***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Respiration , as judged by gas exchange and pulmonary function , is improved in preterm infants kept in the prone rather than the supine position . The influence of position on the breathing pattern as documented by the pneumogram was studied in 14 stable preterm infants with recent clinical apnoea . Ten of the infants had  oximetry and  nasal flow studies  simultaneously with the impedance pneumogram . Each infant had consecutive nocturnal pneumograms , one in the prone , one in the supine position . The infants were kept for more than six hours in the assigned position . A significant increase in apnoea density and in periodic breathing was found in the supine v the prone position ( mean ( SE ) 4.5 (0.7)% v 2.5 (0.5)% , and 13.6 (3.2)% v 7.7 (2.2)% , respectively ) . There was no positional difference in the incidence of bradycardia and prolonged apnoea . The examination of obstructive apnoea , mixed apnoea , and cyanotic spells did not reveal a consistent disparity between the two positions . These findings indicate an increase in central apnoea in preterm infants kept predominantly in the supine position . Possible relations of positional changes to lung mechanics are discussed . When evaluating pneumograms , attention must be given to the position in which they were performed Background : Results of several studies suggest that prone position is beneficial in improving the  preterm infants ’ cardio-respiratory status . Previous studies showed opposite results , and also there is not any available clear study about the effect of this position on cardio-respiratory rates of Nasal Continuous Positive Airway Pressure ( N-CPAP ) treating premature infants . Objectives : This study aim ed at comparing supine and prone positions on cardio-respiratory rates of premature infants with respiratory distress syndrome ( RDS ) who were treated using N-CPAP . Patients and Methods : This was a cross over study which was performed in 2010 on 44 hospitalized 29 - 34 weeks gestation premature infants who were receiving N-CPAP in Neonatal Intensive Care Unit of Al-Zahra Hospital of Tabriz University of Medical Sciences . Infants were r and omly assigned into two groups , and the first group was placed in prone at first and then in supine , and the position of second group was at first supine and then prone .  Infants ’ Heart Rate ( HR ) and Respiratory Rate ( RR ) were assessed three times in each position for 30 minutes . The data was recorded in a data - collection form , and demographic data was analyzed using t test , Chi square and Fisher exact test . Also , repeated measurement ANOVA and Tukey post-hoc tests were used . Results : There was a significant difference in HR and RR of premature infants who were similar in gestational age and clinical condition and placed in two positions . Premature infants ’ HR and RR became lower at prone position than supine in both groups . So it can be concluded that prone position could decrease infants HR and RR , but supine position might increase them ( P < 0.05 ) . Conclusion : Our findings support prone positioning for premature infants . Therefore , it is advisable to NICU staff that if there is no obstacle for changing the infant ’s position , prone position in infants with respiratory complications during receiving N-CPAP in NICU can be useful . Regarding the fact that prone position is a risk factor for sudden infant death syndrome , prone position should be only used when the newborn is being supervised carefully In an attempt to determine physiologic responses to neonatal apnea , we evaluated changes in heart rate and oxygen saturation as measured by pulse oximetry during 2082 episodes of apnea lasting 15 seconds or more in 47 infants less than 34 weeks of gestational age with idiopathic apnea of prematurity . Of these episodes , 832 ( 39.9 % ) were central , 1032 ( 49.6 % ) were mixed , and 218 ( 10.5 % ) were obstructive . Oxygen saturation decreased with increasing duration of apnea regardless of type or treatment , and the decrease in saturation was correlated with preapnea saturation . The baseline heart rate was similar for all apnea types . Infants receiving doxapram had a lower baseline heart rate ( 137.8 + /- 10.5 beats/min ) than did infants receiving no therapy ( 142.8 + /- 16.6 beats/min ) and infants receiving theophylline ( 149.7 + /- 15.0 beats/min ) ( p = < 0.001 ) . A heart rate fall to less than 100 beats/min was seen more frequently with central apnea than with mixed or