Mechanical Ventilation In Prone Position Research Articles

Enteral nutrition in critically ill patients with covid-19 on mechanical ventilation in prone position

Enteral nutrition in critically ill patients with covid-19 on mechanical ventilation in prone position

腹臥位から仰臥位へ体位交換時に肺血栓塞栓症を発症した重症COVID–19肺炎の2例(Two cases of pulmonary embolism after position change from prone position during mechanical ventilation due to severe COVID–19 pneumonia)

COVID–19肺炎では腹臥位呼吸療法の有効性が注目されている。今回，腹臥位から仰臥位への体位交換時に発症した肺血栓塞栓症を2例経験したので報告する。1例目は59歳の男性，発症11日目に人工呼吸を開始し，15日目から腹臥位呼吸療法を開始した。17日目に仰臥位へ体位交換した30分後より，SpO2が94%から85%へと低下し，心拍数も90bpmから120bpmへ上昇した。D–ダイマーが9.2μg/mLから22.5μg/mLへ上昇していたため，肺血栓塞栓症を疑い，造影CTで左肺動脈血栓が判明した。2例目は46歳の男性，発症13日目で人工呼吸を開始し，同日腹臥位呼吸療法を開始した。14日目に仰臥位へ体位交換した10分後より血圧低下，12分後からSpO2が97%から84%へと低下した。D–ダイマーが5.6μg/mLから48.1μg/mLへ上昇していたことと，心臓超音波検査で右心負荷所見がみられたことから肺血栓塞栓症を疑い，造影CTで左内頸静脈血栓と右肺動脈血栓が判明した。今回の2症例は，いずれも腹臥位から仰臥位に体位交換した際に肺血栓塞栓症を発症しており，いずれも中心静脈カテーテル挿入側の内頸静脈に血栓を認めた。長時間の腹臥位から仰臥位への体位交換は，内頸静脈血栓から肺血栓塞栓症を発症させる可能性が示唆され，バイタルサインに留意して行うことが望ましい。 The prone position during mechanical ventilation has been reported to be effective in respiratory failure caused by COVID–19 pneumonia. We report two cases of pulmonary thromboembolism that may have occurred during return to the supine position. A 59–year–old man, with COVID–19 pneumonia, was put on mechanical ventilation in supine position from day 11 to day 15, and prone position from day 15 to day 17. Thirty minutes after returning to the supine position on day 17, he developed hypoxemia and tachycardia. Pulmonary thromboembolism was suspected based upon elevated D–dimer levels. Echo venogram of the right internal jugular vein showed thrombi, and contrast–enhanced computed tomography (CECT) showed thrombi in the left pulmonary artery. A 46–year–old man, with COVID–19 pneumonia, was put on mechanical ventilation in prone position from day 13 to day 14. On day 14, when he was returned to the supine position, he developed hypotension after 10 minutes, and hypoxemia after 12 minutes. CECT showed thrombi in the left internal jugular vein and right pulmonary artery. During mechanical ventilation, a change to the supine position after prolonged prone position may cause pulmonary thromboembolism from thrombi in the internal jugular vein, and should be performed with attention to vital signs. 腹臥位呼吸療法は，acute respiratory distress syndrome（ARDS）の死亡率を低下させる可能性があり 1，COVID–19肺炎にもしばしば実施される。当院でも，集中治療管理を要するCOVID–19肺炎患者に対し，16時から翌日10時の18時間を腹臥位，残りの6時間を仰臥位とする腹臥位呼吸療法を施行した。