Protocolo de tratamiento con polietilenglicol 3350 con electrolitos para el estreñimiento en el niño crítico / Protocol for treatment of constipation with polyethylene glycol 3350 plus electrolytes in critically ill children

Introducción y objetivos: Ningún estudio ha analizado la efectividad del tratamiento del estreñimiento en niños críticamente enfermos. El objetivo de este estudio fue evaluar la implementación, la eficacia y la seguridad de un protocolo de tratamiento con polietilenglicol 3350 con electrolitos (PEG 3350+E) para el estreñimiento en niños en estado crítico. Métodos: Estudio prospectivo unicéntrico, incluyendo niños que ingresaron en cuidados intensivos pediátricos durante más de 72h y que desarrollaron estreñimiento. Se excluyeron los niños con trastornos o afecciones gastrointestinales previas. Los pacientes fueron tratados con enemas rectales o con PEG 3350+E oral a criterio del médico tratante. Se compararon variables clínicas, demográficas y efectos secundarios (diarrea, distensión abdominal y desequilibrio electrolítico). Resultados: Se estudiaron 56 pacientes de 48,2±11,9 meses de edad, siendo el 55,4% varones. Cuarenta y cuatro pacientes (78,6%) fueron tratados con PEG 3350+E y 12 pacientes (21,4%) con enemas rectales. El porcentaje de efectividad del PEG 3350+E (79,5%) fue mayor que el de los enemas (58,3%), pero la diferencia no fue estadísticamente significativa (p=0,151). No existieron diferencias significativas en ninguno de los efectos secundarios entre los 2 grupos. El PEG 3350+E fue más efectivo en los niños menores de 2 años (100%) que en los mayores de esa edad (65,4%), p<0,01, sin diferencias significativas en la aparición de efectos secundarios. Conclusiones: El tratamiento del estreñimiento en los niños en estado crítico con PEG 3350+E es eficaz y tiene pocos efectos secundarios, incluso en niños menores de 2 años. (AU)

Introduction and objectives: No studies have analysed the effectiveness of treatment for constipation in critically ill children. The aim of this study was to assess the implementation, efficacy and safety of a treatment protocol using polyethylene glycol 3350 with electrolytes (PEG 3350+E) for constipation in critically ill children. Methods: We conducted a single-centre prospective study in children admitted to the paediatric intensive care unit for a minimum of 72h and who developed constipation. Children with previous gastrointestinal disorders or diseases were excluded. The patients were treated with rectal enemas or with the oral PEG 3350+E protocol at the discretion of the treating physician. We compared clinical and demographic variables as well as adverse events (diarrhoea, abdominal distension and electrolyte imbalances). Results: The sample included 56 patients with a mean age of 48.2±11.9 months, of who 55.4% were male. Forty-four patients (78.6%) were treated with PEG 3350+E and 12 (21.4%) with rectal enemas. The proportion of patients who responded well to treatment was greater in the PEG 3350+E group (79.5%) compared to the enema group (58.3%), but the difference was not statistically significant (P=.151). There were no significant differences between the groups in any of the adverse effects. Treatment with PEG 3350+E was more effective in children aged less than 2 years (100%) compared to older children (100% vs. 65.4%; P<.01), with no significant differences in the development of adverse events. Conclusions: The PEG 3350+E treatment protocol for constipation in critically ill children was effective and associated with few adverse events, even in children aged less than 2 years. (AU)

Protocol for treatment of constipation with polyethylene glycol 3350 plus electrolytes in critically ill children.

INTRODUCTION AND OBJECTIVES: No studies have analysed the effectiveness of treatment for constipation in critically ill children. The aim of this study was to assess the implementation, efficacy and safety of a treatment protocol using polyethylene glycol 3350 with electrolytes (PEG 3350 + E) for constipation in critically ill children. METHODS: We conducted a single-centre prospective study in children admitted to the paediatric intensive care unit for a minimum of 72 h and who developed constipation. Children with previous gastrointestinal disorders or diseases were excluded. The patients were treated with rectal enemas or with the oral PEG 3350 + E protocol at the discretion of the treating physician. We compared clinical and demographic variables as well as adverse events (diarrhoea, abdominal distension and electrolyte imbalances). RESULTS: The sample included 56 patients with a mean age of 48.2 ±â€¯11.9 months, of who 55.4% were male. Forty-four patients (78.6%) were treated with PEG 3350 + E and 12 (21.4%) with rectal enemas. The proportion of patients that responded well to treatment was greater in the PEG 3350 + E group (79.5%) compared to the enema group (58.3%), but the difference was not statistically significant (P = .151). There were no significant differences between the groups in any of the adverse effects. Treatment with PEG 3350 + E was more effective in children aged less than 2 years (100%) compared to older children (100% vs 65.4%; P < .01), with no significant differences in the development of adverse events. CONCLUSIONS: The PEG 3350 + E treatment protocol for constipation in critically ill children was effective and associated with few adverse events, even in children aged less than 2 years.

