Myofunctional therapy (oropharyngeal exercises) for obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) is a syndrome characterised by episodes of apnoea (complete cessation of breathing) or hypopnoea (insufficient breathing) during sleep. Classical symptoms of the disease - such as snoring, unsatisfactory rest and daytime sleepiness - are experienced mainly by men; women report more unspecific symptoms such as low energy or fatigue, tiredness, initial insomnia and morning headaches. OSA is associated with an increased risk of occupational injuries, metabolic diseases, cardiovascular diseases, mortality, and being involved in traffic accidents. Continuous positive airway pressure (CPAP) - delivered by a machine which uses a hose and mask or nosepiece to deliver constant and steady air pressure- is considered the first treatment option for most people with OSA. However, adherence to treatment is often suboptimal. Myofunctional therapy could be an alternative for many patients. Myofunctional therapy consists of combinations of oropharyngeal exercises - i.e. mouth and throat exercises. These combinations typically include both isotonic and isometric exercises involving several muscles and areas of the mouth, pharynx and upper respiratory tract, to work on functions such as speaking, breathing, blowing, sucking, chewing and swallowing. OBJECTIVES: To evaluate the benefits and harms of myofunctional therapy (oropharyngeal exercises) for the treatment of obstructive sleep apnoea. SEARCH METHODS: We identified randomised controlled trials (RCTs) from the Cochrane Airways Trials Register (date of last search 1 May 2020). We found other trials at web-based clinical trials registers. SELECTION CRITERIA: We included RCTs that recruited adults and children with a diagnosis of OSA. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. We assessed our confidence in the evidence by using GRADE recommendations. Primary outcomes were daytime sleepiness, morbidity and mortality. MAIN RESULTS: We found nine studies eligible for inclusion in this review and nine ongoing studies. The nine included RCTs analysed a total of 347 participants, 69 of them women and 13 children. The adults' mean ages ranged from 46 to 51, daytime sleepiness scores from eight to 14, and severity of the condition from mild to severe OSA. The studies' duration ranged from two to four months. None of the studies assessed accidents, cardiovascular diseases or mortality outcomes. We sought data about adverse events, but none of the included studies reported these. In adults, compared to sham therapy, myofunctional therapy: probably reduces daytime sleepiness (Epworth Sleepiness Scale (ESS), MD (mean difference) -4.52 points, 95% Confidence Interval (CI) -6.67 to -2.36; two studies, 82 participants; moderate-certainty evidence); may increase sleep quality (MD -3.90 points, 95% CI -6.31 to -1.49; one study, 31 participants; low-certainty evidence); may result in a large reduction in Apnoea-Hypopnoea Index (AHI, MD -13.20 points, 95% CI -18.48 to -7.93; two studies, 82 participants; low-certainty evidence); may have little to no effect in reduction of snoring frequency but the evidence is very uncertain (Standardised Mean Difference (SMD) -0.53 points, 95% CI -1.03 to -0.03; two studies, 67 participants; very low-certainty evidence); and probably reduces subjective snoring intensity slightly (MD -1.9 points, 95% CI -3.69 to -0.11 one study, 51 participants; moderate-certainty evidence). Compared to waiting list, myofunctional therapy may: reduce daytime sleepiness (ESS, change from baseline MD -3.00 points, 95% CI -5.47 to -0.53; one study, 25 participants; low-certainty evidence); result in little to no difference in sleep quality (MD -0.70 points, 95% CI -2.01 to 0.61; one study, 25 participants; low-certainty evidence); and reduce AHI (MD -6.20 points, 95% CI -11.94 to -0.46; one study, 25 participants; low-certainty evidence). Compared to CPAP, myofunctional therapy may result in little to no difference in daytime sleepiness (MD 0.30 points, 95% CI -1.65 to 2.25; one study, 54 participants; low-certainty evidence); and may increase AHI (MD 9.60 points, 95% CI 2.46 to 16.74; one study, 54 participants; low-certainty evidence). Compared to CPAP plus myofunctional therapy, myofunctional therapy alone may result in little to no difference in daytime sleepiness (MD 0.20 points, 95% CI -2.56 to 2.96; one study, 49 participants; low-certainty evidence) and may increase AHI (MD 10.50 points, 95% CI 3.43 to 17.57; one study, 49 participants; low-certainty evidence). Compared to respiratory exercises plus nasal dilator strip, myofunctional therapy may result in little to no difference in daytime sleepiness (MD 0.20 points, 95% CI -2.46 to 2.86; one study, 58 participants; low-certainty evidence); probably increases sleep quality slightly (-1.94 points, 95% CI -3.17 to -0.72; two studies, 97 participants; moderate-certainty evidence); and may result in little to no difference in AHI (MD -3.80 points, 95% CI -9.05 to 1.45; one study, 58 participants; low-certainty evidence). Compared to standard medical treatment, myofunctional therapy may reduce daytime sleepiness (MD -6.40 points, 95% CI -9.82 to -2.98; one study, 26 participants; low-certainty evidence) and may increase sleep quality (MD -3.10 points, 95% CI -5.12 to -1.08; one study, 26 participants; low-certainty evidence). In children, compared to nasal washing alone, myofunctional therapy and nasal washing may result in little to no difference in AHI (MD 3.00, 95% CI -0.26 to 6.26; one study, 13 participants; low-certainty evidence). AUTHORS' CONCLUSIONS: Compared to sham therapy, myofunctional therapy probably reduces daytime sleepiness and may increase sleep quality in the short term. The certainty of the evidence for all comparisons ranges from moderate to very low, mainly due to lack of blinding of the assessors of subjective outcomes, incomplete outcome data and imprecision. More studies are needed. In future studies, outcome assessors should be blinded. New trials should recruit more participants, including more women and children, and have longer treatment and follow-up periods.

