Phrenic nerve stimulation at the bedside in children; equipment and validation

Russell, R. I. Ross; Helps, B A; Elliot, Martin; Helms, Peter Joseph Benedict

doi:10.1183/09031936.93.06091332

Cited by 11 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, unlike fluoroscopy, the study of normal controls is ethically practical, and the technique has been extensively studied in adults [19][20][21], and children [22,23]. We used a threshold value of 2 ms as the increase in latency above which we identified electrophysiological damage based on intra-patient variability [16,17]. We have reported on the clinical effects of phrenic nerve damage in children undergoing cardiac surgery, and using this threshold, have demonstrated a significant increase in respiratory morbidity in children so identified [24].…”

Section: Discussionmentioning

confidence: 99%

“…Ptu-t:mc nerve conduction time was measured 24 h preop.eratlvely, ~d between 24 and 48 h postoperatively, usmg a techmque that we have described previously [16,17], and based on original work by SARNOFF et al (18] and NEWSOM DAVJS [19]. Briefly, the phrenic nerve is stimulated in the neck, and the resultant diaphragm compound muscle action potential (CMAP) recorded with surface electrodes on the chest wall.…”

Section: Study Populationmentioning

confidence: 99%

“…Amplification of the s~gnal and its display on a time-based oscilloscope perm1ts measurement of the nerve's latency as the time between stimulus and CMAP [19]. Electrophysiological PND (PNDe) was defined as an increase of more than ~ ms in the latency, when compared with its preopera-tJve value [ 17], as we have evidence that this size of increase is more than double the expected measurement error [16].…”

Section: Study Populationmentioning

confidence: 99%

“…The intra-and inter-observer error variability in chest X-ray reporting was separately assessed in 32 X-rays from the same population. These included preoperative and postoperative films from 16 patients, 8 with normal electrophysiological phrenic nerve function, and 8 with PNDe. Two radiologists reviewed the films independently and in random order, and were presented with the same films again, in a different order, the following day.…”

Section: Those Without Evidence Of Either ("Normal")mentioning

confidence: 99%

“…Chest radiography alone is prone to many interpretation errors, due to factors such as positive pressure ven-Direct measurement of phrenic nerve function offers advantages over existing methods of diagnosing diaphragm injury. It is an objective measure, with high repeatability in adults, and we have recently assessed its interand intra-observer variability in children [16]. It is also noninvasive and well-tolerated, and can be used as early as 24 h following surgery [ 17].…”

mentioning

confidence: 99%

See 4 more Smart Citations

Early assessment of diaphragmatic dysfunction in children in the ITU: chest radiology and phrenic nerve stimulation

Russell¹,

Helps²,

Dicks‐Mireaux³

et al. 1993

Eur Respir J

View full text Add to dashboard Cite

Diaphragmatic dysfunction is a common postoperative complication of cardiac surgery in children, with important effects on respiratory morbidity. Its early diagnosis, followed by prompt surgical intervention, has been shown to reduce morbidity. However, the commonest method of diagnosis, based on hemi-diaphragmatic elevation on the chest radiograph, may be less accurate than direct techniques for assessing phrenic nerve function. We have compared electrophysiological and radiological diagnoses of diaphragmatic abnormality in 100 children (aged 3 days to 17.5 yrs) undergoing cardiac surgery, looking at respiratory morbidity as assessed by the duration of ventilation, the time spent on the cardiac intensive care unit (CICU), and the requirement for reintubation. Despite showing good reproducibility, radiological diagnosis was neither sensitive nor specific in identifying patients with electrophysiological phrenic nerve damage. Analysis of the measures of outcome supported the electrophysiological technique. Patients with electrophysiological evidence of damage had a longer duration of ventilation, spent longer on the CICU, and had a greater incidence of reintubation than either radiologically abnormal or "normal" patients. Chest X-rays are not a good method for diagnosing phrenic nerve damage in the early postoperative period in children. If early diagnosis is needed, then direct assessment of phrenic nerve function, such as the measurement of phrenic latency, may be a better technique.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Study Populationmentioning

confidence: 99%

Section: Study Populationmentioning

confidence: 99%

Section: Those Without Evidence Of Either ("Normal")mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Early assessment of diaphragmatic dysfunction in children in the ITU: chest radiology and phrenic nerve stimulation

Russell¹,

Helps²,

Dicks‐Mireaux³

et al. 1993

Eur Respir J

View full text Add to dashboard Cite

show abstract

Normal values for phrenic nerve latency in children

Russell¹,

Helps²,

Helms³

2001

Muscle and Nerve

View full text Add to dashboard Cite

Data derived from detailed studies of normal phrenic nerve latency in a large group of children are presented. They highlight the major differences between the three previously published studies of normal children. Phrenic nerve latency shows a curvilinear relationship with age, averaging 6.0 ms at 0-6 months, falling to 4.8 ms between 1 and 2 years, then rising to 6.3 ms between 10 and 18 years of age. These data represent the largest published study on normal phrenic nerve latency in children.

show abstract

Twitch airway pressure elicited by magnetic phrenic nerve stimulation in anesthetized healthy children

Rafferty¹,

Mustfa

Man

et al. 2005

Pediatric Pulmonology

View full text Add to dashboard Cite

Children with diaphragm dysfunction may be unable to maintain adequate ventilation. Accurate diagnosis is important, but can only be achieved using an appropriate test and reference range. The aim of this study, therefore, was to measure diaphragm contractility and examine the influence of age and maturation, using magnetic phrenic nerve stimulation in healthy children. Anterolateral magnetic stimulation (MS) of the phrenic nerves was performed using a 43-mm figure-eight coil in 23 children (14 male; mean age, 7.8 years; range, 1.8-15.7) anesthetized for minor surgery with sevoflurane gas. The airway was maintained with a cuffed laryngeal mask airway (LMA) which was briefly occluded during MS. Diaphragm contractility was assessed by measuring the airway pressure (TwPaw) elicited by MS. TwPaw responses were obtained in all subjects, with mean (SD) TwPaw 18.2 (6.8) cm H2O bilateral, 7.3 (3.2) cm H2O left unilateral, and 8.6 (3.1) cm H2O right unilateral. Subgroup analysis was performed in 17 of the children who were prepubertal. Their mean (SD) TwPaw was 17.3 (6.8) cm H2O bilateral, 7.1 (3.7) cm H2O left unilateral, and 8.3 (3.3) right unilateral. The mean (SD) intrapatient coefficients of variation for bilateral and left and right unilateral TwPaw were 8.4% (5.2), 6.7% (3.5), and 11.7% (10.3), respectively. Bilateral and left and right unilateral TwPaw were significantly related to age (P < 0.05). In healthy prepubertal children, diaphragm contractility is primarily influenced by age.

show abstract

Phrenic nerve stimulation at the bedside in children; equipment and validation

Cited by 11 publications

References 20 publications

Early assessment of diaphragmatic dysfunction in children in the ITU: chest radiology and phrenic nerve stimulation

Early assessment of diaphragmatic dysfunction in children in the ITU: chest radiology and phrenic nerve stimulation

Normal values for phrenic nerve latency in children

Twitch airway pressure elicited by magnetic phrenic nerve stimulation in anesthetized healthy children

Contact Info

Product

Resources

About