腹臥位呼吸療法での合併症として，気管チューブ閉塞，事故抜管，静脈路の事故抜去，褥瘡，視力障害，腕神経叢損傷などが報告されている 2。今回，腹臥位から仰臥位への体位交換を契機に発症した肺血栓塞栓症（pulmonary embolism: PE）を2例経験したので報告する。 なお，本症例の報告は倫理委員会の承諾は不要であり，個人情報保護法に基づいて匿名化がなされ，患者・家族の同意を得ている。 患 者：59歳の男性 既往歴：痛風，脂質異常症 現病歴：発熱・頭痛で発症し，同日SARS–CoV–2 PCR陽性と判明した。発症5日目に酸素化不良のため，当院に入院となった。11日目に呼吸状態悪化のため気管挿管し，人工呼吸管理となった。 入院後経過：気管挿管後より，深部静脈血栓症（deep vein venous thrombosis: DVT）予防を目的として，ヘパリンカルシウム5,000単位の皮下注射を1日2回開始した。発症13日目に撮像した体幹部造影CTでは，PE，DVTともに指摘されなかったが，14日目にD–ダイマーが9.8µg/mLと上昇した。超音波検査で，中心静脈カテーテル挿入側である右内頸静脈に血栓を認め（Fig. 1a），リバーロキサバン15mg内服を開始した。また，13日目に撮像したCTでは背側の無気肺が著明であり，人工呼吸器関連肺炎も併発したため，背面開放と体位ドレナージを目的とし，15日目より腹臥位呼吸療法を開始した。17日目に，腹臥位から仰臥位に体位交換した30分後より，SpO2が94%から85%へと低下し，心拍数も90bpmから120bpmへ上昇した（Fig. 2）。 Case 1: Jugular vein echo (a). major and minor axis image showing right internal jugular vein (white arrow). Chest computed tomography (b). Axial view showing left main pulmonary artery thrombus (white triangle). Case 1: Course at onset of pulmonary embolism. ベッドサイドで可能な検査や理学所見では，気胸や痰による閉塞性無気肺を認めなかった。超音波検査では右心拡大を認めなかったが，依然として右内頸静脈に血栓が存在していた。両側大腿静脈，膝窩静脈には，血栓はみられなかった。右内頸静脈血栓があること，D–ダイマーが22.5µg/mLと上昇（前日9.2µg/mL）していること，また長時間の腹臥位から体位交換をした際に起きた酸素化低下と頻脈であることから，PEを強く疑った。既にリバーロキサバン内服が行われていたが，治療量でなかったため30mgに増量し，翌日待機的に造影CTを施行した。造影CTでは，左主肺動脈に血栓塞栓症がみられた（Fig. 1b）。以上の所見より，腹臥位から仰臥位への体位交換を契機に発症したPEと診断した。 その後，COVID–19肺炎後器質化肺炎に対して，プレドニゾロン60mg/day（1mg/kg）を開始した。発症25日目に38度台の発熱があり，膿性痰が出現したため，人工呼吸器関連肺炎としてピペラシリン・タゾバクタム13.5ｇ/日を投与開始した。その後のCTで，左肺に多発空洞影を認め，肺化膿症と診断した。抗菌薬治療を60日間継続した後，発症93日目に，リハビリテーション目的に転院となった。 患 者：49歳の男性 既往歴：慢性中耳炎 現病歴：咽頭痛・発熱で発症し，翌日SARS–CoV–2 PCR陽性と判明した。呼吸困難感が出現したため，発症11日目に前医入院となった。呼吸状態悪化のため翌日当院に転院となり，13日目に気管挿管を施行し，人工呼吸管理を開始した。 入院後経過：気管挿管後より，DVT予防を目的として，ヘパリンカルシウム5,000単位の皮下注射を1日2回開始した。気管挿管後も酸素化が改善しなかったため，同日夕方より腹臥位呼吸療法を開始した。翌日，腹臥位から仰臥位に体位交換した10分後から，徐々に血圧が低下し，SpO2も低下した（Fig. 3）。 Case 2: Course at onset of pulmonary embolism. ベッドサイドで可能な検査や理学所見では，気胸や痰による閉塞性無気肺を認めなかった。超音波検査では，両側大腿静脈，膝窩静脈には血栓を認めなかったが，左内頸静脈の中心静脈カテーテル周囲に血栓を認め，右心拡大も認めた。左内頸静脈血栓があること，D–ダイマーが48.1µg/mLと上昇（前日5.6µg/mL）していること，右心負荷所見があり，長時間の腹臥位から体位交換をした際に起きた血圧低下，酸素化低下であることから，PEを強く疑った。APTTの目標を50secとしてヘパリンナトリウム14,000U/dayの持続静脈注射を開始し，同日に造影CTを施行した。造影CTでは左内頸静脈（下顎角から胸鎖関節付近の鎖骨下静脈合流部），および右肺動脈に血栓を認めた（Fig. 4a, b）。 Case 2: Chest computed tomography. Axial view showing right pulmonary artery thrombus in the middle lobe (a. white triangle). Axial view showing left internal jugular vein thrombus (b. white arrow). 以上の所見より，腹臥位から仰臥位へ体位交換した際に発症したPEと診断した。発症第15日目に人工呼吸器関連肺炎を発症したため，セフェピム3g/日を投与開始した。