Patient In Prone Position Research Articles

Prone position applied to COVID-19 patients: Systematic review-meta-analysis.

Position change and interventions to increase lung capacity should be considered in mechanically ventilated patients. The most effective of these is the prone position. This systematic review and meta-analysis aimed to determine the effects of the prone position on respiratory parameters and outcomes and to guide nurses working in the intensive care unit. This systematic review-meta-analysis was conducted in accordance with the Preferred Reporting in Systematic Reviews and Meta-Analyses guideline. ScienceDirect, CINAHL, Academic Search Complete (EBSCOhost), MEDLINE, EMBASE, Web of Science, Cochrane and PubMed databases were searched between January 2022 and January 2023 to access studies related to prone position in COVID-19 patients. Twenty-three studies were included. This meta-analysis shows that a prone position is feasible and can achieve improvements in gas exchange. Prone position increases PaO2/FiO2 in the majority of patients followed with a diagnosis of COVID-19 and severe hypoxemic. The study has shown that the prone position is effective in improving patients' respiratory function and oxygenation. The results presented in this article support the notion that the prone position can be an effective strategy in the clinical management of COVID-19 patients.

Respiratory effects of prone position in COVID-19 acute respiratory distress syndrome differ according to the recruitment-to-inflation ratio: a prospective observational study

BackgroundImprovements in oxygenation and lung mechanics with prone position (PP) in patients with acute respiratory distress syndrome (ARDS) are inconstant. The objectives of the study were (i) to identify baseline variables, including the recruitment-to-inflation ratio (R/I), associated with a positive response to PP in terms of oxygenation (improvement of the ratio of arterial oxygen partial pressure over the inspired oxygen fraction (PaO2/FiO2) ≥ 20 mmHg) and lung mechanics; (ii) to evaluate whether the response to the previous PP session is associated with the response to the next session.MethodsIn this prospective, observational, single-center study in patients who underwent PP for ARDS due to COVID-19, respiratory variables were assessed just before PP and at the end of the session. Respiratory variables included mechanical ventilation settings and respiratory mechanics variables, including R/I, an estimate of the potential for lung recruitment compared to lung overinflation.ResultsIn 50 patients, 201 PP sessions lasting 19 ± 3 h were evaluated. Neuromuscular blockades were used in 116 (58%) sessions. The PaO2/FiO2 ratio increased from 109 ± 31 mmHg to 165 ± 65 mmHg, with an increase ≥ 20 mmHg in 142 (71%) sessions. In a mixed effect logistic regression, only pre-PP PaO2/FiO2 (OR 1.12 (95% CI [1.01–1.24])/every decrease of 10 mmHg, p = 0.034) in a first model and improvement in oxygenation at the previous PP session (OR 3.69 (95% CI [1.27–10.72]), p = 0.017) in a second model were associated with an improvement in oxygenation with PP. The R/I ratio (n = 156 sessions) was 0.53 (0.30–0.76), separating lower- and higher-recruiters. Whereas PaO2/FiO2 improved to the same level in both subgroups, driving pressure and respiratory system compliance improved only in higher-recruiters (from 14 ± 4 to 12 ± 4 cmH2O, p = 0.027, and from 34 ± 11 to 38 ± 13 mL/cmH2O, respectively, p = 0.014).ConclusionsA lower PaO2/FiO2 at baseline and a positive O2-response at the previous PP session are associated with a PP-induced improvement in oxygenation. In higher-recruiters, lung mechanics improved along with oxygenation. Benefits of PP could thus be greater in these patients.

Efficacy and Safety of Dexmedetomidine in the Prone Position in Elderly Patients with Pneumonia: A Prospective, Double-Blind, Randomized Controlled Study.

