Role of Psychologists in Pediatric Sleep Medicine

Sleep disorders commonly afflict infants, children, and adolescents and have a significant adverse impact on them and their families, sometimes to a severe degree. They can cause immediate stress and suffering and long-term loss of opportunities and potential. Many of these disorders can be well managed by the psychologist and often one is required, either as the sole provider or as an integral part of a team. Sleep disorders have a bidirectional interplay with mental health disorders. The patient may therefore present initially to the psychologist, primary care provider, or the sleep medicine specialist.

Upper Airway Stimulation for Obstructive Sleep Apnea: Durability of the Treatment Effect at 18 Months

OBJECTIVE

To determine the stability of improvement in polysomnographic measures of sleep disordered breathing, patient reported outcomes, the durability of hypoglossal nerve recruitment and safety at 18 months in the Stimulation Treatment for Apnea Reduction (STAR) trial participants.

DESIGN

Prospective multicenter single group trial with participants serving as their own controls.

SETTING

Twenty-two community and academic sleep medicine and otolaryngology practices.

MEASUREMENTS

Primary outcome measures were the apnea-hypopnea index (AHI) and the 4% oxygen desaturation index (ODI). Secondary outcome measures were the Epworth Sleepiness Scale (ESS), the Functional Outcomes of Sleep Questionnaire (FOSQ), and oxygen saturation percent time < 90% during sleep. Stimulation level for each participant was collected at three predefined thresholds during awake testing. Procedure- and/or device-related adverse events were reviewed and coded by the Clinical Events Committee.

RESULTS

The median AHI was reduced by 67.4% from the baseline of 29.3 to 9.7/h at 18 mo. The median ODI was reduced by 67.5% from 25.4 to 8.6/h at 18 mo. The FOSQ and ESS improved significantly at 18 mo compared to baseline values. The functional threshold was unchanged from baseline at 18 mo. Two participants experienced a serious device-related adverse event requiring neurostimulator repositioning and fixation. No tongue weakness reported at 18 mo.

CONCLUSION

Upper airway stimulation via the hypoglossal nerve maintained a durable effect of improving airway stability during sleep and improved patient reported outcomes (Epworth Sleepiness Scale and Functional Outcomes of Sleep Questionnaire) without an increase of the stimulation thresholds or tongue injury at 18 mo of follow-up.

Detection of upper airway status and respiratory events by a current generation positive airway pressure device

STUDY OBJECTIVES

To compare a positive airway pressure (PAP) device's detection of respiratory events and airway status during device-detected apneas with events scored on simultaneous polysomnography (PSG).

DESIGN

Prospective PSGs of patients with sleep apnea using a new-generation PAP device.

SETTINGS

Four clinical and academic sleep centers.

PATIENTS

Forty-five patients with obstructive sleep apnea (OSA) and complex sleep apnea (Comp SA) performed a PSG on PAP levels adjusted to induce respiratory events.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

PAP device data identifying the type of respiratory event and whether the airway during a device-detected apnea was open or obstructed were compared to time-synced, manually scored respiratory events on simultaneous PSG recording. Intraclass correlation coefficients between device-detected and PSG scored events were 0.854 for apnea-hypopnea index (AHI), 0.783 for apnea index, 0.252 for hypopnea index, and 0.098 for respiratory event-related arousals index. At a device AHI (AHIFlow) of 10 events/h, area under the receiver operating characteristic curve was 0.98, with sensitivity 0.92 and specificity 0.84. AHIFlow tended to overestimate AHI on PSG at values less than 10 events/h. The device detected that the airway was obstructed in 87.4% of manually scored obstructive apneas. Of the device-detected apneas with clear airway, a minority (15.8%) were manually scored as obstructive apneas.

CONCLUSIONS

A device-detected apnea-hypopnea index (AHIFlow) < 10 events/h on a positive airway pressure device is strong evidence of good treatment efficacy. Device-detected airway status agrees closely with the presumed airway status during polysomnography scored events, but should not be equated with a specific type of respiratory event.

Upper-airway stimulation for obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea is associated with considerable health risks. Although continuous positive airway pressure (CPAP) can mitigate these risks, effectiveness can be reduced by inadequate adherence to treatment. We evaluated the clinical safety and effectiveness of upper-airway stimulation at 12 months for the treatment of moderate-to-severe obstructive sleep apnea.

