Airway Resistance and Respiratory Compliance in Children with Acute Viral Bronchiolitis Requiring Mechanical Ventilation Support.

BACKGROUND: Acute viral bronchiolitis (AVB) is a very frequent disease that affects the lower airways of young children increasing the inspiratory and expiratory resistance in variable degree as well as reducing the pulmonary compliance. It would be desirable to know whether these variables are associated with the outcome. OBJECTIVES: To evaluate the respiratory mechanics in infants with AVB requiring mechanical ventilation (MV) support and to evaluate if respiratory mechanics predict outcomes in children with AVB supported on MV. To evaluate the respiratory mechanics in infants with AVB submitted to MV. MATERIALS AND METHODS: A prospective observational study was conducted in two pediatric intensive care units (PICUs) between February 2016 and March 2017. Included were infants (1 month to 1 year old) admitted with AVB and requiring MV for >48 hours. Auto-PEEP, dynamic compliance (Cdyn), static compliance (Cstat), expiratory resistance (ExRes), and inspiratory resistance (InRes) were evaluated once daily on the second and third day of MV. RESULTS: A total of 64 infants (median age of 2.8 months and a mean weight of 4.8 ± 1.7 kg) were evaluated. A mean positive inspiratory pressure (PIP) of 31.5 ± 5.2 cmH2O, positive end-expiratory pressure (PEEP) of 5.5 ± 1.4 cmH2O, resulting in a mean airway pressure (MAP) of 12.5 ± 2.2 cmH2O and delta pressure of 22.5 ± 4.4 cmH2O without difference between the two hospitals. Measurements of respiratory mechanics showed high values of InRes and ExRes (median 142 [IQ25-75 106-180] cmH2O/L/s and 158 [IQ25-75 130-195.3] cmH2O/L/s, respectively), accompanied by decreased Cdyn and Cstat (0.46 ± 0.19 and 0.81 ± 0.25 mL/kg/cmH2O, respectively). None of the variables was associated with mortality, length of MV, or length of PICU stay. CONCLUSION: Infants with AVB requiring MV support present very high InRes and ExRes values. These findings might be the reason for the aggressive ventilatory parameters, especially PIP, required to ventilate this group of children with lower airway obstruction. CLINICAL SIGNIFICANCE: Monitoring respiratory mechanics could represent a useful tool to guide the ventilatory strategy to be adopted in patients with AVB. HOW TO CITE THIS ARTICLE: Andreolio C, Piva JP, Bruno F, da Rocha TS, Garcia PCR. Airway Resistance and Respiratory Compliance in Children with Acute Viral Bronchiolitis Requiring Mechanical Ventilation Support. Indian J Crit Care Med 2021;25(1):88-93.

Modes of Death and the Dying Process in Brazilian PICU Over the Last 30 Years: Personal Reflections.

This text is part of the chapter 7 of a special issue supplement called "Death and Dying in PICU" having Christopher S. Parshuram and Karen Dryden-Palmer as the guest editors. I present my personal perception regarding the modes of death and the dying process in Brazilian PICU over the last 30 years. A big change in this regard was observed in our country from the 1980s to nowadays. The PICU mortality rate decreased significantly from over 20% to below 5% as well as the modes of death being observed that the life support limitation is far the most frequent death process in the PICU. Palliative care, in the last 10 years, increased its coverage in our country and being frequently offered as a complementary care to terminal ill patients in the PICU.

Pilot Mechanistic Study of Insulin Modulation of Somatotrophic Hormones, Inflammation, and Lipid Metabolism During Critical Illness in Children.

