Increased inspiratory pressure for reduction of atelectasis in children anesthetized for CT scan

BACKGROUND: Atelectasis is more frequent and more severe in children anesthetized for CT scan than it is in children sedated for CT scan.OBJECTIVE: To determine the effect of increased inspiratory pressure on atelectasis during chest CT in anesthetized children. MATERIALS AND METHODS: Atelectasis on chest CT was assessed by two observers in three groups of patients. Group A comprised 13 children (26 lungs) anesthetized at inspiratory pressures up to and including 25 cm H2O. Group B included 11 children anesthetized at inspiratory pressures > or =30 cm H2O. Group C included 8 children under deep sedation. RESULTS: Atelectasis was significantly more severe in group A than in groups B and C. There was no significant difference between groups B and C. CONCLUSION: An inspiratory pressure of 30 cm H2O is recommended for children anesthetized for CT scan of the chest.     

Chest CT in children: anesthesia and atelectasis

Background

There has been an increasing tendency for anesthesiologists to be responsible for providing sedation or anesthesia during chest CT imaging in young children. Anesthesia-related atelectasis noted on chest CT imaging has proven to be a common and troublesome problem, affecting image quality and diagnostic sensitivity.

Objective

To evaluate the safety and effectiveness of a standardized anesthesia, lung recruitment, controlled-ventilation technique developed at our institution to prevent atelectasis for chest CT imaging in young children.

Materials and methods

Fifty-six chest CT scans were obtained in 42 children using a research-based intubation, lung recruitment and controlled-ventilation CT scanning protocol. These studies were compared with 70 non-protocolized chest CT scans under anesthesia taken from 18 of the same children, who were tested at different times, without the specific lung recruitment and controlled-ventilation technique. Two radiology readers scored all inspiratory chest CT scans for overall CT quality and atelectasis. Detailed cardiorespiratory parameters were evaluated at baseline, and during recruitment and inspiratory imaging on 21 controlled-ventilation cases and 8 control cases.

Results

Significant differences were noted between groups for both quality and atelectasis scores with optimal scoring demonstrated in the controlled-ventilation cases where 70% were rated very good to excellent quality scans compared with only 24% of non-protocol cases. There was no or minimal atelectasis in 48% of the controlled ventilation cases compared to 51% of non-protocol cases with segmental, multisegmental or lobar atelectasis present. No significant difference in cardiorespiratory parameters was found between controlled ventilation and other chest CT cases and no procedure-related adverse events occurred.

Conclusion

Controlled-ventilation infant CT scanning under general anesthesia, utilizing intubation and recruitment maneuvers followed by chest CT scans, appears to be a safe and effective method to obtain reliable and reproducible high-quality, motion-free chest CT images in children.     

Is procedural sedation with propofol acceptable for complex imaging? A comparison of short vs. prolonged sedations in children

Background

Concerns exist in the community of non-anesthesiologist sedation providers regarding the appropriateness of prolonged sedations using propofol for outpatient procedures.

Objective

To investigate interventions required, completion rate and resource use in prolonged vs. short sedations using propofol in outpatients.

Materials and methods

We reviewed retrospectively 213 children sedated with propofol by a non-anesthesiologist sedation service. Cohorts were composed a priori of children sedated for ≥1 h and <1 h. Comparisons were made regarding need for interventions, sedation duration, sedation completion to discharge time, and procedural completion rate.

Results

Most sedations were for MRI (87.5% short vs. 94.5% prolonged) with no statistically significant difference in overall need for interventions (75.2% prolonged vs. 65.4% short) nor completion to discharge times (30.7?±?11.5 min [prolonged] vs. 30.3?±?11.7 min [short]) between both groups. One child failed to complete the intended scan. No one required endotracheal intubation or unplanned admission.

Conclusion

Prolonged outpatient sedations with propofol conducted by appropriately trained non-anesthesiology sedation providers appears effective for imaging procedures with no increase in interventions or increased resource burden compared to short sedations. This information can assist all stakeholders in determining scope of practice and guidelines for moderately longer pediatric sedations with propofol.     