METHODS

Using a multicenter, prospective, single-group, cohort design, we surgically implanted an upper-airway stimulation device in patients with obstructive sleep apnea who had difficulty either accepting or adhering to CPAP therapy. The primary outcome measures were the apnea-hypopnea index (AHI; the number of apnea or hypopnea events per hour, with a score of ≥15 indicating moderate-to-severe apnea) and the oxygen desaturation index (ODI; the number of times per hour of sleep that the blood oxygen level drops by ≥4 percentage points from baseline). Secondary outcome measures were the Epworth Sleepiness Scale, the Functional Outcomes of Sleep Questionnaire (FOSQ), and the percentage of sleep time with the oxygen saturation less than 90%. Consecutive participants with a response were included in a randomized, controlled therapy-withdrawal trial.

RESULTS

The study included 126 participants; 83% were men. The mean age was 54.5 years, and the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 28.4. The median AHI score at 12 months decreased 68%, from 29.3 events per hour to 9.0 events per hour (P<0.001); the ODI score decreased 70%, from 25.4 events per hour to 7.4 events per hour (P<0.001). Secondary outcome measures showed a reduction in the effects of sleep apnea and improved quality of life. In the randomized phase, the mean AHI score did not differ significantly from the 12-month score in the nonrandomized phase among the 23 participants in the therapy-maintenance group (8.9 and 7.2 events per hour, respectively); the AHI score was significantly higher (indicating more severe apnea) among the 23 participants in the therapy-withdrawal group (25.8 vs. 7.6 events per hour, P<0.001). The ODI results followed a similar pattern. The rate of procedure-related serious adverse events was less than 2%.

CONCLUSIONS

In this uncontrolled cohort study, upper-airway stimulation led to significant improvements in objective and subjective measurements of the severity of obstructive sleep apnea. (Funded by Inspire Medical Systems; STAR ClinicalTrials.gov number, NCT01161420.).

The performance of two automatic servo-ventilation devices in the treatment of central sleep apnea

INTRODUCTION

This study was conducted to evaluate the therapeutic performance of a new auto Servo Ventilation device (Philips Respironics autoSV Advanced) for the treatment of complex central sleep apnea (CompSA). The features of autoSV Advanced include an automatic expiratory pressure (EPAP) adjustment, an advanced algorithm for distinguishing open versus obstructed airway apnea, a modified auto backup rate which is proportional to subject's baseline breathing rate, and a variable inspiratory support. Our primary aim was to compare the performance of the advanced servo-ventilator (BiPAP autoSV Advanced) with conventional servo-ventilator (BiPAP autoSV) in treating central sleep apnea (CSA).

STUDY DESIGN

A prospective, multicenter, randomized, controlled trial.

SETTING

Five sleep laboratories in the United States.

PARTICIPANTS

Thirty-seven participants were included.

MEASUREMENTS AND RESULTS

All subjects had full night polysomnography (PSG) followed by a second night continuous positive airway pressure (CPAP) titration. All had a central apnea index ≥ 5 per hour of sleep on CPAP. Subjects were randomly assigned to 2 full-night PSGs while treated with either the previously marketed autoSV, or the new autoSV Advanced device. The 2 randomized sleep studies were blindly scored centrally. Across the 4 nights (PSG, CPAP, autoSV, and autoSV Advanced), the mean ± 1 SD apnea hypopnea indices were 53 ± 23, 35 ± 20, 10 ± 10, and 6 ± 6, respectively; indices for CSA were 16 ± 19, 19 ± 18, 3 ± 4, and 0.6 ± 1. AutoSV Advanced was more effective than other modes in correcting sleep related breathing disorders.

CONCLUSIONS

BiPAP autoSV Advanced was more effective than conventional BiPAP autoSV in the treatment of sleep disordered breathing in patients with CSA.

Pediatric Insomnia: A Behavioral Approach

This article discusses the two common causes of insomnia in children, behavioral insomnia of childhood and delayed sleep phase syndrome. Both of these conditions are primarily treated with behavioral interventions that can be initiated and managed by the primary care provider. A review of these behavioral interventions is provided.

Emergency department cardiopulmonary bypass in the treatment of human cardiac arrest

OBJECTIVE

To study the use of emergency department (ED) femoro-femoral cardiopulmonary bypass (CPB) in the resuscitation of medical cardiac arrest patients.

DESIGN

Prospective, uncontrolled trial.

SETTING

Urban academic ED staffed with board-certified emergency physicians (EPs).

PARTICIPANTS

Ten patients with medical cardiac arrest unresponsive to standard therapy.

INTERVENTIONS

Femoro-femoral CPB instituted by EPs.

RESULTS

The time of cardiac arrest prior to CPB (mean+/-SD) was 32.0+/-13.6 min. The cardiac output while on CPB was 4.09+/-1.03 L/min with an average of 229+/-111 min on bypass. All 10 patients had resumption of spontaneous cardiac activity while on CPB. Seven of these were weaned from CPB with intrinsic spontaneous circulation. Of these, six patients were transferred from the ED to the operating room for cannula removal and vessel repair while the other patient died in the ED soon after discontinuing CPB. Mean survival was 47.8+/-44.7 h in the six patients leaving the ED. Although these patients had successful hemodynamic resuscitation, there were no long-term survivors.