OBJECTIVES: To evaluate the mechanism of insulin modulation on somatotrophic response, inflammation, and lipid metabolism in critically ill children. DESIGN: Open-label randomized mechanistic study. SETTING: Two-center, tertiary PICU study. PATIENTS: Thirty critically ill children between 1 month and 14 years old, requiring mechanical ventilation and with evidence of two or more organ system failures. INTERVENTIONS: Randomized physiologic design of hyperinsulinemic-euglycemic clamp using continuous insulin infusion at 0.1 U/kg/hr versus conventional management. MEASUREMENTS AND MAIN RESULTS: Thirteen children underwent hyperinsulinemic-euglycemic clamp. Blood samples for somatotrophic, inflammatory, and metabolic evaluation were obtained before randomization, and 24 and 72 hours later. A growth hormone oscillation profile was obtained during the first night. There was no difference between groups at baseline. Growth hormone resistance, increased proinflammatory cytokines, and increased lipolysis with low lipoprotein levels were present in all patients. Hyperinsulinemic-euglycemic clamp did not affect growth hormone, insulin-like growth factor-1 or insulin-like growth factor binding protein-3 levels. By day 2, insulin reduced insulin-like growth factor binding protein-1 levels. Tumor necrosis factor-α and interleukin-1ß were similar in both groups, whereas interleukin-6 levels reduced over time only in children receiving hyperinsulinemic-euglycemic clamp. Hyperinsulinemic-euglycemic clamp also decreased free fatty acid levels, which was accompanied by increased low-density lipoprotein cholesterol and relative increase in high-density lipoprotein levels. Total cholesterol and triglycerides were unchanged. CONCLUSIONS: Insulin does not reverse most of the somatotrophic changes induced by the stress of critical illness. Rather, it may improve lipid metabolism and down-regulate some markers of the inflammatory response.

Peak inspiratory pressure lacks accuracy to estimate plateau pressure in infants with severe obstructive lower airway disease.

PURPOSE: In children with acute respiratory distress syndrome receiving mechanical ventilation, the peak inspiratory pressure (PIP) is close to plateau pressure (PPLAT) when inspiratory flow approaches zero. We aimed to evaluate the reliability of PIP to estimate PPLAT in infants with severe respiratory viral infection (SRVI), characterized by increased airway resistance, and the accuracy of an equational model to estimates PPLAT (ePPLAT) based on PIP. METHODS: This was a retrospective observational study including mechanically ventilated children (1 to 24 month old) with SRVI, whose respiratory mechanics measurements were performed to evaluate PIP and PPLAT. The measured PPLAT was compared with the result of the equation: ePPLAT = PIP - [5.067 - (0.858 × static compliance) - (0.018 × inspiratory resistance) - (0.390 × pressure above positive-end expiratory pressure) + (4.989 × inspiratory time)]. RESULTS: Thirty-seven patients were included, with a median age of 3 (2-5) months. They presented a high inspiratory and expiratory resistance (136 ± 43 and 168 ± 66 cmH2O/L/s, respectively) and a moderate reduction in static compliance: 0.75 ± 0.3 mL/kg/cmH2O. PIP overestimated PPLAT (33 ± 3 and 26 ± 5 cmH2O, p = 0.01), with a mean difference of 7.3 ± 4 cmH2O. Moreover, the Bland-Altman analysis demonstrated a mean difference between PPLAT and ePPLAT of 1.0 ± 4.0 cmH2O, with 95% limits of agreement of -6.9 and 8.8. CONCLUSIONS: A significant difference between PIP and PPLAT was observed in infants with SRVI. The equation model was inaccurate for estimating PPLAT based on PIP. Any estimation of PPLAT from PIP needs to consider the resistance component of the respiratory system.

Parents' perspectives on the deaths of their children in two Brazilian paediatric intensive care units.

