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Results for “Prone Position”

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At least 109 records · Page 6Linked to original sources

PubMed1998

Heart rate variability and the prone position under general versus spinal anesthesia.

STUDY OBJECTIVE: To evaluate heart rate (HR) variability in the prone position with power spectral heart rate (PSHR) analysis during spinal and general anesthesia. DESIGN: Prospective, clinical evaluation of HR variability in the prone position. SETTING: Tertiary care teaching hospital. PATIENTS: 20 healthy, ASA physical status I and II patients scheduled for elective lumbar spine surgery in the prone position. INTERVENTIONS: Anesthetic technique was either a standard general anesthetic or spinal anesthetic, based on the preference of the patient. Power spectral heart rate, HR, and blood pressure (BP) readings were determined prior to anesthetic intervention and as soon as a stable PSHR reading was available in the prone position. MEASUREMENTS AND MAIN RESULTS: Heart rate and BP were recorded at baseline prior to anesthesia and at the time of stable PSHR data in the prone position. Power spectral heart rate data included low-frequency activity (LFa), high-frequency activity (HFa), and the ratio (LFa/HFa). Spinal anesthesia level was recorded by thoracic dermatome at complete onset. Data were collected from 20 patients; 12 patients chose spinal anesthesia and 8 chose general anesthesia. The prone position resulted in significant increase in HR in the spinal group and significant decrease in BP in the general anesthesia group. Low-frequency activity and LFa/HFa ratio were unchanged in the spinal anesthesia group and were significantly decreased in the general anesthesia group. Spinal level was T8.7. CONCLUSIONS: The association of less change in LFa activity and preservation of BP on assumption of the prone position in patients during low spinal anesthesia suggests better preservation of autonomic nervous system compensatory mechanisms during low spinal anesthesia than with general anesthesia.

Anesthesia, General↗

PubMed2003

[Effects of prone position, inhaled nitric oxide and surfactant in children with hypoxemic pulmonary disease].

OBJECTIVE: To analyze the therapeutic response to prone position, inhaled nitric oxide (NO) and surfactant in children with hypoxemic pulmonary disease. PATIENTS AND METHODS: We studied the effect of prone position, NO, and surfactant in critically ill children with acute hypoxemic pulmonary disease unresponsive to conventional therapy. We analyzed PaO2, SatO2, the PaO2/FiO2 ratio, oxygenation index and PaCO2 before and after each treatment, as well as the subsequent clinical course. An increase of more than 20 % in the PaO2/FiO2 ratio was considered a positive response. RESULTS: Ninety treatments were administered in 56 patients: 55 patients were treated with NO, 18 with prone position and 17 with surfactant. All three treatments substantially improved oxygenation. The mean increase in the PaO2/FiO2 ratio was 35 % with nitric oxide, 33 % with prone position and 50 % with surfactant. The mean decrease in oxygenation index was 22 % with nitric oxide, 24 % with prone position and 17 % with surfactant. Seventy-one percent of patients treated with NO, 61 % of patients treated with prone position, and 64 % of patients who received surfactant were responders. The three treatments produced a slight decrease in PaCO2 (2.5 mmHg with nitric oxide, 4.7 mmHg with prone position and 5.1 mmHg with surfactant). CONCLUSIONS: Inhaled NO, prone position and surfactant improve oxygenation in some children with hypoxic pulmonary disease.

Adolescent↗

PubMed2001

Positioning of infants in the prone position: a useful technique.

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Anesthesia↗

PubMed2001

Is the sitting or the prone position best for surgery for posterior fossa tumours in children?

BACKGROUND: The aim of this study was to compare complications in children operated for posterior fossa tumours in the sitting position with those in the prone position. METHODS: We retrospectively assessed the perioperative course of posterior fossa tumour (PFT) surgery according to the operating position. Sixty children were operated in the sitting position (SP) and 19 in the prone position (PP). Preoperative data were not different between groups. RESULTS: Patients in the PP group received a larger median (95% confidence interval) volume of intraoperative blood transfusion than patients in the SP group [200 (20-325) versus 0 (0-80) ml, P=0.04]. Intraoperative complications, as well as severe perioperative complications were more frequent in the PP group (P=0.01). The median duration of tracheal intubation [20 (18-24) versus 36 (18-72) h, P=0.037], of ICU stay [2 (2-3) versus 4 (2-5) days, P=0.02] and of hospital stay [11 (9-12) versus 14 (10-20) days, P=0.02] was longer in the PP group compared with the SP group. CONCLUSIONS: PFT surgery in the sitting position in children is not associated with an increased number or severity of perioperative complications, while the postoperative course appears better in this position.

