Transplacental metabolic alkalosis.

We present a newborn with hypochloraemic metabolic alkalosis due to severe metabolic alkalosis of his mother. Hypoventilation as a leading symptom resolved quickly with treatment but may be life-threatening if not detected. In this case, the mother had a probable eating disorder. Little is known about transplacentally acquired electrolyte disorders in this setting. In the absence of symptoms, most of the cases might be undetected. The usual neonatal outcome of anorexia and/or bulimia nervosa in pregnancy is a lower birthweight and a lower risk for instrumental delivery.

Enoxaparin therapy for arterial thrombosis in infants with congenital heart disease.

OBJECTIVE: To investigate efficacy and safety of enoxaparin for catheter-related arterial thrombosis in infants with congenital heart disease. DESIGN: Prospective observational study. SETTING: Pediatric Intensive Care and Cardiology Unit at the University Children's Hospital of Zurich. PATIENTS: A cohort of 32[Symbol: see text]infants aged 0-12[Symbol: see text]months treated with enoxaparin for catheter-related arterial thrombosis from 2002 to 2005. MEASUREMENTS: Dose requirements of enoxaparin, resolution of thrombosis by Doppler ultrasound, and bleeding complications. RESULTS: Catheter-related arterial thrombosis was located in the iliac/femoral arteries in 31 (97%) infants and aorta in 1 infant, and was related to indwelling catheters and cardiac catheterization in 17 (53%) and 15 (47%) cases, respectively. Newborns required increased doses of enoxaparin to achieve therapeutic anti-FXa levels (mean 1.62[Symbol: see text]mg/kg per dose) compared with infants aged 2-12 months (mean 1.12 mg/kg per dose; p=0.0002). Complete resolution of arterial thrombosis occurred in 29 (91%) infants at a mean of 23 days after initiation of enoxaparin therapy. Partial or no resolution was observed in 1 (3%) and 2 (6%) infants, respectively, at a mean follow-up time of 4.3 months. Bleeding complications occurred in 1 (3%) infant. CONCLUSION: Enoxaparin is efficient and safe for infants with congenital heart disease and catheter-related arterial thrombosis, possibly representing a valid alternative to the currently recommended unfractionated heparin.

Congenital prothrombotic disorders in children with peripheral venous and arterial thromboses.

AIMS: To evaluate the prevalence of congenital prothrombotic disorders in children with peripheral venous and arterial thromboses. METHODS: Deficiencies in antithrombin (AT), proteins C (PC) and S (PS), and increased lipoprotein (a), and the presence of factor V (FV) G1691A, prothrombin G20210A and methylenetetrahydrofolate reductase (MTHFR) mutations were investigated. RESULTS: Forty-eight patients (mean age, 3.4 years) were investigated. Of these patients, 23 had venous thrombosis, 22 had arterial thrombosis, and 3 had both. No patients had AT, PC or PS deficiency. FV G1691A mutation was present in 2 (7.6%) and 3 (12%) patients with venous and arterial thromboses, respectively. The prothrombin G20210A mutation was present in 1 (4%) patient with arterial thrombosis. Homozygous MTHFR C677T mutation was detected in 4 (18%) and 2 (9%) patients with venous and arterial thromboses, respectively. Increased lipoprotein (a) was present in 2 (10%) and 1 (4.5%) patients with venous and arterial thromboses, respectively. Regarding acquired risk factors, 79% of all thrombotic events were related to catheter usage. An underlying disease was present in 96% of the patients. CONCLUSIONS: Compared to acquired risk factors, congenital prothrombotic disorders are rarely present in children with peripheral venous and arterial thromboses. These results do not support general screening of children with venous and arterial thromboses for congenital prothrombotic disorders.

The role of somatostatin in the treatment of persistent chylothorax in children.

