Neonatal Life-Threatening Nonoliguric Hyperkalemia Under Therapeutic Hypothermia.

To illustrate our experience with two cases of neonatal life-threatening hyperkalemia during therapeutic hypothermia (TH) despite a normal acid-base status, urine output, and preserved renal function. Clinical cases are presented from Pediatric Intensive Care Unit (PICU) admission to the onset of the hyperkalemia, with related complications and after resolution. Similar cases were not retrieved from a critical review of pertinent literature. Severe hyperkalemia pathophysiology and risk factors have been debated. Two full-term adequate for weight female neonates were admitted to PICU because of perinatal asphyxia who underwent TH. Prenatal history was completely uneventful, nor hereditary genetic conditions were reported; moreover, long-term follow-up ruled out any metabolic or renal disease. Despite an accurate evaluation of previous clinical series and literature on TH and perinatal asphyxia, these hyperkalemic episodes remain unexplained. The hypoxic-ischemic insult may affect multiple organs, mainly central nervous system, heart, lung, and kidneys; acute muscle breakdown and consequent rising of myoglobin may also have a precipitating role in acute kidney failure (AKF) and hyperkalemia. Electrolyte imbalance is a possible finding as a consequence of combined cell injury and AKF. In contrast, an isolated severe hyperkalemia is exceedingly rare in nonoliguric neonates.

Effects of dopamine infusion on forearm blood flow in critical patients.

BACKGROUND: In critical care, dopamine is administered by infusion at low doses (or=5 microg/kg/min) for assessment of hemodynamics. The present study was conducted to explore the effects of dopamine infusion on the vast microvascular network of skeletal muscle in the early phases of sepsis. MATERIAL/METHODS: An observational study was performed which included twelve critically ill patients. Patients' response to dopamine infusion (3 microg/kg/min) was studied within 24 hours from admission to the ICU. The forearm blood flow (FBF) and vascular resistance (FVR) were measured by near-infrared spectroscopy (NIRS). RESULTS: Dopamine did not ameliorate forearm regional oxygenation. The infusion of dopamine caused an increase in MAP, while FBF decreased with the resistance increase (p>0.05). CONCLUSIONS: NIRS was suitable to measure bedside the vascular resistance and to test the effects of low doses of dopamine on forearm blood flow. A dopamine infusion of 3.0 microg/kg/min caused a reduction in forearm blood flow and an increase in vascular resistance in our patients.

Alfentanil does not increase resistance of the respiratory system in ASA I patients ventilated mechanically during general anesthesia.

PURPOSE: Several experimental and clinical studies have demonstrated a direct bronchoconstrictor effect of opioids on smooth bronchial musculature following iv administration. The aim of this study was to evaluate the effects of alfentanil on respiratory system mechanics in a group of ASA I patients ventilated mechanically during general anesthesia. CLINICAL FEATURES: Twenty consecutive ASA I patients (ten men and ten women) scheduled for general surgery interventions were studied (mean age 45.4 +/- 9.9 yr, mean weight 61.9 +/- 6.7 kg). Exclusion criteria were a history of chronic obstructive pulmonary disease, asthma or other pulmonary disease, atopy, wheezes, smoking and age below 18 yr. Subjects were randomly divided in two groups: Group A, receiving alfentanil at a 15 microg x kg(-1) dose and Group B receiving alfentanil at a 30 microg x kg(-1) dose. Respiratory mechanic variables were acquired at baseline (T0) and after three, ten and 15 min (T1, T2 and T3, respectively). We compared the basal values to the values measured at each time interval; basal values, prior to drug administration, served as control for each patient. P values < 0.05 were considered statistically significant. RESULTS: We did not observe significant differences in respiratory mechanic variables after the administration of alfentanil, 15 and 30 microg x kg(-1). More specifically, respiratory system compliance and the different subcomponents of respiratory system resistances (i.e., maximum, minimum and delta resistance of respiratory system) were within normal limits and did not vary after alfentanil administration. CONCLUSION: No respiratory adverse effect was reported after alfentanil iv administration.