Comparison of sedation regimens for pediatric outpatient CT

The purpose of this study was to compare the concurrent use of chloral hydrate (CH), intramuscular Nembutal (IMN) and intravenous Nembutal (IVN) for sedation. Data was collected on all pediatric outpatients requiring sedation for CT over a 2.5-year period. During this period, 2178 outpatients required sedation of whom, 1324 (60.8%) received IMN, 710 (32.6%) IVN and 110 (5%) CH. The overall success rate was 97% and was similar in all three groups. IVN however, produced betterquality sedation than IMN or CH. The IVN group received a significantly lower dose of Nembutal than the IMN group (p=0.001). Patients receiving IVN had a significantly lower induction time (p=0.0001) and total examination time (p=0.001) than IMN or CH. There was an increased occurrence of desaturation in patients sedated with IVN, especially in those with airway obstruction. IVN sedation permits faster, more efficient and better-quality sedation for outpatient CT scanning than IMN or CH in patients requiring intravenous contrast but may not be appropriate for departments that perform relatively few sedations or lack proper resuscitation facilities.     

Reduced need for sedation in patients undergoing helical CT of the chest and abdomen

Since 15 July 1993, we have used helical CT exclusively in chest and abdomen exams. The purpose of this study was to compare sedation rates in children undergoing conventional and helical CT of the chest and abdomen. Data for all CT examinations of the head (n=1121), chest (n=427), and abdomen (n=315) performed between 1 April 1993 and 31 October 1993 were evaluated. Examinations were divided by anatomic site, patient age, date, whether motion was noted in the radiology report, and whether or not sedation was used. The oldest patient requiring sedation was 5 years old. All examinations in patients 5 years old or less (n=1048) formed the study group. Because no head CT examinations were done helically, this constituted a control group. Comparisons of motion and sedation rates before and after 15 July 1993 were made with the ² test. There was no statistically significant difference in the sedation rate in the control group (patients having conventional head CT examinations). In contrast, the use of helical technique for chest and abdomen CT coincided with a reduction of the sedation rate from 18% to 10% (P=0.3). There was no statistically significant difference in reported motion for either head or chest/abdomen examinations over the study period. The implementation of helical CT coincided with a 45% reduction in the sedation rate of patients undergoing CT of the chest and abdomen. At the current volume of CT examinations at our institution, this decrease would result in an estimated 60 fewer sedations per year.     

Initial experience with intravenous pentobarbital sedation for children undergoing MRI at a tertiary care pediatric hospital: the learning curve

Objective. Our purpose is to describe the initial experience with intravenous pentobarbital sedation in children undergoing MRI at a tertiary pediatric hospital to identify errors associated with inexperience.¶Subjects and methods. The study included the first 100 children sedated with intravenous pentobarbital prior to magnetic resonance examination at a tertiary pediatric hospital. The protocol included a maximum dose of 6 mg/kg administered in three divided doses with the total dose not to exceed 200 mg. Flow sheets documenting vital signs, administered drug doses, and adverse reactions were maintained contemporaneous to sedation.¶Results. Sedation was successful in 92 children. Of the eight children who failed sedation, three were at least 12 years old and three weighed more than 50 kg. χ ² tests identified significantly greater failure rates in children older than 11 years or weight greater than 50 kg. Two children had prolonged sedation after the maximum suggested dose was exceeded.¶Conclusions. The success rate was good, but could have been improved by restricting the use of pentobarbital to children less than 12 years of age and weighing less than 50 kg. Radiologists inexperienced with intravenous sedation should strictly observe the maximum suggested dose of pentobarbital to prevent prolonged sedation.     

Moderate sedation for MRI in young children with autism

Autism is a pervasive neurodevelopmental disorder. Because of the deficits associated with the condition, sedation of children with autism has been considered more challenging than sedation of other children. Objective: To test this hypothesis, we compared children with autism against clinical controls to determine differences in requirements for moderate sedation for MRI. Materials and methods: Children ages 18–36 months with autism (group 1, n = 41) and children with no autistic behavior (group 2, n = 42) were sedated with a combination of pentobarbital and fentanyl per sedation service protocol. The sedation nurse was consistent for all patients, and all were sedated to achieve a Modified Ramsay Score of 4. Demographics and doses of sedatives were recorded and compared. Results: There were no sedation failures in either group. Children in group 1 (autism) were significantly older than group 2 (32.02±3.6 months vs 28.16±6.7 months) and weighed significantly more (14.87±2.1 kg vs 13.42±2.2 kg). When compared on a per-kilogram basis, however, group 1 had a significantly lower fentanyl requirement than group 2 (1.25±0.55 mcg/kg vs 1.57±0.81 mcg/kg), but no significant difference was found in pentobarbital dosing between groups 1 and 2, respectively (4.92±0.92 mg/kg vs 5.21±1.6 mg/kg). Conclusion: Autistic children in this age range are not more difficult to sedate and do not require higher doses of sedative agents for noninvasive imaging studies.     