OBJECTIVE: To analyze the success rate of somatostatin in children with persistent chylothorax who failed dietary treatment options (fat-free nutrition, total parenteral nutrition) and to work out predictive factors for a successful therapy with somatostatin. METHODS: Retrospective cohort study over a 5-year period (2000-2004) in a neonatal and pediatric intensive care unit of a tertiary university hospital. We analyzed the data of 85 neonatal and pediatric patients. Treatment of chylothorax occurred according to a multistage protocol with progressing invasiveness: (1) fat-free enteral nutrition, (2) total parenteral nutrition, (3) somatostatin infusion, (4) surgery. The percentages of patients successfully treated at the progressing steps were recorded. The somatostatin group was analyzed regarding to physiologic, diagnostic, treatment and outcome parameters. Somatostatin-responders were compared with non-responders. RESULTS: Seventy-six of the 85 patients had chylothorax after cardiac surgery. Sixty-six percent could be treated with fat-free nutrition alone, 19% needed treatment with total parenteral nutrition and in 15% somatostatin was added. Of the whole sample, 4.7% required a surgical intervention. Of the 13 patients treated with somatostatin, all had bilateral chylothorax. Six patients (46%) responded to somatostatin. Responders and non-responders did not differ significantly regarding age, day of postoperative diagnosis of chylothorax, amount of chylous effusion before somatostatin infusion, triglyceride concentration and lymphocyte percentage in chylous, and central venous pressure (p=0.066). CONCLUSIONS: Somatostatin, integrated in a treatment algorithm, was successful in resolving persistent chylothorax in around 50% of patients. With this strategy, some children may be prevented from undergoing an operation. However, factors predicting successful therapy with somatostatin could not be elicited.

Antithrombin activity in children with chylothorax.

OBJECTIVE: To determine whether increased antithrombin loss is present in children with chylothorax after cardiac surgery. METHODS: Plasma and pleural effusion samples of children with chylous and non-chylous pleural effusion were assayed for antithrombin activity. RESULTS: Ten children with chylothorax and five children with non-chylous pleural effusion were investigated. There was statistically significant increase in mean antithrombin activity in chylous samples (32.2+/-11.4%) compared to non-chylous samples (14.4+/-13.9%), and significant decrease in plasma of children with chylothorax (44.6+/-15.4%) compared to children with non-chylous pleural effusion (69.9+/-22.4%). Seven of 10 children with chylous and none of the children without chylous developed thrombosis (p<0.007). CONCLUSIONS: Increased loss of antithrombin is present in children with chylothorax, potentially predisposing these children to an increased risk of thrombosis. Repeated antithrombin substitution should be considered in critically ill children with chylothorax.

Performance of a novel pressure release valve for cuff pressure control in pediatric tracheal tubes.

BACKGROUND: Acute and chronic hyperinflation of tracheal tube cuffs represents a persistent risk factor for airway damage in children when cuffed tracheal tubes are used. In order to overcome this particular risk, a cuff pressure (CP) pop-off valve has been designed to avoid CP exceeding 20 cmH(2)O. METHODS: The performance of the novel pop-off valve has been evaluated in an in vitro set-up during slow and rapid air insufflation by a syringe or a CP manometer or inadvertent compression of the cuff pilot balloon while measuring cuff and tracheal wall pressure (WP) in ID 3.0 mm cuffed tracheal tubes. Steady-state performance was evaluated during nitrous oxide exposure of tracheal tube cuffs (ID 3.0 mm). RESULTS: The novel CP pop-off valve avoided cuff hyperinflation during rapid air volume changes and showed reliable performance during steady-state nitrous oxide exposure to the tube cuff. CONCLUSIONS: These preliminary results show that the CP pop-off valve limits the effect of rapid, potentially dangerous manual cuff inflation maneuvers and reliably prevents CP exceeding the predetermined level of 20 cmH(2)O when exposed to nitrous oxide.

Cuff filling volumes and pressures in pediatric laryngeal mask airways.