OBJECTIVES: To evaluate the quality of care offered to terminally ill children and their families in the last days of life in two Brazilian Paediatric Intensive Care Units (PICUs) from the parents' perspectives. METHODS: This was a qualitative, exploratory study. Parents of a child who had died in one of the PICUs 6-12 months previously were invited to take part in two interviews: a private meeting with the PICU assistant physician who cared for their child, to discuss and review any outstanding issues related to the diagnosis, treatment, and prognosis, and a recorded interview with a researcher who was not involved in the child's treatment. Data from the interviews with the researcher were posteriorly grouped in categories according to recurrent terms. RESULTS: Six categories emerged, three of which are reported here. The quality of communication was low; the medical staff frequently used technical terms, limiting understanding. Parental participation in the decision-making process was scarce; decisions were based on the medical perspective. Finally, families reported uncompassionate attitudes from the medical staff and excessive technology in the final moments surrounding the child's death, although nurses were highly involved with palliative care measures and demonstrated sympathetic and supportive postures. CONCLUSION: The interviews uncovered deficiencies in the care provided to parents in the PICUs, indicating a need for changes in practice.

Lamellar body count and stable microbubble test on tracheal aspirates from infants for the diagnosis of respiratory distress syndrome.

OBJECTIVES: To evaluate the performance of lamellar body count in tracheal aspirates from intubated preterm babies to predict respiratory distress syndrome. DESIGN: Case-control study. SETTING: Three neonatal intensive care units. PATIENTS: Seventy-two patients not older than 3 days were included in the study, 38 preterm infants with respiratory distress syndrome, 16 preterms without respiratory distress syndrome, and 18 term infants. All required mechanical ventilation. INTERVENTIONS: Lamellar body count was performed in an automated cell counter. Tracheal samples were diluted in dithiothreitol without centrifugation and kept frozen at -20°C until use. Samples were placed in a dithiothreitol-containing test tube at a ratio of one part tracheal aspirate to six parts dithiothreitol solution, vortexed for 10 secs, and aspirated by the cell counter. Lamellar body count was performed using the platelet channel. All results were multiplied by seven. The stable microbubble test was done for comparison. MEASUREMENTS: Lamellar body count and stable microbubble test. MAIN RESULTS: Lamellar body count was significantly lower in the respiratory distress syndrome group compared with the non respiratory distress syndrome preterm group and also with the term group. The median and interquartile range obtained for lamellar body count were 38,500/µL (14,000-112,000) for the respiratory distress syndrome group, 822,500/µL (442,000-962,500) for the non respiratory distress syndrome preterm group, and 633,000/µL (322,000-1,608,000) for the term group (p < .001). The sensitivity and specificity of lamellar body count and stable microbubble test for the diagnosis of respiratory distress syndrome were calculated, taking into consideration the respiratory distress syndrome and the non respiratory distress syndrome preterm groups. Considering a cutoff point of 200,000 lamellar bodies/µL, lamellar body count sensitivity was 92.1% (95% confidence interval 78.6-98.3) and lamellar body count specificity was 93.8% (95% confidence interval 69.8-99.8). The area under the curve was 0.94 (95% confidence interval 0.84-1.00). CONCLUSIONS: Lamellar body count and stable microbubble test can be rapidly and easily performed on tracheal aspirates and they seem to have very good performance for diagnosing respiratory distress syndrome in intubated patients.

Profile and consequences of children requiring prolonged mechanical ventilation in three Brazilian pediatric intensive care units.

OBJECTIVE: To describe the characteristics of children submitted to prolonged mechanical ventilation (MV), and evaluate their mortality, and associated factors as well as the potential impact at admissions to the pediatric intensive care unit (PICU). METHODS: We conducted a retrospective study enrolling all children admitted to three Brazilian PICUs between January 2003 and December 2005 submitted to MV > or =21 days. The three selected PICUs were located in university-affiliated hospitals. From the medical charts were reported anthropometric data, diagnosis, ventilator parameters on the 21st day, length of MV, length of stay in the PICU, specific interventions (e.g., tracheostomy), and outcome. RESULTS: One hundred eighty-four children (190 admissions) were submitted to prolonged MV (2.5% of all admissions to these 3 Brazilian PICUs), with a median age of 6 months. The mortality rate was 48% and the median time on MV was 32 days. Tracheostomy was performed on only 19% of the patients and, on average after 32 days of intubation. Mortality was associated with peak inspiratory pressure >25 cm H2O (odds ratio = 2.3; 1.1-5.1), fraction of inspired oxygen >0.5 (odds ratio = 6.3; 2.2-18.1), and vasoactive drug infusion (odds ratio = 2.6; 1.1-5.9) on the 21st day of MV. Seventy-six children (1% of the all admissions) were dependent on MV without other organ failures were 830 PICU admissions and were potentially prevented. CONCLUSIONS: A small group of children admitted to the PICU requires prolonged MV. The elevated mortality rate is associated with higher ventilatory parameters and vasoactive drug support on the 21st day of MV. Stable children requiring prolonged MV in the PICU potentially prevent additional admissions of a large number of acute and unstable patients.