We aimed to identify a safe and effective method to assist older adults with pneumonia in tolerating the prone position for a longer duration. This was a randomized, controlled, double-blinded study performed at the Shanghai Fourth People's Hospital. Eighty patients with pneumonia aged ≥ 65years were included. The patients were able to spontaneous breath in the prone position and were administered intravenous dexmedetomidine or an isotonic sodium chloride solution. The cumulative daily durations of prone positioning for all patients in the two groups were recorded. The primary outcome was the percentage of patients who completed ≥ 9h/day in the prone position. The secondary outcomes included the incidence of complications in the prone position and patient outcomes. Eighty patients were included (average age: 79.6 ± 8.9years). The percentage of patients who completed ≥ 9h/day in the prone position was significantly higher in the dexmedetomidine group than in the placebo group (P = 0.011). The percentage of patients who completed ≥ 12h/day in the prone position was also significantly greater in the dexmedetomidine group than in the placebo group (P = 0.008). There were no significant differences in other variables between the two groups. The results of this study demonstrate that intravenous dexmedetomidine injection can significantly prolong the duration of spontaneous breathing in the prone position in elderly pneumonia patients without obvious adverse events. We provide a safe and effective method to help patients with pneumonia, especially those with delirium or cognitive impairment, who cannot tolerate the length of time needed for spontaneous breathing in the prone position to be effective. The study was registered with the Chinese Clinical Trial Center (registration number: ChiCRT2300067383) on 2023-01-05.

Effect of early prone positioning among critically ill patients admitted with acute respiratory distress syndrome during the COVID-19 pandemic: A comparative retrospective observational study

Background and objective: COVID-19 has offered an opportunity to the clinicians to try and study various oxygenation enhancing maneuvers in the patients. These included lung protective measures and prone positioning of participants admitted to the ICU with acute respiratory distress syndrome. We aimed to identify the effects of early prone positioning on the length of stay, discharge rate, and frequency of tracheostomies in the ICU patients. Methodology: This retrospective study was conducted on critically ill patients needing mechanical ventilation with lung protective strategy, admitted to the Intensive Care Units of Al-Azhar University Hospitals between March 2020 to April 2022. All patients in the study were interpreted retrospectively by examining the patient's records. Group A (n = 39) included patients who had been early placed in prone positions within 24 h of intubation, and Group B (n = 31) included patients who had not been placed in prone positions. All patients received a lung protective strategy for ARDS. In both groups, PaO2, PaCO2, pH, SpO2, and PaO2/FiO2 ratio were checked initially and later every 24 h for 6 days. Data was evaluated for the total days of both hospital and ICU length of stay, number of successful discharges to home from the hospital, and the total number of tracheostomized patients. Results: After prone positioning, lower SOFA and APACHE II scores were noticed in the prone group. There was no significant difference in the rate of discharge between the two groups. We observed non-significant shorter hospital and ICU stays and higher frequency of tracheostomy procedures in the prone group. We noticed a significant improvement in PaO2/FiO2 ratios in the prone group starting from day 2 to day 6. We observed a significant improvement in PO2 in the prone group in comparison to the non-prone group. Conclusions: Early prone positioning of patients admitted to the ICU with acute respiratory distress syndrome during COVID-19 pandemic led to a significant improvement in both PaO2 and PaO2/FiO2 ratio with a non-significant decrease in both hospital and ICU length of stay as shown by the collected data over consecutive six days. Abbreviations: ARDS- acute respiratory distress syndrome; FiO2: The fraction of inspired oxygen; CPAP: Continuous Positive Airway Pressure; PaO2: Arterial oxygen partial pressure; PEEP: Positive End-Expiratory Pressure; SOFA- Sequential Organ Failure Assessment Keywords: Prone; Lung protective measures; ARDS; APACHI II; SOFA Citation: Seyam SHA, Ahmed IMA. Effect of early prone positioning among critically ill patients admitted with acute respiratory distress syndrome during the COVID-19 pandemic: a comparative retrospective observational study. Anaesth. pain intensive care 2024;28(4):626−632; DOI: 10.35975/apic.v28i4.2504 Received: February 12, 2024; Reviewed: May 14, 2024; Accepted: May 15, 2024

Investigation of the Usefulness of Implants With Locking Mechanisms for Diffuse Idiopathic Skeletal Hyperostosis (DISH)-Induced Thoracic and Lumbar Fractures in Patients Operated in the Prone Position.

