As the novel coronavirus spread through New York City in late March, doctors at Mount Sinai Hospital noticed something strange happening to patients' blood.
Signs of blood thickening and clotting were being detected in different organs by doctors from different specialties. This would turn out to be one of the alarming ways the virus ravages the body, as doctors there and elsewhere were starting to realize.
At Mount Sinai, nephrologists noticed kidney dialysis catheters getting plugged with clots. Pulmonologists monitoring Covid-19 patients on mechanical ventilators could see portions of lungs were oddly bloodless. Neurosurgeons confronted a surge in their usual caseload of strokes due to blood clots, the age of victims skewing younger, with at least half testing positive for the virus.
Coronavirus across the globe
Coronavirus across the globe
In order to raise awareness against the spread of the coronavirus, a worker at Madame Tussauds attraction in Istanbul, places a mask on the wax figure of Albert Einstein during a photo-op, Saturday, July 11, 2020. Turkish authorities have made the wearing of masks mandatory in most of the country to curb the spread of COVID-19 following an uptick in confirmed cases since the reopening of many businesses. (AP Photo/Emrah Gurel)
Coronavírus: Por que milhares de israelenses foram às ruas protestar em meio à pandemia de covid-19
Dengue prevention efforts stifled by coronavirus pandemic, doctors warn
Personal electoral con mascarillas para combatir los contagios de coronavirus en las elecciones autonómicas del País Vasco, en el pueblo de Durango, España, el domingo 12 de julio de 2020. (AP Foto/Álvaro Barrientos)
Civic workers sanitize the entrance of Bollywood superstar Amitabh Bachchan's residence after Bachchan and his son tested positive for the coronavirus and were hospitalized in Mumbai, India, Sunday, July 12, 2020. (AP Photo/Rafiq Maqbool)
An employee wearing a protective mask and face shield to help curb the spread of the coronavirus bows guests as elevator doors close at a building Thursday, July 9, 2020, in Tokyo. (AP Photo/Eugene Hoshiko)
Players of Fluminense celebrate with their trophy after defeating Flamengo in a penalty shootout at the the Rio de Janeiro soccer league final match at the Maracana stadium in Rio de Janeiro, Brazil, Wednesday, July 8, 2020. The match was played without spectators to curb the spread of COVID-19. (AP Photo/Leo Correa)
Ultra-Orthodox Jews pray a morning prayer next to their house as synagogues limited to twenty people following the government's measures to help stop the spread of the coronavirus in Bnei Brak, Israel, Thursday, July 9, 2020. Israel is going through a new coronavirus outbreak that is hammering both the economy and public health. The country is reporting more than 1,000 new cases a day and out of work Israelis are irate at the lack of government aid. (AP Photo/Oded Balilty)
Catalonian police officers tell at a woman that the use of a face mask is mandatory, in Las Ramblas of Barcelona, Spain, Thursday, July 9, 2020. Authorities in northeast Spain will start fining individuals who do not wear face masks 100 euros ($113) as of Thursday when their use becomes obligatory in Barcelona and the surrounding Catalonia region. (AP Photo/Emilio Morenatti)
Commuters with face mask as a precaution against the coronavirus wait for a bus in Kolkata, India, Thursday, July 9, 2020. India has overtaken Russia to become the third worst-affected nation by the coronavirus pandemic. (AP Photo/Bikas Das)
Workers wearing masks walk by the New York Stock Exchange during the coronavirus pandemic, Thursday, July 9, 2020, in New York. (AP Photo/Mark Lennihan)
A worker stands next to a freshly-dug grave at the Honingnestkrans Cemetery, North of Pretoria, South Africa, Thursday, July 9, 2020. The Africa Centers for Disease Control and Prevention says the coronavirus pandemic on the continent is reaching "full speed" after cases surpassed a half-million and a South African official said a single province is preparing 1.5 million grave. (AP Photo/Shiraaz Mohamed)
Protestors gather in Toulouse, south of France, Thursday, July 9, 2020, to demonstrate against European aircraft manufacturer Airbus planning to eliminate 15,000 jobs over the next year. The jobs will mostly be lost in Europe. Airbus is struggling with the financial hit of the coronavirus pandemic. (AP Photo/Manuel Blondeau)
Serbian army soldiers prepare a makeshift field hospital to accommodate patients infected by COVID-19 inside the Belgrade Arena, on July 6, 2020. - Serbia on July 2 restricted gatherings of more than five people in towns hit by a spike of coronavirus cases. After reining in its first outbreak of COVID-19 in early May, the Balkan state is now reporting a second surge with around 300 cases daily this week compared to around 50 or less a month ago. Since early June, the Balkan countries have a higher rate of infections, with up to more than 300 daily in Serbia. (Photo by Oliver BUNIC / AFP) (Photo by OLIVER BUNIC/AFP via Getty Images)
