氧氣供應成了抗擊新冠疫情的最新瓶頸。
許多感染新冠病毒后住院的患者都有肺部感染并且需要輸氧,其中甚至包括那些病情還未嚴重到需要上呼吸機的患者。
根據這些患者的數量及其需要的氧氣量估算,醫院的儲備很快將被耗盡,而氧氣廠商則很難跟上需求的步伐。
醫院通常建有大型集中式液氧儲罐,其中的液氧經氣化后通過管道輸送到醫院各處。有些醫院還會使用小容量液氧瓶。
但在意大利,有報道稱由于需要呼吸機及其他方式輸氧的病患人數激增,新冠疫情期間醫院的氧氣日用量已經增長了兩倍以上。在意大利北部疫情最嚴重的地區,有些醫院已經被迫安裝了新的大型液氧儲罐,以確保氧氣供應充足。
在英國,據稱倫敦一家大型醫院的氧氣上周末就將消耗殆盡。受此影響,英國國家醫療服務體系(NHS)緊急發函,要求醫生計算自家醫院氧氣能同時滿足的患者人數,同時限制CPAP(持續氣道正壓呼吸機)的使用。CPAP的作用是幫助那些病情還未嚴重到需要呼吸機的患者。
CPAP及其他被稱為“經鼻高流量氧療”的治療方式是將氧氣管插入患者鼻孔后直接輸氧,其每小時氧氣消耗量往往遠高于呼吸機。NHS稱,過多病患同時使用這樣的治療方法還可能讓醫院的氧氣管網壓力失衡,從而使整個管網突然失靈,而這會讓醫院中所有使用壁式供氧裝置的患者陷入危險之中。
NHS的警告表明,就算英國能為新冠肺炎患者生產出足夠的呼吸機,氧氣的供應問題也將成為一大限制。
與此同時,紐約市的許多醫生都說自己的醫院也處于管道氧氣即將耗盡的危險境地。有報道稱,因為所有的管道氧氣供氧設備都已被占用,一些醫院開始用氧氣瓶治療患者,而醫生表示氧氣瓶的數量也不多了。
總部設在新澤西州克拉克鎮的全球供應鏈咨詢公司GEP副總裁比瑞·莫漢是制藥和醫療保健行業專家。他說對醫療氧氣需求量增幅的預測范圍很大,介于25%-500%之間。莫漢指出,大多數氧氣廠商平時會保留約20%的后備產能,他們應該有能力滿足醫院需求的增長,特別是在建筑、石油和天然氣等其他行業的氧氣需求因經濟陷入停滯而直線下降的時候。
取自空氣
理論上,有幾個因素限制著氧氣廠商的產量。大多數生產商都用空氣制氧。他們將空氣過濾后采用低溫制氧工藝,也就是用空氣壓縮機將空氣溫度降至極低水平,然后將其中的氧氣、氮氣等分離出來。分離出的氣體還將進一步凈化和純化為液體,或者裝入壓力儲罐和小型氧氣瓶中。大多數工序都由基本的物理反應和熱反應推動,幾乎不使用化學原料。
莫漢說,更大的實際問題在于醫院接受的通常都是液氧,他們隨后會把液氧氣化,然后通過管道輸送到醫院各處。而醫院的液氧儲存能力有限,因此運輸車輛必須往返更多次才能保持醫院的液氧儲備水平。
本月初,英國重癥監護協會負責人、加內什·孫塔拉林加姆醫生在英國麻醉醫師協會主辦的在線研討會上說,大多數醫院的氧氣儲罐都裝有傳感器,當氧氣量降至一定水平時傳感器就會自動訂購氧氣。但由于氧氣消耗速度遠高于正常水平,再加上如此多的醫院同時出現大量需求,“讓醫院的氧氣不耗盡,這很難做到”。
他指出,某些情況下醫院可能會發現自己的氧氣儲備會在“幾小時而不是幾天內”消耗完畢。
莫漢認為,醫院應有可能借助工業用戶通常使用的大型氧氣瓶為自己的氧氣管網供氧,但此舉面臨一些監管障礙,原因是此類氧氣瓶并未獲準用于醫療。全球最大醫用氣體生產商之一法國液化空氣集團已經表示,它正在考慮就此向監管部門提出申請。
在英國,政府已經要求氧氣生產企業、NHS官方供應商BOC將產量提高到原來的四倍,以便滿足今后幾周新冠肺炎患者數量達到峰值時的預期需求。BOC的母公司林德集團是全球最大工業氣體制造商之一。BOC發表聲明稱:“BOC正在和英國政府部門密切合作,以便制定程序來應對與目前新冠疫情相關的氣體需求增長。”
BOC表示,該公司一直在提高醫用氣體庫存,而且也已經增加了向醫院運氣的罐車數量,目的就是為本次疫情做準備。英國軍方也已處于待命狀態,如果BOC的司機患病或自我隔離,軍方將派人駕駛這些罐車。
BOC和法國液化空氣集團均已要求使用氧氣瓶的醫療行業客戶歸還空氧氣瓶,以便他們為空瓶充氣并再次輸送出去。
Air Products也是一家大型工業氣體制造商,總部設在賓夕法尼亞州阿倫敦。該公司發布公告稱它“目前并未因為新冠疫情出現任何產品短缺”,而且“一直在檢查和評估整個穩固的供應鏈、冗余后備方案以及設施網絡,以便滿足顧客需求。”