Impact of the odors of vanilla extract and breast milk on the frequency of apnea in preterm neonates.

AIM: We developed this study using an experimental design to determine the impact of the odors of vanilla extract and breast milk on apnea frequency in preterm neonates. MATERIALS AND METHODS: We obtained the study data from 42 preterm neonates (16 vanilla, 13 breast milk, 13 control group) who had been admitted to the Neonatal Intensive Care Unit of Istanbul University meeting the case selection criteria. All groups were monitored on the first day without any intervention. On the second and third days, breast milk was placed in the incubators of the babies in the breast milk group and the sterile gauze that was vanilla-impregnated was placed in the incubators of the babies in the vanilla group. On the fourth day, the babies were watched without any interference. RESULTS: On the second, third and fourth days of the study, we determined that apnea frequency in the vanilla group neonates was significantly lower (P < .00) as compared to the breast milk and control groups. CONCLUSION: Using vanilla extract in neonates suffering from apnea to reduce its frequency is an effective method.

Ambiguous Genitalia Associated with an Extremely Rare Syndrome: A Case Report of XLAG Syndrome and Review of the Literature.

X-linked lissencephaly, absent corpus callosum, and epilepsy of neonatal onset with ambiguous genitalia comprises the XLAG syndrome and only 15 cases have been reported in literature. Due to its rarity, the exact clinical course and outcome are not known. Exact associations of this disease are also elusive. Hereby we are reporting this extremely rare entity and we searched the English literature extensively to get consolidated knowledge regarding this entity that would help the readers. Pre-natal radiological work-up can detect these malformations, which should be followed by medical termination, counseling and karyotyping. Till date the longest survival noted was 4 years only.

Breath-Holding Spells in Pediatrics: A Narrative Review of the Current Evidence.