Doppler ultrasound in the assessment of renal perfusion before and during continuous kidney replacement therapy in the pediatric intensive care unit.

BACKGROUND: This study aimed to assess observer variability and describe renal resistive index (RRI) and pulsatility index (PI) before and after onset of continuous kidney replacement therapy (CKRT). A secondary objective was to correlate Doppler ultrasound findings with those from direct measurement of renal blood flow (RBF). METHODS: This is a prospective observational study in hemodynamically stable Maryland piglets with and without acute kidney injury (AKI) and in hemodynamically unstable critically ill children requiring CKRT. Doppler-based RRI and PI were assessed for each subject. Measurements were made by two different operators (pediatric intensivists) before and after CKRT onset. RESULTS: Observer variability assessment in the measurement of RRI and PI rendered a moderate correlation for both RRI (ICC 0.65, IQR 0.51-0.76) and PI (ICC 0.63, IQR 0.47-0.75). RRI and PI showed no correlation with RBF or urine output. Baseline RRI and PI were normal in control piglets [RRI 0.68 (SD 0.02), PI 1.25 (SD 0.09)] and those with AKI [RRI 0.68 (SD 0.03), PI 1.20 (SD 0.13)]. Baseline RRI and PI were elevated in critically ill children (RRI 0.85, PI 2.0). PI and RRI did not change with CKRT in any study group. CONCLUSIONS: Observer variability between inexperienced pediatric intensivists was comparable with that between senior and junior operators. Doppler-based calculations did not correlate with invasive measurements of RBF. RRI and PI were normal in hemodynamically stable piglets with and without AKI. RRI and PI were high in hemodynamically unstable patients requiring CKRT. RRI and PI did not change after CKRT onset, despite changes in hemodynamic status. A higher resolution version of the Graphical abstract is available as Supplementary information.

Hemodynamic disturbances and oliguria during continuous kidney replacement therapy in critically ill children.

BACKGROUND: About 1.5% of patients admitted to the Pediatric Intensive Care Unit (PICU) will require continuous kidney replacement therapy (CKRT)/renal replacement therapy (CRRT). Mortality of these patients ranges from 30 to 60%. CKRT-related hypotension (CKRT-RHI) can occur in 19-45% of patients. Oliguria after onset of CKRT is also common, but to date has not been addressed directly in the scientific literature. METHODS: A prospective observational study was conducted to define factors involved in the hemodynamic changes that take place during the first hours of CKRT, and their relationship with urinary output. RESULTS: Twenty-five patients who were admitted to a single-center PICU requiring CKRT between January 1, 2014, and December 31, 2018, were included, of whom 56.3% developed CKRT-RHI. This drop in blood pressure was transient and rapidly restored to baseline, and significantly improved after the third hour of CKRT, as core temperature and heart rate decreased. Urine output significantly decreased after starting CKRT, and 72% of patients were oliguric after 6 h of therapy. Duration of CKRT was significantly longer in patients presenting with oliguria than in non-oliguric patients (28.7 vs. 7.9 days, p = 0.013). CONCLUSIONS: The initiation of CKRT caused hemodynamic instability immediately after initial connection in most patients, but had a beneficial effect on the patient's hemodynamic status after 3 h of therapy, presumably owing to decreases in body temperature and heart rate. Urine output significantly decreased in all patients and was not related to negative fluid balance, patient's hemodynamic status, CKRT settings, or kidney function parameters.

Microcirculatory Differences in Children With Congenital Heart Disease According to Cyanosis and Age.