Astrocytoma↗

PubMed2005

Comparison of prone positioning and high-frequency oscillatory ventilation in patients with acute respiratory distress syndrome.

OBJECTIVE: Both prone position and high-frequency oscillatory ventilation (HFOV) have the potential to facilitate lung recruitment, and their combined use could thus be synergetic on gas exchange. Keeping the lung open could also potentially be lung protective. The aim of this study was to compare physiologic and proinflammatory effects of HFOV, prone positioning, or their combination in severe acute respiratory distress syndrome (ARDS). DESIGN: : Prospective, comparative randomized study. SETTING: A medical intensive care unit. PATIENTS: Thirty-nine ARDS patients with a Pao2/Fio2 ratio <150 mm Hg at positive end-expiratory pressure > or =5 cm H2O. INTERVENTIONS: After 12 hrs on conventional lung-protective mechanical ventilation (tidal volume 6 mL/kg of ideal body weight, plateau pressure not exceeding the upper inflection point, and a maximum of 35 cm H2O; supine-CV), 39 patients were randomized to receive one of the following 12-hr periods: conventional lung-protective mechanical ventilation in prone position (prone-CV), HFOV in supine position (supine-HFOV), or HFOV in prone position (prone-HFOV). MEASUREMENTS AND MAIN RESULTS: Prone-CV (from 138 +/- 58 mm Hg to 217 +/- 110 mm Hg, p < .0001) and prone-HFOV (from 126 +/- 40 mm Hg to 227 +/- 64 mm Hg, p < 0.0001) improved the Pao2/Fio2 ratio whereas supine-HFOV did not alter the Pao2/Fio2 ratio (from 134 +/- 57 mm Hg to 138 +/- 48 mm Hg). The oxygenation index ({mean airway pressure x Fio2 x 100}/Pao2) decreased in the prone-CV and prone-HFOV groups and was lower than in the supine-HFOV group. Interleukin-8 increased significantly in the bronchoalveolar lavage fluid (BALF) in supine-HFOV and prone-HFOV groups compared with prone-CV and supine-CV. Neutrophil counts were higher in the supine-HFOV group than in the prone-CV group. CONCLUSIONS: Although HFOV in the supine position does not improve oxygenation or lung inflammation, the prone position increases oxygenation and reduces lung inflammation in ARDS patients. Prone-HFOV produced similar improvement in oxygenation like prone-CV but was associated with higher BALF indexes of inflammation. In contrast, supine-HFOV did not improve gas exchange and was associated with enhanced lung inflammation.

Adult↗

PubMed2002

Prone positioning in acute respiratory failure: survey of Belgian ICU nurses.

OBJECTIVE: To determine the frequency of use and attitudes towards prone positioning in patients with acute respiratory failure. DESIGN AND SETTING: Verbal questionnaire survey in all 79 intensive care units in French-speaking Belgium. METHODS: Of the 79 ICUs 29 performed prone-positioning, and 25 agreed to participate in the questionnaire. MEASUREMENTS AND RESULTS: Nurses at 9 of the 25 hospitals expressed reluctance to use prone positioning. The time schedules associated with prone positioning varied among the units surveyed, with no consensus. Units used two to six members of staff to turn a patient, with three most commonly being employed. Patients were most commonly positioned with both arms above the head and cushions under the chest, head, and legs, but there was considerable variation among units. The complications most commonly reported were facial edema and decubitus ulcers, with only three of the units reporting accidental extubation. Only two of the units had an established protocol for prone positioning although nurses from 14 of the units felt this would be useful. CONCLUSIONS: Prone positioning is approached with some reluctance by ICU staff. If the use of prone positioning in patients with acute respiratory distress syndrome is deemed worthwhile, discussion and development of departmental protocols may facilitate its use.