Air Products表示:“情況變化不定,因而很難預測其未來影響或確切的持續時間。”(財富中文網)
譯者:Charlie
審校:夏林
氧氣供應成了抗擊新冠疫情的最新瓶頸。
許多感染新冠病毒后住院的患者都有肺部感染并且需要輸氧,其中甚至包括那些病情還未嚴重到需要上呼吸機的患者。
根據這些患者的數量及其需要的氧氣量估算,醫院的儲備很快將被耗盡,而氧氣廠商則很難跟上需求的步伐。
醫院通常建有大型集中式液氧儲罐,其中的液氧經氣化后通過管道輸送到醫院各處。有些醫院還會使用小容量液氧瓶。
但在意大利,有報道稱由于需要呼吸機及其他方式輸氧的病患人數激增,新冠疫情期間醫院的氧氣日用量已經增長了兩倍以上。在意大利北部疫情最嚴重的地區,有些醫院已經被迫安裝了新的大型液氧儲罐,以確保氧氣供應充足。
在英國,據稱倫敦一家大型醫院的氧氣上周末就將消耗殆盡。受此影響,英國國家醫療服務體系(NHS)緊急發函,要求醫生計算自家醫院氧氣能同時滿足的患者人數,同時限制CPAP(持續氣道正壓呼吸機)的使用。CPAP的作用是幫助那些病情還未嚴重到需要呼吸機的患者。
CPAP及其他被稱為“經鼻高流量氧療”的治療方式是將氧氣管插入患者鼻孔后直接輸氧,其每小時氧氣消耗量往往遠高于呼吸機。NHS稱,過多病患同時使用這樣的治療方法還可能讓醫院的氧氣管網壓力失衡,從而使整個管網突然失靈,而這會讓醫院中所有使用壁式供氧裝置的患者陷入危險之中。
NHS的警告表明,就算英國能為新冠肺炎患者生產出足夠的呼吸機,氧氣的供應問題也將成為一大限制。
與此同時,紐約市的許多醫生都說自己的醫院也處于管道氧氣即將耗盡的危險境地。有報道稱,因為所有的管道氧氣供氧設備都已被占用,一些醫院開始用氧氣瓶治療患者,而醫生表示氧氣瓶的數量也不多了。
總部設在新澤西州克拉克鎮的全球供應鏈咨詢公司GEP副總裁比瑞·莫漢是制藥和醫療保健行業專家。他說對醫療氧氣需求量增幅的預測范圍很大,介于25%-500%之間。莫漢指出,大多數氧氣廠商平時會保留約20%的后備產能,他們應該有能力滿足醫院需求的增長,特別是在建筑、石油和天然氣等其他行業的氧氣需求因經濟陷入停滯而直線下降的時候。
取自空氣
理論上,有幾個因素限制著氧氣廠商的產量。大多數生產商都用空氣制氧。他們將空氣過濾后采用低溫制氧工藝,也就是用空氣壓縮機將空氣溫度降至極低水平,然后將其中的氧氣、氮氣等分離出來。分離出的氣體還將進一步凈化和純化為液體,或者裝入壓力儲罐和小型氧氣瓶中。大多數工序都由基本的物理反應和熱反應推動,幾乎不使用化學原料。
莫漢說,更大的實際問題在于醫院接受的通常都是液氧,他們隨后會把液氧氣化,然后通過管道輸送到醫院各處。而醫院的液氧儲存能力有限,因此運輸車輛必須往返更多次才能保持醫院的液氧儲備水平。
本月初,英國重癥監護協會負責人、加內什·孫塔拉林加姆醫生在英國麻醉醫師協會主辦的在線研討會上說,大多數醫院的氧氣儲罐都裝有傳感器,當氧氣量降至一定水平時傳感器就會自動訂購氧氣。但由于氧氣消耗速度遠高于正常水平,再加上如此多的醫院同時出現大量需求,“讓醫院的氧氣不耗盡,這很難做到”。
他指出,某些情況下醫院可能會發現自己的氧氣儲備會在“幾小時而不是幾天內”消耗完畢。
莫漢認為,醫院應有可能借助工業用戶通常使用的大型氧氣瓶為自己的氧氣管網供氧,但此舉面臨一些監管障礙,原因是此類氧氣瓶并未獲準用于醫療。全球最大醫用氣體生產商之一法國液化空氣集團已經表示,它正在考慮就此向監管部門提出申請。
在英國,政府已經要求氧氣生產企業、NHS官方供應商BOC將產量提高到原來的四倍,以便滿足今后幾周新冠肺炎患者數量達到峰值時的預期需求。BOC的母公司林德集團是全球最大工業氣體制造商之一。BOC發表聲明稱:“BOC正在和英國政府部門密切合作,以便制定程序來應對與目前新冠疫情相關的氣體需求增長。”
BOC表示,該公司一直在提高醫用氣體庫存,而且也已經增加了向醫院運氣的罐車數量,目的就是為本次疫情做準備。英國軍方也已處于待命狀態,如果BOC的司機患病或自我隔離,軍方將派人駕駛這些罐車。