BACKGROUND: Breath-holding spells are common, frightening, but fortunately benign events. Familiarity with this condition is important so that an accurate diagnosis can be made. OBJECTIVE: To familiarize physicians with the clinical manifestations, diagnosis, evaluation, and management of children with breath-holding spells. METHODS: A PubMed search was completed in Clinical Queries using the key term "breath-holding spells". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article. RESULTS: Breath-holding spells affect 0.1 to 4.6% of otherwise healthy young children. The onset is usually between 6 and 18 months of age. The etiopathogenesis is likely multifactorial and includes autonomic nervous system dysregulation, vagally-mediated cardiac inhibition, delayed myelination of the brain stem, and iron deficiency anemia. Breath-holding spells may be cyanotic or pallid. The former are usually precipitated by anger or frustration while the latter are more often precipitated by pain or fear. In the cyanotic type, the child usually emits a short, loud cry, which leads to a sudden involuntary holding of the breath in forced expiration. The child becomes cyanosed, rigid or limp, followed by a transient loss of consciousness, and a long-awaited inspiration and resolution of the spell. In the pallid type, crying may be minimal or "silent". The apneic period in the pallid type is briefer than that in the cyanotic type prior to the loss of consciousness and posture. The episode in the pallid type then proceeds in the same manner as a cyanotic spell except that the child in the pallid type develops pallor rather than cyanosis. In both types, the entire episode lasts approximately 10 to 60 seconds. The spells usually disappear spontaneously by 5 years of age. CONCLUSION: Although breath-holding spells are benign, they can be quite distressing to the parents. Confident reassurance and frank explanation are the cornerstones of treatment. Underlying cause, if present, should be treated. Interventions beyond iron supplementation may be considered for children with severe and frequent breath-holding spells which have a strong impact on the lifestyle of both the child and family.

A pilot study of limb stimulation for the treatment of neonatal apnea.

This study explored the feasibility effect and safety of the limb stimulation (LS) for the treatment of neonatal apnea (NAP).The cases of 30 eligible premature infants with NAP were included in this retrospective study. These cases were equally divided into an intervention group (n = 15) and a control group (n = 15). The infants in both groups received caffeine treatment. Moreover, cases in the intervention group also received LS for a total 30 hours, while the subjects in the control group did not receive LS during this period. The primary outcome included apnea frequency (number of episodes per 24 hours), and apnea rate. The secondary outcomes consisted of desaturation (number of episodes per 24 hours), and heart rate (beats per minute). Additionally, adverse events were also documented during the treatment period.After treatment, LS did not show better outcomes in apnea frequency (P = .48), apnea rate (P = .33), desaturation (P = .55), and heart rate (P = .41). Furthermore, no significant differences of all adverse events were found between 2 groups.The results of this pilot study demonstrated that LS might be not efficacious for premature infants with NAP.

Exposure to biological maternal sounds improves cardiorespiratory regulation in extremely preterm infants.

OBJECTIVE: Preterm infants experience frequent cardiorespiratory events (CREs) including multiple episodes of apnea and bradycardia per day. This physiological instability is due to their immature autonomic nervous system and limited capacity for self-regulation. This study examined whether systematic exposure to maternal sounds can reduce the frequency of CREs in NICU infants. METHODS: Fourteen preterm infants (26-32 weeks gestation) served as their own controls as we measured the frequency of adverse CREs during exposure to either Maternal Sound Stimulation (MSS) or Routine Hospital Sounds (RHS). MSS consisted of maternal voice and heartbeat sounds recorded individually for each infant. MSS was provided four times per 24-h period via a micro audio system installed in the infant's bed. Frequency of adverse CREs was determined based on monitor data and bedside documentation. RESULTS: There was an overall decreasing trend in CREs with age. Lower frequency of CREs was observed during exposure to MSS versus RHS. This effect was significantly evident in infants ≥ 33 weeks gestation (p=0.03), suggesting an effective therapeutic window for MSS when the infant's auditory brain development is most intact. CONCLUSION: This study provides preliminary evidence for short-term improvements in the physiological stability of NICU infants using MSS. Future studies are needed to investigate the potential of this non-pharmacological approach and its clinical relevance to the treatment of apnea of prematurity.

Sir Victor Horsley's contributions to the study and treatment of gunshot wounds of the head.