Background: Congenital heart disease (CHD) is one of the main causes of morbidity and mortality in children. Microcirculatory changes in CHD patients have previously been investigated using a variety of techniques. Handheld videomicroscopy enables non-invasive direct visualization of the microcirculatory bed. The aim of our study was to determine if there are microcirculatory differences among CHD patients based on age and the presence of cyanosis. Methods: A prospective observational study was carried out. Patients with CHD undergoing corrective surgery were evaluated after anesthetic induction prior to surgery. Microcirculation was evaluated using sidestream dark field (SDF) imaging. Hemodynamics and respiratory, biochemical, and tissue perfusion parameters were analyzed. Results: A total of 30 patients were included, of whom 14 were classified as cyanotic and 16 as non-cyanotic. Cyanotic patients had a higher total vessel density (TVD) (p = 0.016), small vessel density (p = 0.004), and perfused small vessel density (p = 0.013), while their microvascular flow index (MFI) was lower (p = 0.013). After adjustment for age and PaO2, cyanotic patients showed increased TVD (p = 0.023), and small vessel density (p = 0.025) compared to non-cyanotic patients but there were no differences on the MFI. Age was directly correlated with total MFI (spearman's rho = 0.499, p = 0.005) and small vessel MFI (spearman's rho = 0.420, p = 0.021). After adjustment for the type of CHD (cyanotic vs. non-cyanotic) patients with MFI and small MFI vessels <3 were younger than those with values ≥3 (p = 0.033 and p = 0.037). Conclusions: SDF-based evaluation of microcirculation in CHD patients showed that patients with cyanotic defects had higher vascular density, as compared to patients with non-cyanotic defects. Younger patients were more likely to have a low MFI regardless of their type of CHD.

Comparison between synchronized and non-synchronized ventilation and between guided and non-guided chest compressions during resuscitation in a pediatric animal model after asphyxial cardiac arrest.

INTRODUCTION: There are no studies comparing synchronized and non-synchronized ventilation with bag-valve mask ventilation (BVMV) during cardiopulmonary resuscitation (CPR) in pediatric patients. The main aim is to compare between synchronized and non-synchronized BVMV with chest compressions (CC), and between guided and non-guided CC with a real-time feedback-device in a pediatric animal model of asphyxial cardiac arrest (CA). The secondary aim is to analyze the quality of CC during resuscitation. METHODS: 60 piglets were randomized for CPR into four groups: Group A: guided-CC and synchronized ventilation; Group B: guided-CC and non-synchronized ventilation; Group C: non-guided CC and synchronized ventilation; Group D: non-guided CC and non-synchronized ventilation. Return of spontaneous circulation (ROSC), hemodynamic and respiratory parameters, and quality of CC were compared between all groups. RESULTS: 60 piglets were included. Twenty-six (46.5%) achieved ROSC: A (46.7%), B (66.7%), C (26.7%) and D (33.3%). Survival rates were higher in group B than in groups A+C+D (66.7% vs 35.6%, p = 0.035). ROSC was higher with guided-CC (A+B 56.7% vs C+D 30%, p = 0.037). Piglets receiving non-synchronized ventilation did not show different rates of ROSC than synchronized ventilation (B+D 50% vs A+C 36.7%, p = 0.297). Non-synchronized groups showed lower arterial pCO2 after 3 minutes of CPR than synchronized groups: 57 vs 71 mmHg, p = 0.019. No differences were found in arterial pH and pO2, mean arterial pressure (MAP) or cerebral blood flow between groups. Chest compressions were shallower in surviving than in non-surviving piglets (4.7 vs 5.1 cm, p = 0.047). There was a negative correlation between time without CC and MAP (r = -0.35, p = 0.038). CONCLUSIONS: The group receiving non-synchronized ventilation and guided-CC obtained significantly higher ROSC rates than the other modalities of resuscitation. Guided-CC achieved higher ROSC rates than non-guided CC. Non-synchronized ventilation was associated with better ventilation parameters, with no differences in hemodynamics or cerebral flow.

Sedative and Analgesic Drug Rotation Protocol in Critically Ill Children With Prolonged Sedation: Evaluation of Implementation and Efficacy to Reduce Withdrawal Syndrome.