Background Diffuse idiopathic skeletal hyperostosis (DISH) is a disease that causes bone growth in the spine and musculoskeletal system, and even minor trauma can cause fractures that often require surgery. DISH-induced fractures show a tendency for bone loss when operated in the prone position, which can lead to poor fusion and implant failure; therefore, surgery in the lateral recumbent position is often recommended. However, inserting a pedicle screw (PS) in the lateral recumbent position is technically difficult. This study examined the effectiveness of the repair and fixation of thoracic and lumbar spine fractures using implants with locking mechanisms in the prone position in patients with DISH. Methods We retrospectively analyzed the data from 11 patients (six males and five females; mean age: 87 years) who underwent surgery for thoracic and lumbar fractures caused by DISH between December 2023 and June 2024. Surgery was performed in the prone position using PSs or transdiscal screws (TSDs) for DISH. Ennovate® implants manufactured by B-BRAUN were used. The fixed range was three above-three below for PSs and two above-two below for TSDs. The evaluation parameters were the height/level of injury, operative time, blood loss, local kyphosis angle, anterior wall height ratio, and complications. The local kyphosis angle was measured as the angle between the upper and lower endplates of the fractured vertebrae. The ratio of the anterior wall height was evaluated. Results The average operative time was 87 min (52-172 min), and the average blood loss was 40ml (10-140 ml). The preoperative and postoperative local kyphosis angle was -8.7° and -2.4°, respectively, and the average local kyphosis angle improvement was 6.3° (0.1-14°). The preoperative and postoperative anterior wall height ratio was 132% and 110%, respectively, and the average anterior wall height ratio improvement was 22% (2-82%). No complications, such as screw deviation, implant loosening, loss of correction, or skin problems, were observed. Conclusion This study demonstrated that DISH-induced thoracic and lumbar spine fractures could be repaired and fixed using implants with locking mechanisms in the prone position. The prone position is familiar to spine surgeons and is considered safe. Additionally, screw migration may occur due to decreased bone density in the vertebral bodies with DISH; in such cases, it would be better to fix the screw without forcing it to be repositioned.

Determination of the best point of entry of percutaneous insertion of sacroiliac screws depending on patient positioning for surgery: A cadaveric study.

The standard starting point for percutaneous sacroiliac screw insertion was initially determined at the intersection of the line posterior to the anterior superior iliac spine and the line continuing the anatomical axis of the femur. The technique was pioneered in patients lying prone in surgery, although it has been used with patients in the supine position. The optimal starting point for patients in both prone and supine positions remains uncertain. This cadaveric study aimed to determine the best entry point for the percutaneous insertion of sacroiliac screws depending on the patient's positioning for surgery. Kirschner wires (K-wires) were percutaneously inserted into the sacral body of 8th human cadavers. In addition to the so-called standard sacroiliac screw entry point (point A), points located consecutively 1 cm (point B) and 2 cm (point C) cranially from the point along the line, prolonging the femoral axis were also studied. The K-wires were inserted into the studied entry points on the right side in a supine position and on the left side of the same cadaver in a prone position. The placement of the K-wires was assessed using radiographic imaging and cadaver dissection. An analysis of the K-wire placement in the supine position revealed incorrect positioning of 100% of the K-wires inserted at entry point A and 87% at entry point B. All the K-wires inserted in the supine position at entry point C were correctly placed. All K-wires inserted in the prone position were correctly positioned. All 3 studied entry points enabled the correct placement of orthopedic implants for prone position surgery. The best entry point for surgery performed in the supine position was located 2 cm cranially from the standard entry point, along the line prolonging the femoral axis.

Prolonged vs shorter awake prone positioning for COVID-19 patients with acute respiratory failure: a multicenter, randomised controlled trial

PurposeAwake prone positioning has been reported to reduce endotracheal intubation in patients with coronavirus disease 2019 (COVID-19)-related acute hypoxemic respiratory failure (AHRF). However, it is still unclear whether using the awake prone positioning for longer periods can further improve outcomes.MethodsIn this randomized, open-label clinical trial conducted at 12 hospitals in China, non-intubated patients with COVID-19-related AHRF were randomly assigned to prolonged awake prone positioning (target > 12 h daily for 7 days) or standard care with a shorter period of awake prone positioning. The primary outcome was endotracheal intubation within 28 days after randomization. The key secondary outcomes included mortality and adverse events.ResultsIn total, 409 patients were enrolled and randomly assigned to prolonged awake prone positioning (n = 205) or standard care (n = 204). In the first 7 days after randomization, the median duration of prone positioning was 12 h/d (interquartile range [IQR] 12–14 h/d) in the prolonged awake prone positioning group vs. 5 h/d (IQR 2–8 h/d) in the standard care group. In the intention-to-treat analysis, intubation occurred in 35 (17%) patients assigned to prolonged awake prone positioning and in 56 (27%) patients assigned to standard care (relative risk 0.62 [95% confidence interval (CI) 0.42–0.9]). The hazard ratio (HR) for intubation was 0.56 (0.37–0.86), and for mortality was 0.63 (0.42–0.96) for prolonged awake prone positioning versus standard care, within 28 days. The incidence of pre-specified adverse events was low and similar in both groups.ConclusionProlonged awake prone positioning of patients with COVID-19-related AHRF reduces the intubation rate without significant harm. These results support prolonged awake prone positioning of patients with COVID-19-related AHRF.