Sir Victor Horsley'S many contributions to neurological surgery include experimental and clinical studies of gunshot wounds (GSW) of the head. Horsley's publications from 1894 to 1897 and 1914 to 1915 on GSWs were reviewed. Horsley described GSWs in animal and clay models, illustrating characteristics of the primary missile tract and secondary cavitation. A transcranial GSW model in 67 dogs related intracranial damage to the projectile's velocity and sectional area, producing a marked sudden increase in intracranial pressure that presumably "tunneled" to the medullary respiratory and cardiac centers. If the resultant sudden apnea was treated with artificial respiration and prompt surgical decompression, the animal often survived. In these animal experiments, Horsley clearly described increased intracranial pressure, hypertension, and bradycardia-later recognized as the Cushing response or triad. With the onset of World War I, Horsley again reviewed the ballistics of military weaponry, emphasizing projectile spin and velocity as the main wounding mechanisms. He was outspoken against the "wicked tradition" of neglecting cranial GSWs and personally treated cases with aggressive respiratory support and prompt decompression of devitalized tissue. Horsley's contributions to the experimental and clinical aspects of GSWs to the head are consistent with his other important contributions to neurosurgery and have largely stood the test of time.

[Attacks of apnea in a newborn aged 18 days]. / Apnoe-Anfälle bei einem 18 Tage alten Neugeborenen.

Clinical case of an 18-day-old newborn of the 40th + 1 pregnancy week with postpartum respiratory adjustment disorder including periodical decreases in blood oxygen saturation. On day 8 postpartum the newborn developed myoclonic cramps of unknown origin combatted with phenobarbital. 6 days later Cheyne-Stokes breathing began under normal phenobarbital level being the cause for an additional homeopathic therapy trial. After a single dose of opium C 30 the breathing improved significantly, suspending the breaks in breathing and the decreases in blood oxygen saturation.

Role of carnitine supplementation in apnea of prematurity: a systematic review.

OBJECTIVE: To determine the role of carnitine supplementation in premature infants on apnea of prematurity, length of ventilation and duration of hospital stay. METHODS: Two reviewers independently conducted a literature search for relevant studies. No language restrictions were applied. Decisions to include studies for the review, and methodological quality of the included studies were assessed in duplicate based on predetermined criteria. RESULTS: Three studies met the selection criteria (reproducibility-kappa 0.76+/-SE 0.122). One study was later excluded. Both included studies were randomized double-blind placebo control prevention trials among babies <1500 g of weight. There was no difference among the groups for outcomes of bedside nurse recorded frequency of apnea episodes, continuous objective recording of apnea, length of ventilation (WMD -3.24 days, 95% CI -8.39, 1.92) or length of hospital stay (WMD -5.4 days, 95% CI -15.53, 4.72). CONCLUSION: Present evidence does not support the regular use of carnitine for the prevention of apnea of prematurity.

Clinical effects of L-carnitine supplementation on apnea and growth in very low birth weight infants.

OBJECTIVE: Systemic carnitine deficiency may present with apnea, hypotonia, and poor growth. Premature infants often manifest these symptoms and are at risk of developing carnitine deficiency because of immaturity of the biosynthetic pathway, lack of sufficient predelivery transplacental transport, and lack of sufficient exogenous supplementation. This study was undertaken to examine the effect of carnitine supplementation in premature infants. METHODS: Eighty preterm infants <1500 g were enrolled in a prospective, double-blind, placebo-controlled study of carnitine supplementation within 96 hours of delivery. Growth, length of hospital stay, and frequency and severity of apnea were the primary outcome measures. RESULTS: Weight gain and change in length, fronto-occipital head circumference, mid arm circumference, and triceps skinfold thickness were similar between the carnitine-supplemented and placebo groups. The amount and severity of apnea and the overall length of hospitalization were also similar between the 2 groups. The carnitine levels in the supplemented group were significantly higher than in the placebo group at 4 and 8 weeks after study entry. CONCLUSION: Although preterm infants <1500 g have low carnitine levels, routine supplementation with carnitine has no demonstrable effect on growth, apnea, or length of hospitalization and thus seems to be unnecessary.

Role of L-carnitine in apnea of prematurity: a randomized, controlled trial.