OBJECTIVES: The first aim of this study was to assess the implementation of a sedative and analgesic drug rotation protocol in a PICU. The second aim was to analyze the incidence of withdrawal syndrome, drug doses, and time of sedative or analgesic drug infusion in children after the implementation of the new protocol. DESIGN: Prospective observational study. SETTING: PICU of a tertiary care hospital between June 2012 and June 2016. PATIENTS: All patients between 1 month and 16 years old admitted to the PICU who received continuous IV infusion of sedative or analgesic drugs for more than 4 days were included in the study. INTERVENTIONS: A sedative and analgesic drug rotation protocol was designed. The level of sedation, analgesia, and withdrawal syndrome were monitored with validated scales. The relationship between compliance with the protocol and the incidence of withdrawal syndrome was studied. MEASUREMENTS AND MAIN RESULTS: One-hundred pediatric patients were included in the study. The protocol was followed properly in 35% of patients. Sixty-seven percent of the overall cohort presented with withdrawal syndrome. There was a lower incidence rate of withdrawal syndrome (34.3% vs 84.6%; p < 0.001), shorter PICU length of stay (median 16 vs 25 d; p = 0.003), less time of opioid infusion (median 5 vs 7 d for fentanyl; p = 0.004), benzodiazepines (median 5 vs 9 d; p = 0.001), and propofol (median 4 vs 8 d; p = 0.001) in the cohort of children in which the protocol was followed correctly. CONCLUSIONS: Our results show that compliance with the drug rotation protocol in critically ill children requiring prolonged sedation may reduce the appearance of withdrawal syndrome without increasing the risk of adverse effects. Furthermore, it may reduce the time of continuous IV infusions for most sedative and analgesic drugs and the length of stay in PICU.

Comparison between manual and mechanical chest compressions during resuscitation in a pediatric animal model of asphyxial cardiac arrest.

AIMS: Chest compressions (CC) during cardiopulmonary resuscitation are not sufficiently effective in many circumstances. Mechanical CC could be more effective than manual CC, but there are no studies comparing both techniques in children. The objective of this study was to compare the effectiveness of manual and mechanical chest compressions with Thumper device in a pediatric cardiac arrest animal model. MATERIAL AND METHODS: An experimental model of asphyxial cardiac arrest (CA) in 50 piglets (mean weight 9.6 kg) was used. Animals were randomized to receive either manual CC or mechanical CC using a pediatric piston chest compressions device (Life-Stat®, Michigan Instruments). Mean arterial pressure (MAP), arterial blood gases and end-tidal CO2 (etCO2) values were measured at 3, 9, 18 and 24 minutes after the beginning of resuscitation. RESULTS: There were no significant differences in MAP, DAP, arterial blood gases and etCO2 between chest compression techniques during CPR. Survival rate was higher in the manual CC (15 of 30 = 50%) than in the mechanical CC group (3 of 20 = 15%) p = 0.016. In the mechanical CC group there was a non significant higher incidence of haemorrhage through the endotracheal tube (45% vs 20%, p = 0.114). CONCLUSIONS: In a pediatric animal model of cardiac arrest, mechanical piston chest compressions produced lower survival rates than manual chest compressions, without any differences in hemodynamic and respiratory parameters.

Different Respiratory Rates during Resuscitation in a Pediatric Animal Model of Asphyxial Cardiac Arrest.

AIMS: Actual resuscitation guidelines recommend 10 respirations per minute (rpm) for advanced pediatric life support. This respiratory rate (RR) is much lower than what is physiological for children. The aim of this study is to compare changes in ventilation, oxygenation, haemodynamics and return of spontaneous circulation (ROSC) rates with three RR. METHODS: An experimental model of asphyxial cardiac arrest (CA) in 46 piglets (around 9.5 kg) was performed. Resuscitation with three different RR (10, 20 and 30 rpm) was carried out. Haemodynamics and gasometrical data were obtained at 3, 9, 18 and 24 minutes after beginning of resuscitation. Measurements were compared between the three groups. RESULTS: No statistical differences were found in ROSC rate between the three RR (37.5%, 46.6% and 60% in the 10, 20 and 30 rpm group respectively P = 0.51). 20 and 30 rpm groups had lower PaCO2 values than 10 rpm group at 3 minutes (58 and 55 mmHg vs 75 mmHg P = 0.08). 30 rpm group had higher PaO2 (61 mmHg) at 3 minutes than 20 and 10 rpm groups (53 and 45 mmHg P = 0.05). No significant differences were found in haemodynamics or tissue perfusion between hyperventilated (PaCO2 <30 mmHg), normoventilated (30-50 mmHg) and hypoventilated (>50 mmHg) animals. PaO2 was significantly higher in hyperventilated (PaO2 153 mmHg) than in normoventilated (79 mmHg) and hypoventilated (47 mmHg) piglets (P<0.001). CONCLUSIONS: Our study confirms the hypothesis that higher RR achieves better oxygenation and ventilation without affecting haemodynamics. A higher RR is associated but not significantly with better ROSC rates.

Microcirculatory alterations during haemorrhagic shock and after resuscitation in a paediatric animal model.