Attitude of Health Personnel↗

PubMedDate not supplied

[Short-term effects of prone positioning on the oxygenation of pediatric patients submitted to mechanical ventilation]

OBJECTIVE: To analyze the short-term effects of prone positioning on the oxygenation of mechanically-ventilated children suffering from severe hypoxemia. MATERIALS AND METHODS: A prospective, nonrandomized trial (each patient as his/her own control) was conducted between July 1998 and July 1999. Mechanically-ventilated children with peak inspiratory pressure greater than or equal to 30 cm H(2)O, FiO(2) greater than or equal to 0.5, and PaO(2)/FiO(2) ratio less than or equal to 200 were included in the study. Each patient was kept in the prone position for two hours, returning to the supine position after this period. Oxygenation was assessed by means of PaO(2)/FiO(2) in the supine position (one hour before prone positioning), one hour after prone positioning, and one hour after returning to the supine position. Patients who presented an increase of at least 20 in PaO(2)/FiO(2) were considered responsive. The results were compared by Student t-test, Friedman test, chi-square test, Fishers exact test, and confidence interval. RESULTS: Eighteen children (10 males), whose mean age was 11.5 -/+11.5 months, with initial PaO(2)/FiO(2) of 96.06 -/+ 41.78, participated in the study. After one hour in the prone position, 27.7% of the patients (5/18) improved their PaO(2)/FiO(2) ratio (P=0.045). Six of these patients presented reduced lung compliance (four of them had acute respiratory distress syndrome); and twelve patients showed increased airway resistance (six of them presented bronchiolitis). No significant difference was observed between these two groups (reduced lung compliance x increased airway resistance) in terms of age, sex, duration of ventilation prior to change in position, peak inspiratory pressure, FiO(2), severity of hypoxemia, and outcome. CONCLUSION: Prone positioning during mechanical ventilation of children with severe hypoxemia may improve the PaO(2)/FiO(2) ratio in the first hour.

Journal Article↗

PubMed1998

Pulmonary gas exchange improves in the prone position with abdominal distension.

Arterial blood oxygenation in patients with adult respiratory distress syndrome is often improved in the prone position. Critically ill patients often have abdominal distension and whether similar improvements in gas exchange occur with the prone position is not known. We therefore studied the effect of posture on gas exchange in eight ketamine-anesthetized pigs with abdominal distension. A rubber balloon, placed in the abdominal cavity, was filled with water to increase intra-abdominal pressure. The animals were mechanically ventilated with FIO2 = 0.4, and PaCO2 was kept constant. Gas exchange was measured in the supine and prone positions, with and without abdominal distension, in random order, using the multiple inert gas elimination technique (MIGET). When the abdomen was normal, the prone position increased PaO2 by 16 +/- 21 mm Hg (p < 0.05), accompanied by a small, but statistically insignificant, decrease in AaPO2 (p = 0.08) and no change in ventilation/perfusion (V A/Q) heterogeneity measured by MIGET. In the presence of abdominal distension, the prone position increased Pa O2 by 26 +/- 18 mm Hg (p < 0.01) and decreased AaPO2 (p < 0.05) and V A/Q heterogeneity as measured by the log standard deviation of the perfusion distribution (p < 0.01) and the arterial-alveolar difference area (p < 0.05). In addition, intragastric pressure was lower in the prone position (p < 0.01). We conclude that in anesthetized, mechanically ventilated pigs, the prone position improves pulmonary gas exchange to a greater degree in the presence of abdominal distension than when the abdomen is normal.

Abdomen↗

PubMed2001

Prone position improves gas exchange--but how?

* 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.

Anesthesia↗

PubMed1995

The prone positioning during general anesthesia minimally affects respiratory mechanics while improving functional residual capacity and increasing oxygen tension.