OBJECTIVE: Carnitine is thought to be a conditionally essential biological cofactor for premature infants. A preliminary study suggested that carnitine could significantly reduce apnea of prematurity. The objective of this study was to evaluate critically the role of carnitine in idiopathic apnea of prematurity and to determine whether the use of carnitine would facilitate discontinuation of mechanical ventilatory support, shorten the duration of ventilatory support, and reduce the amount of time that such infants are exposed to both mechanical ventilation and oxygen. We also wanted to determine the effects of supplemental carnitine on weight gain, time to regain birth weight, time to achieve full enteral feedings, and length of hospital stay. METHODS: A prospective, randomized, blinded trial was conducted on 44 preterm infants who were from the same neonatal intensive care unit and who were < or =32 weeks' gestational age with a postnatal age <48 hours and a birth weight <1500 g and required total parenteral nutrition (TPN). Infants were randomized to receive carnitine supplementation or placebo without crossover. Carnitine-supplemented infants received 30 mg/kg/d carnitine in their TPN until the they were tolerating 120 mL/kg/d enteral feedings, and then they received 30 mg/kg/d oral carnitine. The placebo group received TPN without supplemental carnitine; when they tolerated 120 mL/kg/d enteral feedings, they received an oral placebo. The 2 groups continued on their respective supplemental carnitine or placebo until 34 weeks' adjusted age, at which time the study period was completed. Twelve-hour cardiorespiratorygrams to record heart rate, respiratory impedance, and oxygen saturation, and a nasal thermistor to detect expiratory airflow were performed every 4 days on 3 occasions and at 30 and 34 weeks' adjusted age. Plasma carnitine levels were measured at day 14. RESULTS: There were no significant differences between the 2 groups in the occurrence of apnea as detected by cardiorespiratorygram or nursing observation. There were no significant differences between the groups in regard to total days on ventilator, days of nasal continuous positive airway pressure, time to regain birth weight, time to reach enteral feedings of 120 mL/kg/d, discharge weight, adjusted age at discharge, need for oxygen at 28 days' and 36 weeks' adjusted age, or length of stay. The plasma carnitine level was a median of 15.5 micromol/L (range: 7.6-30.5) for the placebo infants compared with a median of 195.3 micromol/L (range: 71.7-343.6) for the carnitine infants. CONCLUSIONS: In this blinded, randomized, placebo-controlled study, we found that infants who received supplemental carnitine did not demonstrate any reduction in apnea of prematurity, ventilator or nasal continuous positive airway pressure days, or the need for supplemental oxygen therapy. Although carnitine may be of significant nutritional benefit for very low birth weight infants, our study does not support its use to reduce apnea of prematurity or decrease dependence on mechanical ventilation.

Kinesthetic stimulation versus theophylline for apnea in preterm infants.

BACKGROUND: Apnea of prematurity may lead to hypoxemia and bradycardia requiring resuscitative measures being instituted. Many treatments have been used in infants with apnea of prematurity, such as theophylline. Kinesthetic stimulation, which uses various forms of oscillating mattress, might also prevent apnea without using a standard drug such as theophylline. OBJECTIVES: Main question: in preterm infants, how does kinesthetic stimulation compare with methylxanthine therapy in the treatment of apnea of prematurity. SEARCH STRATEGY: The standard search strategy of the Neonatal Review Group was used. This included searches of the Oxford Database of Perinatal Trials, Cochrane Controlled Trials Register, MEDLINE, previous reviews including cross references, abstracts, conferences and symposia proceedings, expert informants and journal handsearching mainly in the English language. SELECTION CRITERIA: All trials using random or quasi-random patient allocation, in which kinesthetic stimulation was compared to methylxanthine therapy for apnea of prematurity, were eligible. No trials were excluded from the review that met these criteria. DATA COLLECTION AND ANALYSIS: Standard methods of the Cochrane Collaboration and its Neonatal Review Group were used with separate evaluation of trial quality, data extraction by both authors and synthesis of data using relative risk and weighted mean difference. MAIN RESULTS: A single small study of 20 infants (Saigal 1986) demonstrated a significant benefit to the infants receiving theophylline compared to those on an oscillating water bed in terms of mean rates of clinically important apnea (apnea > 14 seconds and bradycardia < 100, and cyanosis or receiving stimulation). There were no significant differences in adverse effects (death, sleep states, the Albert Einstein Neurobehavioural Index, adverse neurological outcomes, and the Bayley Mental Development Index at six and 12 months), although the infants on the OWB had a higher psychomotor index at six but not 12 months. There were some differences between the groups in incidence and severity of respiratory distress syndrome, and baseline apnea rates. REVIEWER'S CONCLUSIONS: The results of this review should be treated with caution. Theophylline has been shown in one small study to be superior to kinesthetic stimulation at treating clinically important apnea of prematurity. There are currently no clear research questions regarding the comparison of methylxanthines and kinesthetic stimulation to treat apnea of prematurity.