BACKGROUND: Haemorrhagic shock is frequent in paediatric trauma patients and after cardiac surgery, especially after cardiopulmonary bypass. It has demonstrated to be related to bad outcome. OBJECTIVES: To evaluate changes on microcirculatory parameters during haemorrhagic shock and resuscitation in a paediatric animal model. To determine correlation between microcirculatory parameters and other variables routinely used in the monitoring of haemorrhagic shock. METHODS: Experimental study on 17 Maryland pigs. Thirty minutes after haemorrhagic shock induction by controlled bleed animals were randomly assigned to three treatment groups receiving 0.9% normal saline, 5% albumin with 3% hypertonic saline, or 5% albumin with 3% hypertonic saline plus a bolus of terlipressin. Changes on microcirculation (perfused vessel density (PVD), microvascular blood flow (MFI) and heterogeneity index (HI)) were evaluated and compared with changes on macrocirculation and tisular perfusion parameters. RESULTS: Shock altered microcirculation: PVD decreased from 13.5 to 12.3 mm mm(-2) (p=0.05), MFI decreased from 2.7 to 1.9 (p<0.001) and HI increased from 0.2 to 0.5 (p<0.001). After treatment, microcirculatory parameters returned to baseline (PVD 13.6 mm mm(-2) (p<0.05), MFI 2.6 (p<0.001) and HI 0.3 (p<0.05)). Microcirculatory parameters showed moderate correlation with other parameters of tissue perfusion. There were no differences between treatments. CONCLUSIONS: Haemorrhagic shock causes important microcirculatory alterations, which are reversed after treatment. Microcirculation should be assessed during haemorrhagic shock providing additional information to guide resuscitation.

Constipation in the Critically Ill Child: Frequency and Related Factors.

OBJECTIVE: To analyze the incidence and factors associated with constipation in critically ill children. STUDY DESIGN: We performed a prospective observational study that included children admitted to the pediatric intensive care unit for more than 3 days. Constipation was defined as more than 3 days without a bowel movement. Relationships between constipation and demographic data; clinical severity score; use of mechanical ventilation, use of vasoconstrictors, sedatives, and muscle relaxants; nutritional data; electrolyte disturbances; and clinical course were analyzed. RESULTS: Constipation developed in 46.7% of the 150 patients studied (mean age, 34.3 ± 7.1 months). It was most common in postoperative, older, and higher-body-weight patients, and in those with fecal continence (P < .01). Compared with patients without constipation, patients with constipation had higher severity scores and more frequently received midazolam, fentanyl, muscle relaxants, and inotropic support (P < .05). Patients with constipation also started nutrition later and with a lower volume of nutrition (P < .01). There were no between-group differences in mortality or length of pediatric intensive care unit stay. In multivariate analysis, independent factors associated with constipation were body weight (OR, 1.08; 95% CI, 1.03-1.13), Pediatric Index of Mortality 2 score (OR, 1.05; 95% CI, 1.02-1.09), admission after surgery (OR, 7.64; 95% CI, 2.56-22.81), and treatment with vasoconstrictors (OR, 10.28; 95% CI, 3.53-29.93). CONCLUSION: Constipation is common in critically ill children. Body weight, Pediatric Index of Mortality 2 clinical severity score, admission after surgery, and the need for vasoconstrictor therapy are major independent risk factors associated with constipation.

Comparison of normal saline, hypertonic saline albumin and terlipressin plus hypertonic saline albumin in an infant animal model of hypovolemic shock.