obstructive events , and in infants who were not receiving therapy . Falls in heart rate were significantly less in infants receiving doxapram ( 27.8 % + /- 18.0 % ) than in infants receiving theophylline ( 44.5 % + /- 19.0 % ) or no therapy ( 48.4 % + /- 18.3 % ) ( p = < 0.001 ) . The most common heart rate pattern overall was a gradual decrease interrupted by accelerations , whereas an initial heart rate acceleration was the most common pattern in obstructive apnea . We conclude that heart rate response to  neonatal apnea is a complex and is dependent on therapy and on type and duration of apnea OBJECTIVE : The purpose of this study was to determine the effects of prone and supine positioning on the cardiorespiratory stability of preterm infants with apnea and bradycardia . METHODS : A total of 22 preterm infants with symptomatic apnea and bradycardia ( gestational age of 26.9 ± 1.8 weeks and birth weight of 865 ± 235 gm ) were monitored for 24 hours ( in four sequential 6-hour blocks ) for apnea , bradycardia , and oxygen desaturation in alternating positions ( prone or supine ) following r and omization . Postconceptional age at the time of study was 31.9 ± 3.0 weeks . Respiratory rate , heart rate , and transcutaneous oxygen saturation were continuously monitored . All episodes of apnea ( ≥10 seconds ) , bradycardia ( < 100 beats per minute ) , and oxygen desaturation ( < 90 % ) were recorded on an event monitor . Episodes of apnea , bradycardia , and oxygen desaturation were defined as clinical ly significant if the following criteria were met : apnea , ≥15 seconds ; bradycardia , < 90 beats per minute ; and oxygen desaturation , < 80 % . All other recorded episodes were considered mild . The episodes were analyzed for statistical significance using the paired t-test . RESULTS : No significant differences ( p > 0.05 ) in the incidence of clinical ly significant apnea , bradycardia , or desaturation between supine and prone positions were seen in these preterm infants . CONCLUSION : Our results suggest that the cardiorespiratory stability of preterm infants is not significantly compromised by supine positioning To determine the influence of body position on chest wall and pulmonary function , we studied the ventilatory , pulmonary mechanics , and thoracoabdominal motion profiles in 20 preterm infants recovering from respiratory disease who were positioned in both the supine and prone position . Thoracoabdominal motion was assessed from measurements of relative rib cage and abdominal movement and the calculated phase angle ( an index of thoracoabdominal synchrony ) of the rib and abdomen Lissajous figures . The ventilatory and pulmonary function profiles were assessed from simultaneous measurements of transpulmonary pressure , airflow , and tidal volume . The infants were studied in quiet sleep , and the order of positioning was r and omized across patients . The results demonstrated no significant difference in ventilatory and pulmonary function measurements as a function of position . In contrast , there was a significant reduction ( -49 % ) in the phase angle of the Lissajous figures and an increase ( + 66 % ) in rib cage motion in prone compared with the supine position . In addition , the degree of improvement in phase angle in the prone position was correlated to the severity of asynchrony in the supine position . We speculate that the improvement in thoracoabdominal synchrony in the prone position is related to alterations of chest wall mechanics and respiratory muscle tone mediated by a posturally related shift in the area of apposition of the diaphragm to the anterior inner rib cage wall and increase in passive tension of the muscles of the rib cage . This study suggests that the mechanical advantage associated with prone positioning may confer a useful alternative breathing pattern to the preterm infant in whom elevated respiratory work loads and respiratory musculoskeletal immaturity may predispose to respiratory failure BACKGROUND Apnea of prematurity , a common disorder , can severely compromise an infant 's condition unless correctly diagnosed and treated . Infants with a history of apnea of prematurity can be discharged home but then be rehospitalized for an apneic event , an apparent life-threatening event , or sudden infant death syndrome . The definition of a clinical ly significant cardiopulmonary event , such events ' documentation , and the treatment approach were st and ardized , and discharge criteria were refined . METHODS A prospect i ve , single-center comparison was conducted between a group of premature infants before and after implementation of the st and ard approach .  