16日目に，P/F ratioが191から289へ改善し，18日目に気管チューブを抜去した。また，19日目にヘパリンからリバーロキサバン30mg/dayへ変更し，22日目に前医に再転院となった。 PEの塞栓源は，約90%が下肢あるいは骨盤内の静脈とされている。しかし，2例とも内頸静脈に血栓があり，超音波検査と造影CTで，両下肢静脈内に明らかな血栓はみられなかった。このことから，内頸静脈血栓からの塞栓子が原因で，PEを発症したと考えられる。集中治療を行う場合，内頸静脈への中心静脈カテーテル留置を行う機会が多いが，中心静脈カテーテルの挿入は内頸静脈血栓形成のリスクとして知られている 3。また，2例ともヘパリンの予防投与を行っていたが，中心静脈カテーテル挿入側の内頸静脈に血栓を認めた。COVID–19では，血管内皮細胞にもSARS–CoV–2感染が成立する。ウイルス感染により障害された血管内皮細胞からの凝固第VIII因子とvon Willebrand factorの放出や，サイトカインストームが血栓傾向の誘引となり，深部静脈血栓症の発症率が上昇するとされている 4。 なお，今回の2症例目では，中心静脈カテーテルを挿入した同日16時ごろから翌日10時ごろまで腹臥位呼吸療法を行い，仰臥位に体位交換をした際にPEを生じている。中心静脈カテーテル挿入時の超音波検査では血栓を認めておらず，腹臥位呼吸療法を行っている18時間の間に，血栓が形成された可能性が高い。鎖骨による鎖骨下静脈合流部への圧迫で内頸静脈の血流うっ滞が生じ，内頸静脈血栓の形成に腹臥位が寄与していた可能性が考えられる。1例目においても，長時間の腹臥位が，既存の内頸静脈血栓の伸展を助長した可能性がある。このような血栓形成のリスクが重なり，ヘパリン予防投与を行っていたにもかかわらず血栓が形成されたと考えられる。 DVTは，通常発生部位から中枢へ成長する過程で，血栓中枢端や伸展血栓が遊離，もしくは血栓の静脈壁接着面が剥離して塞栓子となる。関節周囲や下腿筋ポンプ内のような特殊な状況では，起立，歩行などの際に下肢の筋肉が収縮し，伸展血栓が容易に塞栓化しやすいとされている 5。腹臥位呼吸療法において，腹臥位から仰臥位へ体位交換したことを契機としてPEを発症したという報告は，我々の渉猟する限りみられなかったが，脊椎手術では数例報告されている 6, 7。腹臥位中は，鎖骨による圧迫や胸腔内圧上昇に伴い，内頸静脈や下大静脈のうっ滞が起こることが示唆されている。腹臥位から仰臥位への体位交換で，これらが解除されることにより，血行動態が一時的に変化しうる。それにより，体位交換という受動的な運動であっても，長時間の腹臥位の間に伸展，形成された内頸静脈血栓が遊離した可能性が考えられる。 腹臥位から仰臥位に体位交換した際の酸素化低下はしばしば経験され，原病が重篤，あるいは背側無気肺が著明である場合は，対症療法を行うのみで見過ごされてしまう可能性もある。しかし，今回1例目は頻脈，2例目では血圧低下と，SpO2の低下以外にもバイタルサインの変化を認めていた。COVID–19の血栓症発症リスクが高いことも踏まえ 8, 9，PEを鑑別にあげて対応し，治療介入することができた。さらに2例目は，1例目の経験から，仰臥位への体位交換が内頸静脈血栓を塞栓子としたPE発症の契機となる可能性があることを認識していた。そのため，ベッドサイドでの超音波検査で，両側大腿静脈に加え内頸静脈も観察を行い，内頸静脈血栓を認知することができ，PEを鑑別疾患の上位に挙げることができた。なお，両症例ともPE発症日の採血でD–ダイマーの上昇がみられていた。腹臥位呼吸療法施行中のD–ダイマー上昇は，血栓形成もしくは伸展を示唆している可能性があり，仰臥位に復帰した際にバイタルサイン変動がみられた場合には，PEの発症を疑う必要があると考える。なお，ARDS患者の腹臥位では健常人と異なり，換気血流比不均等の改善による右心負荷の軽減や，左心前負荷増大により，心拍出量が増加する 10。仰臥位への体位交換時には，これらの血行動態の変化は速やかに元に戻り，心拍出量は低下する。これは，PEを発症した際の重症度を高める可能性がある。 当院では，腹臥位からの体位交換時はSpO2，心電図，end–tidal CO2などの観血的動脈圧以外の一部モニターを外していた。同様にモニターを外しており初期症状であるバイタルサインの変化を察知できずに 11，心停止まで至った脊椎手術症例の報告もある 6。今回2例とも，モニターは仰臥位復帰後早急に再装着され，バイタルサインの変化に早期に気づくことができた。モニター未装着となる時間を短縮することが，早期にPEの兆候を察知するために重要である。なお，PE発症時にSpO2低下はよくみられるが，より劇的な症例では急激にend–tidal CO2が低下することが知られており，脊椎手術中end–tidal CO2低下がPE発症覚知の一助となった報告もある 12。当院では腹臥位から仰臥位への体位交換時，end–tidal CO2モニターを外していることがほとんどであった。end–tidal CO2モニターは，頭側で回路混線せずに装着したまま安全に体位交換できるため，今後の腹臥位療法では，装着を継続して体位交換することも，検討の余地がある。 腹臥位呼吸療法時は，内頸静脈還流のうっ滞などにより形成・伸展した内頸静脈血栓が，仰臥位への体位交換で遊離しPEを発症する恐れがあるため，注意して体位交換を行う必要がある。また，腹臥位からの体位復帰時に生じる循環虚脱や肺酸素化能の低下にはPEが関与している可能性があり，これらのバイタルサインの変化を早期に察知するために，装着可能なモニターはできる限り装着を継続し，困難な場合にもモニター未装着時間を可能な限り短縮して迅速な体位交換を行うことが望ましい。 著者全員に本論文に関する利益相反はない。