We investigated the effects of the prone position on the mechanical properties (compliance and resistance) of the total respiratory system, the lung, and the chest wall, and the functional residual capacity (FRC) and gas exchange in 17 normal, anesthetized, and paralyzed patients undergoing elective surgery. We used the esophageal balloon technique together with rapid airway occlusions during constant inspiratory flow to partition the mechanics of the respiratory system into its pulmonary and chest wall components. FRC was measured by the helium dilution technique. Measurements were taken in the supine position and after 20 min in the prone position maintaining the same respiratory pattern (tidal volume 10 mL/kg, respiratory rate 14 breaths/min, FIO2 0.4). We found that the prone position did not significantly affect the respiratory system compliance (80.9 +/- 16.6 vs 75.9 +/- 13.2 mL/cm H2O) or the lung and chest wall compliance. Respiratory resistance slightly increased in the prone position (4.8 +/- 2.5 vs 5.4 +/- 2.7 cm H2O.L-1.s,P < 0.05), mainly due to the chest wall resistance (1.3 +/- 0.6 vs 1.9 +/- 0.8 cm H2O.L-1.s, P < 0.05). Both FRC and PaO2 markedly (P < 0.01) increased from the supine to the prone position (1.9 +/- 0.6 vs 2.9 +/- 0.7 L, P < 0.01, and 160 +/- 37 vs 199 +/- 16 mm Hg, P < 0.01, respectively), whereas PaCO2 was unchanged. In conclusion, the prone position during general anesthesia does not negatively affect respiratory mechanics and improves lung volumes and oxygenation.

Adult↗

PubMed2005

Unexpected blood clot-induced acute airway obstruction in a patient with inactive pulmonary tuberculosis during lumbar spine surgery in the prone position--a case report.

Airway obstruction is always a life-threatening event, and it must be recognized and managed immediately. We report an instance of acute airway obstruction associated with hemoptysis in an elderly patient with inactive advanced pulmonary tuberculosis (TB) while undergoing spine surgery. Airway obstruction was highly suspected in consequence of postural change because immediate resolution was rewarded after reversion of the position from prone to supine. The chest surgeon consulted intraoperatively did a fiberoptic bronchoscopy and found that the blood was mainly surging from the branching bronchus of right lower lobe, and thus the source of bleeding was confirmed. Hence, in this presentation we discuss the contributory factors which led to the occurrence of hemoptysis and the appropriate perioperative management of this kind of airway obstruction.

Acute Disease↗

PubMed2000

The effects of early and repeated prone positioning in pediatric patients with acute lung injury.

STUDY OBJECTIVE: To describe the physiologic changes and to evaluate the safety of placing pediatric patients with acute lung injury (ALI) prone for 20 h/d during the acute phase of their illness. DESIGN: Single-center prospective case series. SETTING: Tertiary-level pediatric ICU. PATIENTS: Consecutive patients with bilateral pulmonary parenchymal disease requiring intubation and mechanical ventilation with a PaO(2)/fraction of inspired oxygen (FIO(2)) ratio </= 300 mm Hg. INTERVENTIONS: Patients were enrolled as soon as possible after meeting criteria and were placed in a prone position for 20 h/d daily until clinical improvement or death occurred. MEASUREMENTS AND RESULTS: Twenty-five pediatric patients who had ALI/ARDS, ranging in age from 2 months to 17 years, were placed in a prone position within 19 h of meeting the study criteria for a median time of 4 days, which accounted for 47% of their time receiving mechanical ventilation. Eighty-four percent of patients (n = 21) were categorized as overall responders to prone positioning because they experienced more days of increases of >/= 20 mm Hg in PaO(2)/FIO(2) ratio or a decrease of >/= 10% in oxygenation index when shifted from a supine to a prone position during the study period. During the 107 patient-days and 214 positioning cycles, no critical incidents occurred. Furthermore, no patient experienced a persistent decrease in oxygen saturation as measured by pulse oximetry (SpO(2)) of > 10% from values obtained when in the supine position, failed to keep their SpO(2) at > 85%, or experienced an increased respiratory rate of > 40 breaths/min when prone. Using the COMFORT score, patients were objectively rated to be equally comfortable in both the supine and prone positions. Patients also were able to resume spontaneous ventilation and to progress toward endotracheal extubation while in the prone position. Iatrogenic injury associated with prolonged prone positioning included stage II pressure ulcers in six patients (24%). CONCLUSIONS: The pediatric patients in this series demonstrated improvements in oxygenation without serious iatrogenic injury after prone positioning. This study provides a foundation for a prospective randomized study investigating the effect of early and repeated prone positioning on clinical outcomes in pediatric patients with ALI.