BOC和法國液化空氣集團均已要求使用氧氣瓶的醫療行業客戶歸還空氧氣瓶,以便他們為空瓶充氣并再次輸送出去。
Air Products也是一家大型工業氣體制造商,總部設在賓夕法尼亞州阿倫敦。該公司發布公告稱它“目前并未因為新冠疫情出現任何產品短缺”,而且“一直在檢查和評估整個穩固的供應鏈、冗余后備方案以及設施網絡,以便滿足顧客需求。”
Air Products表示:“情況變化不定,因而很難預測其未來影響或確切的持續時間。”(財富中文網)
譯者:Charlie
審校:夏林
Oxygen supplies have emerged as the latest choke point in the battle against the coronavirus.
Many patients hospitalized with COVID-19 infections, even those not sick enough to be placed on a mechanical ventilator, have impaired lung function and require supplemental oxygen.
The number of these patients—and the amount of oxygen they are requiring—is threatening to exhaust hospitals’ supply, and industrial gas producers are scrambling to keep pace with the demand.
Hospitals normally have large central tanks for the storage of liquid oxygen, which is then evaporated into a gas and piped throughout the facility. Some also use smaller canisters of liquid oxygen.
But in Italy, hospitals have reported their daily consumption of oxygen has more than tripled during the pandemic as the number of patients needing ventilators and other forms of supplemental oxygen has soared. Some hospitals in the north of the country, the region at the epicenter of the outbreak, have been forced to install additional large storage tanks to ensure an adequate supply.
In the U.K., one major London hospital reportedly came close to exhausting its oxygen supply last weekend. This resulted in an urgent letter from the National Health Service instructing doctors to calculate the maximum number of patients they can support on oxygen at any one time, and to limit the use of continuous positive airway pressure (CPAP) machines, which doctors have been using to help patients who are not yet sick enough to require a ventilator.