Awake fiberoptic intubation of a patient with severe multiple trauma in prone position: a case report

BackgroundFiberoptic-guided intubation is considered as “gold standard” of difficult airway management. Management of the airway in prone position in patients with severe trauma presenting with penetrating waist and hip injury poses a major challenge to the anesthesiologist.Case presentationA man presented with severe multiple trauma and hemorrhagic shock as a result of an industrial accident with several deformed steel bars penetrating the left lower waist and hip. It was decided to schedule an exploratory laparotomy following extracting the deformed steel bars. Successful administration of awake fiberoptic nasotracheal intubation, performed in a prone position under airway blocks and appropriate sedation, allowed for the procedure. The exploratory laparotomy revealed damage to multiple organs, which were repaired sequentially during a 7-hour surgical operation. The patient’s recovery was uneventful, and he was discharged from the hospital one month after the surgery.ConclusionsAwake fiberoptic nasotracheal intubation, along with airway blocks and appropriate sedation, can be a viable option in patients with severe multiple trauma in the prone position.

Intubation of a Patient in Prone Position with the Videolaryngoscope in a Street Trauma

Intubation of a Patient in Prone Position with the Videolaryngoscope in a Street Trauma

Application effect and influencing factors of early awake prone position in patients with mild-to-moderate acute respiratory distress syndrome

To investigate the application effect of early awake prone position in mild-to-moderate acute respiratory distress syndrome (ARDS) patients, and analyze the related factors affecting the prone position outcome. A prospective cohort study was conducted. The mild-to-moderate ARDS patients admitted to the emergency department of Yingshang County People's Hospital from January 2020 to June 2023 were enrolled as the research subjects. According to the results of prone tolerance test, the patients were divided into awake prone position group and non-prone position group. All patients were given high flow nasal cannula (HFNC) according to the standard procedures. The patients in the awake prone position group received prone position treatment within 12 hours after admission, in addition to the standard treatment. This could be performed in several times, at least once a day, and at least 2 hours each time. In order to prolong the prone position as much as possible, the patients were allowed to move or keep a small angle side prone. The changes of oxygenation index (PaO2/FiO2) at 0, 24, 48, and 72 hours after admission, the rate of intensive care unit (ICU) transfer, the use rate and use time of non-invasive ventilation (NIV), the total hospital stay, and the daily prone position time and 2-hour ROX index [ratio of pulse oxygen saturation/fraction of inspired oxygen (SpO2/FiO2) and respiratory rate (RR)] of prone position patients were recorded. The successful termination of HFNC was defined as the successful prone position, and the failure of prone position was defined as switching to NIV or transferring to ICU. Subgroup analysis was performed, and the binary multivariate Logistic regression analysis was used to screen the influencing factors of the early awake prone position outcome. A total of 107 patients were finally enrolled, with 61 in the awake prone position group and 46 in the non-prone position group. Both groups showed a gradual increase in PaO2/FiO2 with prolonged admission time. The PaO2/FiO2 at 24 hours after admission in the awake prone position group was significantly higher than that at 0 hour [mmHg (1 mmHg ≈ 0.133 kPa): 191.94±17.86 vs. 179.24±29.27, P < 0.05], while the difference in the non-prone position group was only statistically significant at 72 hours (mmHg: 198.24±17.99 vs. 181.24±16.62, P < 0.05). Furthermore, the PaO2/FiO2 at 48 hours and 72 hours after admission in the awake prone position group was significantly higher than that in the non-prone position group. The use rate of NIV in the awake prone position group was significantly lower than that in the non-prone position group [36.1% (22/61) vs. 56.5% (26/46), P < 0.05]; Kaplan-Meier curve analysis further confirmed that the patients in the awake prone position group used NIV later, and the cumulative rate of NIV usage was significantly lower than that in the non-prone position group (Log-Rank test: χ 2 = 5.402, P = 0.020). Compared with the non-prone position group, the ICU transfer rate in the awake prone position group was significantly lowered [11.5% (7/61) vs. 28.3% (13/46), P < 0.05], and the HFNC time, NIV time, and total hospital stay were significantly shortened [HFNC time (days): 5.71±1.45 vs. 7.24±3.36, NIV time (days): 3.27±1.28 vs. 4.40±1.47, total hospital stay (days): 11 (7, 13) vs. 14 (10, 19), all P < 0.05]. Of the 61 patients who underwent awake prone positioning, 39 were successful, and 22 failed. Compared with the successful group, the patients in the failure group had a higher body mass index [BMI (kg/m2): 26.61±4.70 vs. 22.91±5.50, P < 0.05], lower PaO2/FiO2, proportion of asymptomatic hypoxemia and 2-hour ROX index of prone position [PaO2/FiO2 (mmHg): 163.73±24.73 vs. 185.69±28.87, asymptomatic hypoxemia proportion: 18.2% (4/22) vs. 46.2% (18/39), 2-hour ROX index of prone position: 5.75±1.18 vs. 7.21±1.45, all P < 0.05], and shorter daily prone positioning time (hours: 5.87±2.85 vs. 8.05±1.99, P < 0.05). Binary multivariate Logistic regression analysis showed that all these factors were influencing factors for the outcome of awake prone positioning (all P < 0.05), among which BMI [odds ratio (OR) = 1.447, 95% confidence interval (95%CI) was 1.105-2.063] and non-asymptomatic hypoxemia (OR = 13.274, 95%CI was 1.548-117.390) were risk factors for failure of prone position, while PaO2/FiO2 (OR = 0.831, 95%CI was 0.770-0.907), daily prone positioning time (OR = 0.482, 95%CI was 0.236-0.924), and 2-hour ROX index of prone position (OR = 0.381, 95%CI was 0.169-0.861) were protective factors. Early awake prone positioning in patients with mild-to-moderate ARDS supported by HFNC is safe and feasible, reducing the use rate and duration of NIV, lowering the ICU transfer rate, and shortening the hospital stay. High BMI and non-asymptomatic hypoxemia are risk factors for failed prone position, while higher PaO2/FiO2 and the ROX index within 2 hours of prone position (the patient's good response to prone position), and prolonged daily prone position can improve the success rate of prone position.