A survey of post-discharge side effects of conscious sedation using chloral hydrate in pediatric CT and MR imaging

Background. Limited information is available on post-discharge side effects of chloral hydrate sedation in pediatric imaging. Objective. To prospectively study the post-discharge side effects of chloral hydrate sedation in pediatric CT and MR imaging. Materials and methods. A total of 119 children undergoing CT and MRI were sedated using chloral hydrate with 89 % success (mean initial dose, 72 mg/kg body weight) and 98 % success after augmentation (mean total, 78 mg/kg body weight). The frequency of each post-discharge side effect was correlated with other side effects and 12 patient/technical parameters. Results. The survey was completed in 80 children. Sleepiness lasted for > 4 h in 28 %. Unsteadiness occurred in 68 % and hyperactivity in 29 %. Appetite became poor in 14 % and vomiting occurred in 15 %. Normal activity was resumed after > 4 h in 54 %. Sleep deprivation did not result in increased success or earlier onset of sedation and might be associated with hyperactivity. A higher dose did not result in an increased success rate or earlier onset of sedation within the dose range used in this study. Conclusion. Data on the post-discharge side effects of chloral hydrate sedation will be useful to radiologists, technologists, and nurses explaining to parents about sedation using this agent. Received: 18 June 1998 Accepted: 5 November 1998     

Sedation for pediatric radiological procedures: analysis of potential causes of sedation failure and paradoxical reactions

Background. Sedation for diagnostic imaging and interventional radiologic procedures in pediatrics has greatly increased over the past decade. With appropriate patient selection and monitoring, serious adverse effects are infrequent, but failure to sedate and paradoxical reactions do occur. Objective. The purpose of this study was to determine, among patients undergoing sedation for radiologic procedures, the incidence of sedation failure and paradoxical reaction to pentobarbital and to identify potentially correctable causes. Materials and methods. Records of 1665 patients who were sedated in the radiology department from 1 November 1997 to 1 July 1998 were reviewed. Patients failing sedation or experiencing paradoxical reaction were compared with respect to sex, age group, diagnosis, scan type, time of day, NPO status, use of IV contrast and type of sedation agent using the Fisher exact test, Pearson chi-square, analysis of variance (ANOVA), the Student t-test, and logistic regression. Results. Data analysis revealed a sedation failure rate of 1 % and paradoxical reaction rate of 1.2 %. Stepwise multiple logistic regression revealed that the only significant independent multivariate predictor of failure was the need for the administration of a combination of pentobarbital, fentanyl, and midazolam IV. Conclusion. The low rate of sedation failure and paradoxical reactions to pentobarbital was near optimal and probably cannot be improved with the currently available sedatives. Received: 8 March 1999 Accepted: 21 May 1999     

Sedation and anesthesia issues in pediatric imaging

Sedation and anesthesia for pediatric imaging departments has changed dramatically for the following reasons: (1) radiologists have stopped sedating patients; (2) the majority of sedations are not for CT (because of the speed of the procedure) but for MR, which lasts 45 min or greater; (3) a cadre of services--pediatricians, emergency medicine physicians, hospitalists and intensivists, as well as anesthesiologists--can provide the services. These changes have significantly influenced the type of agents utilized for sedation and anesthesia and, most important, have created operational issues for MR departments. Nevertheless, it is important for each imaging department to create a uniform approach to sedation, taking into account patient expectations, efficiency of through-put, facilities and personnel available, and institutional costs.     