INTRODUCTION: In series of cases and animal models suffering hemorrhagic shock, the use of vasopressors has shown potential benefits regarding hemodynamics and tissue perfusion. Terlipressin is an analogue of vasopressin with a longer half-life that can be administered by bolus injection. We have previously observed that hypertonic albumin improves resuscitation following controlled hemorrhage in piglets. The aim of the present study was to analyze whether the treatment with the combination of terlipressin and hypertonic albumin can produce better hemodynamic and tissular perfusion parameters than normal saline or hypertonic albumin alone at early stages of hemorrhagic shock in an infant animal model. METHODS: Experimental, randomized animal study including 39 2-to-3-month-old piglets. Thirty minutes after controlled 30 ml/kg bleed, pigs were randomized to receive either normal saline (NS) 30 ml/kg (n = 13), 5% albumin plus 3% hypertonic saline (AHS) 15 ml/kg (n = 13) or single bolus of terlipressin 15 µg/kg i.v. plus 5% albumin plus 3% hypertonic saline 15 ml/kg (TAHS) (n = 13) over 30 minutes. Global hemodynamic and tissular perfusion parameters were compared. RESULTS: After controlled bleed a significant decrease of blood pressure, cardiac index, central venous saturation, carotid and peripheral blood flow, brain saturation and an increase of heart rate, gastric PCO2 and lactate was observed. After treatment no significant differences in most hemodynamic (cardiac index, mean arterial pressure) and perfusion parameters (lactate, gastric PCO2, brain saturation, cutaneous blood flow) were observed between the three therapeutic groups. AHS and TAHS produced higher increase in stroke volume index and carotid blood flow than NS. CONCLUSIONS: In this pediatric animal model of hypovolemic shock, albumin plus hypertonic saline with or without terlipressin achieved similar hemodynamics and perfusion parameters than twice the volume of NS. Addition of terlipressin did not produce better results than AHS.

Adrenaline, terlipressin, and corticoids versus adrenaline in the treatment of experimental pediatric asphyxial cardiac arrest.

OBJECTIVE: To analyze if treatment with adrenaline (epinephrine) plus terlipressin plus corticoids achieves higher return of spontaneous circulation than adrenaline in an experimental infant animal model of asphyxial cardiac arrest. DESIGN: Prospective randomized animal study. SETTING: Experimental department in a University Hospital. SUBJECTS: Forty-nine piglets were studied. INTERVENTIONS: Cardiac arrest was induced by at least 10 minutes of removal of mechanical ventilation and was followed by manual external chest compressions and mechanical ventilation. After 3 minutes of resuscitation, piglets that did not achieve return of spontaneous circulation were randomized to two groups: adrenaline 0.02 mg kg every 3 minutes (20 animals) and adrenaline 0.02 mg kg every 3 minutes plus terlipressin 20 µg kg every 6 minutes plus hydrocortisone 30 mg kg one dose (22 animals). Resuscitation was discontinued when return of spontaneous circulation was achieved or after 24 minutes. MEASUREMENT AND MAIN RESULTS: Return of spontaneous circulation was achieved in 14 piglets (28.5%), 14.2% with only cardiac massage and ventilation. Return of spontaneous circulation was achieved in 25% of piglets treated with adrenaline and in 9.1% of those treated with adrenaline plus terlipressin plus hydrocortisone (p = 0.167). Return of spontaneous circulation was achieved in 45.4% of animals with pulseless electric activity, 20% with asystole, and 0% with ventricular fibrillation (p = 0.037). Shorter duration of cardiac arrest, higher mean blood pressure and EtCO2 and lower PaCO2 before resuscitation, and higher mean blood pressure during resuscitation were associated with higher return of spontaneous circulation. CONCLUSIONS: Treatment with adrenaline plus terlipressin plus corticoids does not achieve higher return of spontaneous circulation than that with adrenaline in an infant animal model of asphyxial cardiac arrest.

Comparison of normal saline, hypertonic saline and hypertonic saline colloid resuscitation fluids in an infant animal model of hypovolemic shock.

PURPOSE: Incorrect resuscitation after hypovolemic shock is a major contributor to preventable pediatric death. Several studies have demonstrated that small volumes of hypertonic or hypertonic-hyperoncotic saline can be an effective initial resuscitation solution. However, there are no pediatric studies to recommend their use. The aim of this study is to determine if in an infant animal model of hemorrhagic shock, the use of hypertonic fluids, as opposed to isotonic crystalloids, would improve global hemodynamic and perfusion parameters. METHODS: Experimental, randomized animal study including thirty-four 2-to-3-month-old piglets. 30 min after controlled 30 mL kg(-1) bleed, pigs were randomized to receive either normal saline (NS) 30 mL kg(-1) (n=11), 3% hypertonic saline (HS) 15 mL kg(-1) (n=12), or 5% albumin plus 3% hypertonic saline (AHS) 15 mL kg(-1) (n=11). RESULTS: High baseline heart rate (HR) and low mean arterial pressure (MAP), cardiac index (CI), brain tissue oxygenation index (bTOI), and lactate were recorded 30 min after volume withdrawal, with no significant differences between groups. Thirty minutes after volume replacement there were no significant differences between groups for HR (NS, 188±14; HS, 184±14; AHS, 151±14 bpm); MAP (NS, 80±7; HS, 86±7; AHS, 87±7 mmHg); CI (NS, 4.1±0.4; HS, 3.9±0.4; AHS, 5.1±0.4 mL min(-1)m(-2)); lactate (NS, 2.8±0.7; HS, 2.3±0.6; AHS, 2.4±0.6 mmol L(-1)); bTOI (NS, 43.9±2.2; HS, 40.1±2.5; AHS, 46.1±2.3%). CONCLUSIONS: In this model of hypovolemic shock, hypertonic fluids achieved similar end-points as twice the volume of NS. Animals treated with albumin plus hypertonic saline presented prolonged increase in blood volume parameters and recovery of the oxygen debt.