Serbian soldiers set up beds for the treatment of possible COVID-19 infected patients inside of the Belgrade Arena, in Belgrade, Serbia, Monday, July 6, 2020. Serbian authorities have declared an emergency in the capital Belgrade because of a surge in the new coronavirus cases. Emergency measures also have been introduced in several other towns in Serbia where hospitals have been overwhelmed by COVID-19 patients in recent days. (AP Photo/Darko Vojinovic)
FRANKFURT AM MAIN, GERMANY - JUNE 15: A staff member of the Balearic Islands Tourist Office holts a fakt sheeet for the tourists waiting to check in for a TUIfly flight to Mallorca at Frankfurt Airport on the first day that package tours are resuming since March during the coronavirus pandemic on June 15, 2020 in Frankfurt, Germany. The travellers are participating in a test project in which the Spanish government is allowing up to 11,000 tourists from Germany to travel to the Balearic Islands. Spain, which was hit especially hard by Covid-19, has begun to ease pandemic lockdown measures, though tourist travel is still restricted. The project is meant to test the viability of reopening the country to tourism. (Photo by Thomas Lohnes/Getty Images)
A woman waves San Fermin's red kerchief from a window as local police wear face masks as protection against coronavirus, on the day the ''txupinazo'' would usually take place to start the famous San Fermin festival, which was due canceled this year by the conoravirus, in Pamplona, northern Spain, Monday, July 6, 2020. (AP Photo/Alvaro Barrientos)
A resident, wearing white clothes and a traditional red scarf, looks out of her window on the day the ''txupinazo'' would usually take place to start the famous San Fermin festival, which was due canceled this year by the conoravirus, in Pamplona, northern Spain, Monday, July 6, 2020. (AP Photo/Alvaro Barrientos)
CORONAVIRUS: PLUS DE 1.000 DÉCÈS EN VINGT-QUATRE HEURES AU BRÉSIL
CORONAVIRUS: UN NOMBRE RECORD DE CONTAMINATIONS DANS LE MONDE EN UNE JOURNÉE
A calligraphist paints the name of Luz Maria Gonzalez onto the cross adorning her grave, as family members tidy the adjacent grave of her son 29-year-old son Francisco Javier, in the Municipal Cemetery of Valle de Chalco on the outskirts of Mexico City, Saturday, July 4, 2020. Gonzalez, 56, who had long suffered from asthma, diabetes, and hypertension, died two days after her son, who was hospitalized for breathing problems and a cough before dying of complications said to be related to pneumonia and undiagnosed diabetes. (AP Photo/Rebecca Blackwell)
An LGBTQ member prepares before a streamed performance of "Pride at Home," at the National Theatre in Caracas, Venezuela, Saturday, July 4, 2020. To celebrate 20 years of gay pride in Venezuela, LGBTQ members organized a presentation of different artistic shows via live streaming amid the new coronavirus pandemic. (AP Photo/Matias Delacroix)
The shadow of an LGBTQ member is reflected on the wall before a streamed performance of "Pride at Home," at the National Theatre in Caracas, Venezuela, Saturday, July 4, 2020. To celebrate 20 years of gay pride in Venezuela, LGBTQ members organized a presentation of different artistic shows via live streaming amid the new coronavirus pandemic. (AP Photo/Matias Delacroix)
A server wearing a mask checks orders for people in their cars watching the movie "Jumanji," Saturday, July 4, 2020, at Sacramento drive-in cinema in Asuncion, Paraguay. Several drive-in cinemas were started this weekend to aid in social distancing amid the coronavirus pandemic. (AP Photo/Jorge Saenz)
CORRECTS TO BROADWALK, INSTEAD OF BOARDWALK Tim Wirtz sits along the Hollywood Beach Broadwalk during the new coronavirus pandemic, Thursday, July 2, 2020, in Hollywood, Fla. In hard-hit South Florida, beaches from Palm Beach to Key West will be shut down for the Fourth of July holiday weekend. Restaurants and businesses along the Boardwalk will remain open. (AP Photo/Lynne Sladky)
A woman walks past benches taped off for social distancing outside a restaurant, Thursday, July 2, 2020, in La Habra, Calif. California's mood has gone from optimistic to sour as coronavirus cases and hospitalizations are on the rise heading into the July 4th weekend. Gov. Gavin Newsom has ordered bars and indoor restaurant dining closed in most of the state, many beaches are off limits, and he's imploring Californians to avoid holiday gatherings with family and friends. (AP Photo/Jae C. Hong)
A staff member talks to visitors to the Universal Studios Singapore theme park on the resort island of Sentosa in Singapore on July 3, 2020, as the attraction reopened after being temporarily closed due to concerns about the COVID-19 novel coronavirus. (Photo by Roslan RAHMAN / AFP) (Photo by ROSLAN RAHMAN/AFP via Getty Images)
Aspect of the La Boqueria market practically empty and without tourists, something unusual at this time of year in Barcelona, Spain on July 2, 2020. (Photo by Joan Valls/Urbanandsport /NurPhoto via Getty Images)