CONCLUSION

CPB instituted by EPs is feasible and effective for the hemodynamic resuscitation of cardiac arrest patients unresponsive to advanced cardiac life support therapy. Future efforts need to focus on improving long-term outcome.

Progress in pediatric cardiopulmonary resuscitation

The success rate for cardiopulmonary resuscitation (CPR) in children is dismal. This review discusses the physiology of CPR, the basis for pharmacologic therapy, and the rationale for advanced interventions. It focuses attention on those areas in which research indicates hope for improved outcomes.

Mastering pediatric cardiopulmonary resuscitation

Premature and unexpected death, especially in children, is tragic and very unacceptable. Effective treatments for sudden death of pediatric patients continue to emerge. Modern cardiopulmonary resuscitation function began with the widespread introduction of closed-chest cardiac massage in 1960; however, despite 35 years of research and refinement, more than 90% of children who receive cardiopulmonary resuscitation do not survive. This article summarizes and expands on current treatment concepts for pediatric sudden death. Emphasis is placed on procedures and techniques that likely are accessible in most medical centers caring for critically ill and injured children.

High atrial natriuretic peptide concentrations blunt the pressor response during cardiopulmonary resuscitation in humans

OBJECTIVE

To determine the relationship of circulating atrial natriuretic peptide concentrations to the pressor response to high-dose epinephrine in patients undergoing cardiopulmonary resuscitation (CPR) for cardiac arrest.

DESIGN

Prospective study.

PATIENTS

Fourteen normothermic, adult, prehospital and emergency department patients suffering unexpected cardiac arrest.

INTERVENTION

Patients received high-dose epinephrine (0.2 mg/kg) i.v. when standard advanced cardiac life support (including multiple 1-mg dosages of epinephrine) failed to result in return of spontaneous circulation.

MEASUREMENTS AND MAIN RESULTS

Cardiac arrest patients were separated into those patients with and without detectable serum atrial natriuretic peptide concentrations, and were termed the "low atrial natriuretic peptide" and "high atrial natriuretic peptide" groups, respectively. Their aortic pressure response to high-dose (0.02 mg/kg) epinephrine was compared. The proportion with positive assays was compared with a group of healthy control subjects. Fourteen patients were studied. Eight patients had low serum atrial natriuretic peptide concentrations and six patients had high circulating atrial natriuretic peptide concentrations. The mean concentration in the high atrial natriuretic peptide group was 151 +/- 82 pg/mL. The proportion with positive assays (six of 14 patients) was greater than in the group in spontaneous circulation (three of 29 patients) (p = .002). The maximal increase in the aortic relaxation-phase pressures after high-dose epinephrine was 9 +/- 7 torr (1.2 +/- 0.9 kPa) in the low atrial natriuretic peptide group and 0 +/- 5 torr (0 +/- 0.7 kPa) in the high atrial natriuretic peptide group (p = .03). The maximal increase in the aortic compression pressures after high-dose epinephrine was 17 +/- 13 torr (2.3 +/- 1.7 kPa) in the low atrial natriuretic peptide group and 2 +/- 10 torr (0.3 +/- 1.3 kPa) in the high atrial natriuretic peptide group (p = .03). Thus, pressor responses after high-dose epinephrine administration were observed in patients in the low atrial natriuretic peptide group, but this response was absent in patients in the high atrial natriuretic peptide group.

CONCLUSIONS

Cardiac arrest patients receiving CPR have higher circulating atrial natriuretic peptide concentrations than healthy subjects. High serum atrial natriuretic peptide concentrations may antagonize the vasopressor response to epinephrine. Blocking this effect of atrial natriuretic peptide may improve outcomes in patients suffering cardiac arrest.

Simultaneous radial, femoral, and aortic arterial pressures during human cardiopulmonary resuscitation

OBJECTIVE

To examine the validity of interchanging arterial sites and their responses to graded doses of epinephrine during human cardiopulmonary resuscitation (CPR).

DESIGN

Consecutive case series.

SETTING

Large, urban Emergency Department.

PATIENTS

Adult, normothermic, nonhemorrhagic cardiac arrest patients.

INTERVENTIONS

While receiving advanced cardiac life support, patients received right atrial (n = 40), aortic (n = 40), radial (n = 40), and femoral (n = 17) artery catheters. Pressures were measured simultaneously at baseline, after 0.01 mg/kg and 0.2 mg/kg of epinephrine.