CPAP machines and other forms of what’s known as “high-flow nasal oxygen,” which deliver oxygen directly into a patient’s nostrils through tubing, often consume far more oxygen per hour than ventilators. Hooking too many patients up to high-flow piped oxygen simultaneously can also create pressure imbalances across the hospital’s oxygen network, leading the entire system to suddenly fail, jeopardizing all the patients in the hospital who are currently receiving wall-based oxygen, the NHS said.
The NHS warning raises the prospect that even if the U.K. is able to produce enough ventilators to meet the demand from coronavirus patients, the available supply of oxygen may ultimately become a limiting factor in the number of patients able to receive lifesaving treatment.
Meanwhile, in New York City, a number of doctors have said their hospitals have also come perilously close to running out of piped oxygen. They have reported running low on oxygen canisters, which some hospitals have begun using to treat patients because all of their piped oxygen connections are already in use.
Biju Mohan, a vice president at GEP, a global supply-chain consulting firm based in Clark, N.J., and a specialist in the pharmaceutical and health care industries, said estimates of the surge in demand for medical oxygen range widely between 25% and 500%. He said most manufacturers operate with about 20% spare capacity during normal times and that they should have the ability to meet the surging hospital requirements, especially as demand from other users, such as the construction and oil and gas industry, has plummeted as the economy has ground to a halt.
Pulled from the air
In theory, there are few limits on the amount of oxygen manufacturers can produce. Most producers take in air from the atmosphere, filter it, and then use a cryogenic process, in which the air is cooled to extreme temperatures by an air compressor to separate it into its constituent gases, such as oxygen and nitrogen. These are then further purified and distilled into a liquid or bottled in pressurized cylinders and small canisters. Most of the process is driven by basic physics and heat, with few chemical supplies involved.
The bigger practical problem, Mohan said, is that hospitals normally receive oxygen in liquid form, which is then evaporated into gas and piped throughout the hospital. Hospitals have limited storage capacity for liquid oxygen, and delivery fleets are having to make many more trips than normal to keep these tanks filled, he says.
Ganesh Suntharalingam, a doctor who is president of the U.K.’s Intensive Care Society, said during an online seminar sponsored by the Association of Anaesthetists earlier this month, that most hospitals’ oxygen tanks have sensors that automatically order more supply when tank levels drop to a certain threshold. But with the rate of oxygen depletion much higher than normal—and high demand from so many hospitals occurring at the same time—“for that hospital to not run out that day is going to be a challenge.”
In some cases, he said, hospitals could find their oxygen supplies completely depleted “within hours rather than days.”
Mohan said that it should be possible for hospitals to supplement their piped oxygen supplies with large cylinders of oxygen, which are normally used for industrial customers, but that there are regulatory obstacles to doing so—these cylinders are not licensed for use in medical settings. Air Liquide, one of the world’s largest medical gas suppliers, has said it is considering asking for regulatory approval to do this.
In the U.K., the government has asked BOC, an oxygen producer and official supplier to the National Health Service, to quadruple production to meet the anticipated demand as coronavirus cases peak in the coming weeks. “BOC is working closely with government departments within the U.K. to develop processes and procedures to cope with an increased demand of medical gases associated with the current COVID-19 outbreak,” the company, which is a subsidiary of Linde, one of the world’s largest industrial gas producers, said in a statement.
BOC has been building up stocks of medical gases in preparation for the pandemic, the company said, and has also increased its fleet of tankers for trucking gas to hospitals. The British military has been placed on standby to help drive oxygen tankers if BOC’s own drivers start to fall ill or have to self-isolate.
BOC and Air Liquide have both asked medical customers who use oxygen gas in canisters to return empty ones promptly so they can be refilled and sent out again.
Air Products, another major industrial gases producer headquartered in Allentown, Pa., said in a statement that it is “not currently experiencing any production shortages” owing to the pandemic and that it “continues to review and evaluate its entire robust supply chain, redundant backup plans, and network of facilities to meet customers’ demands.
“This is a dynamic and fluid situation, which makes it difficult to predict its future impact or exact duration,” the company said.