Aspect of the La Boqueria market practically empty and without tourists, something unusual at this time of year, in Barcelona, Spain on July 2, 2020. (Photo by Joan Valls/Urbanandsport /NurPhoto via Getty Images)
A tourist reacts as she arrives with others at Nikos Kazatzakis International Airport in Heraklion, Crete island, Greece, on Wednesday, July 1, 2020. The passengers most of them from Germany who came from Hamburg, with the first international flight to arrive in the island. Regional airports across Greece, including their tourist destination islands, began accepting direct international flights again on Wednesday, for the first time since flights were banned as part of the country's lockdown to prevent the spread of the coronavirus. (AP Photo/ Harry Nakos )
Tourists, arrive at Nikos Kazatzakis International Airport in Heraklion, Crete island, Greece, on Wednesday, July 1, 2020. The passengers most of them from Germany who came from Hamburg, with the first international flight to arrive in the island. Regional airports across Greece, including their tourist destination islands, began accepting direct international flights again on Wednesday, for the first time since flights were banned as part of the country's lockdown to prevent the spread of the coronavirus. (AP Photo/ Harry Nakos )
A man wearing a face mask and gloves to protect against coronavirus casts his ballot at a polling station in Moscow, Russia, Wednesday, July 1, 2020. The vote on the constitutional amendments that would reset the clock on Russian President Vladimir Putin's tenure and enable him to serve two more six-year terms is set to wrap up Wednesday. (AP Photo/Alexander Zemlianichenko)
Women wearing protective face masks pass an advertisement promoting awareness of the coronavirus outbreak at a shopping mall in Jakarta, Indonesia, Wednesday, July 1, 2020. The government of Indonesia's capital region is extending the first transition phase from large-scale social restrictions in Jakarta as the number of new confirmed coronavirus cases continues to rise. (AP Photo/Tatan Syuflana)
A woman, wearing a face mask and gloves to protect against coronavirus and observing social distancing guidelines, casts her ballot at a polling station with a portrait of former Soviet leader Josef Stalin on the wall in Volgograd, former Stalingrad, Russia, Wednesday, July 1, 2020. The vote on the constitutional amendments that would reset the clock on Russian President Vladimir Putin's tenure and enable him to serve two more six-year terms is set to wrap up Wednesday. (AP Photo/Dmitry Rogulin)
A woman, wearing a face mask to protect against coronavirus casts her ballot, observes social distancing guidelines, at a polling station in Grozny, Russia, Wednesday, July 1, 2020. Russia's vote on constitutional amendments that could allow President Vladimir Putin to extend his rule until 2036 entered its final day Wednesday amid widespread reports of pressure on voters and other irregularities. (AP Photo/Musa Sadulayev)
Spain's Prime Minister Pedro Sanchez gestures farewell to Portugal's Prime Minister Antonio Costa, right, as he departs after a ceremony to mark the reopening of the Portugal/Spain border in Elvas, Portugal, Wednesday, July 1, 2020. The border was closed for three and a half months due to the coronavirus pandemic. (AP Photo/Armando Franca)
People protest against Coronavirus trials in Africa, outside the University of the Witwatersrand in Johannesburg, South Africa, Wednesday, July 1, 2020. A protest against Africa’s first COVID-19 vaccine trial is underway as experts note a worrying level of resistance and misinformation around testing on the continent. (AP Photo/Themba Hadebe)
For demonstration purposes, an employee of the Centogene company takes a throat swab from a colleague at the airport in Frankfurt, Germany, Monday, June 29, 2020. In the future, people will be able to be tested for the corona virus within a few hours at Germany's first "Airport Corona Test" centre. (AP Photo/Michael Probst)
A security guard wearing a mask to curb the spread of the coronavirus watches over a gate in Beijing on Monday, June 29, 2020. Even as the world surpassed two sobering coronavirus milestones Sunday -- 500,000 confirmed deaths, 10 million confirmed cases -- and hit another high mark for daily new infections, China on Monday reported a further decline in new confirmed cases, with a total of just 12, including seven cases of domestic transmission in Beijing, where nearly 8.3 million people have now undergone testing in recent weeks. (AP Photo/Ng Han Guan)
A Greenpeace activists wearing protective gear to help curb the spread of the coronavirus arranges mannequins used to display posters during a protest outside the parliament in Jakarta, Indonesia, Monday, June 29, 2020. About a dozen of activists staged the protest against the government's omnibus bill on job creation that was intended to boost economic growth and create jobs, saying that it undermined labor rights and environmental protection. (AP Photo/Dita Alangkara)