Exogenous surfactant reduces inflammation and redox imbalance in rats under prone or supine mechanical ventilation.

Mechanical ventilation (MV) is a lifesaving therapy for patients with acute or chronic respiratory failure. Despite, it can also cause lung injury by inducing or worsening inflammatory responses and oxidative stress. Several clinical approaches have protective effects on the lungs, including the prone position and exogenous surfactant; however, few studies have evaluated the association between the two strategies, especially in individuals without previous lung injury. We tested the hypothesis that the effects of the homogenization in lung aeration caused by the prone position in association with the anti-inflammatory properties of exogenous surfactant pre-treatment could have a cumulative protective effect against ventilator-induced lung injury. Therefore, Wistar rats were divided into four experimental groups: Mechanical Ventilation in Supine Position (MVSP), Mechanical Ventilation in Prone position (MVPP), Mechanical Ventilation in Supine Position + surfactant (MVSPS), and Mechanical Ventilation in Prone Position + Surfactant (MVPPS). The intranasal instillation of a porcine surfactant (Curosurf®) was performed in the animals of MVSPS and MVPPS 1 h before the MV, all the rats were subjected to MV for 1 h. The prone position in association with surfactant decreased mRNA expression levels of pro-inflammatory cytokines in ventilated animals compared to the supine position; in addition, the NfκB was lower in MVPP, MVSPS and MVPPS when compared to MVSP. However, it had no effects on oxidative stress caused by MV. Pre-treatment with exogenous surfactant was more efficient in promoting lung protection than the prone position, as it also reduced oxidative damage in the lung parenchyma. Nevertheless, the surfactant did not cause additional improvements in most parameters that were also improved by the prone position. Our results indicate that the pre-treatment with exogenous surfactant, regardless of the position adopted in mechanical ventilation, preserves the original lung histoarchitecture, reduces redox imbalance, and reduces acute inflammatory responses caused by mechanical ventilation in healthy adult Wistar rats.

Hemodialysis vascular access in prone position for critically ill patients with ARDS.

Acute respiratory distress syndrome (ARDS) is defined in critically ill patients with acute hypoxemia and positive-pressure ventilation in association with several clinical disorders including trauma, pneumonia, sepsis, and aspiration. The prone position has been used for many years and is now recommended for patients with severe or moderate-to-severe ARDS on invasive mechanical ventilation. Acute kidney injury (AKI) is a common complication in patients with ARDS, with up to a 35% incidence rate. Initiation of Kidney Replacement Therapy (KRT) requires wise clinical judgment and collaboration between nephrologists and intensivists. A properly functioning vascular access is critical for an optimized KRT. Our institute is a national referral center for respiratory diseases. We describe 11 cases of dialysis catheter placement for KRT in critically ill patients with ARDS on mechanical ventilation in prone position. The catheter was placed in the first puncture attempt in nine cases, Blood flows (Qb) achieved were 283.4 ± 20.4 ml/min during the session, in six cases the radiologic tip location was achieved in the peri cavoatrial junction; in four cases was achieved in mid to- deep right atrium. The dialysis quality standards were based on KTV and in URR; in nine cases (81.81%) KTV was in 1.3 and in all cases (100%) URR was >65%, lumen dysfunction was reported only in two cases (18.1%), but these cases did respond to mobilization maneuvers. The procedure time of placement was 29.8 min, no arterial punctures or complications were reported. We demonstrate that in our study hemodialysis non-tunneled catheter placement in the prone position is safe and effective. We believe this practice could be frequently used in the near future and represent an opportunity window for the training of interventional nephrologists and related areas.

Physiological effect of prone positioning in mechanically ventilated SARS-CoV-2- infected patients with severe ARDS: An observational study.

Background and Aims:Mechanical ventilation in prone position was associated with a reduction in mortality and increase in arterial oxygenation in acute respiratory distress syndrome (ARDS) patients. However, physiological effects of prone position in COVID ARDS patients are unknown.Material and Methods:In this prospective observational study, data of n = 47 consecutive real time RT- PCR confirmed SARS-CoV-2-infected patients with severe ARDS were included. Respiratory mechanics and oxygenation data of recruited patients were collected before and after prone position.Results:Median (Interquartile range, IQR) age of the recruited patients was 60 (50–67) years and median (IQR) PaO2/FiO2 ratio of 61.2 (54–80) mm Hg with application of median (IQR) positive end expiratory pressure (PEEP) of 12 (10–14) cm H2O before initiation of prone position. Out of those patients, 36 (77%) were prone responders at 16 hours after prone session, evident by increase of PaO2 by at least 20 mm Hg or by 20% as compared to baseline, and 73% patients were sustained responders (after returning to supine position). Plateau airway pressure (p < 0.0001), peak airway pressure (p < 0.0001), and driving pressure (p < 0.0001) were significantly reduced in prone position, and static compliance (p = 0.001), PaO2/FiO2 ratio (p < 0.0001), PaO2 (p = 0.0002), and SpO2 (p = 0.0004) were increased at 4 hours and 16 hours since prone position and also after returning to supine position.Conclusion:In SARS-CoV-2-infected patients, mechanical ventilation in prone position is associated with improvement in lung compliance and oxygenation in almost three-fourth of the patients and persisted in supine position in more than 70% of the patients.