Adolescent↗

PubMed2004

A randomized trial of supine vs. prone positioning in patients undergoing escalated dose conformal radiotherapy for prostate cancer.

BACKGROUND AND PURPOSE: The optimal treatment position for patients receiving radical radiation therapy for prostate cancer has been a source of controversy. To resolve this issue, we conducted a randomized trial to evaluate the effects of supine and prone positioning on organ motion, positioning errors, and dose to critical organs during escalated dose conformal irradiation for localized prostate cancer and patient and therapist satisfaction with setup technique. PATIENTS AND METHODS: Twenty eight patients were randomized to commence treatment immobilized in the supine or prone position and were subsequently changed to the alternate positioning for the latter half of their treatment. Patients underwent CT simulation and conformal radiotherapy planning and treatment in both positions. The clinical target volume encompassed the prostate gland. Alternate day lateral port films were compared to corresponding simulator radiographs to measure the isocentre positioning errors (IPE). Prostate motion (PM) and total positioning error (TPE) were measured from the same films by the displacements of three implanted fiducial markers. Dose volume histograms (DVHs) for the two treatment positions were compared at the 95, 80 and 50% dose (D%) levels. The patients and radiation therapists completed weekly questionnaires regarding patient comfort and ease of setup. RESULTS: Seven patients, who started in the supine position, subsequently refused prone position and received their whole treatment supine. Small bowel in the treatment volume, not present in the supine position, prevented one patient from being treated prone. PM in anterior posterior direction was statistically significantly less in the supine position (P<0.05). There was no significant difference in superior inferior PM for the two treatment positions. No statistically significant difference between supine and prone positioning was observed in isocentre positioning error (IPE) or total positioning error (TPE) due to a policy of daily pre-treatment correction. However, more pre-treatment corrections were required for patients in the prone position. The DVH analysis demonstrated larger volumes of the bladder wall, rectal wall and small bowel within the D95, D80 and D50% when comparing the planning target volumes (PTVs) actually treated for prone positioning. When the prone PTV was expanded to account for the greater PM encountered in that position, a statistically significant difference (P<0.007) was observed in favour of the supine position at all dose levels. In the prone position, four patients had small bowel within the 60 Gray (Gy) isodose and in the supine position, no patients had small bowel in the 60 or 38Gy volumes. Supine position was significantly more comfortable for the patients and setup was significantly easier for the radiation therapists. The median patient comfort score was 0.79 (Standard deviation (SD) 0.03) supine and 0.45 (SD 0.05) prone (P<0.001) The therapist convenience of setup was 0.80 (SD 0.016) supine and 0.54 (SD 0.025) prone (P<0.005). No statistically significant difference was seen for the other parameters studied. CONCLUSIONS: We demonstrated significantly less PM in the supine treatment position. There was no difference for either treatment position in IPE or TPE, however, more pre-treatment corrections were required in the prone position. Prone position required a larger PTV with resulting increased dose to critical organs. There were statistically significant improvements at all dose levels for small bowel, rectal wall and bladder wall doses in the supine position once corrections were made for differences in organ motion. Linear analogue scores of patient comfort and radiation therapist convenience demonstrated statistically significant improvement in favour of the supine position. Supine positioning has been adopted as the standard for conformal prostatic irradiation at our centre.

Aged↗

PubMed2000

Short-term effect of inhaled nitric oxide and prone positioning on gas exchange in patients with severe acute respiratory distress syndrome.