MEASUREMENTS AND MAIN RESULTS

The mean aortic compression-phase pressure was 9.3 +/- 10 (SD), 8.1 +/- 11, and 4.4 +/- 9.5 mm Hg higher than radial artery pressure at baseline, after 0.01 mg/kg, and 0.2 mg/kg of epinephrine, respectively (all statistically significant). When compared with the femoral artery at the same time points, the mean aortic compression-phase pressure was also 3.0 +/- 6.8, 1.9 +/- 8, and 0.6 +/- 7.7 mm Hg higher, respectively (none statistically significant). The aortic relaxation-phase pressure was 1.3 +/- 3.6, 1.1 +/- 3.8, and 1.6 +/- 2.5 mm Hg lower than the radial artery at baseline, after 0.01 mg/kg and 0.2 mg/kg of epinephrine, respectively (all statistically significant). When compared with the femoral artery at the same time points, the aortic relaxation-phase pressure was 0.6 +/- 2.0, 0.3 +/- 3.3, and 0.3 +/- 2.4 mm Hg lower, respectively (none statistically significant).

CONCLUSIONS

Radial artery relaxation-phase pressure, although statistically higher, correlated with aortic relaxation-phase pressure. Femoral artery relaxation-phase pressure was not statistically different from aortic relaxation-phase pressure. Aortic pressure was statistically higher and had a lower correlation with radial artery pressures during compression phase. The aortic to radial artery and aortic to femoral artery compression-phase gradients abated with increasing doses of epinephrine therapy. Caution must be used when substituting compression-phase pressure obtained at radial or femoral artery sites for aortic pressure during human CPR. Coronary artery perfusion pressures obtained with radial and femoral arteries correlate with aortic pressure when measuring the response to vasopressor therapy during CPR when an interpretable waveform exists.

Functional responses to extremely high plasma epinephrine concentrations in cardiac arrest

OBJECTIVE

To evaluate the action of high-dose epinephrine by measuring simultaneously its vasopressor and norepinephrine releasing effects in humans during cardiac arrest.

DESIGN

A prospective study on consecutive patients admitted with cardiac arrest.

SETTING

Emergency Department in a large, urban hospital.

PATIENTS

Eighteen patients with out-of-hospital cardiac arrest undergoing cardiopulmonary resuscitation (CPR).

INTERVENTIONS

Catheterization of both the aorta and right atrium for the recording of pressure and collection of blood samples. Throughout the study period (12.5 mins), 18 patients received epinephrine at both the standard dose (1 mg, approximately 0.015 mg/kg) and high dose (0.2 mg/kg). Blood samples were drawn five times, every 2.5 mins.

MEASUREMENTS AND MAIN RESULTS

Plasma epinephrine and norepinephrine concentrations; aorta, right atrial, and coronary perfusion pressures. Epinephrine concentrations (normal at rest = 160 +/- 10 [SEM] pmol/L) were increased at the time of the first sample (2.5 mins) by approximately 3,000-fold (to approximately 0.5 mumol/L), and, increased further to 12,000-fold (approximately 2.0 mumol/L) during the study. Aortic pressure increased from 20 +/- 3 to 28 +/- 3 mm Hg (p < .001), and coronary perfusion pressure increased from 4 +/- 3 to 10 +/- 3 mm Hg (p < .001). Simultaneous plasma norepinephrine concentrations were 30-fold higher than the normal resting value of 1.30 +/- 0.04 nmol/L, and increased by 90-fold during the study (p < .001). The spectral distributions of the individual correlations between plasma epinephrine and norepinephrine concentrations were segregated into high correlations (r > .83) in 12 of 18 patients and low r values (r = .29 to .79) in the remaining six patients. The distribution of the correlations was nonuniform by the Kolmogorov-Smirnov goodness-of-fit test with p < .001; this profile suggests that norepinephrine responsiveness to epinephrine can separate two populations, one of which (r > .83) would have preserved viability of the corresponding epinephrine receptors. The correlations between plasma epinephrine concentrations and coronary perfusion pressures were distributed more evenly, also in a nonuniform pattern (p < .02 by Kolmogorov-Smirnov goodness-of-fit test) and the relationship between the two sets of correlations was not significant.

CONCLUSIONS

Despite the very high prevailing plasma epinephrine concentrations during cardiac arrest, further epinephrine increases still elicit biological responses. The present work provides physiologic support for the use of large doses of epinephrine during the course of CPR.

The clinical implications of continuous central venous oxygen saturation during human CPR

STUDY OBJECTIVE

The purpose of this study was to observe, measure, and describe the changes in central venous oxygen saturation during CPR and immediately after return of spontaneous circulation. It also was to examine the clinical utility of continuous central venous oxygen saturation monitoring as a indicator of return of spontaneous circulation during CPR in human beings.