An Indian man wearing a face mask as a precaution against the coronavirus sleeps outside closed shops during the reimposed lockdown in Gauhati, India, Monday, June 29, 2020. India has reported a new daily record of nearly 20,000 new infections as several Indian states reimpose partial or full lockdowns to stem the spread of the coronavirus. (AP Photo/Anupam Nath)
An Indian woman walks on a road painted with circles to help people maintain social distancing in Mumbai, India, Monday, June 29, 2020. Governments are stepping up testing and warily considering their next moves as the number of newly confirmed coronavirus cases surges in many countries. India reported more than 20,000 new infections on Monday. (AP Photo/Rajanish Kakade)
A sign on the door of the West Alabama Icehouse reads "Closed by the Governor", Monday, June 29, 2020, in Houston. Texas Gov. Greg Abbott shut down bars again and scaled back restaurant dining on Friday as cases climbed to record levels after the state embarked on one of America's fastest reopening. (AP Photo/David J. Phillip)
Empty tables are shown at the closed West Alabama Icehouse Monday, June 29, 2020, in Houston. Texas Gov. Greg Abbott shut down bars again and scaled back restaurant dining on Friday as cases climbed to record levels after the state embarked on one of America's fastest reopenings. (AP Photo/David J. Phillip)
A man wears a mask while voting, Monday, June 29, 2020, in Houston. Early voting for the Texas primary runoffs began Monday. (AP Photo/David J. Phillip)
A woman wearing a mask to curb the spread of the coronavirus holds her dog as they pass by a mall in Beijing on Monday, June 29, 2020. Even as the world surpassed two sobering coronavirus milestones Sunday -- 500,000 confirmed deaths, 10 million confirmed cases -- and hit another high mark for daily new infections, China on Monday reported a further decline in new confirmed cases. (AP Photo/Ng Han Guan)
A priest wearing a protective mask to avoid COVID-19 spread stands in St. Peter's Square during the Angelus prayer celebrated by Pope Francis from his studio window on the occasion of the Feast of Rome's Patrons Saints Peter and Paul, at the Vatican, Monday, June 29, 2020. (AP Photo/Riccardo De Luca)
Activists of Communist Party of India Marxist wearing face shields and hold placards during a protest asking the state government to increase testing and free treatment for all COVID-19 patients in Hyderabad, India, Monday, June 29, 2020. Governments are stepping up testing and warily considering their next moves as the number of newly confirmed coronavirus cases surges in many countries. India reported more than 20,000 new infections on Monday. (AP Photo/Mahesh Kumar A.)
Financial union members wearing face masks to help protect against the spread of the new coronavirus attend a rally against government's financial policy in front of the Financial Supervisory Service in Seoul, Monday, June 29, 2020. (AP Photo/Ahn Young-joon)
A roadside vendor sells mobile phone covers as she waits for customers at a closed market amid concerns over the spread of the COVID-19 coronavirus in Leh, the joint capital of the union territory of Ladakh, on June 28, 2020. (Photo by Tauseef MUSTAFA / AFP) (Photo by TAUSEEF MUSTAFA/AFP via Getty Images)
PARIS, FRANCE - JUNE 28: A man walks past electoral posters against Paris Mayor, Socialist Anne Hidalgo, who is fighting for a second term, as Parisians go to the polls today in the second round of Municipal elections on June 28, 2020 in Paris, France. The second-round vote, which was postponed by more than three months due to the coronavirus pandemic has forced candidates to conduct remote campaigns as restrictions have meant they were unable to canvas door to door, shake hands or distribute campaign material. (Photo by Kiran Ridley/Getty Images)
MELBOURNE, AUSTRALIA - JUNE 28: A general view of a pop-up Covid-19 testing tent during a COVID-19 testing blitz in the suburb of Broadmeadows on June 28, 2020 in Melbourne, Australia. Victoria's confirmed COVID-19 infection numbers continue to rise, with 49 new coronavirus cases recorded overnight. Health authorities are continuing on a testing blitz in Melbourne suburbs that have been identified as community transmission hotspots for coronavirus. Restrictions in Victoria have been tightened in response to the spike in new cases across the state with premier Daniel Andrews extending the current state of emergency for at least four weeks to allow police the power to enforce social distancing rules. (Photo by Asanka Ratnayake/Getty Images)