Early administration of two intravenous bolus of aminophylline added to the standard treatment of children with acute asthma.

OBJECTIVES: Evaluate the efficacy of adding two intravenous bolus of aminophylline to the standard treatment of acute asthma episode in children admitted to the pediatric emergency room (PER). METHODS: Between March 2001 and February 2002, 60 children (2-5 years old), admitted to the PER at Hospital de Clínicas de Porto Alegre (Brazil), due to an episode of acute asthma, refractory to conventional therapy (an oral dose of steroids and at least three doses of inhaled albuterol, associated or not with oxygen) were enrolled in a randomized, double blind, placebo controlled clinical trial. The randomization was performed in blocks of 10 patients, who received a "bronchodilator solution" (either saline or aminophylline), in two doses: on arrival at the PER and again 6h later. The intervention group received aminophylline 5mg/kg/dose diluted in normal saline (NS) solution up to a 20 mL volume, while the placebo group received plain NS, both in an infusion rate of 1 cc/min. The main outcomes were total length of hospital stay, length of supplemental oxygen use, number of bronchodilator nebulizations and/or aerosol inhalations performed and patient destination. The groups were compared using the Students t-test, Mann-Whitney test and Chi-Square test, accepting p<0.05 as significant. RESULTS: Comparing the main outcomes, we did not find differences between the placebo and aminophylline groups: 29.0+/-14.7 versus 26.2+/-13.4 beta-agonist nebulizations per patient (p=0.46); 2.4+/-10.6 versus 5.6+/-14.2 aerosol inhalations per patient (p=0.32); 24.7+/-30.0 versus 26.0+/-25.2h for oxygen supplement (p=0.86); 43.2+/-30.0 versus 43.6+/-23.7h for length of hospital stay (p=0.95). We also did not find differences between the two groups related to the blood pressure, heart rate, respiratory rate and oxygen saturation. CONCLUSION: In children aged 2-5 years admitted to a PER with asthma, two intravenous doses of 5mg/kg of aminophylline given 6h apart did not change the length of stay in hospital, the number of nebulizations given or the duration of oxygen therapy required. We are unable to tell whether there would be benefit with higher doses of aminophylline designed to give levels in the usual therapeutic range.

Bromopride, metoclopramide, or ondansetron for the treatment of vomiting in the pediatric emergency department: a randomized controlled trial.

OBJECTIVE: To compare the effectiveness of a single intramuscular dose of bromopride, metoclopramide, or ondansetron for treating vomiting. METHODS: Randomized controlled trial including children 1-12 years of age presenting with acute vomiting at the pediatric emergency department. OUTCOMES: Number of children that stopped vomiting at one, six, and 24h following treatment; episodes of diarrhea; acceptance of oral liquids; intravenous rehydration; return to hospital and side effects. RESULTS: There were 175 children who completed the study. Within the first hour after treatment, all drugs were equally effective, with ondansetron preventing vomiting in 100%, bromopride in 96.6%, and metoclopramide in 94.8% of children (p=0.288). Within six hours, ondansetron was successful in preventing vomiting in 98.3% of children, compared to bromopride and metoclopramide, which were successful in 91.5% and 84.4% of patients, respectively (p=0.023). Within 24h, ondansetron was superior to both other agents, as it remained efficacious in reducing vomiting in 96.6% of children, as opposed to 67.8% and 67.2% with bromopride and metoclopramide, respectively (p=0.001). The ondansetron group showed better acceptance of oral liquids (p=0.05) when compared to the bromopride and metoclopramide. The ondansetron group did not show any side effects in 75.9% of cases, compared to 54.2% and 53.5% in the bromopride and metoclopramide groups, respectively. Somnolence was the most common side effect. CONCLUSIONS: A single dose of ondansetron is superior to bromopride and metoclopramide in preventing vomiting six hours and 24h following treatment. Oral fluid intake after receiving medication was statistically better with Ondansetronwhile also having less side effects compared to the other two agents.