DESIGN AND SETTING

Eight-month, prospective, non-outcome, observational, nonrandomized case series in the ED of a large urban hospital. TYPES OF PATIENTS: Adult normothermic, nontraumatic, out-of-hospital cardiopulmonary arrests.

INTERVENTIONS

All patients were managed according to advanced cardiac life support guidelines. A proximal aortic and double-lumen central venous catheter was placed. Central venous oxygen saturation was measured continuously spectrophotometrically with a fiberoptic catheter in the central venous location.

MEASUREMENTS

Aortic blood pressure and central venous oxygen saturation were simultaneously measured throughout each resuscitation. Return of spontaneous circulation was defined as a systolic blood pressure of more than 60 mm Hg for more than five minutes.

RESULTS

One hundred patients who experienced 68 episodes of cardiac arrest were studied. Patients with return of spontaneous circulation had a higher initial and statistically higher mean and maximal central venous oxygen saturation than those without return of spontaneous circulation (P = .23, .0001, and .0001, respectively; P less than .05 is significant). No patient attained return of spontaneous circulation without reaching a central venous oxygen saturation of at least 30%. Only one of 68 episodes of return of spontaneous circulation was attained without reaching a central venous oxygen saturation of at least 40%. A central venous oxygen saturation of greater than 72% was 100% predictive of return of spontaneous circulation.

CONCLUSION

Continuous central venous oxygen saturation monitoring can serve as a reliable indicator of return of spontaneous circulation during CPR in human beings.

Aortic pressure during human cardiac arrest. Identification of pseudo-electromechanical dissociation

We measured aortic pressure during clinically apparent cardiac electromechanical dissociation (EMD). Patients with pulse pressures were designated as having pseudo-EMD; those without, as having true EMD. Of the 200 patients studied, 54 presented with EMD, and 40 others developed it during resuscitation. Of the 94 with EMD, 39 were found to have pseudo-EMD. We compared the two types of EMD for electrocardiographic duration, return of palpable pulses, and response to standard- and high-dose epinephrine. The mean resting aortic pressure was 18 +/- 11 mm Hg in patients with true EMD and 28 +/- 11 mm Hg in those with pseudo-EMD. The mean pulse pressure in patients with pseudo-EMD was 6.3 +/- 3.5 mm Hg. Patients with pseudo-EMD had a higher proportion of witnessed arrests, higher PaO2, and lower PaCO2 than patients with true EMD. Patients with pseudo-EMD had shorter QR and QRS durations than patients with true EMD. They had a better response to standard- and high-dose epinephrine than patients with true EMD. Many patients diagnosed clinically to be in EMD have mechanical cardiac activity; this should be considered when interpreting the results of cardiac arrest research.

Aortic-carotid artery pressure differences and cephalic perfusion pressure during cardiopulmonary resuscitation in humans

OBJECTIVE

Animal studies have shown an aortic-carotid artery pressure difference during cardiopulmonary resuscitation (CPR), which compromises cerebral perfusion. This pressure difference is most marked with prolonged CPR and can be abolished with administration of high doses of epinephrine. To better understand the mechanism of cerebral blood flow during CPR in humans, we determined the aortic-carotid artery pressure difference, the cephalic perfusion pressure (the carotid artery-jugular vein pressure difference), and thoracic inlet venous "valving" (the central venous-jugular vein pressure difference), while administering standard doses of epinephrine.

DESIGN

Prospective study with randomization as to which side the carotid artery was catheterized.

SETTING

The resuscitation room of a large urban hospital's emergency department.

PATIENTS

Fifteen adults in normothermic, nontraumatic prehospital cardiac arrest treated according to Advanced Cardiac Life Support guidelines, including administration of 1 mg epinephrine iv every 5 mins.

INTERVENTIONS

The descending aorta, cervical common carotid artery, internal jugular vein, and central venous system were catheterized. Pressures were recorded during standard CPR for 5 mins after administration of 1 mg epinephrine iv.

MEASUREMENTS AND MAIN RESULTS

Most patients received CPR for greater than 20 mins before the first epinephrine dose and for greater than 45 mins before pressure recording as described above. There was no significant difference between aortic and carotid artery compression and relaxation phase pressures. The mean +/- SD compression central venous-jugular vein pressure difference was 22.1 +/- 15.0 mm Hg, and the mean cephalic perfusion pressure was 20.8 +/- 19.5 mm Hg.

CONCLUSIONS

There is no clinically important aortic-carotid artery pressure difference during human CPR using the standard dose of epinephrine, even with prolonged CPR. Despite carotid artery patency and thoracic inlet venous valving, the cephalic perfusion pressure is low during CPR in humans.