Inter- and intra-observer variability in the assessment of atelectasis and consolidation in neonatal chest radiographs

Background. Radiology is an essential part of neonatal intensive care. Interpretation of chest radiographs frequently contributes to respiratory management of neonates, but there has been little assessment of the consistency of this interpretation. Objective. To assess the inter- and intra-observer variability for the reporting of atelectasis and/or consolidation in neonatal chest radiographs. Materials and methods. A total of 585 chest radiographs from the 220 babies ventilated in our nursery over a 2-year period were coded by two radiologists for generalised, lobar and segmental atelectasis and/or consolidation. Two months later one of the radiologists re-coded a random sample of these films (n = 117, 20 %). Agreement was assessed by the kappa statistic and by proportions of agreement for normality and abnormality. Results. The reported incidence of focal atelectasis was low (5–6 %). Focal changes of any nature were found in 21–26 % of films. Inter-observer agreement was fair to moderate (kappa = 0.25–0.44). Intra-observer agreement was mostly moderate to good (kappa = 0.38–0.66). Conclusion. The poor inter-observer agreement for the diagnosis of pulmonary parenchymal abnormalities on chest radiographs of neonates receiving intensive care suggests that abnormalities should be described rather than diagnoses given or that a list of differential diagnoses be offered. When research involves radiographic interpretation, the potential lack of consistency in reporting abnormalities must be borne in mind. Received: 20 July 1998 Accepted: 30 November 1998     

Efficacy and safety of deep sedation by non-anesthesiologists for cardiac MRI in children

Background

Cardiac MRI has become widespread to characterize cardiac lesions in children. No study has examined the role of deep sedation performed by non-anesthesiologists for this investigation.

Objective

We hypothesized that deep sedation provided by non-anesthesiologists can be provided with a similar safety and efficacy profile to general anesthesia provided by anesthesiologists.

Materials and methods

This is a retrospective chart review of children who underwent cardiac MRI over a 5-year period. The following data were collected from the medical records: demographic data, cardiac lesion, American Society of Anesthesiologists (ASA) physical status, sedation type, provider, medications, sedation duration and adverse events or interventions. Image and sedation adequacy were recorded.

Results

Of 1,465 studies identified, 1,197 met inclusion criteria; 43 studies (3.6%) used general anesthesia, 506 (42.3%) had deep sedation and eight (0.7%) required anxiolysis only. The remaining 640 studies (53.5%) were performed without sedation. There were two complications in the general anesthesia group (4.7%) versus 17 in the deep sedation group (3.4%). Sedation was considered inadequate in 22 of the 506 deep sedation patients (4.3%). Adequate images were obtained in 95.3% of general anesthesia patients versus 86.6% of deep sedation patients.

Conclusion

There was no difference in the incidence of adverse events or cardiac MRI image adequacy for children receiving general anesthesia by anesthesiologists versus deep sedation by non-anesthesiologists. In summary, this study demonstrates that an appropriately trained sedation provider can provide deep sedation for cardiac MRI without the need for general anesthesia in selected cases.     

Three-dimensional computed tomography for detection of tracheobronchial foreign body aspiration in children

Foreign body aspiration (FBA) into the tracheobronchial tree is a frequent and serious cause of respiratory problems in children. Chest X-ray (CXR) is often inaccurate in diagnosing FBA when the object is radiolucent. Three-dimensional computed tomography (CT) is a noninvasive technique that can detect the narrowing of the airway resulting from the presence of a foreign body. We conducted a retrospective study comparing the performance of CT scan and CXR in the diagnosis of FBA. Eleven patients (mean age 2.1 years) with a history suggestive of foreign body aspiration were examined by three-dimensional chest CT and CXR during the study. The presence of foreign bodies was confirmed and they were removed by rigid or flexible bronchoscopy under general anesthesia. Foreign body aspiration (FBA) was detected in all the 11 patients by CT scan (sensitivity, 100%), but CXR of three of the patients showed no evidence of FBA (sensitivity, 72.7%). The foreign bodies were located in the right main bronchus (n = 4), the left main bronchus (n = 5), and the trachea (n = 2). The mean length of hospital stay was 3.8 days. In our study, three-dimensional chest CT scan was more sensitive than CXR in detecting the presence of aspirated foreign bodies in children. The superior sensitivity and short time required for CT should help to reduce delays in diagnosis. These benefits may prompt further studies to determine whether CT could be used to reduce the number of unnecessary bronchoscopies performed in children being evaluated for FBA.     