Physician-Assisted Suicide and Euthanasia: Emerging Issues From a Global Perspective.

Medical professional societies have traditionally opposed physician-assisted suicide and euthanasia (PAS-E), but this opposition may be shifting. We present 5 reasons why physicians shouldn't be involved in PAS-E. 1. Slippery slopes: There is evidence that safeguards in the Netherlands and Belgium are ineffective and violated, including administering lethal drugs without patient consent, absence of terminal illness, untreated psychiatric diagnoses, and nonreporting; 2. Lack of self-determination: Psychological and social motives characterize requests for PAS-E more than physical symptoms or rational choices; many requests disappear with improved symptom control and psychological support; 3. Inadequate palliative care: Better palliative care makes most patients physically comfortable. Many individuals requesting PAS-E don't want to die but to escape their suffering. Adequate treatment for depression and pain decreases the desire for death; 4. Medical professionalism: PAS-E transgresses the inviolable rule that physicians heal and palliate suffering but never intentionally inflict death; 5. Differences between means and ends: Proeuthanasia advocates look to the ends (the patient's death) and say the ends justify the means; opponents disagree and believe that killing patients to relieve suffering is different from allowing natural death and is not acceptable. CONCLUSIONS: Physicians have a duty to eliminate pain and suffering, not the person with the pain and suffering. Solutions for suffering lie in improving palliative care and social conditions and addressing the reasons for PAS-E requests. They should not include changing medical practice to allow PAS-E.

Adrenal response in children with septic shock.

OBJECTIVE: To describe the serum cortisol profile and evaluate the adrenal response in children with septic shock, and determine the influence of these factors on the outcome and mortality in this group. METHODS: Between May and November 2003, 22 children with septic shock admitted to two pediatric intensive care units in southern Brazil were followed. Adrenal function was evaluated based on the levels of cortisol measured on the occasion of the diagnosis of septic shock and on the response of serum cortisol 30 min after the administration of intravenous corticotrophin (0.5 microg/1.73m(2)). Adrenal insufficiency was defined as a baseline serum cortisol below 690 nmol/l and/or a cortisol response to corticotrophin less than 250 nmol/l. RESULTS: Adrenal insufficiency was detected in 17 patients (77.3%). All patients who died had baseline cortisol higher than 690 nmol/l. A cortisol response to corticotrophin less than 250 nmol/l was associated with a 60% mortality (RR = 7.2, 1.03-50.28). Regression analysis showed that the combination of baseline cortisol higher than 690 nmol/l and a cortisol response to corticotrophin less than 250 nmol/l were associated with mortality after correction for gender and PRISM. CONCLUSIONS: Adrenal insufficiency is a frequent finding in children with septic shock. The low-dose corticotrophin stimulation test seems to be an important tool to distinguish between a normal cortisol response to stress and evidence of adrenal failure. Mortality was significantly higher in children that failed to respond to a corticotrophin stimulation test.

Nutritional status, breastfeeding, and evolution of Infants with acute viral bronchiolitis.