Central venous accesses in prone position during the pandemic period: A narrative review.

The unprecedented challenges posed by the global COVID-19 pandemic have magnified the significance of managing intensive care patients in prone positions, particularly those requiring mechanical ventilation. Central venous access is crucial for delivering essential therapies to patients, particularly in intensive care settings. However, the shift in patient management during the pandemic, necessitating prone positioning for improved oxygenation, presented unique hurdles in maintaining and establishing central venous access. Before the pandemic, scant literature detailed the insertion of vascular access devices in prone or unconventional positions. Limited case reports and letters highlighted the feasibility of procedures like ultrasound-guided central catheter placement in patients undergoing surgery or with specific clinical needs. During the pandemic, a surge in case reports and series illuminated the complexities faced by clinicians in maintaining vascular access during pronation procedures. These reports delineated critical scenarios, ranging from rapid clinical deterioration necessitating immediate interventions to challenges with vascular access device (VAD) malfunctions or misplacements during prone maneuvers. Patient selection and device types emerged as critical considerations. Various scenarios, including patients transitioning to prone position from non-invasive ventilation and those requiring additional access for therapies like dialysis, posed challenges in device selection and placement. Successful VAD insertion techniques in prone patients encompassed multiple anatomical sites, including the internal jugular, brachial, femoral, and popliteal veins. However, challenges persisted, particularly with respect to anatomical variations and technical complexities in cannulation. Further research, standardized protocols, and randomized studies are needed to refine and validate the proposed strategies in both pandemic and non-pandemic settings.

The usefulness of trans-splenic retrocardiac imaging in prone positioned critically ill patients.

In the last few years prone positioning has been used increasingly in the treatment of patients with acute respiratory distress syndrome and this maneuver is now considered a simple and safe method to improve oxygenation. Hemodynamic monitoring by echocardiography may be required but prone positioning imposes certain challenges limiting standard examination. The article describes the application of the "trans-splenic retrocardiac view," a little-known echographic window for obtaining Doppler parameters from the back in prone-positioned patients.

The prone position in COVID-19 impacts the thickness of peripapillary retinal nerve fiber layers and macular ganglion cell layers.

