated maximum volume that did not cause diaphragmatic block was 4.29 ml (R(2): 0.84, 95% CI: 3.56-4.98 ml). Effective postoperative analgesia was achieved with 2.34 ml (R(2): 0.87, 95% CI: 0.48-11.47 ml). CONCLUSIONS: The MEV(90) of 0.5% bupivacaine with epinephrine (1:200 000) for US-guided ISBPB was 0.95 ml. Adequate postoperative analgesia and a reduced incidence of diaphragmatic block can be obtained using from 2.34 to 4.29 ml. ClinicalTrials.gov. Registry NCT01244932.

Incidence, risk factors and prognostic factors of acute renal failure in patients admitted to an intensive care unit

The objective of the present study was to assess the incidence, risk factors and outcome of patients who develop acute renal failure (ARF) in intensive care units. In this prospective observational study, 221 patients with a 48-h minimum stay, 18-year-old minimum age and absence of overt acute or chronic renal failure were included. Exclusion criteria were organ donors and renal transplantation patients. ARF was defined as a creatinine level above 1.5 mg/dL. Statistics were performed using Pearsons' chi2 test, Student t-test, and Wilcoxon test. Multivariate analysis was run using all variables with P < 0.1 in the univariate analysis. ARF developed in 19.0 percent of the patients, with 76.19 percent resulting in death. Main risk factors (univariate analysis) were: higher intra-operative hydration and bleeding, higher death risk by APACHE II score, logist organ dysfunction system on the first day, mechanical ventilation, shock due to systemic inflammatory response syndrome (SIRS)/sepsis, noradrenaline use, and plasma creatinine and urea levels on admission. Heart rate on admission (OR = 1.023 (1.002-1.044)), male gender (OR = 4.275 (1.340-13642)), shock due to SIRS/sepsis (OR = 8.590 (2.710-27.229)), higher intra-operative hydration (OR = 1.002 (1.000-1004)), and plasma urea on admission (OR = 1.012 (0.980-1044)) remained significant (multivariate analysis). The mortality risk factors (univariate analysis) were shock due to SIRS/sepsis, mechanical ventilation, blood stream infection, potassium and bicarbonate levels. Only potassium levels remained significant (P = 0.037). In conclusion, ARF has a high incidence, morbidity and mortality when it occurs in intensive care unit. There is a very close association with hemodynamic status and multiple organ dysfunction.

Incidence, risk factors and prognostic factors of acute renal failure in patients admitted to an intensive care unit.

The objective of the present study was to assess the incidence, risk factors and outcome of patients who develop acute renal failure (ARF) in intensive care units. In this prospective observational study, 221 patients with a 48-h minimum stay, 18-year-old minimum age and absence of overt acute or chronic renal failure were included. Exclusion criteria were organ donors and renal transplantation patients. ARF was defined as a creatinine level above 1.5 mg/dL. Statistics were performed using Pearsons' chi2 test, Student t-test, and Wilcoxon test. Multivariate analysis was run using all variables with P < 0.1 in the univariate analysis. ARF developed in 19.0% of the patients, with 76.19% resulting in death. Main risk factors (univariate analysis) were: higher intra-operative hydration and bleeding, higher death risk by APACHE II score, logist organ dysfunction system on the first day, mechanical ventilation, shock due to systemic inflammatory response syndrome (SIRS)/sepsis, noradrenaline use, and plasma creatinine and urea levels on admission. Heart rate on admission (OR = 1.023 (1.002-1.044)), male gender (OR = 4.275 (1.340-13642)), shock due to SIRS/sepsis (OR = 8.590 (2.710-27.229)), higher intra-operative hydration (OR = 1.002 (1.000-1004)), and plasma urea on admission (OR = 1.012 (0.980-1044)) remained significant (multivariate analysis). The mortality risk factors (univariate analysis) were shock due to SIRS/sepsis, mechanical ventilation, blood stream infection, potassium and bicarbonate levels. Only potassium levels remained significant (P = 0.037). In conclusion, ARF has a high incidence, morbidity and mortality when it occurs in intensive care unit. There is a very close association with hemodynamic status and multiple organ dysfunction.

Inalaçäo de oxido nitrico em SARA / Inhaled nitric oxide in ARDS

Os autores discutem sua experiência preliminar na administração de NO em nove pacientes adultos(30-75 anos)com SARA (LIS _> 3). A concentração de No foi ajustada a partir do efeito da inalação(de 1,5,10 ou 20 ppm)deste gás sobre a oxigenação arterial(Pa)2/FIO2). Observou-se em sete pacientes,melhora clinicamente significativa(_> 20 por cento do controle)da oxigenação. Em seis casos,a melhora permitiu interromper a administração de NO. Três mortes(choques hemorrágicos e séptico e broncopneumonia)foram registrados durante o tratamento,sem que fosse possível estabelecer relação causal entre a inalação de NO e o decesso.Discutem ainda diversos aspectos da utilização de NO na SARA. concluem que a inalação de NO representa alternativa simples,segura e eficaz no controle da hipoxemia grave,podendo com vantagem ser associada as alternativas(PEEO e posição prona)correntemente disponíveis em ventilação artificial