Acute viral bronchiolitis is a common respiratory infectious disease of infancy. A prospective study was carried out with 175 infants aged up to six months to evaluate their nutritional and breastfeeding status as possible risk factors for unfavourable evolution of previously-healthy infants from a care hospital. Immunofluorescence test for virus and anthropometric assessment were performed. Outcomes were length of oxygen-use, length of hospital stay, and type of hospital unit needed. Seventy-three percent of the infants were well-nourished, 6% undernourished, 8.6% at a nutritional risk, 10.9% overweight, and 1.7% obese. Eighty-one percent of the undernourished and nutritionally at-risk infants and 72% of the well-nourished, overweight, and obese infants did not receive exclusive breastfeeding. The median length of hospital stay was four days and of oxygen-use was 60 hours. The nutritional status did not affect the clinical course of previously-healthy infants with acute viral brochiolitis. The duration of exclusive breastfeeding, but not type of breastfeeding, was inversely related to the length of oxygen-use and the length of hospital stay. Shorter exclusive breastfeeding was observed in infants who were assigned to a paediatric ward or to an intensive care unit. In conclusion, longer duration of breastfeeding was associated with better clinical outcomes.

Current perspectives for treating children with diabetic ketoacidosis.

OBJECTIVE: To review current concepts of physiopathology, diagnosis and treatment of diabetic ketoacidosis (DKA) in childhood, as well as preventive measures to avoid cerebral edema. SOURCES: The authors selected articles from MEDLINE with the keywords diabetes, ketoacidosis, hyperglycemia and cerebral edema, and priority was given to studies including children and that contained complete texts published in English, Portuguese or Spanish. Chapters of books published in Brazil describing the treatment of DKA in pediatric intensive care unit were also reviewed. Based on the reviewed literature and on the author's experience, the most efficient and recommended measures for DKA management are presented. SUMMARY OF THE FINDINGS: Normal saline solution (NaCl 0.9%) has been increasingly used for fast replacement and hydration, as a substitute to diluted (hypotonic) solutions, as well as contraindication of sodium bicarbonate to repair metabolic acidosis in DKA. Regular insulin should be used as continuous infusion (0.1 IU/kg/h) without the need of a loading dose. For fast corrections of glucose oscillations, a practical scheme using two bags of electrolytic solutions is presented. Cerebral edema, its physiopathological mechanism and current treatment are reviewed. CONCLUSIONS: Use of continuous infusion of regular insulin associated with adequate water and electrolyte replacement using isotonic solutions, besides being an effective treatment for DKA, preserves plasma osmolarity and prevents cerebral edema.

Hemodynamic and metabolic effects of vasopressin infusion in children with shock.

OBJECTIVE: Vasopressin is a neuropeptide hormone which has been used clinically for more than 50 years and plays a major role in circulatory homeostasis and in the regulation of serum osmolality. Recent work has emphasized its role in the treatment of septic shock. This paper reviews the physiology of this neurohormone and the available evidence in favor of its use as a vasodilator for children in shock. SOURCES: MEDLINE, using the terms vasopressin, vasodilation, shock and septic shock, plus synonyms and related terms. Classic publications on the topic were also reviewed and selected depending on their relevance to the study objectives. SUMMARY OF THE FINDINGS: Vasopressin is synthesized in the neurohypophysis and released in response to a decrease in plasma volume or an increase in serum osmolality. The action of vasopressin is mediated by the activation of oxytocin receptors and of several G protein-coupled receptors, which are classified according to their location and intracellular transmission routes as V1 receptors (or V1b), V2 and V3 receptors (or V1b). The main role of vasopressin is to induce vasoconstriction. However, in certain organs, it can also induce selective vasodilation. Several clinical studies in adults and children have reported that the effects of vasopressin for the treatment of vasodilatory septic shock, due to a variety of causes, are both beneficial and safe. CONCLUSIONS: The evidence is restricted. Most studies are retrospective and include a small number of patients. Nevertheless, there is significant experience concerning the use of vasopressin in Pediatrics. Vasopressin has a beneficial clinical effect in children and can be indicated in the treatment of refractory vasodilatory shock, after adequate volume resuscitation and when high doses of other vasopressors are not effective.