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Acta Anaesthesiologica Scandinavica Feb 2001* Mechanically ventilated patients with severe acute lung insufficiencies dramatically improve their gas exchange when treated in the prone position. * ventilation... (Review)
Review
* Mechanically ventilated patients with severe acute lung insufficiencies dramatically improve their gas exchange when treated in the prone position. * ventilation heterogeneity is greater in the supine then in the prone position during CMV. * the dominant dorsal Q while supine is not turned into a dominant ventral Q in the prone position. * in the presence of an abdominal distension, the prone position more clearly improves gas exchange than at normal abdominal pressures. * CPAP enhances the dominant dorsal lung perfusion while supine. In the prone position lung perfusion is more uniform. * V/Q matching is improved in the prone position during CMV.
Topics: Anesthesia; Humans; Prone Position; Pulmonary Circulation; Pulmonary Gas Exchange; Respiratory Mechanics
PubMed: 11167159
DOI: No ID Found -
PloS One 2023Supine sleep position is associated with stillbirth, likely secondary to inferior vena cava compression, and a reduction in cardiac output (CO) and uteroplacental... (Review)
Review Meta-Analysis
INTRODUCTION
Supine sleep position is associated with stillbirth, likely secondary to inferior vena cava compression, and a reduction in cardiac output (CO) and uteroplacental perfusion. Evidence for the effects of prone position in pregnancy is less clear. This study aimed to determine the effect maternal prone position on maternal haemodynamics and fetal heart rate, compared with left lateral position.
METHODS
Twenty-one women >28 weeks' gestation underwent non-invasive CO monitoring (Cheetah) every 5 minutes and continuous fetal heart rate monitoring (MONICA) in left lateral (20 minutes), prone (30 minutes), followed by left lateral (20 minutes). Anxiety and comfort were assessed by questionnaires. Regression analyses (adjusted for time) compared variables between positions. The information derived from the primary study was used in an existing mathematical model of maternal circulation in pregnancy, to determine whether occlusion of the inferior vena cava could account for the observed effects. In addition, a scoping review was performed to identify reported clinical, haemodynamic and fetal effects of maternal prone position; studies were included if they reported clinical outcomes or effects or maternal prone position in pregnancy. Study records were grouped by publication type for ease of data synthesis and critical analysis. Meta-analysis was performed where there were sufficient studies.
RESULTS
Maternal blood pressure (BP) and total vascular resistance (TVR) were increased in prone (sBP 109 vs 104 mmHg, p = 0.03; dBP 74 vs 67 mmHg, p = 0.003; TVR 1302 vs 1075 dyne.s-1cm-5, p = 0.03). CO was reduced in prone (5.7 vs 7.1 mL/minute, p = 0.003). Fetal heart rate, variability and decelerations were unaltered. However, fetal accelerations were less common in prone position (86% vs 95%, p = 0.03). Anxiety was reduced after the procedure, compared to beforehand (p = 0.002), despite a marginal decline in comfort (p = 0.04).The model predicted that if occlusion of the inferior vena cava occurred, the sBP, dBP and CO would generally decrease. However, the TVR remained relatively consistent, which implies that the MAP and CO decrease at a similar rate when occlusion occurs. The scoping review found that maternal and fetal outcomes from 47 included case reports of prone positioning during pregnancy were generally favourable. Meta-analysis of three prospective studies investigating maternal haemodynamic effects of prone position found an increase in sBP and maternal heart rate, but no effect on respiratory rate, oxygen saturation or baseline fetal heart rate (though there was significant heterogeneity between studies).
CONCLUSION
Prone position was associated with a reduction in CO but an uncertain effect on fetal wellbeing. The decline in CO may be due to caval compression, as supported by the computational model. Further work is needed to optimise the safety of prone positioning in pregnancy.
TRIAL REGISTRATION
This trial was registered at clinicaltrials.gov (NCT04586283).
Topics: Pregnancy; Female; Humans; Pregnancy Trimester, Third; Prone Position; Cohort Studies; Prospective Studies; Hemodynamics; Heart Rate, Fetal
PubMed: 37819872
DOI: 10.1371/journal.pone.0287804 -
Paediatric Anaesthesia Mar 2022
Topics: Face; Head; Humans; Patient Positioning; Prone Position; Supine Position
PubMed: 34741775
DOI: 10.1111/pan.14327 -
Critical Care Medicine Mar 2021
Topics: Humans; Patient Positioning; Prone Position; Respiratory Distress Syndrome
PubMed: 33616354
DOI: 10.1097/CCM.0000000000004840 -
Medicine, Science, and the Law Jul 2022
Topics: Humans; Patient Positioning; Prone Position
PubMed: 34730061
DOI: 10.1177/00258024211051544 -
Pediatric Research Jul 2021Prone sleeping is used in preterm infants undergoing intensive care to improve respiratory function, but evidence suggests that this position may compromise autonomic...