The prone position reduces mortality in severe cases of COVID-19 with acute respiratory distress syndrome. However, visual loss and changes to the peripapillary retinal nerve fiber layer (p-RNFL) and the macular ganglion cell layer and inner plexiform layer (m-GCIPL) have occurred in patients undergoing surgery in the prone position. Moreover, COVID-19-related eye problems have been reported. This study compared the p-RNFL and m-GCIPL thicknesses of COVID-19 patients who were placed in the prone position with patients who were not. This prospective longitudinal and case-control study investigated 15 COVID-19 patients placed in the prone position (the "Prone Group"), 23 COVID-19 patients not in the prone position (the "Non-Prone Group"), and 23 healthy, non-COVID individuals without ocular disease or systemic conditions (the "Control Group"). The p-RNFL and m-GCIPL thicknesses of the COVID-19 patients were measured at 1, 3, and 6 months and compared within and between groups. The result showed that the Prone and Non-Prone Groups had no significant differences in their p-RNFL thicknesses at the 3 follow-ups. However, the m-GCIPL analysis revealed significant differences in the inferior sector of the Non-Prone Group between months 1 and 3 (mean difference, 0.74 μm; P = 0.009). The p-RNFL analysis showed a significantly greater thickness at 6 months for the superior sector of the Non-Prone Group (131.61 ± 12.08 μm) than for the Prone Group (118.87 ± 18.21 μm; P = 0.039). The m-GCIPL analysis revealed that the inferior sector was significantly thinner in the Non-Prone Group than in the Control Group (at 1 month 80.57 ± 4.60 versus 83.87 ± 5.43 μm; P = 0.031 and at 6 months 80.48 ± 3.96 versus 83.87 ± 5.43 μm; P = 0.044). In conclusion, the prone position in COVID-19 patients can lead to early loss of p-RNFL thickness due to rising intraocular pressure, which is independent of the timing of prone positioning. Consequently, there is no increase in COVID-19 patients' morbidity burden.

Prone positioning in awake patients without ventilatory support does not alter major clinical outcomes in severe COVID-19: results from a retrospective observational cohort study, systematic review and meta-analysis

ABSTRACT Objectives During the Coronavirus disease (COVID-19) pandemic, clinicians recommended awake-prone positioning (APP) to avoid the worst outcomes. The objectives of this study were to investigate if APP reduces intubation, death rates, and hospital length of stay (HLOS) in acute COVID-19. Methods We performed a retrospective cohort with non-mechanically ventilated patients hospitalized in a reference center in Manaus, Brazil, 2020. Participants were stratified into APP and awake-not-prone positioning (ANPP) groups. Also, we conducted a systematic review and performed a meta-analysis to understand if this intervention had different outcomes in resource-limited settings (PROSPERO CRD42023422452). Results A total of 115 participants were allocated into the groups. There was no statistical difference between both groups regarding time to intubation (HR: 0.861; 95CI: 0.474-1.1562; p=0.622) and time to death (HR: 1.666; 95CI: 0.939-2.951; p=0.081). APP was not significantly associated with reduced HLOS. A total of 86 articles were included in the systematic review, of which 76 (88,3%) show similar findings after APP. Also, low/middle, and high-income countries were similar regarding such outcomes. Conclusion APP in COVID-19 does not present clinical improvement that affects mortality, intubation rate and HLOS. The lack of a prone position protocol, obtained through a controlled study, is necessary. After 3 years, APP benefits are still inconclusive.

Application and significance of prone position in the treatment of patients with severe pneumonia in intensive care unit