WARSAW, POLAND - JUNE 28: A father and son wearing protective face masks cast a ballot in the Polish presidential election during the coronavirus pandemic on June 28, 2020 in Warsaw, Poland. The two lead candidates are current Polish President Andrzej Duda of the socially conservative Law and Justice (PiS) party and Warsaw Mayor Rafal Trzaskowski of the of the centrist Civic Platform (PO). Today’s election to determine the next Polish president, who serves a five-year term, was originally scheduled for May but was delayed due to the coronavirus pandemic. (Photo by Sean Gallup/Getty Images)
Iran announced new measures to combat the spread of the novel coronavirus as the country counted 144 new fatalities, its highest death toll for a single day in almost three months (AFP Photo/ATTA KENARE)
TOPSHOT - Roadside vendors carry vegetables at a closed market amid concerns over the spread of the COVID-19 coronavirus in Leh, the joint capital of the union territory of Ladakh, on June 28, 2020. (Photo by Tauseef MUSTAFA / AFP) (Photo by TAUSEEF MUSTAFA/AFP via Getty Images)
A brig with scarlet sails on the Finnish Gulf coast during a rehearsal for the the Scarlet Sails festivities marking school graduation which will take place on June 27 in St.Petersburg, Russia, early Friday, June 26, 2020. This year the festival will not be held in the city center, but on the Finnish Gulf. Due to the coronavirus pandemic, there will be no spectators but the event will be broadcast on television. (AP Photo/Dmitri Lovetsky)
Sri Lankan Municipal health workers spray disinfectant to another colleague who conducted blood tests for COVID-19 antibody tests at a market place in Colombo, Sri Lanka, Friday, June 26, 2020. (AP Photo/Eranga Jayawardena)
A brig with scarlet sails travels on the Finnish Gulf coast during a rehearsal for the the Scarlet Sails festivities marking school graduation which will take place on June 27 in St.Petersburg, Russia, early Friday, June 26, 2020, with the setting moon in the background. This year the festival will not be held in the city center, but on the Finnish Gulf. Due to the coronavirus pandemic, there will be no spectators but the event will be broadcast on television. (AP Photo/Dmitri Lovetsky)
Tubers prepare to float the Comal River despite the recent spike in COVID-19 cases, Thursday, June 25, 2020, in New Braunfels, Texas. Texas Gov. Greg Abbott said Wednesday that the state is facing a "massive outbreak" in the coronavirus pandemic and that some new local restrictions may be needed to protect hospital space for new patients. (AP Photo/Eric Gay)
Staff of a cinema spray disinfectant at the cinema hall to prepare for reopening on July 1 in Kuala Lumpur, Malaysia, Friday, June 26, 2020. Malaysia entered the Recovery Movement Control Order (RMCO) after three months of coronavirus restrictions. (AP Photo/Vincent Thian)
Seguidores del Liverpool festejan con bengalas frente al estadio Anfield, el jueves 25 de junio de 2020, cuando el equipo se coronó en la Liga Premier con una victoria del Chelsea sobre el Manchester City (AP Foto/Jon Super)
People wearing face masks shop for accessories at a mobile shop in Hyderabad, India, Thursday, June 25, 2020. India is the fourth hardest-hit country by the pandemic in the world after the U.S., Russia and Brazil. (AP Photo/Mahesh Kumar A.)
A vendor wearing a face mask waits for customers under a flyover bridge in Hyderabad, India, Thursday, June 25, 2020. India is the fourth hardest-hit country by the pandemic in the world after the U.S., Russia and Brazil. (AP Photo/Mahesh Kumar A.)
A member of the election commission checks the temperature of a voter, both wearing face masks to protect against coronavirus at a polling station in Moscow, Russia, Thursday, June 25, 2020. Polls have opened in Russia on Thursday for a week-long vote on a constitutional reform that would allow President Vladimir Putin to stay in power until 2036. (AP Photo/Alexander Zemlianichenko)
Voters wearing face masks to protect against coronavirus stand in front of a ballot box, observing social distancing guidelines, at a polling station at a school in Moscow, Russia, Thursday, June 25, 2020. Polls have opened in Russia on Thursday for a week-long vote on a constitutional reform that would allow President Vladimir Putin to stay in power until 2036. (AP Photo/Alexander Zemlianichenko)
A Yemeni pharmacist wearing a protective face mask serves his customers behind a glass shield installed as a precautionary measure against the spread of the coronavirus at a pharmacy in Sanaa, Yemen, Thursday, June 25, 2020. (AP Photo/Hani Mohammed)
Senegalese students wear masks to curb the spread of the coronavirus as they return to classes on the first day back after more than three months away, at the Sacre Coeur college in Dakar, Senegal Thursday, June 25, 2020. (AP Photo/Sylvain Cherkaoui)
Senegalese students learn about health and the coronavirus during an English lesson as they returned to classes on the first day back after more than three months away, at the Sacre Coeur college in Dakar, Senegal Thursday, June 25, 2020. (AP Photo/Sylvain Cherkaoui)