BACKGROUND
Prone sleeping is used in preterm infants undergoing intensive care to improve respiratory function, but evidence suggests that this position may compromise autonomic cardiovascular control. To test this hypothesis, this study assessed the effects of the prone sleeping position on cardiovascular control in preterm infants undergoing intensive care treatment during early postnatal life.
METHODS
Fifty-six preterm infants, divided into extremely preterm (gestational age (GA) 24-28 weeks, nā=ā23) and very preterm (GA 29-34 weeks, nā=ā33) groups, were studied weekly for 3 weeks in prone and supine positions, during quiet and active sleep. Heart rate (HR) and non-invasive blood pressure (BP) were recorded and autonomic measures of HR variability (HRV), BP variability (BPV), and baroreflex sensitivity (BRS) using frequency analysis in low (LF) and high (HF) bands were assessed.
RESULTS
During the first 3 weeks, prone sleeping increased HR, reduced BRS, and increased HF BPV compared to supine. LF and HF HRV were also lower prone compared to supine in very preterm infants. Extremely preterm infants had the lowest HRV and BRS measures, and the highest HF BPV.
CONCLUSIONS
Prone sleeping dampens cardiovascular control in early postnatal life in preterm infants, having potential implications for BP regulation in infants undergoing intensive care.
Topics: Baroreflex; Cardiovascular Physiological Phenomena; Female; Heart Rate; Humans; Infant, Newborn; Infant, Premature; Intensive Care Units, Neonatal; Male; Prone Position; Sleep
PubMed: 33173173
DOI: 10.1038/s41390-020-01254-z -
Anesthesiology Dec 2010
Topics: Acute Lung Injury; Anesthesia; Humans; Lung; Positive-Pressure Respiration; Prone Position; Pulmonary Alveoli; Pulmonary Gas Exchange; Respiratory Distress Syndrome; Supine Position
PubMed: 21042196
DOI: 10.1097/ALN.0b013e3181fcd97e -
British Journal of Anaesthesia Feb 2008Prone positioning of patients during anaesthesia is required to provide operative access for a wide variety of surgical procedures. It is associated with predictable... (Review)
Review
Prone positioning of patients during anaesthesia is required to provide operative access for a wide variety of surgical procedures. It is associated with predictable changes in physiology but also with a number of complications, and safe use of the prone position requires an understanding of both issues. We have reviewed the development of the prone position and its variants and the physiological changes which occur on prone positioning. The complications associated with this position and the published techniques for various practical procedures in this position will be discussed. The aim of this review is to identify the risks associated with prone positioning and how these risks may be anticipated and minimized.
Topics: Anesthesia; Hemodynamics; Humans; Intraoperative Care; Intraoperative Complications; Postoperative Complications; Prone Position; Respiratory Mechanics
PubMed: 18211991
DOI: 10.1093/bja/aem380 -
Critical Care Nurse Oct 2022
Topics: Humans; Intubation, Intratracheal; Patient Positioning; Prone Position
PubMed: 36180052
DOI: 10.4037/ccn2022354 -
Head & Neck Nov 2007Certain head and neck surgical cases require the patient to be positioned prone. Such positioning carries with it an attendant subset of risks and complications not... (Review)
Review
Certain head and neck surgical cases require the patient to be positioned prone. Such positioning carries with it an attendant subset of risks and complications not otherwise encountered in more traditional supine positioning. Gaining awareness of these risks and complications, and developing proactive positioning strategies, will enable the surgical team to position the patient optimally for the procedure and provide for every consideration of patient safety. This article consists of a specific literature review of those issues directly related to the anatomical and physiological concerns arising from prone positioning. Particular attention is paid to the cardiopulmonary, renal, ophthalmologic, and neurological vulnerabilities unique to this position. Proper planning by the surgical team and utilization of the correct equipment are a necessity. A tailored approach to the needs of the individual patient and an intimate awareness of the potential pitfalls will contribute to better outcomes when using the prone position.
Topics: Blood Pressure; Head and Neck Neoplasms; Humans; Intraocular Pressure; Preoperative Care; Prone Position; Total Lung Capacity
PubMed: 17712853
DOI: 10.1002/hed.20650