Regional cerebrovascular oxygen saturation measured by optical spectroscopy in humans

Regional cerebrovascular oxygen saturation, a quantitative measure of hemoglobin saturation in the combined arterial, venous, and microcirculatory compartments of the brain, can be measured noninvasively with near infrared spectroscopy. We assessed the sensitivity of this aggregate saturation to cerebral hypoxia during transient cerebral hypoxic hypoxia in seven human subjects. Regional cerebrovascular oxygen saturation measured over the middle frontal gyrus and analog electroencephalogram were recorded. We compared the time to achieve two end points: the earliest paroxysmal burst of theta-delta background slowing and a cerebrovascular oxygen saturation of less than 55%. Saturation fell below 55% prior to the electroencephalographic change (p less than 0.05). In a related effort, we also compared spectroscopically measured regional cerebrovascular oxygen saturation with an estimate of this value calculated from arterial and cerebral mixed venous saturation in nine patients. A positive linear relation (n = 68, R2 = 0.55, s = 4.2) was noted.

Jugular bulb catheterization does not increase intracranial pressure

Cerebral venous monitoring through jugular bulb catheterization (JBC) allows assessment of global oxygen delivery adequacy. Because of concern that venous obstruction by catheterization may cause or exacerbate intracranial hypertension, physicians are reluctant to puncture this vessel in brain-injured patients. We evaluated the impact of JBC on intracranial pressure (ICP). 37 consecutive pediatric patients with jugular bulb catheters and ICP monitoring were studied. ICP was monitored in 28 patients during JBC. Also immediately after JBC and daily thereafter the contralateral, ipsilateral, and bilateral jugular veins were compressed in all 37 patients to assess patency of these vessels. Change in ICP was noted. If ICP increased more than 5 torr, compression was stopped. Preinsertion ICP was 17.3 +/- 5.1 and postinsertion 17.2 +/- 5.1 torr. The maximum rise in ICP was 2 torr in a single patient while 6 others had a decrease in ICP. 120 compression tests were performed. Compression ipsilateral to the catheter caused the ICP to rise from 16.0 +/- 4.3 to 18.4 +/- 4.4 torr, and in contralateral compression 15.9 +/- 4.2 to 17.0 +/- 4.4. Neither the duration of catheterization nor the precompression ICP correlated with the rise in ICP. These data revealed no evidence of jugular venous obstruction in the catheterized vessel. We conclude that JBC can be performed in patients without aggravating an elevated ICP.

Treatment of acute hypoxemic respiratory failure caused by chlorine exposure

Chlorine inhalation may rapidly cause pulmonary edema, leading to acute hypoxemic respiratory failure. We report a 12 year old with acute respiratory failure from inhalation injury after he accidentally dropped chlorine tablets into a swimming pool. Supplemental oxygen alone failed to provide adequate arterial oxygenation. We administered positive end expiratory pressure (PEEP) in the emergency department, resulting in markedly improved oxygenation. Early institution of PEEP should be considered in patients with chlorine poisoning when supplemental oxygen alone is insufficient.

The effect of standard- and high-dose epinephrine on coronary perfusion pressure during prolonged cardiopulmonary resuscitation

We studied the effect of standard and high doses of epinephrine on coronary perfusion pressure during cardiopulmonary resuscitation in 32 patients whose cardiac arrest was refractory to advanced cardiac life support. Simultaneous aortic and right atrial pressures were measured and plasma epinephrine levels were sampled. Patients remaining in cardiac arrest after multiple 1-mg doses of epinephrine received a high dose of 0.2 mg/kg. The increase in the coronary perfusion pressures was 3.7 +/- 5.0 mm Hg following a standard dose, not a statistically significant change. The increase after a high dose was 11.3 +/- 10.0 mm Hg; this was both statistically different than before administration and larger than after a standard dose. High-dose epinephrine was more likely to raise the coronary perfusion pressure above the previously demonstrated critical value of 15 mm Hg. The highest arterial plasma epinephrine level after a standard dose was 152 +/- 162 ng/mL, and after a high dose, 393 +/- 289 ng/mL. Because coronary perfusion pressure is a good predictor of outcome in cardiac arrest, the increase after high-dose epinephrine may improve rates of return of spontaneous circulation.

High-dose epinephrine improves outcome from pediatric cardiac arrest

STUDY OBJECTIVE

Animal studies suggest that the standard dose of epinephrine (SDE) for treatment of cardiac arrest in human beings may be too low. We compared the outcome after SDE with that after high-dose epinephrine (HDE) in children with refractory cardiac arrest.

DESIGN

Prospective intervention versus historic control groups.

TYPE OF PARTICIPANTS

Two similar groups of 20 consecutive patients each (median ages, 2.5 and 3 years) with witnessed cardiac arrest who remained in arrest after at least two SDEs (0.01 mg/kg).