Hospital workers demonstrate in front of the Robert Debre hospital, in Paris Thursday, June 25, 2020. French hospital workers are protesting to demand better pay and more investment in France's public hospital system, which is considered among the world's best but struggled to handle a flux of virus patients after years of cost cuts. (AP Photo/Christophe Ena)
Hospital workers demonstrate in front of the Robert Debre hospital, in Paris Thursday, June 25, 2020. French hospital workers are protesting to demand better pay and more investment in France's public hospital system, which is considered among the world's best but struggled to handle a flux of virus patients after years of cost cuts. Banner reads «Hospital workers. Users. All united for our health». (AP Photo/Christophe Ena)
Protesters wearing protective masks and maintaining social distancing attend a metalworkers demonstration asking for measures against economic crisis worsened by the Covid-19 pandemic, in Rome, Thursday, June 25, 2020. (AP Photo/Riccardo De Luca)
Police officers stop motorcyclists from entering a restricted area that is sealed off to control the spread of the coronavirus, in Lahore, Pakistan, Thursday, June 25, 2020. (AP Photo/K.M. Chaudhry)
People queue up prior to visit the Eiffel Tower, in Paris, Thursday, June 25, 2020. The Eiffel Tower reopens after the coronavirus pandemic led to the iconic Paris landmark's longest closure since World War II. (AP Photo/Thibault Camus)
WUHAN, CHINA - JUNE 25: (CHINA OUT) People wear face masks while uses a iPhone at the Auto Fair during Dragon Boat Festival holiday on June 25, 2020 in Wuhan, China. Since June 13 the response level of public health emergencies in Hubei Province has been reduced to level 3. Wuhan's health commission said that the city had no asymptomatic cases as of June 15, and there are no more close contacts under medical observation. (Photo by Getty Images)
Passengers travel wearing facemasks on a tram in Zagreb on June 25, 2020, as the wearing of masks on public transport in Croatia became mandatory on June 23, due to an increase of coronavirus infections after the relaxation of lockdown conditions. (Photo by DENIS LOVROVIC / AFP) (Photo by DENIS LOVROVIC/AFP via Getty Images)
MADRID, SPAIN - JUNE 25: The minister of Defense, Margarita Robles, is seen during the closing and recognition ceremony of the 'Balmis' operation, at the Retamares Base at the town of Pozuelo de Alarcón, on June 25, 2020 in Madrid, Spain. The 'Balmis' operation has been the largest military deployment in Spain in peacetime. During the last 98 days of state of alarm the military has carried out almost 20,000 interventions to combat Covid-19 in a total of 2,300 locations, throughout the territory. (Photo by Eduardo Parra/Europa Press via Getty Images) (Photo by Europa Press News/Europa Press via Getty Images)
Spain´s King Felipe VI (2R) and Queen Letizia (2L) walk at Palma Beach in Palma de Mallorca on June 25, 2020, during their national tour after the national lockdown to stop the spread of the novel coronavirus was lifted. (Photo by JAIME REINA / AFP) (Photo by JAIME REINA/AFP via Getty Images)
Dutch King Willem-Alexander visits Nedschroef in Helmond on June 25, 2020. - The visit focuses on the impact of the coronavirus crisis on the automotive industry. (Photo by Rob ENGELAAR / various sources / AFP) / Netherlands OUT (Photo by ROB ENGELAAR/ANP/AFP via Getty Images)
MOSCOW, RUSSIA - JUNE 24, 2020: A Russian soldier wears a face mask in Lenin Square during a Victory Day military parade marking the 75th anniversary of the victory in World War II. Victory Day parades across Russia have been postponed from 9 May to 24 June due to restrictions imposed to prevent the spread of the novel coronavirus. Kirill Kukhmar/TASS (Photo by Kirill Kukhmar\TASS via Getty Images)
Medics from Beijing Fengsheng Special Hospital of Traditional Medical Traumatology and Orthopaedics prepare for their shift at the Jinrong Street testing site, inside a room where a Communist Party flag and a piece of red tissue with words that reads "Beijing Fengsheng Special Hospital of Traditional Medical Traumatology and Orthopaedics" (back on wall) in Beijing on June 24, 2020. - China reported 12 new cases of COVID-19, including seven cases domestic cases in Beijing. (Photo by NICOLAS ASFOURI / AFP) (Photo by NICOLAS ASFOURI/AFP via Getty Images)
People leave a Costco outlet with a trolley full of toilet paper as fears of a second wave of COVID-19 have sparked a rush on some supermarket items in Melbourne on June 24, 2020. - Major supermarkets in the state of Victoria have reimposed buying limits on toilet paper and other essentials after a renewed escalation in demand sparked fears of a return to scenes of panic-buying seen early in the pandemic. (Photo by William WEST / AFP) (Photo by WILLIAM WEST/AFP via Getty Images)
VLADIVOSTOK, RUSSIA - JUNE 24, 2020: A woman takes a picture as WWII-era military hardware from the collection of the 20th Century Hardware in Primorsky Territory patriotic club takes part in a Victory Day military parade marking the 75th anniversary of the victory in World War II. Victory Day parades across Russia have been postponed from 9 May to 24 June due to restrictions imposed to prevent the spread of the novel coronavirus. Yuri Smityuk/TASS (Photo by Yuri Smityuk\TASS via Getty Images)