Breath-holding spells in a patient with transient erythroblastopenia of childhood.

We describe a child with transient erythroblastopenia of childhood and breath-holding spells. The spells resolved after oral iron supplementation but before the anemia resolved. The physiologic role of iron in autonomic nervous system regulation and its potential role in the treatment of breath-holding spells are discussed.

Long-term intramuscular electrical activation of the phrenic nerve: efficacy as a ventilatory prosthesis.

The efficacy of a system for long-term intramuscular activation of the phrenic nerve as a ventilatory prosthesis was evaluated in seven dogs. (The safety and reliability of this system is addressed in a companion paper.) Five dogs underwent chronic bilateral intramuscular diaphragm stimulation (IDS) for 61 to 183 days at stimulus parameters selected to evoke at least 120% of the animal's basal ventilation. Two dogs maintained as controls did not undergo chronic stimulation. The ability of IDS to provide long-term ventilation without diaphragm fatigue was evaluated in terms of the ventilatory capacity of IDS, the effects of chronic IDS on diaphragm contractile properties, and the phrenic nerve recruitment properties of chronic IDS electrodes. Hemidiaphragms with electrodes placed within 2 cm of the phrenic nerve trunk could be completely activated by 25 mA pulses having a 100 microsecond pulse width. The tidal volume evoked by IDS in this study was 167% (+/- 48 s.d.) of that required for full-time basal ventilation without diaphragm fatigue. Evoked tidal volume increased after 8 to 9 weeks of chronic IDS for stimulus pulse intervals longer than 50 mS. Electrode recruitment properties were stable for both active and passive implanted electrodes. We conclude from these studies that with properly placed electrodes IDS is capable of providing reliable full-time ventilatory support without fatiguing the diaphragm.

Transesophageal electroventilation. Optimization and improvement.

For electroventilation, short duration pulse trains (0.1 ms) were applied between two axillary pads (transchest) and compared with transesophageal electroventilation where pulses passed between the same pads to an esophageal electrode in apneic, pentobarbitone-anesthetized pigs. Significantly greater tidal volumes were produced by transesophageal electroventilation in comparison with transchest. As measured by maintained tidal volumes, duration of inspiratory air flow, peak flow, percentage hemoglobin oxygen saturation (%SaO2), and end tidal carbon dioxide concentration (ETCO2), the optimal requirements for transesophageal electroventilation were pulse frequency 40 Hz, 0.7 s duration pulses, at 60 to 100 V, pulse width 0.1 ms, with the esophageal electrode proximal to the gastroesophageal junction without producing brachial plexus stimulation. The efficiency of transesophageal electroventilation falls off rapidly following ventricular fibrillation. Thus, the application of this technique would be in respiratory arrest with maintained circulation, eg, in drug-induced respiratory depression, severe smoke inhalation, severe emphysema, high cervical cord lesion, and weaning from prolonged mechanical ventilation.

Apnea in postsurgical hypnotherapy of an esophageal cancer patient: a brief communication.