OBJECTIVE: To compare the short-term effects of inhaled nitric oxide (NO) and prone positioning in improving oxygenation in acute respiratory distress syndrome (ARDS). METHODS: Charts of consecutive ARDS patients (lung injury score >2) during a 2-yr period, tested for both inhaled NO and prone positioning efficacy were retrospectively reviewed. Variations in the Pao2/Fio2 ratio induced by inhaled NO and prone positioning were evaluated. MEASUREMENTS AND MAIN RESULTS: Twenty-seven patients (age, 42+/-17 yrs) were included. Simplified Acute Physiology Score II was 45+/-14. Mortality rate in the intensive care unit was 63%. The causes of ARDS were pneumonia (n = 14), extra-lung infection (n = 5), and noninfectious systemic inflammatory response syndrome (n = 8). Lung injury score was 2.7+/-0.3. At baseline, before the initiation of inhaled NO, the Pao2/Fio2 ratio was 97+/-46 torr and before prone positioning, 92+/-26 torr. Variations in the Pao2/Fio2 ratio were lower at start of NO therapy (11+/-4 ppm) than that observed at prone positioning initiation (23+/-31 vs. 62+/-78 torr, p<.05). An increase in variations in the Pao2/Fio2 ratio of >15 torr was associated with prone positioning in 16 patients (59%) and with NO inhalation in 13 patients (48%) (not significant). An increase in variations in the Pao2/Fio2 ratio of >15 torr was associated with both techniques in only six patients (22%). There was no correlation between the response to prone positioning and the response to inhaled NO (r2 = .005; p = .73). CONCLUSIONS: Prone positioning improves hypoxemia significantly better than does inhaled NO. The response to one technique is not predictive of the response to the other technique.

APACHE↗

PubMed2006

Prone positioning can be safely performed in critically ill infants and children.

OBJECTIVE: To describe the effects of prone positioning on airway management, mechanical ventilation, enteral nutrition, pain and sedation management, and staff utilization in infants and children with acute lung injury. DESIGN: Secondary analysis of data collected in a multiple-center, randomized, controlled clinical trial of supine vs. prone positioning. SETTING: Seven pediatric intensive care units located in the United States. PATIENTS: One hundred and two pediatric patients (51 prone and 51 supine) with acute lung injury. INTERVENTIONS: Patients randomized to the supine group remained supine. Patients randomized to the prone group were positioned prone per protocol during the acute phase of their illness for a maximum of 7 days. Both groups were managed using ventilator and sedation protocols and nutrition and skin care guidelines. MEASUREMENTS AND MAIN RESULTS: Airway management and mechanical ventilatory variables before and after repositioning, enteral nutrition management, pain and sedation management, staff utilization, and adverse event data were collected for up to 28 days after enrollment. There were a total of 202 supine-prone-supine cycles. There were no differences in the incidence of endotracheal tube leak between the two groups (p = .30). Per protocol, 95% of patients remained connected to the ventilator during repositioning. The inadvertent extubation rate was 0.85 for the prone group and 1.03 for the supine group per 100 ventilator days (p = 1.00). There were no significant differences in the initiation of trophic (p = .24), advancing (p = .82), or full enteral feeds (p = .80) between the prone and supine groups; in the average pain (p = .81) and sedation (p = .18) scores during the acute phase; and in the amount of comfort medications received between the two groups (p = .91). There were no critical events during a turn procedure. While prone, two patients experienced an obstructed endotracheal tube. One patient, supported on high-frequency oscillatory ventilation, experienced persistent hypercapnea when prone and was withdrawn from the study. The occurrence of pressure ulcers was similar between the two groups (p = .71). Compared with the supine group, more staff (p </= .001) and more time were necessary to reposition patients in the prone group. CONCLUSIONS: Our data show that prone positioning can be safely performed in critically ill pediatric patients and that these patients can be safely managed while in the prone position for prolonged periods of time.

Analgesia↗

PubMed2001

Comparison of the response to the prone position between pulmonary and extrapulmonary acute respiratory distress syndrome.