A woman reacts as she has her nasal swab sample collected by a health worker during a mass test for the new coronavirus at the local district office in Tanah Abang in Jakarta, Indonesia, Sunday, June 21, 2020. (AP Photo/Dita Alangkara)
Afghan yoga enthusiasts perform to mark International Yoga Day amid the COVID-19 pandemic lockdown, on the outskirts of Kabul, Afghanistan, Sunday, June 21, 2020. (AP Photo/Rahmat Gul)
Sergej Trifunovic, the leader of the Free Citizens Movement (PSG), an opposition party, casts his ballot for the parliamentary election at a polling station in Belgrade, Serbia, Sunday, June 21, 2020. Serbia's ruling populists are set to tighten their hold on power in a Sunday parliamentary election held amid concerns over the spread of the coronavirus in the Balkan country and a partial boycott by the opposition. (AP Photo/Marko Drobnjakovic)
A man wearing a mask as a precaution against coronavirus performs rituals at Sangam, the confluence of rivers the Ganges and the Yamuna during solar eclipse in Prayagraj, India, Sunday, June 21, 2020. (AP Photo/Rajesh Kumar Singh)
A lifeguard stand is decorated with a large mask to remind people to wear masks as precaution against the new coronavirus at a beach in Tel Aviv, Israel, Sunday, June 21, 2020. (AP Photo/Sebastian Scheiner)
People wearing face masks to protect against the new coronavirus take photos of a partial solar eclipse near the Forbidden City in Beijing, Sunday, June 21, 2020. (AP Photo/Mark Schiefelbein)
A man sits wearing a mask as a precaution against coronavirus as Hindu devotees perform rituals at Sangam, the confluence of rivers the Ganges and the Yamuna during solar eclipse in Prayagraj, India, Sunday, June 21, 2020. (AP Photo/Rajesh Kumar Singh)
A man, wearing a protective face mask, pushes a dolly filled with empty containers, as he and a child go in search of water in Caracas, Venezuela, Saturday, June 20, 2020, during a relaxation of restrictive measures amid the new coronavirus pandemic. (AP Photo/Ariana Cubillos)
Bride Jazmin Sanabria and her groom Joel Adorno, wearing protective face masks amid the new coronavirus pandemic, walk down the aisle in the first wedding ceremony since 101 days of quarantine at the Virgen del Rosario church, in Luque, Paraguay, Saturday, June 20, 2020. The government is easing restrictive measures, authorizing the opening of some stores, restaurants and churches that had been closed since March 10, as part of a plan coined, "Intelligent Quarantine." (AP Photo/Jorge Saenz)
Women buy vegetables through a protective plastic due to COVID-19, in a street market in Barranco neighborhood, in Lima, Peru, Saturday, June 20, 2020. (AP Photo/Rodrigo Abd)
People participate in an anti-government demonstration one week ahead of the presidential election in Warsaw, Poland, Saturday, June 20, 2020.(AP Photo/Czarek Sokolowski)
ISTANBUL, TURKEY - JUNE 18: Kid mannequins with masks are placed by the tables diagonally to protect customers' social distance as part of coronavirus (Covid-19) precaution at Beyoglu district in Istanbul, Turkey on June 18, 2020. (Photo by Emrah Yorulmaz/Anadolu Agency via Getty Images)
dpatop - 14 October 2020, Brazil, Sao Paulo: Cemetery workers in protective suits shoveling earth at the Vila Formosa cemetery in the Brazilian city of Sao Paulo in the middle of the Corona pandemic. Photo: Lincon Zarbietti/dpa (Photo by Lincon Zarbietti/picture alliance via Getty Images)
A member of a university laboratory wearing protective gear is pictured at a community health centre as the government collects swab samples from residents to test for the COVID-19 coronavirus in Banda Aceh on June 17, 2020. (Photo by CHAIDEER MAHYUDDIN / AFP) (Photo by CHAIDEER MAHYUDDIN/AFP via Getty Images)
Commuters have their temperatures checked as they arrive at the entrance to Hong Kong's Disneyland on June 17, 2020, a day before the theme park's doors reopen following nearly five months of closure in a fresh boost for a city that has largely managed to defeat the COVID-19 coronavirus. - It is just the second Disneyland around the world to resume services during the pandemic after Shanghai turned its lights and rides back on last month. (Photo by Anthony WALLACE / AFP) (Photo by ANTHONY WALLACE/AFP via Getty Images)
A waiter answers a client at La Coupole restaurant, Monday, June 15, 2020 in Paris. Paris is rediscovering itself, as its cafes and restaurants reopen for the first time since the fast-spreading virus forced them to close their doors March 14. Restaurants outside the Paris region opened earlier this month, and Paris cafes were allowed to serve people outside but not open their doors. After three months of losses, some restaurateurs fear it will take a long time for business to come back. (AP Photo/Christophe Ena)