Considerations of invasive mechanical ventilation in prone position. A narrative review

The evidence regarding logistic considerations and safety events associated with prone position ventilation (PPV) is summarized and a flow diagrama for safe provision of mechanical ventilation in the setting of the COVID-19 pandemic is proposed. A review of the literature was conducted in the Medline via Pubmed, Embase, and Lilacs databases, the Cochrane Database of Systematic Reviews, Cochrane Central Register of Randomized Controlled Trials, Cochrane Database of Abstracts of Reviews of Effects, ProQuest Nursing and Allied Health Database, and Google scholar. Overall, 31 articles were selected for the analysis. The incidence of PPV-related safety events varies between 1% and 11.9% and the most frequent complications are pressure ulcers and airway complications. Early initiation of enteral nutrition is recommended, and transfers are possible in patients on PPV. There is controversy regarding contraindications and recommendations for PPV. Recommendations for its safe provision are based on expert opinions and the establishment of protocols for healthcare staff training. Clinical studies are required to determine which are the recommendations that should be considered for safe and reproducible PPV use during this pandemic.

Nursing care and prevalence of adverse events in prone position: Characteristics of mechanically ventilated patients with severe SARS-CoV-2 pulmonary infection.

BackgroundBecause of the coronavirus disease 2019 (COVID‐19) pandemic, the use of prone positioning has dramatically increased in the intensive care unit (ICU). Because this manoeuvre is related to several complications, it must be performed in a protocolized manner by the appropriate personnel.AimTo determine the prevalence of adverse events (AEs) in patients admitted to the ICU with a diagnosis of COVID‐19‐related acute respiratory distress syndrome (C‐ARDS) undergoing mechanical ventilation in prone position (PP).DesignDescriptive ambispective study of patients admitted to the ICU diagnosed with C‐ARDS undergoing mechanical ventilation who were in the PP at least once.The number of PP manoeuvres and the time spent in the PP were recorded for each subject. AEs proportions and frequencies were calculated, and analysis of variance was used to assess mean differences in the number of manoeuvres and total hours in PP stratified by the number of facial pressure ulcers. IBM SPSS Statistics v.25.0. and EPIDAT 4.1 software were used.ResultsForty‐four patients were analysed, and 130 PP manoeuvres were performed. The most frequently observed AEs were facial oedema in 26 patients (80.3%) and facial pressure ulcers in 20 (60.6%). There was a significant positive association between the time spent in PP and the development of facial pressure ulcers (P < .001). Enteral nutrition was well tolerated, and no serious AEs or sentinel events were noted.ConclusionDespite the stressful, demanding situation during the peak of the pandemic, the large number of PP manoeuvres, and long duration spent in this position, no serious AEs occurred. This study highlights the need to implement preventive measures to avoid the development of pressure ulcers secondary to prone positioning.Relevance to practiceProne positioning requires a nursing protocol to prevent the occurrence of AEs that may reduce the quality of nursing care.

Nutritional Management of Critically Ill Patients Infected with SARS-CoV-2

AbstractEarly nutritional therapy is essential to ensure the maintenance of adequate energy/protein intake for critically ill patients infected with severe acute respiratory syndrome caused by COVID-19 (SARS-CoV-2) infection. However, this poses a major challenge when it comes to individuals on mechanical ventilation in prone position. Therefore, the present work presents a nutritional therapy flowchart developed for patients with SARS-CoV-2 infection to guide nutritional management and ensure that energy/protein intake goals are met, thus favoring a positive clinical outcome.

Cardiopulmonary Resuscitation in Prone Position

Mechanical ventilation in prone position is an alternative strategy for patients with acute respiratory discomfort syndrome (ARDS) to improve oxygenation in situations when traditional ventilation modalities have failed. However, due to the significant increase in ARDS cases during the SARS-CoV-2 pandemic and the experimental therapeutic use of potentially arrhythmogenic drugs, cardiopulmonary resuscitation in this unusual position could be needed. Therefore, we will review the available scientific evidence of cardiopulmonary resuscitation in prone position. Cardiopulmonary Resuscitation in Prone Position

Trans-thoracic Echocardiography in Prone Positioning COVID-19 Patients: a Small Case Series

During SARS-CoV-2 pandemic, several subjects were treated in our intensive care unit (ICU) because of acute respiratory failure following COVID-19 pneumonia. Most of them required mechanical ventilation and someone in prone position (PP) too, because of acute respiratory distress syndrome (ARDS). During PP, trans-esophageal echocardiography (TEE) is not always easy, mainly due to the forced position of the neck of the patient. Moreover, during a pandemic, given the great number of patients needing treatment, TEE probes and monitoring devices are not widely available. Then, trans-thoracic echocardiography (TTE) plays a crucial role as it is non-invasive, repeatable, and available every time it is needed. Moreover, it can be safely performed also in prone position (TTEp). According to in-hospital protocol, TTEp was performed using the apical-four-chamber (A-4-C) view in 8 patients. We temporarily deflated the lower thoracic section of the air-mattress to place the probe between the mattress surface and the thorax of the patient. We collected both TEE and hemodynamics data. The main result of our retrospective analysis is that TTE can be performed in patients in prone positioning and is reliable and repeatable; the single apical-four-chamber view provides sufficient data to evaluate the cardiac performance in case of scarce availability of hemodynamic monitoring devices, like in a pandemic setting. TTE may be a helpful tool for cardiac performance evaluation and diagnosis not only in supine or anterolateral positioning like in echocardiographic lab, but also in subjects admitted to ICU due to ARDS needing of mechanical ventilation in prone positioning.

Personal knowledge on novel coronavirus pneumonia.

Personal knowledge on novel coronavirus pneumonia.