To investigate the effect of prone position on the prognosis of patients with severe pneumonia in intensive care unit (ICU). A retrospective cohort study was conducted. The patients with severe pneumonia admitted to the ICU of Qingdao Municipal Hospital from May 2022 to August 2023 were enrolled. The general information, etiology, underlying diseases, vital signs and laboratory indicators at ICU admission, clinical treatment and prognosis during ICU hospitalization were collected. The above clinical data of patients with different prognosis were compared. Multifactorial Logistic regression analysis was used to screen the related factors affecting survival during ICU in patients with severe pneumonia. The change in oxygenation index (PaO2/FiO2) of patients with severe pneumonia were observed at 1 hour before the first prone position, 1 hour after the first prone position, and 1 hour after the end of the first prone position. The effect of prone position on oxygenation in patients with severe pneumonia was analyzed. Spearman correlation analysis was used to investigate the correlation between the duration to first prone position and the change in the PaO2/FiO2 before and after prone position in patients with severe pneumonia. Finally, a total of 144 patients with severe pneumonia were enrolled, 45 survived and 99 died during ICU hospitalization, with a mortality of 68.8%. Compared with the survival group, the patients in the death group were older [years old: 81.00 (70.75, 86.00) vs. 71.00 (60.50, 81.50), P < 0.01], the proportion of pre-existing lung disease, heart rate (HR), respiratory rate (RR), blood lactic acid (Lac) and the ratio of continuous renal replacement therapy (CRRT) were higher [ratio of pre-existing lung disease: 23.2% (23/99) vs. 8.9% (4/45), HR (bpm): 99.61±22.47 vs. 91.49±18.76, RR (times/min): 22.50 (19.75, 29.25) vs. 20.00 (17.50, 24.50), Lac (mmol/L): 2.00 (1.55 , 3.25) vs. 1.60 (1.20, 1.95), CRRT ratio: 25.3% (25/99) vs. 6.7% (3/45), all P < 0.05], and the proportion of prone position was lower [41.4% (41/99) vs. 68.9% (31/45), P < 0.01]. Multifactorial Logistic regression analysis showed that age [odds ratio (OR) = 0.946, 95% confidence interval (95%CI) was 0.912-0.980, P = 0.002] and Lac (OR = 0.563, 95%CI was 0.340-0.930, P = 0.025) were negatively correlated with survival during ICU hospitalization in severe pneumonia patients, while prone position was positively correlated with survival (OR = 2.551, 95%CI was 1.067-6.095, P = 0.035), indicating that prone position was beneficial for improving ICU prognosis in severe pneumonia patients. The results of PaO2/FiO2 at different time points in prone position showed that PaO2/FiO2 at 1 hour of the first prone position in the patients with severe pneumonia was significantly higher than that at 1 hour before the first prone position [mmHg (1 mmHg ≈ 0.133 kPa): 146.69 (113.92, 257.25) vs. 111.75 (70.15, 212.20), P < 0.01], indicating that the prone position had a relevant effect on the improvement of oxygenation in patients. Spearman correlation analysis showed that the duration of the first prone position in patients with severe pneumonia was significantly and positively correlated with the improvement of oxygenation at 1 hour of the first prone position (r = 0.565, P < 0.001). The prone position is a therapeutic measure that can independently influence the prognosis of patients with severe pneumonia during ICU hospitalization. The prone position effectively improves oxygenation in patients with severe pneumonia and the first change in oxygenation in patients is related to the duration of the prone position.

284 CT-Based Assessment of Prone Versus Lateral Pedicle Screw Placement Accuracy: A Retrospective Single-surgeon Study

INTRODUCTION: Lateral lumbar interbody fusion (LLIF) including the anterior-to-psoas oblique lumbar interbody fusion (OLIF) has conventionally relied on pedicle screw placement (PSP) for construct stabilization. Single-position surgery with lumbar interbody fusion (LIF) in the lateral decubitus position with concomitant PSP has been associated with increased operative efficiency. What remains unclear is the accuracy of PSP with robotic guidance when compared to the more familiar prone patient positioning. METHODS: We identified all consecutive patients treated with interbody fusion and PSP in the prone or lateral position by a single surgeon between January 2019 and October 2022. All pedicle screws placed were analyzed using CT imaging to determine appropriate positioning according to the Gertzbein-Robbins Classification Grading System. Multivariate logistic regression models were constructed to identify risk factors for the occurrence of a radiographically significant breach. RESULTS: 89 consecutive patients were included (n = 690 screws), of whom 46 were treated in the prone position (n = 477 screws) and 43 in the lateral decubitus position (n = 213 screws). There were fewer breaches in the prone (n = 13; 2.7%) versus lateral decubitus group (n = 15; 7.0%; p = 0.012). Nine (1.9%) radiographically significant breaches occurred in the prone group compared to 10 (4.7%) in the lateral decubitus group (p = 0.019), for a prone vs. lateral decubitus pedicle screw accuracy rate of 98.1% vs. 95.3%. There were no significant differences in BMI between prone vs. lateral decubitus cohorts (30.1 vs. 29.6) or breached patients vs. non-breached patients (31.2 vs. 29.5). In multivariate models, prone position was the only significant protective factor for screw accuracy; we did not identify any other significant risk factors for screw breach. CONCLUSIONS: The present data suggest pedicle screws placed with robotic assistance have higher placement accuracy in the prone position.