INTERVENTIONS

Treatment with an additional SDE versus HDE (0.2 mg/kg).

MEASUREMENTS AND MAIN RESULTS

The rates of return of spontaneous circulation and long-term survival were compared. Fourteen of the HDE group (70%) had return of spontaneous circulation, whereas none of the SDE group did (P less than .001). Eight children survived to discharge after HDE, and three were neurologically intact at follow-up. No significant toxicity from HDE was observed.

CONCLUSION

HDE provided a higher return of spontaneous circulation rate and a better long-term outcome than SDE in our series of pediatric cardiac arrest. HDE may warrant incorporation into standard resuscitation protocols at an early enough point to prevent irreversible brain injury.

Systemic atropine administration during cardiac arrest does not cause fixed and dilated pupils

OBJECTIVES

Systemic administration of atropine during CPR may postpone brain death determination because of its reputed ability to produce fixed and dilated pupils. We studied the effect of atropine administered in the usual doses as an adjunct to endotracheal intubation and for cardiac arrest to determine if it would interfere with neurological assessment.

DESIGN

Two groups of children were studied. Group 1 consisted of 28 patients who received atropine (0.03 +/- 0.003 mg/kg) prior to endotracheal intubation. Group 2 consisted of 21 patients previously without evidence of brainstem disease who suffered a witnessed arrest and had prompt return of spontaneous circulation and received an atropine dose of 0.03 +/- 0.01 mg/kg.

RESULTS

In group 1, pupillary size averaged 4.02 +/- 0.78 mm before and 4.75 mm +/- .84 mm after atropine (P less than .001). In group 2, the pupillary examination was conducted 30 minutes after return of spontaneous circulation. The pupillary diameter was 4.80 +/- 0.91 mm. All pupils were reactive to light in both groups.

CONCLUSION

Atropine administration in conventional dose causes slight pupillary dilation but does not abolish pupillary light reactivity.

Right atrial-jugular venous pressure gradients during CPR in children

OBJECTIVE

This study measured the internal jugular vein and right atrium pressures during pediatric CPR to detect and quantify venous pressure gradients across the thoracic inlet.

DESIGN

Ten children from 2 months to 15 years old who underwent CPR had simultaneous pressure measurements recorded from the right atrium and jugular vein.

RESULTS

The right atrium-jugular vein peak compression-phase gradient was 18.3 +/- 4.7 mm Hg (mean +/- SD), and the end-relaxation gradient was 0.7 +/- 0.6. Jugular vein pressure exceeded the right atrium only in the early-relaxation phase (right atrium-jugular vein = -2.1 +/- 1.2). Thoracic inlet venous valving persisted throughout the duration of CPR.

CONCLUSION

There is a large venous gradient across the thoracic inlet during chest compressions in children, facilitating cerebral blood flow. This gradient reversed only in the early-relaxation phase. The data suggest that jugular venous return occurs only in the early-relaxation phase, whereas cerebral venous drainage persists throughout the CPR cycle.

Intussusception encephalopathy: an underrecognized cause of coma in children

Intestinal intussusception is a common cause of bowel obstruction in infancy and early childhood. Typically the presenting signs and symptoms are referable to the abdomen. On occasion the most prominent presenting feature is depressed level of consciousness. We describe 3 patients who presented with coma associated with intussusception.

Jugular bulb catheterization: experience with 123 patients

Jugular bulb catheterization (JBC) provides cerebral venous access for titration of brain-specific therapy. Little has been written about the catheterization procedure. We prospectively studied the time, number of punctures, success rate, and complications during JBC for a 24-month period in our ICUs. One hundred twenty-three patients (mean age 6.7 yr, range 12 hours to 21 yr) underwent JBC. Procedure time was 15.6 +/- 5.0 (SD) min. Median number of skin punctures was two. All but four were successful on first attempt. Three of the remaining were catheterized on second attempt. Inadvertent carotid puncture occurred in 3%. No other significant complications were noted. Radiography confirmed proper position in 97%. Duration of indwelling venous catheters was 2.5 +/- 1.6 days. All catheters functioned well until removal. We conclude that our technique of JBC is safe and highly successful. It compares favorably with previous, smaller series and with standard anterograde internal jugular catheterization in both children and adults.

High dose epinephrine in refractory pediatric cardiac arrest

Cardiac arrest has a poor prognosis, regardless of age group. Children who fail to respond to two standard doses of epinephrine (0.01 mg/kg) rarely survive to hospital discharge, and most die without the return of spontaneous circulation (ROSC). We treated seven consecutive children in cardiac arrest with high dose epinephrine (0.2 mg/kg) after failure to respond to two standard doses. Six had prompt and sustained ROSC. By comparison, in the previous 20 consecutive pediatric patients with cardiac arrest in which there was no response to two standard doses of epinephrine, none had ROSC. Previous animal data as well as anecdotal human experience suggest that the standard epinephrine dose (0.01 mg/kg) may be much too low.