Data were collected prospect ively from August 1 , 2005 , through July 21 , 2006 , for the  prest and ard-approach group and from August 1 , 2006 , through September 16 , 2007 , for the st and ard-approach group . RESULTS Twenty-two ( 35 % ) of the 63 infants in the prest and ard-approach group experienced discharge delays because of poor documentation , whereby the clinician could not determine the safety of discharge . This result ed in 59 additional hospital days ( mean length-of-stay [ LOS ] increase , 5.7 days ) . The st and ard-approach group of 72 infants experienced no discharge delays and no additional hospital days , and LOS decreased ( all p < .0001 ) . Annual charges were reduced by more than $ 58,000 in avoiding unnecessary hospital days . Readmission to the hospital for apnea of prematurity occurred for 5 ( 7.9 % ) of the prest and ard-approach group but none of the st and ard-approach group ( p = .0203 ) . Overall compliance with the st and ardization process has been maintained at > or = 96 % . CONCLUSION Implementation of a st and ard approach to the definition of apnea of prematurity and its treatment and documentation decreases LOS and reduces cost OBJECTIVE We investigated whether nursing in the head elevated tilt position ( HETP ) , compared with the horizontal position , has any effect on the incidence of bradycardic and hypoxemic episodes in preterm infants . METHODS Twelve spontaneously breathing preterm infants with idiopathic recurrent apnea were studied in a r and omized controlled crossover trial . Nine infants were treated with aminophylline . Each spent a total of 24 hours in the horizontal prone position and a total of 24 hours in HETP ( prone , 15 degrees ) . The position was changed in r and om order every 6 hours . Thoracic impedance , heart rate , and arterial oxygen saturation were recorded continuously . The frequency of isolated hypoxemia ( arterial saturation < 80 % ) , of isolated bradycardia ( heart rate < 90 beats per minute ) , and of mixed events was analyzed and compared without knowledge of the allocated position . RESULTS In total , there were significantly fewer bradycardic and /or hypoxemic episodes ( 28.2 % ) in HETP compared with the horizontal position ( mean difference , 13.35 episodes/24 hours ; 95 % confidence interval [ CI ] : 5.9- 20.8 ) . The decrease was largest for isolated hypoxemic episodes ( 48.5 % ; mean difference , 11.74 episodes/24 hours ; 95 % CI : 6.1 - 17.4 ) . Isolated bradycardic episodes ( mean difference , 2.27 episodes/24 hours ; 95 % CI : -0.78 - 5.31 ) and mixed events were not decreased significantly in HETP . CONCLUSIONS Nursing in a moderately tilted position ( 15 degrees ) reduces hypoxemic events in preterm infants . This intervention is easy to apply , quickly reversible , and can be combined with drugs such as aminophylline OBJECTIVE To compare breathing patterns and lung function in the supine , lateral , and prone positions in oxygen-dependent preterm infants . STUDY DESIGN Respiratory function in preterm infants receiving nasal continous positive airway pressure therapy for mild respiratory failure was evaluated by respiratory inductive plethysmography . Infants were r and omized to supine , left lateral , and prone positions for 3 hours . A nest provided a semiflexed posture for the infants placed in the left lateral position , similar to the in utero position . Tidal volume ( Vt ) , phase angle between abdominal and thoracic movements , rib cage contribution to Vt , and dynamic elevation of end-expiratory lung volume were measured . RESULTS Fraction of inspired O2 was similar in the 3 positions for 19 infants ( mean gestational age , 27±2 weeks ; mean birth weight , 950±150 g ; mean postnatal age , 17±5 days ) . However , arterial O2 saturation and Vt were higher in the left lateral and prone positions than in the supine position ( P<.05 ) . The phase angle between abdominal and thoracic movements was lower and rib cage contribution to Vt was higher in the left lateral and prone positions than in 
    Output:
    
We found insufficient evidence to determine effects of body positioning on apnoea , bradycardia and oxygen saturation in preterm infants .
Large , multi-centre studies are warranted to provide conclusive evidence , but it may be plausible to conclude that positioning of spontaneously breathing preterm infants has no effect on their cardiorespiratory parameters