High-flow oxygen therapy: pressure analysis in a pediatric airway model.

BACKGROUND: The mechanism of high-flow oxygen therapy and the pressures reached in the airway have not been defined. We hypothesized that the flow would generate a low continuous positive pressure, and that elevated flow rates in this model could produce moderate pressures. The objective of this study was to analyze the pressure generated by a high-flow oxygen therapy system in an experimental model of the pediatric airway. METHODS: An experimental in vitro study was performed. A high-flow oxygen therapy system was connected to 3 types of interface (nasal cannulae, nasal mask, and oronasal mask) and applied to 2 types of pediatric manikin (infant and neonatal). The pressures generated in the circuit, in the airway, and in the pharynx were measured at different flow rates (5, 10, 15, and 20 L/min). The experiment was conducted with and without a leak (mouth sealed and unsealed). Linear regression analyses were performed for each set of measurements. RESULTS: The pressures generated with the different interfaces were very similar. The maximum pressure recorded was 4 cm H(2)O with a flow of 20 L/min via nasal cannulae or nasal mask. When the mouth of the manikin was held open, the pressures reached in the airway and pharynxes were undetectable. Linear regression analyses showed a similar linear relationship between flow and pressures measured in the pharynx (pressure = -0.375 + 0.138 × flow) and in the airway (pressure = -0.375 + 0.158 × flow) with the closed mouth condition. CONCLUSIONS: According to our hypothesis, high-flow oxygen therapy systems produced a low-level CPAP in an experimental pediatric model, even with the use of very high flow rates. Linear regression analyses showed similar linear relationships between flow and pressures measured in the pharynx and in the airway. This finding suggests that, at least in part, the effects may be due to other mechanisms.

Pulmonary arterial thermodilution, femoral arterial thermodilution and bioreactance cardiac output monitoring in a pediatric hemorrhagic hypovolemic shock model.

AIM: Bioreactance is a new non-invasive method for cardiac output measurement (NICOM). There are no studies that have analysed the utility of this technique in a pediatric animal model of hemorrhagic shock. METHODS: A prospective study was performed using 9 immature Maryland pigs weighing 9 to 12 kg was performed. A Swan-Ganz catheter, a PiCCO catheter and 4 dual surface electrodes were placed at the four corners of the anterior thoracic body surface. Shock was induced by withdrawing a blood volume of 30 mL/kg, and then after, 30 mL/kg of Normal saline was administered. Seven simultaneous measurements of cardiac index (CI) were made by pulmonary artery thermodilution (PATD), Femoral artery thermodilution (FATD), and NICOM before, during, and after hypovolaemia and during and after volume expansion. RESULTS: The mean difference (bias) of differences (limits of agreement) between PATD and FATD was 0.84 (-1.87-3.51)L/min/1.77 m(2), between PATD and NICOM was 1.95 (-1.79-5.69)L/min/1.77 m(2), and between FATD and NICOM was 1.06 (-1.40-3.52)L/min/1.77 m(2). A moderate correlation was found between PATD and FATD (r=0.43; P=0.01), but no correlation was found between bioreactance and either PATD or FATD. Hypovolemia and volume expansion produced important significant differences in CI as measured by PATD and FATD, while the changes with bioreactance were small and non significant. CONCLUSIONS: PATD and FATD measurements showed similar responses to hypovolemic shock and volume expansion. Bioreactance persistently underestimates the CI and is not significantly altered by either inducing hemorrhagic shock, or later, through volume expansion. Bioreactance is not a suitable method for monitoring the CI in pediatric hemorrhagic shock.

Chest compressions versus ventilation plus chest compressions: a randomized trial in a pediatric asphyxial cardiac arrest animal model.