Simultaneous aortic, jugular bulb, and right atrial pressures during cardiopulmonary resuscitation in humans. Insights into mechanisms

Pressure gradients across and between the head and chest were studied during mechanical cardiopulmonary resuscitation (CPR) in 22 humans. Patients in medical cardiac arrest, managed by ACLS guidelines, underwent placement of aortic arch (Ao), jugular venous bulb (JVB), and right atrial (RA) catheters. Simultaneous pressures were measured, and intercatheter gradients were calculated. The JVB to RA pressure difference is the gradient between the cervical and central venous circulations. It was negative when averaged throughout the CPR cycle and was more negative during compression than relaxation, -19 +/- 12 and -2 +/- 6 mm Hg, respectively. This indicates that the intrathoracic pressure rise was not transmitted to the jugular venous system, supporting the concept of a competent jugular valve mechanism during CPR. It is consistent with the thoracic pump model of cerebral perfusion. JVB to RA was positive only during early relaxation, allowing blood return from the head. The Ao to JVB gradient, although not equal to cerebral perfusion pressure, is the maximum potential pressure gradient for blood flow across the cerebral vasculature. It was positive throughout CPR, 25 +/- 17 during compression, and 9 +/- 10 mm Hg during relaxation. The Ao to RA gradient during the relaxation phase is CPR coronary perfusion pressure. In most patients, it was minimally positive in both phases of the CPR cycle: 7 +/- 14 in compression and 7 +/- 9 mm Hg during relaxation. This appears to be inadequate in providing sufficient blood flow to meet the metabolic needs of the myocardium. Four patients had larger gradients during compression suggestive of cardiac compression.(ABSTRACT TRUNCATED AT 250 WORDS)

Status epilepticus during labor. A case report

Epileptic seizures during labor are seen rarely. A patient in labor had a 70-minute tonic-clonic convulsion. Maternal acid-base status and oxygenation remained normal. Fetal monitoring showed no evidence of distress. This case suggests that fetal bradycardia during maternal seizures is due to hypoxia and acidosis, not to other factors.

Massive hemorrhage into intracranial neurinomas

Massive bleeding into an intracranial neurinoma is a rare event. The 12th case of this particular occurrence, which was precipitated by weight lifting, is described and a review of the literature is presented. Risk factors for bleeding appear to be tumor size and vascularity. Presenting symptomatology is abrupt and includes headache, nausea, vomiting, and depressed consciousness. Preexisting symptoms referrable to and marked dysfunction of the cranial nerve of origin are present. Deficits of neighboring cranial nerves are frequent. Computed tomography demonstrates the hemorrhages and the tumors. Mild head injury and physical exertion were precipitating factors in two cases. One-fourth of the patients died, while the others made good recoveries.

Catamenial exacerbation of action myoclonus: successful treatment with acetazolamide

Images

Neurotoxicity of meperidine

Meperidine neurotoxicity manifests as shakiness, tremors, myoclonus, and seizures. It is generally seen with repeated parenteral use. We report a case of meperidine neurotoxicity from oral use by an otherwise healthy woman. The pharmacology and clinical implications are discussed.

Tuberous sclerosis with cardiogenic cerebral embolism: magnetic resonance imaging

A girl with tuberous sclerosis and intracardiac masses had at least two episodes of cardiogenic cerebral embolization, the attacks characterized by acute onset of prolonged neurologic dysfunction arising from different vascular distributions in both cerebral hemispheres. Renal embolization was suggested by hematuria. Magnetic resonance imaging (MRI) demonstrated ischemic lesions in cerebral locations predicted by the clinical signs. MRI also demonstrated extensive areas compatible with the dysmyelination of tuberous sclerosis.

Regeneration in the cerebellum following methylazoxymethanol-induced destruction of the external germinal layer. Morphological and biochemical studies

In the cerebellum external germinal layer (EGL) regeneration was maximal 10 days following methylazoxymethanol-induced destruction of the postnatal mouse EGL. Similar patterns of EGL repair and delayed disappearance were observed in both anterior and posterior cerebellar lobes. Final reduction in granule cell number to 30-50% of control exceeded the reduction in basket and stellate cells. Morphological changes in GABAergic cell populations were paralleled by alterations in glutamic acid decarboxylase activity. These studies suggest that the regenerating EGL may be similar to the normal EGL with respect to the emerging cell types, but that granule cells which develop later are less completely represented.