Laura Nimkoff

Continuous infusion of ketamine in mechanically ventilated children with refractory bronchospasm.

ObjectiveTo determine whether ketamine infusion to mechanically ventilated children with refractory bronchospasm is beneficial.DesignRetrospective chart review.SettingPediatric intensive care unit (PICU) of a childrens hospital.PatientsSeventeen patients, ages ranging from 5 months to 17 years (mean 6±5.7 years), were admitted to our PICU over a 3-year period and received ketamine infusion during a course of mechanical ventilation. The patients had acute respiratory failure associated with severe bronchospasm due to status asthmaticus (n=11), bronchiolitis caused by respiratory syncytial virus (n=4), and bacterial pneumonia (n=2).InterventionsAll patients had been mechanically ventilated for 1–5 days (2.2±1.5 days) and received conventional treatment to relieve bronchospasm for more than 24 h prior to the initiation of ketamine treatment. An intravenous bolus of ketamine of 2 mg/kg, followed by continuous infusions of 20–60 μg/kg per minute (32±10 μg/kg per minute) was administered to all patients without changing their preexisting bronchodilatory regimen. Benzodiazepines were also given intravenously to all patients during the ketamine treatment.Measurements and main resultsThe PaO2/FIO2 ratio in all patients (n=17) and the dynamic compliance in the volume-preset mechanically ventilated patients (n=12) were calculated. The PaO2/FIO2 ratio increased significantly from 116±55 before ketamine, to 174±82, 269±151, and 248±124 at 1, 8, and 24 h respectively, after the initiation of the ketamine infusion (p<0.0001). Dynamic compliance increased from 5.78±2.8 cm3/cmH2O to 7.05±3.39, 7.29±3.37, and 8.58±3.69, respectively (p<0.0001). PaCO2 and peak inspiratory pressure followed a similar trend of improvement with ketamine administration. The mean duration of the ketamine infusion was 40±31 h. One patient required glycopyrrolate 0.4 mg/day to control excessive airway secretions and one patient required an additional dose of diazepam to control hallucinations while emerging from ketamine. All patients were successfully weaned from mechanical ventilation and discharged from the PICU.ConclusionContinuous infusion of ketamine to mechanically ventilated patients with refractory bronchospasm significantly improves gas exchange and dynamic compliance of the chest.

The needle-wire-dilator technique for the insertion of chest tubes in pediatric patients

We evaluated the needle-wire-dilator (NWD) technique, using commercially available sets, for insertion of chest tubes in 24 pediatric patients who were admitted to our pediatric intensive care unit (PICU). Fourteen patients had pneumothoraces, three had hemothoraces, two had pneumonia with empyema, four had pleural transudate effusions, and one had chylothorax. The ages of the patients ranged from four months to 24 years, and the sizes of the inserted chest tubes ranged from 10F to 20F. All insertions were successful, and the time from invasion of the pleural space by the needle to completion of chest tube insertion and connection to the tubing drainage system ranged from four to seven minutes. In four patients the procedure had to be performed while a significant coagulopathy existed. However, none of the 24 patients developed hemorrhagic complications. The only complication observed was a kink in the chest tube in five patients, resulting in recurrence of pneumothorax in four and pleural effusion in one. These adverse occurrences were corrected by repositioning the chest tubes in three patients, and by replacing the chest tubes with the stiffer, trochar type, chest tubes in the other two. We conclude that the NWD technique for chest tube insertion is quick, safe, and easy to perform in all pediatric age groups. The commercially available chest tubes used in our study were somewhat softer than the trochar type chest tubes available, which explains the occurrence of kinks in some of them.

Transvenous right ventricular pacing during cardiopulmonary resuscitation of pediatric patients with acute cardiomyopathy

We describe the cardiopulmonary resuscitation efforts on five patients who presented in acute circulatory failure from myocardial dysfunction. Three patients had acute viral myocarditis, one had a carbamazepine-induced acute eosinophilic myocarditis, and one had cardiac hemosiderosis resulting in acute cardiogenic shock. All patients were continuously monitored with central venous and arterial catheters in addition to routine noninvasive monitoring. An introducer sheath, a pacemaker, and sterile pacing wires were made readily available for the patients, should the need arise to terminate resistant cardiac dysrhythmias. All patients developed cardiocirculatory arrest associated with extreme hypotension and dysrhythmias within the first 48 hours of their admission to the pediatric intensive care unit (PICU). Right ventricular pacemaker wires were inserted in all of them during cardiopulmonary resuscitation (CPR). In four patients, cardiac pacing was used, resulting in a temporary captured rhythm and restoration of their cardiac output. These patients had a second event of cardiac arrest, resulting in death, within 10 to 60 minutes. In one patient, cardiac pacing was not used, because he converted to normal sinus rhythm by electrical defibrillation within three minutes of initiating CPR. We conclude that cardiac pacing during resuscitative efforts in pediatric patients suffering from acute myocardial dysfunction may not have long-term value in and of itself; however, if temporary hemodynamic stability is achieved by this procedure, it may provide additional time needed to institute other therapeutic modalities.

Acute lung injury/Airway

Background Acute respiratory distress syndrome (ARDS) is a therapeutic challenge in pediatric intensive care in view of the high mortality. In 1992 about 50 German paediatric hospitals founded a working group aiming on collaborative clinical research in this field. Aim and methods The aim of both a prospective and retrospective survey conducted in German pediatric intensive care units in 1993 was to accumulate data on the epidemiology, risk factors, natural history and treatment strategies in a large group of pediatric ARDS patients who were treated in the three year period from 1991 to 1993.All patients had acute bilateral alveolar infiltration of noncardiogenic origin and a pO2/FiO2 ratio < 150mmHg. The influence of sex, underlying disease and single organ failure was analyzed using the Fischers exact test, the influence of additional organ failure on mortality was tested with the Cochran-Mantel-Haenszel statistics. Results 112 patients were reported giving an incidence of 7 cases per 1000 admissions to pediatric ICUs. Median age was 24 month. In 43% of the cases, ARDS was associated with a pulmonary, in 39% with a systemic underlying disease. In 20% immunocompetence was impaired. Mortality was 46% and not dependent on age, sex and triggering event. The number of associated organ failures, however, strongly influenced mortality. Mortality in immunocompromised patients was 81%. The Analysis of treatment modalities employed in the patients revealed a lack of uniform therapeutic strategies. On the other hand, the patients were exposed to interventions not yet supported by controlled trials. Conclusions The observation of the lack of uniform treatment strategies led to the elaboration of recommendations on ventilator therapy and patient monitoring within the working group. The data gathered in this survey provide the basis for the design of prospective multicenter studies urgently needed to evaluate innovative treatment modalities in pediatric ARDS.