BEIJING, CHINA - JUNE 16: A nurse wearing a protective suit and mask takes a nucleic acid test for COVID-19 from a person who either visited or lives near the Xinfadi Market at a testing facility at a Sport Center on June 16, 2020 in Beijing, China. From June 11 to June 16, Beijing reported a total of 106 new confirmed cases of coronavirus (covid-19), the number of new infection has risen after no new cases for nearly two months. (Photo by Lintao Zhang/Getty Images)
Cemetery workers wearing protective gear against the new coronavirus, walk after carrying the coffin of 72-year-old Monica Lagos to her grave at the Manantial cemetery in Santiago, Chile, Monday, June 15, 2020. According to her grandaughter Ninoska Vasquez, who works as an assistant at a health center, Lagos died from complications related to COVID-19. (AP Photo/Esteban Felix)
Discover More Like This
BACK TO SLIDE
"It's very striking how much this disease causes clots to form," Dr. J Mocco, a Mount Sinai neurosurgeon, said in an interview, describing how some doctors think Covid-19, the illness caused by the coronavirus, is more than a lung disease. In some cases, Mocco said, a stroke was a young patient's first symptom of Covid-19.
As colleagues from various specialties pooled their observations, they developed a new treatment protocol. Patients now receive high doses of a blood-thinning drug even before any evidence of clotting appears.
"Maybe, just maybe, if you prevent the clotting, you can make the disease less severe," said Dr. David Reich, the hospital president. The new protocol will not be used on certain high-risk patients because blood thinners can lead to bleeding in the brain and other organs.
"FUNNY YOU MENTIONED THAT"
In the three weeks beginning mid-March, Mocco saw 32 stroke patients with large blood blockages in the brain, double the usual number for that period.
Five were unusually young, under age 49, with no obvious risk factors for strokes, "which is crazy," he said. "Very, very atypical." The youngest was only 31.
At least half of the 32 patients would test positive for Covid-19, Mocco said.
Meanwhile, Dr. Hooman Poor, a Mount Sinai lung specialist, found himself working a late shift with 14 patients on ventilators. The ventilator readings were not what he expected.
The lungs did not seem stiff, as is common in pneumonia. Instead, it seemed blood was not circulating freely through the lungs to be aerated with each breath.
Poor ran into a kidney doctor that night, who remarked that dialysis catheters were often getting blocked with clots.
"And I said, 'It's funny that you mentioned that because I feel like all these patients have blood clots in their lungs,'" Poor recalled.
Reich, the hospital president, told Poor about the surge in strokes seen by Mocco and said the two doctors should team up, setting off days of discussions and meetings with the hospital's department heads.
At 2:46 a.m. on Easter Sunday, Poor sent Mocco his first draft of what would become the new treatment protocol.
DOCTORS SHARE FINDINGS
As their wards began to overflow with Covid-19 patients, the Mount Sinai doctors read papers describing similar findings from doctors in China's Hubei province and other hard-hit areas, and discussed them with their peers in phone calls and webinars.
Mocco called neurosurgeons he knows elsewhere in the country. At Philadelphia's Thomas Jefferson University Hospital, Dr. Pascal Jabbour had begun to see a similar surge in strokes among people with Covid-19. The way his patients' blood congealed reminded him of congenital conditions such as lupus, or certain cancers.
"I've never seen any other viruses causing that," Jabbour said.
In Boston, the Beth Israel Deaconess Medical Center began a clinical trial earlier this month to see if tPA, an anti-clotting drug, could help severely sick Covid-19 patients.
Clotting can develop in anyone who gets very sick and spends long periods of time immobile on a ventilator, but doctors say the problem seemed to show up sooner in Covid-19 patients as a more direct consequence of the virus.
At Mount Sinai, patients in intensive care often receive the blood-thinning agent heparin in weaker prophylactic doses. Under the new protocol, higher doses of heparin normally used to dissolve clots will be given to patients before any clots are detected.
The treatment joins a growing toolbox at the hospital, where some patients are receiving the antibody-rich plasma of recovered Covid-19 patients or experimental antiviral drugs.
The American Society of Hematology, which has also noted the clotting, says in its guidance to physicians that the benefits of the blood-thinning therapy for Covid-19 patients not already showing signs of clotting are "currently unknown."
"I certainly wouldn't expect harps to play and angels to sing and people to just rip out their intravenous lines and waltz out of the hospital," said Reich. "It's likely going to be something where it just moderates the extent of the disease."