Use of clinical hypnosis in the postsurgical psychotherapy of an esophageal cancer patient who could not swallow involved reenactment of the successful surgery and producing hallucinations of taste and smell, as well as working through emotions relations to the surgery and her disease. An apnea that occurred in a late phase of the treatment was addressed with the familiar arm pumping technique that had been used as a deepening technique, resulting in the patient's resuming normal breathing. The experience reminds the practitioner of the possible unexpected professional demands when working in a medical environment. It also provides clues as to the underlying psychological mechanisms and their role in successful symptom removal. A 6-year follow-up confirmed the lasting effect of this brief psychotherapy.

Anesthesia and apnea. Perioperative considerations in the former preterm infant.

Former preterm infants younger than 44 weeks postconceptual age are at increased risk for developing postoperative apnea and PB. When surgery cannot be deferred until the infant is developmentally more mature, several measures should be taken to minimize the risk of ventilatory dysfunction. First, outpatient surgery is not advisable for infants younger than 44 weeks postconceptual age. All infants should be admitted to the hospital and monitored for apnea and bradycardia for at least 12 to 18 hours after surgery. Second, we recommend the use of intravenous caffeine base 10 mg/kg in all infants at risk for postoperative apnea following general anesthesia. Preliminary studies of a small number of patients indicate that spinal anesthesia without sedation is associated with less apnea than is general anesthesia or spinal anesthesia with ketamine sedation. This option warrants further consideration. Infants with anemia of prematurity, generally a benign condition, are at increased risk for postoperative apnea. It is therefore preferable to delay elective surgery and supplement the feeds with iron until the Hct is above 30%. When surgery cannot be deferred, anemic infants must be observed and monitored carefully in the postoperative period.

Diaphragmatic pacing: an alternative to long-term mechanical ventilation.

Electrical percutaneous stimulation of the phrenic nerves was first employed in 1948 by Sarnoff to provide temporary artificial ventilation in patients with respiratory failure. However, the technique was limited by development of infection around the electrode. Short-term radiofrequency stimulation of the phrenic nerves was first utilised by Glenn in 1964 and adapted to long-term use in patients with central hypoventilation in 1968 and with traumatic quadriplegia in 1972. The technique employed alternate pacing of each hemidiaphragm with high frequency stimulation (25-30 Hz) with a respiratory rate of 12 to 17 per minute which, in a series of 17 quadriplegic adults, although initially successful, was self-limiting because of eventual damage to the nerves and diaphragms. More recently, continuous bilateral simultaneous low frequency (up to 8 Hz) stimulation with a respiratory rate of 5 to 9 per minute has not induced myopathic changes. This phenomenon has been attributed to: 1. the conversion of the mixture of slow and fast twitch fibres in the diaphragm to a uniform population of fatigue resistant fibres induced by low frequency stimulation, and 2. the reduction in the total current necessary to achieve adequate gas exchange when both diaphragms contract simultaneously with the less frequent stimulation at lower energy. Diaphragmatic pacing has been applied to infants and children with emphasis on the selection of patients and optimum setting of stimulus parameters. This communication presents a case report of diaphragmatic pacing in a child with a review of the principles of application. The advantages and disadvantages compared to mechanical ventilation are also discussed.

[A respiratory syndrome in patients with neurocirculatory dystonia]. / Respiratornyi sindrom u bol'nykh neirotsirkuliatornoi distoniei.

The purpose of the work was to evaluate the compensatory and adaptive possibilities of oxygen transport systems in moderate hypoxic hypoxia to define the sensitivity to hypoxia of patients suffering from neurocirculatory dystonia (NCD) with the respiratory syndrome and to elaborate training therapy methods. 40 patients suffering from cardial NCD were examined. Of these, 23 complained of dyspnea. The general hypoxemic test (GHT) was used; parameters of external respiration, hemodynamics, gas composition of blood, and the content of oxidation substrates were examined. Analysis of the clinical picture of respiratory disorders in patients with cardial NCD revealed the differences in their nature. In addition to psychogenic factors of dyspnea, of importance was a decrease in the compensatory and adaptive possibilities of the body as regards hypoxia, which occurs in mental, physical stress, changes in meteorological conditions, in closed premises, and in vegetovascular crises.