The evaluation of a non-invasive respiratory monitor in ards patients in supine and prone position

Purpose: The Prone positioning in addition to non invasive respiratory support is commonly used in patients with acute respiratory failure. The aim of this study was to assess the accuracy of an impedance-based non-invasive respiratory volume monitor (RVM) in supine and in prone position. Methods: In sedated, paralyzed and mechanically ventilated patients in volume-controlled mode with acute respiratory distress syndrome scheduled for prone positioning it was measured and compared non-invasively tidal volume and respiratory rate provided by the RVM in supine and, subsequently, in prone position, by maintaining unchanged the ventilatory setting. Results: Forty patients were enrolled. No significant difference was found between measurements in supine and in prone position either for tidal volume (p = 0.795; p = 0.302) nor for respiratory rate (p = 0.181; p = 0.604). Comparing supine vs. prone position, the bias and limits of agreements for respiratory rate were 0.12 bpm (-1.4 to 1.6) and 20 mL (-80 to 120) for tidal volume. Conclusions: The RVM is accurate in assessing tidal volume and respiratory rate in prone compared to supine position. Therefore, the RVM could be applied in non-intubated patients with acute respiratory failure receiving prone positioning to monitor respiratory function.

Sacral Neuromodulation: Device Improvement and Current Applications in Urology.

Sacral neuromodulation (SNM) offers a therapeutic approach to urological patients suffering from idiopathic overactive bladder (OAB) syndrome, with or without incontinence and non-obstructive urinary retention (NOR), who are not responding to or are not compliant with conservative or medical therapies. The exact mechanism of action of SNM is not fully understood but modulation of the spinal cord reflexes and brain networks by peripheral afferents is regarded as the main pathway. Over the years, surgical techniques improved, leading to the development of the modern two-stage implantation technique. The quadripolar lead is positioned percutaneously under fluoroscopy guidance through the third sacral foramen following the trajectory of S3. The procedure can be performed under local or general anesthesia with the patient in prone position. Current applications of sacral neuromodulation in urology are increasing thanks to the recent improvements of the devices that make this a valuable option not only in conditions such as overactive bladder and non-obstructing urinary retention but also neurogenic lower urinary tract dysfunction.

Supine versus prone percutaneous nephrolithotomy in management of patient with complex renal stone diseases.

Compare the surgical outcomes, safety, stone free rate, hospital stay, and complication of prone and supine PCNL in case of complex renal stone. This is an observational study conducted in our institute, it consist of 120 patients over the period of 2 years from July 2021 to June 2023, all the patients were divided into two groups: 60 patients underwent modified supine percutaneous nephrolithotomy (PCNL) and remaining 60 patients underwent standard prone PCNL. The measured data included operative time, number of punctures, blood loss, stone-free rate, length of hospital stays, and rate of complications. The two groups were comparable in mean age, male to female ratio, number of punctures, number of tract, size of tract, residual calculi in follow up period, blood transfusion, re-do surgery, chest complication, hospital stay, and postoperative fever and pain. The mean operating time was 1.59 h in supine PCNL and 2.49 h in prone PCNL. The p value was significant (p = 0.001). By this study we observed that the supine PCNL is associated with statistically significant reduced operating time as compared to conventional prone PCNL with advantages of not putting the patient in prone position. The postoperative complications such as pain and fever were not significant when compared in both groups. We conclude our study and found that, the supine PCNL is an equally effective in treating complex renal stone as compared to prone PCNL.

The Impact of Patient-Specific Positions on the Relationship between Iliac Blood Vessels and Lumbar Intervertebral Discs: Anatomical Significance and Clinical Implications

This study explores the anatomical relationship between iliac blood vessels and the lower lumbar spine during supine and prone patient positions. The average height of participants was 174.02 cm ± 9.01, while the average weight was 80.38 kg ± 13.48. Body mass index (BMI) analyses showed differences (p = 0.002), with 34.7% classified as normal weight, 53.1% as overweight, and 12.2% as moderately obese. The study examined the distances between iliac arteries and veins in relation to intervertebral anterior and posterior disc contours. Patient positioning significantly affected these measurements at both L4/L5 and L5/S1 levels. The findings highlight the critical influence of body position on anatomical relationships in the context of lower lumbar spine surgery. The study underscores the importance of preoperative awareness of vascular anatomy to prevent iatrogenic lesions during spine surgery, contributing valuable insights for optimizing surgical approaches and minimizing complications in spine surgery, particularly microdiscectomy.