Pulmonary nodular opacities in children with hereditary hemorrhagic telangiectasia

Background Hereditary hemorrhagic telangiectasia (HHT) is a rare inherited disorder of vascular endothelium that can result in the formation of pulmonary arteriovenous malformations (pAVMs). We observed that small pulmonary nodules, possibly representing early vascular malformations, are more common in these children than in the general population. Objective To describe and characterize the small pulmonary nodules seen on chest CT examination in the lungs of children with HHT. Materials and methods We followed 19 children who had undergone chest CT as part of their initial diagnostic evaluation in the HHT clinic of a pediatric hospital. Chest CT scans were reviewed independently by two radiologists blinded to clinical data. Pulmonary nodules were analyzed according to lobar distribution, anatomic position in the lung (outer, mid, inner third), shape (round, linear, V- or Y-shaped, ill-defined), presence of overt AVMs, and nodule size (≤ or >5 mm). We also reviewed a control group of chest CT scans performed on 25 age-matched children. Results A total of 35 pulmonary nodules were identified on the CT scans in 15 of the 19 children. Multiple nodules were seen in eight children (42%), solitary nodules were seen in seven children (37%) and no nodules were seen in the remaining four children (21%). The nodules were found to be nonspecific with regard to multiple factors other than their anatomic position within the lung. The chest CT scans of 2 of the 25 age-matched controls revealed a total of only four nodules, a significantly lower total (P = 0.0001 vs. children with HHT). Conclusion Nonspecific nodules are commonly seen in children with HHT.     

Correlation of clinical and chest radiograph findings in pediatric submersion cases

Background

Submersion injuries are a leading cause of injury death in children in the United States. The clinical course of a submersion patient varies depending on the presence of anoxic brain injury and acute respiratory failure.

Objective

We studied changes in clinical findings and chest radiograph findings and determined the sensitivity/specificity of the presenting chest radiograph in predicting clinical improvement within the first 24 h in pediatric submersion cases.

Materials and methods

We conducted a cross-sectional study of pediatric submersion patients through age 18 years treated at a children’s hospital from 2010 to 2013. We reviewed demographics, comorbidities, prehospital/hospital course and chest radiographic findings. Clinical improvement occurred when a child demonstrated normal vital signs and mentation. We compared radiographic findings among children based on clinical improvement up to 24 h post submersion. Using odds ratios, we calculated associations between radiographic findings and clinical improvement. We studied the sensitivity/specificity of the presenting chest radiograph in predicting clinical improvement within 24 h.

Results

One hundred forty-two of 262 (54%) patients had initial chest radiographs; 41% had follow-up radiographs. The odds of an abnormal initial chest radiograph were 4 times higher in children with respiratory distress or abnormal mentation at emergency department (ED) presentation compared to children without these findings (odds ratio [OR]=4.83; 95% confidence interval [CI]=2.1–10.85; P<0.001). Improvement in radiographic findings occurred in 85% of children within 24 h. Children with an abnormal initial chest radiograph were 87% less likely to improve clinically by 24 h (P<0.001). A presenting chest radiograph that was normal or with mild pulmonary edema/atelectasis predicted clinical improvement within 24 h (sensitivity 95%, specificity 57%).

Conclusion

Most chest radiographic findings improve in pediatric submersion patients who recover within the first 24 h. An initial chest radiograph that is normal or with mild pulmonary edema/atelectasis satisfactorily predicts clinical improvement by 24 h post submersion.

     

Atelectasis: mechanisms,diagnosis and management

The term atelectasis describes a state of collapsed and non-aerated region of the lung parenchyma, which is otherwise normal. This pathological condition is usually associated with several pulmonary and chest disorders and represents a manifestation of the underlying disease, not a disease per se. Atelectasis may occur in three ways: (i) airway obstruction; (ii) compression of parenchyma by extrathoracic, intrathoracic, chest wall processes; and (iii) increased surface tension in alveoli and bronchioli. Chest radiographs using both the anterior-posterior and lateral projections are mandatory to document the presence of atelectasis. Differentiation from lobar consolidation may be a clinical dilemma. The treatment of atelectasis varies depending on duration and severity of the causal disease from chest physiotherapy to postural drainage, bronchodilator and anti-inflammatory therapy. Persistent mucous plugs should be removed by bronchoscopy.     