Feasibility, tolerance and effectiveness of enteral feeding in critically ill patients in prone position.

To assess the feasibility, tolerance and effectiveness of enteral nutrition in critically ill patients receiving invasive mechanical ventilation in the prone position for severe Acute Respiratory Distress Syndrome (ARDS). Prospective observational study conducted in a multidisciplinary critical care unit of a tertiary care hospital from January 2013 until July 2015. All patients with ARDS who received invasive mechanical ventilation in prone position during the study period were included. Patients' demographics, severity of illness (Acute Physiology and Chronic Health Evaluation (APACHE II) score), baseline markers of nutritional status (subjective global assessment (SGA) and body mass index), details of nutrition delivery during prone and supine hours and outcomes (Length of stay and discharge status) were recorded. Fifty-one patients met inclusion criteria out of whom four patients were excluded from analysis since they did not receive any enteral nutrition due to severe hemodynamic instability. The mean age of patients was 46.4 ± 12.9 years, with male:female ratio of 7:3. On admission, SGA revealed moderate malnutrition in 51% of patients and the mean APACHE II score was 26.8 ± 9.2. The average duration of prone ventilation per patient was 60.2 ± 30.7 h. All patients received continuous nasogastric/orogastric feeds. The mean calories (kcal/kg/day) and protein (g/kg/day) prescribed in the supine position were 24.5 ± 3.8 and 1.1 ± 0.2 while the mean calories and protein prescribed in prone position were 23.5 ± 3.6 and 1.1 ± 0.2, respectively. Percentage of prescribed calories received by patients in supine position was similar to that in prone position (83.2% vs. 79.6%; P = 0.12). Patients received a higher percentage of prescribed protein in supine compared to prone position (80.8% vs. 75%, P = 0.02). The proportion of patients who received at least 75% of the caloric and protein goals was 37 (78.7%) and 37 (78.7%) in supine and 32 (68.1%) and 21 (44.6%) in prone position. In critically ill patients receiving invasive mechanical ventilation in the prone position, enteral nutrition with nasogastric/orogastric feeding is feasible and well tolerated. Nutritional delivery of calories and proteins in prone position is comparable to that in supine position.

Clinical observation of prone position ventilation combined with lung recruitment maneuver in the treatment of severe ARDS patients

Objective To investigate the effect of mechanical ventilation in prone position combined with lung recruitment on severe acute respiratory distress syndrome (ARDS). Methods From February 2015 to February 2017, 82 patients with ARDS admitted to ICU of the Second Hospital of Shanxi Medical University were divided into two groups according to random number table, with 41 cases in each group.The study group was treated with mechanical ventilation in prone position combined with lung recruitment therapy, and the control group was treated with mechanical ventilation in supine position combined with lung recruitment therapy.The differences of heart rate (HR), central venous pressure (CVP), mean arterial pressure (MAP), partial pressure of oxygen (PaO2), oxygenation index (PaO2/FiO2), plateau pressure (Pplat), and static pulmonary compliance (Cst) were compared between the two groups before treatment (T0), and 1h (T1), 2h (T2), 6h (T3) after treatment. Results The PaO2 and PaO2/FiO2 levels of the two groups increased significantly after lung recruitment.In the study group at different time after treatment, PaO2[(69.17±7.51)mmHg, (74.64±6.78)mmHg, (82.52±10.37)mmHg], PaO2/FiO2 [(116.91±15.57)mmHg, (123.06±16.34)mmHg, (135.23±18.41)mmHg]were higher than those in the control group[PaO2: (64.23±7.72)mmHg, (68.51±8.05)mmHg, (73.43±9.12)mmHg; PaO2/FiO2: (106.50±12.97)mmHg, (115.42±13.19)mmHg, (123.42±14.95)mmHg], the differences were statistically significant (t=3.225, 3.254, 4.245, 3.954, 3.886, 4.135, all P<0.05). HR and CVP increased at T2-T3, T3 decreased, MAP decreased at T2-T3, and T3 increased in both two groups.HR at T1-T3 in the study group were (123.17±13.41)times/min, (114.64±10.08)times/min, (102.52±6.57)times/min, which were lower than those in the control group[(129.23±12.75)times/min, (117.51±10.35)times/min, (108.43±9.77)times/min], the differences between the two groups were statistically significant (t=3.884, 4.215, 4.667, all P<0.05). Conclusion Prone position mechanical ventilation combined with lung recruitment can effectively improve the oxygenation status of severe ARDS, and has less effect on hemodynamics, and the effect is better than supine position mechanical ventilation combined with lung recruitment. Key words: Respiratory distress syndrome, adult; Respiration, artificial; Prone position ventilation; Lung recruitment; Treatment

Application and nursing progress of mechanical ventilation in prone position in patients with respiratory failure

The prone position ventilation, as a new type of mechanical ventilation treatment technology, has been widely used in clinical practice. Patient populations and disease types have been obviously expanded. The implementation of the technology needs medical staff's cooperation. The intervention effect, safety and quality critically depend on nursing work. In the whole process, the nursing quality has been put forward higher request. In recent years, increasing scholars have paid attention to the related researches. This paper summarizes the clinical application, nursing points, and the challenges of the prone position ventilation in patients with respiratory failure, in order to provide reference for the development and optimization of the clinical nursing. Key words: Review; Prone position; Respiration, artificial; Respiratory failure; Nursing progress

Prone position and pressure control inverse ratio ventilation in H1N1 patients with severe acute respiratory distress syndrome.