PURPOSE: To compare survival, oxygenation, ventilation, and hemodynamic variables achieved with chest compressions or ventilation plus chest compressions. METHODS: This randomized experimental study was conducted in the experimental department of a university hospital. Thirty infant pigs with asphyxial cardiac arrest were randomized into two groups of cardiopulmonary resuscitation (CPR): group 1, continuous chest compressions plus non-coordinated ventilation with a mask and mechanical ventilator (inspired oxygen fraction 0.21) (VC); group 2, chest compressions only (CC). Nine minutes of basic resuscitation was performed initially in both groups, followed by advanced resuscitation. CPR was terminated on achieving return of spontaneous circulation (ROSC) or after 30 min of total resuscitation time without ROSC. RESULTS: Three animals (18.8%) in the VC group and 1 (7.1%) in the CC group achieved ROSC (P = 0.351). Oxygenation and ventilation during basic CPR were insufficient in both groups, though they were significantly better in the VC group than in the CC group after 9 min (PaO(2), 26 vs. 19 mmHg, P = 0.008; PaCO(2), 84 vs. 101 mmHg, P = 0.05). Cerebral saturation was higher in the VC group (61%) than in the CC group (30%) (P = 0.06). There were no significant differences in mean arterial pressure. CONCLUSIONS: Neither of the basic CPR protocols achieved adequate oxygenation and ventilation in this model of asphyxial pediatric cardiac arrest. Chest compressions plus ventilation produced better oxygenation, ventilation, and cerebral oxygenation with no negative hemodynamic effects. Survival was higher in the VC group, though the difference was not statistically significant.

Terlipressin versus adrenaline in an infant animal model of asphyxial cardiac arrest.

PURPOSE: The objective of this study was to compare the efficacy of terlipressin versus adrenaline in an experimental infant animal model of asphyxial cardiac arrest (ACA). DESIGN: Prospective randomised animal study. SETTING: Laboratory research department of a university hospital. METHODS: Seventy-one, 2-month-old, mechanically ventilated piglets were investigated. ACA was induced by removal of mechanical ventilation. Resuscitation was performed by means of manual external chest compressions and mechanical ventilation (CC + V). After 3 min of CC + V, return of spontaneous circulation (ROSC) was observed in 11 animals. The 60 piglets without ROSC were then randomised to the four study groups: adrenaline standard dose (Asd): 0.01 mg/kg/3 min; adrenaline high dose (Ahd): first dose (0.01 mg/kg) and subsequent doses (0.1 mg/kg/3 min); terlipressin (T): 20 microg/kg/6 min; and adrenaline standard dose plus terlipressin (Asd + T). MEASUREMENTS AND RESULTS: The relationship between haemodynamic (heart rate, blood pressure, ECG rhythm, cardiac index), respiratory (end-tidal CO(2), blood gas analysis) and tissue perfusion (gastric intramucosal pH, central, cerebral and renal saturation) parameters and ROSC was analysed. ROSC was achieved in three piglets treated with Asd (20%), four treated with Ahd (26.7%), one treated with T (6.7%) and seven treated with Asd + T (46.7%) (P = 0.099). ROSC was achieved in 43.1% of animals with pulseless electrical activity, 30.4% with asystole and none with ventricular fibrillation (P = 0.0001). CONCLUSION: In this infant animal model of cardiac arrest, there was a non-significant trend towards better outcome when terlipressin was combined with adrenaline compared with the use of adrenaline or terlipressin alone.

Clinical course of children requiring prolonged continuous renal replacement therapy.

A prospective observational study was performed to analyze the clinical course of critically ill children who require continuous renal replacement therapy (CRRT). Variables associated with prolonged CRRT were analyzed. Of the 174 children treated with CRRT, 32 (18.3%) required CRRT for >14 days and 20 (11.5%) for >21 days. Prolonged CRRT was more common in patients with heart disease and those requiring mechanical ventilation, hemodiafiltration, and higher doses of heparin. The same factors were found when patients with CRRT for >14 days and 21 days were studied. Overall mortality rate was 35.6%; it was slightly higher in patients on prolonged CRRT (43.7% with CRRT > 14 days and 45% with CRRT >21 days), though the differences were not statistically significant. We conclude that there were no differences in the pre-CRRT clinical characteristics, severity of illness, and renal function in critically ill children requiring prolonged CRRT. Prolonged CRRT was more frequently required by patients with heart disease and those on mechanical ventilation. Patients with prolonged CRRT required more frequent hemodiafiltration and higher doses of heparin. Mortality was slightly higher in children with longer CRRT, though this difference did not reach statistical significance.