OBJECTIVES: To determine whether the response to the prone position differs between acute respiratory distress syndrome (ARDS) resulting from a pulmonary cause (ARDSp) and that from an extrapulmonary cause (ARD-Sexp). DESIGN AND SETTING: Prospective observational study in a medical ICU of a university-affiliated hospital. SUBJECTS: A consecutive series of 31 patients with ARDSp and 16 with ARDSexp within 3 days of onset of ARDS. INTERVENTION: Prone position for at least 2 h. MEASUREMENTS AND RESULTS: In ARDSp, compared with the supine position (121 +/- 49 mmHg), PaO2/FIO2 was not increased after 0.5 h but was increased after 2 h in the prone position (158 +/- 60 mmHg). In ARDSexp, compared with the supine position (106 +/- 53 mmHg), PaO2/FIO2 was increased after 0.5 h (155 +/- 91 mmHg), but was not further changed after 2 h. Marked oxygenation response (increase in PaO2/FIO2 > 40% from baseline) after 0.5 h was 23% in ARDSp and 63% in ARDSexp, and that after 2 h was 29% and 63%, respectively. Static respiratory compliance decreased in the prone position in ARDSexp (30 +/- 11 ml/cmH2O at baseline, 27 +/- 11 after 0.5 h and 25 +/- 9 after 2 h) but not in ARDSp. Consolidation score as determined on the first chest radiography taken in the prone position decreased to a greater degree in ARDSexp (-2.4 +/- 4.1) than in ARDSp (0.3 +/- 4.1). CONCLUSION: Pulmonary ARDS and extrapulmonary ARDS in their early stages respond differently to the prone position with regard to the time course of oxygenation, respiratory mechanical behaviour, and radiographic change. These findings suggest that the early pathophysiology of ARDS differs according to the type of primary insult to the lung.

Aged↗

PubMed2001

Clinical guidelines for the use of the prone position in acute respiratory distress syndrome.

The mortality associated with acute respiratory distress syndrome (ARDS) remains high. It has been suggested that use of the prone position may improve survival. However, approaches to the use of the position are often haphazard. The development of clinical guidelines indicating the need for the prone position in ARDS and the process by which the manoeuvre may be performed were thought to be important for two reasons. Primarily, we sought to improve oxygenation through the use of the prone position whilst promoting patient safety. Secondly, we wished to standardize our approach to the use of the prone position and make recommendations for practice so that its use was no longer seen as a last resort in the management of ARDS. The process associated with the development of clinical guidelines is first described. This is followed by presentation of the clinical guidelines. Included in these are the criteria and discussion which indicate consideration of the prone position, potential exclusion criteria, pre-turn considerations, the turning technique, monitoring the effectiveness of the prone position, passive movements and limb positioning and, finally, documentation of the problems associated with use of the prone position. The paper concludes with discussion concerning the potential for future research in this area.

Algorithms↗

PubMed2006

High frequency oscillatory ventilation and prone positioning in a porcine model of lavage-induced acute lung injury.

BACKGROUND: This animal study was conducted to assess the combined effects of high frequency oscillatory ventilation (HFOV) and prone positioning on pulmonary gas exchange and hemodynamics. METHODS: Saline lung lavage was performed in 14 healthy pigs (54 +/- 3.1 kg, mean +/- SD) until the arterial oxygen partial pressure (PaO2) decreased to 55 +/- 7 mmHg. The animals were ventilated in the pressure controlled mode (PCV) with a positive endexpiratory pressure (PEEP) of 5 cmH2O and a tidal volume (VT) of 6 ml/kg body weight. After a stabilisation period of 60 minutes, the animals were randomly assigned to 2 groups. Group 1: HFOV in supine position; group 2: HFOV in prone position. After evaluation of prone positioning in group 2, the mean airway pressure (Pmean) was increased by 3 cmH2O from 16 to 34 cmH2O every 20 minutes in both groups accompanied by measurements of respiratory and hemodynamic variables. Finally all animals were ventilated supine with PCV, PEEP = 5 cm H2O, VT = 6 ml/kg. RESULTS: Combination of HFOV with prone positioning improves oxygenation and results in normalisation of cardiac output and considerable reduction of pulmonary shunt fraction at a significant (p < 0.05) lower Pmean than HFOV and supine positioning. CONCLUSION: If ventilator induced lung injury is ameliorated by a lower Pmean, a combined treatment approach using HFOV and prone positioning might result in further lung protection.

Journal Article↗