Chest radiographic features of thoracic metastatic disease in adolescents with colon cancer

This study describes chest radiographic features of thoracic metastatic disease (TMD) in patients referred for colon cancer to a pediatric oncology hospital. The study group was comprised of 9 patients (7 males, 2 females, age 13–19 years) with serial chest radiographs demonstrating TMD from colon cancer. All patients had a chest radiograph performed within the 2 months prior to death. The median interval from diagnosis of colon cancer to appearance of radiographic TMD was 3 months. Four of nine patients had TMD at presentation, eight of nine patients within 2 years of diagnosis. All abnormalities progressed on serial radiographs. The median interval from appearance of radiographic abnormalities to death was 2 months. Radiographic findings included pleural effusions (n=6), lymphadenopathy (n=5), lymphangitic carcinomatosis (n=4), solitary pulmonary nodule (n=2), and lobar atelectasis (n=1). Five patients with pleural effusions initially had right-sided effusions. Radiographic TMD in adolescents with colon cancer usually occurs within 2 years of diagnosis. Once TMD manifests, the prognosis is dismal. Findings include pleural effusions, lymphadenopathy, lymphangitic carcinomatosis, solitary pulmonary nodules, and lobar atelectasis. We suggest that metastatic colon carcinoma should be included in the differential diagnosis for lymphangitic spread of tumor in adolescents.Supported in part by National Cancer Institute Cancer Center Support (Core) grant P30CA21765, CA 23099, and by the American Lebanese Syrian Associated Charities (ALSAC)     

Sedation with nitrous oxide compared with no sedation during catheterization for urologic imaging in children

Background Various strategies to mitigate children’s distress during voiding cystourethrography (VCUG) have been described. Sedation with nitrous oxide is comparable to that with oral midazolam for VCUG, but a side-by-side comparison of nitrous oxide sedation and routine care is lacking. Objective The effects of sedation/analgesia using 70% nitrous oxide and routine care for VCUG and radionuclide cystography (RNC) were compared. Materials and methods A sample of 204 children 4–18 years of age scheduled for VCUG or RNC with sedation or routine care were enrolled in this prospective study. Nitrous oxide/oxygen (70%/30%) was administered during urethral catheterization to children in the sedated group. The outcomes recorded included observed distress using the Brief Behavioral Distress Score, self-reported pain, and time in department. Results The study included 204 patients (99 nonsedated, 105 sedated) with a median age of 6.3 years (range 4.0–15.2 years). Distress and pain scores were greater in nonsedated than in sedated patients (P < 0.001). Time in department was longer in the sedated group (90 min vs. 30 min); however, time from entry to catheterization in a non-imaging area accounted for most of the difference. There was no difference in radiologic imaging time. Conclusion Sedation with nitrous oxide is effective in reducing distress and pain during catheterization for VCUG or RNC in children.     

Detection of pulmonary metastases with pathological correlation: effect of breathing on the accuracy of spiral CT

Background. CT of the chest for suspected pulmonary metastases in adults is generally performed using a breath-hold technique. The results may not be applicable to young children in whom breath-holding may be impossible. Objective. Determine the effect of breathing on the accuracy of pulmonary metastasis detection by spiral CT (SCT). Materials and methods. Prior to euthanasia four anesthetized dogs with metastatic osteosarcoma underwent SCT with a collimation of 5 mm and a pitch of 2, during both induced breath-hold and normal quiet breathing. Images were reconstructed as contiguous 5-mm slices. Macroscopically evident metastases were noted at postmortem. Hard-copy SCT images were reviewed by ten radiologists, each of whom circled all suspected metastases. SCT images were compared with postmortem results to determine true and false positives. Results. The pathologist identified 132 macroscopically evident pulmonary metastases. For metastasis detection, there was no significant difference between breath-hold SCT and breathing SCT. Conclusion. In our animal model, SCT can be performed during normal resting breathing without significant loss of accuracy in the detection of pulmonary metastases. Received: 18 December 1996 Accepted: 19 February 1997