Aim:To observe the 28 and 90 days mortality associated with prone position and assist control-pressure control (with inverse ratio) ventilation (ACPC-IRV).Materials and Methods:All patients who were admitted to our medical Intensive Care Unit (ICU) who are positive for H1N1 viral infection with severe acute respiratory distress syndrome (ARDS) and requiring invasive mechanical ventilation in prone position were included in our prospective observational study. Six patients who are positive for H1N1 required invasive ventilation in prone position. These patients were planned to ventilate in prone for 16 h and in supine for 8 h daily until P/F ratio >150 with FiO2 of 0.6 or less and positive end-expiratory pressure <10 cm of H2 O.Results:At admission, among these six patients the mean tidal volume generated was about 376.6 ml which was in the range of 6–8 ml/kg predicted body weight. The mean lung injury score was 3.79, mean PaO2 /FiO2 ratio was 52.66 and mean oxygenation index was 29.83. The mean duration of ventilation was 9.4 days (225.6 h). The ICU length of stay was 11.16 days. There was no mortality at 28 and 90 days.Conclusion:Early prone combined with ACPC-IRV in H1N1 patients having severe ARDS can be used as a rescue therapy and it should be confirmed by large observational studies.

Meralgia Paresthetica after Prone Positioning Ventilation in the Intensive Care Unit.

Meralgia paresthetica (MP) is a mononeuropathy of the lateral femoral cutaneous nerve (LFCN) caused by external compression of the nerve during its course close to the anterior superior iliac spine. We present a case of a patient with acute respiratory distress induced by Legionella pneumonia who was admitted to the intensive care unit (ICU) for mechanical ventilation. In the ICU, the patient received one session of prone position ventilation for 8.5 consecutive hours. At evaluation six months later, the patient reported persistent bilateral numbness of the anterolateral thigh, which he complained had begun right after he woke up at the ICU. He was referred for further neurological and neurophysiological examination and was diagnosed with bilateral MP, a condition never previously described as a complication to mechanical ventilation in prone position in the ICU.

Enteral Nutrition in Patients Receiving Mechanical Ventilation in a Prone Position.

Patients treated with mechanical ventilation in the prone position (PP) could have an increased risk for feeding intolerance. However, the available evidence supporting this hypothesis is limited and contradictory. To examine the feasibility and efficacy of enteral nutrition (EN) support and its associated complications in patients receiving mechanical ventilation in PP. Prospective observational study including 34 mechanically ventilated intensive care patients who were turned to the prone position over a 3-year period. End points related to efficacy and safety of EN support were studied. In total, more than 1200 patients were admitted to the intensive care unit over a period of 3 years. Of these, 34 received mechanical ventilation in PP. The mean days under EN were 24.7 ± 12.3. Mean days under EN in the supine position were significantly higher than in PP (21.1 vs 3.6; P < .001), but there were no significant differences in gastric residual volume adjusted per day of EN (126.6 vs 189.2; P = .054) as well as diet volume ratio (94.1% vs 92.8%; P = .21). No significant differences in high gastric residual events per day of EN (0.06 vs 0.09; P = .39), vomiting per day of EN (0.016 vs 0.03; P = .53), or diet regurgitation per day of EN (0 vs 0.04; P = .051) were found. EN in critically ill patients with severe hypoxemia receiving mechanical ventilation in PP is feasible, safe, and not associated with an increased risk of gastrointestinal complications. Larger studies are needed to confirm these findings.

Effectiveness of Prone Ventilation in patients with Acute Respiratory Distress Syndrome: a systematic review.

Review question/objective The objective of this review is to identify and synthesize the best available evidence related to the benefits of prone ventilation in critically ill adult patients with Acute Respiratory Distress Syndrome. More specifically, the objectives are to identify: the effectiveness of prone positioning in critically ill adult patients requiring mechanical ventilation due to Acute Respiratory Distress Syndrome on mortality, oxygenation and duration of mechanical ventilation. Inclusion criteria Types of participants This review will consider studies that include patients older than 18 years, regardless of gender or ethnicity, who are critically ill, admitted to ICU for Acute Lung Injury or Acute Respiratory Distress Syndrome as defined by European-American Consensus4 and have failed conventional modes of ventilation. Studies with control group who did not receive tidal volume of 6-8 mL/Kg IDBW ventilation as per ARDS protocol will be excluded. Types of intervention(s)/phenomena of interest This review will consider as the intervention of interest, the mechanical ventilation in prone position as compared with the mechanical ventilation in supine position. Types of outcomes The primary outcome of interest is reported mortality. The secondary outcomes of interest are: improvement in oxygenation measured as ratio of arterial partial pressure of oxygen over fraction of inhaled oxygen (PaO2/FiO2); duration of mechanical ventilation measured as number of days that the patient required mechanical ventilation until discharge from the hospital.