BACKGROUND: Hyperinflation of LMA cuffs carries the risk of airway morbidity by exerting pressure on laryngeal and pharyngeal structures. Cuff hyperinflation in LMAs can result from nitrous oxide diffusion into the LMA cuff and from deliberate manual cuff inflation. METHODS: In an in vitro set up, maximum recommended cuff filling volumes for size 1, 1.5, 2, 2.5, 3 disposable LMAs from different manufacturers [SoftSeal LMA (Portex); Unique LMA (Intavent); Marshall LAD, LaryngoSeal (Tyco)] and reusable Classic and ProSeal LMAs (Intavent) were inflated into completely emptied LMA-cuffs and into LMA-cuffs at resting volume. Cuff pressures were measured using a cuff manometer. Experiments were performed eight times using two exemplars of each brand/size. RESULTS: Maximum recommended cuff filling volumes for pediatric LMAs resulted in hyperinflation (cuff pressure >60 cmH(2)O) in almost all LMAs, starting with emptied cuff. Starting from resting cuff volume, the maximum recommended inflation volume resulted in cuff pressures of >120 cmH(2)O in all LMAs and sizes except in the ProSeal size 3 (101 +/- 1 cmH(2)O). CONCLUSIONS: Since the volume of air which is effectively required depends on several factors and varies between patients, the cuffs should be inflated only with the minimum volume of air required to form an effective seal with the respiratory and gastrointestinal tracts and the cuff pressure should be controlled.

Evaluation of a new combined transcutaneous measurement of PCO2/pulse oximetry oxygen saturation ear sensor in newborn patients.

OBJECTIVE: Arterial oxygen saturation (Sao(2)) and arterial carbon dioxide partial pressure (Paco(2)) are 2 of the most important respiratory parameters in the treatment of critically ill neonates. Noninvasive monitoring of these parameters is desirable for continuous estimating of the respiratory status and reducing blood loss because of repeated blood gas analyses. Transcutaneous measurement of Pco(2) (Ptcco(2)) represents a simple and noninvasive technique for continuous monitoring of ventilation. However, sensor preparation, positioning, taping, and repeated changes of the sensor location make the handling difficult and complicate its use in the neonatal care unit. Recently, a new sensor for combined assessment of pulse oximetry oxygen saturation (Spo(2)) and Ptcco(2) has been introduced (TOSCA Monitor; Linde Medical Sensors, Basel, Switzerland). The monitor combines pulse oximetry and Ptcco(2) measurement in a single ear sensor, which works at 42 degrees C to enhance blood flow in capillaries below the sensor. METHODS: In a prospective, open, nonrandomized study of 60 ill neonates, the new ear sensor for combined assessment of Spo(2) and Ptcco(2) at 42 degrees C was tested. The sensor was adapted to the ear of a neonate with a Varihesive layer (Conva Tec; Princeton, NJ). Data obtained from the ear sensor were compared with Spo(2 Finger/Heel), Sao(2), and Paco(2) obtained from arterial blood gas in 30 patients and with a capillary blood gas in an additional 30 patients using Bland Altman bias analysis. Data are presented as median (range). RESULTS: The postconceptional age of the patients was 38.3 weeks (range: 28 5/7-40 5/7) in the arterial group and 37.9 weeks (range: 29 6/7-41 0/7) in the capillary group. Age of the newborns studied was 3.5 days (range: 1-28) in the arterial blood sample group (n = 30) and 6 days (range: 2-28) in the capillary blood sample group (n = 30). Patient weight was 3.02 kg (range: 1.5-4.5) in the arterial group and 2.76 kg (range: 1.0-3.71) in the other group. Three patients had weights of <1500 g. Twenty-one of 60 patients were conventionally ventilated, 4 patients received high-frequency oscillation, and 35 were not ventilated. Mean difference (bias) and precision (2 SD of the mean difference) between Ptcco(2 TOSCA) and Paco(2) were -0.44 kPa (-3.21 mm Hg) and 0.82 kPa (6.02 mm Hg) and between Ptcco(2 TOSCA) and Pcapco(2) were -0.09 kPa (-0.67 mm Hg) and 1.11 kPa (8.07 mm Hg), respectively. Spo(2) assessment by the TOSCA revealed slightly higher values compared with Sao(2) (bias: -0.48%), whereas Spo(2) (Finger/Heel) values were slightly lower than Sao(2) (bias: 0.52%). CONCLUSION: The TOSCA monitor with the ear sensor adapted to ears of neonates allows reliable estimation of Sao(2) and Paco(2). A potential benefit is the reduction in motion artifacts because of less head movement in newborns and that only a single cable leads form the patient to the monitor. In addition, the sensor is not removed for chest radiograph or for nursing the infant on his or her parent's lap. Long-term studies in a large population with continuous measurements are required to confirm these preliminary findings and to elucidate the benefits in detection of respiratory deterioration and the potential side effects of this sensor.