Prone or PEEP, PEEP and prone

Dear Editor, Recently in your journal, Sud et al. [1] reported on a meta-analysis of randomized controlled trials of mechanical ventilation in the prone position. They found a 16% reduction in relative risk of mortality among patients with baseline PaO2/FiO2 <100 mmHg, which was consistent with their a priori hypothesis that improved oxygenation during prone ventilation would be clinically important in patients at high risk of death from profound hypoxemia. Furthermore, post hoc analysis showed that the statistically significant difference between the relative risks of mortality in the more severely hypoxemic patients versus the less severely hypoxemic patients was robust across several PaO2/FiO2 thresholds up to 140 mmHg. This meta-analysis could help bedside clinicians in their decisions to mechanically ventilate patients in the prone position, or not. The investigators chose a threshold PaO2/FiO2 of 100 mmHg because this value was used to stratify patients in a recent randomized controlled trial of mechanical ventilation in prone position [2], and because bedside clinicians can readily determine whether a patient’s PaO2/FiO2 is above or below this threshold. However, a practical question facing bedside clinicians when deciding to use or forego mechanical ventilation in the prone position is interpretation of the effects of the level of positive end-expiratory pressure (PEEP). Higher levels of PEEP recruit collapsed alveoli, and as such improve oxygenation. Thus, higher levels of PEEP could erroneously give the impression that acute respiratory distress syndrome (ARDS) is not present or resolving, causing bedside clinicians to forego the use of mechanical ventilation in the prone position. Of course, it should be noted that the investigators chose to use the baseline PaO2/FiO2 as a threshold in their analysis. Frequently the baseline PaO2/FiO2 is not greatly influenced by PEEP, since the level of PEEP usually is low at the moment it is calculated (i.e., directly after initiation of mechanical ventilation). However, this may not always be true, especially not in intensive care units familiar with use of higher levels of PEEP (i.e., where PEEP is titrated on peripheral oxygenation, frequently before any arterial blood sample is obtained). In addition, patients may develop ARDS during the course of mechanical ventilation [3]. In these patients, higher levels of PEEP are used even more regularly. Probably it was not possible to obtain sufficient data to calculate the Lung Injury Score [4] or the Oxygenation Index [5] from the trials that were meta-analyzed. Both the Lung Injury Score and the Oxygenation Index take into account the level of PEEP (or mean airway pressure). It can be questioned, however, whether bedside clinicians can readily determine these scores, and thus adequately use them in their decisions to use or forego mechanical ventilation in the prone position. We developed a more practical approach in our intensive care unit (Fig. 1). In case of acute respiratory distress syndrome with profound hypoxemia (defined as PaO2/FiO2 <125 mmHg) we first raise the level of PEEP stepwise to 15 cmH2O. Each step may or may not be preceded by recruitment maneuvers by using sustained inflation. From then, the prone position is used, irrespective of PaO2/FiO2, with the knowledge that PaO2/FiO2 would decline if the level of PEEP would be reduced. Prone ventilation is continued as long as the level of PEEP to be used is ≥15 cmH2O. If PaO2/FiO2 remains <125 mmHg with prone ventilation, the level of PEEP is further increased and inversed ratio ventilation is used. This approach is not evidence based, though it is practical and in harmony with the findings of the meta-analysis by Sud et al. [1]. In our center, neither extracorporeal membrane oxygenation nor high-frequency oscillation nor ventilation with nitric oxide is used. Fig. 1 Schematic presentation of the local mechanical ventilation guideline; mechanical ventilation in the prone position is used when the level of PEEP is >15 cmH2O, aiming for PaO2/FiO2 >125 mmHg (below the dotted line); prone ...

Effects of prone and supine position on oxygenation and inflammatory mediator in a hydrochloric acid-induced lung dysfunction in rats

To compare the effectiveness of mechanical ventilation of supine versus prone position in hydrochloric acid (HCl)-induced lung dysfunction. Twenty, adult, male, Wistar-EPM-1 rats were anesthetized and randomly grouped (n=5 animals per group) as follows: CS-MV (mechanical ventilation in supine position); CP-MV (mechanical ventilation in prone position); bilateral instillation of HCl and mechanical ventilation in supine position (HCl+S); and bilateral instillation of HCl and mechanical ventilation in prone position (HCl+P). All groups were ventilated for 180 minutes. The blood partial pressures of oxygen and carbon dioxide were measured in the time points 0 (zero; 10 minutes before lung injury for stabilization), and at the end of times acid injury, 60, 120 and 180 minutes of mechanical ventilation. At the end of experiment the animals were euthanized, and bronchoalveolar lavages (BALs) were taken to determine the contents of total proteins, inflammatory mediators, and lungs wet-to-dry ratios. In the HCl+P group the partial pressure of oxygen increased when compared with HCl+S (128.0+/-2.9 mmHg and 111.0+/-6.7 mmHg, respectively) within 60 minutes. TNF-alpha levels in BAL do not differ significantly in the HCl+P group (516.0+/-5.9 pg/mL), and the HCl+S (513.0+/-10.6 pg/mL). The use of prone position improved oxygenation, but did not reduce TNF-alpha in BAL upon lung dysfunction induced by HCl.