In the City of God, a Rio slum made famous by a movie of the same name, the local clinic used to treat minor ailments like the flu or stomach aches.
In recent months, however, it has come to operate more like a field hospital in a war zone, handling an increasing number of bullet wounds.
Last Friday, at 10 pm, the first patient arrived: a bulky 38-year-old with a gunshot to the hand, and signs of a beating over all his body, leaving a trail of blood as he was taken into the emergency room.
While babies with fevers cried on their mothers' necks and some senior citizens waited to be seen, the doctors and nurses on duty gave him first aid with their basic supplies so he could be transported to a nearby hospital with the necessary surgical staff and facilities.
The scene repeated itself early Monday, though more dramatically: an intense shootout between heavily armed cops and drug dealers shut down the favela as bullets flew wild.
Three patients with bullet wounds turned up at the same time, filling all but one of the emergency room beds. The three -- a 17-year-old boy shot in the chest, a 63-year-old man wounded in the belly, and an 82-year-old woman who was struck in the chest as she slept in her home.
"We are doing war medicine, literally, because on top of those shot, the (clinical) units are located in conflict zones," the head of the 24-hour clinic, Luiz Alexandre Essinger, told AFP.
- Rise in shootings -
The facility is one of 14 Rio de Janeiro's municipality has opened in the past eight years in the city's favelas, where an estimated 1.5 million residents -- a quarter of Rio's population -- live.
Essinger, a surgeon with 30 years of experience in emergency wards, compared the current situation in Rio to a high-crime, high-conflict period it lived in the 1990s.
Just months after the Olympic Games' torch went out in Rio last year, the shootings picked up, adding to a climate of rising crime against a backdrop of Rio state's bankruptcy and the disintegration of a favela "pacification" started in 2008.
"Our policy is one of non-confrontation," Rio's state secretary for security, Roberto Sa, said, asserting that police opening fire were only defending themselves from drug dealers who had become bolder.
But the return of this "urban warfare" between police, dealers and vigilante militias often counting police or former cops in their ranks can be seen in the gunshot statistics compiled by Rio's seven municipal hospitals.
In 2015, there were 720 shooting cases recorded by the hospitals. In 2016 that rose to 1,652. In the first three months of 2017 there were already 593 counted, according to data given by RioSaude, the health service.
Those numbers are much lower than three decades ago. But the seriousness of the wounds are far worse.
The clinics, like the unit in the City of God, are no longer seeing bullet holes corresponding to revolvers or 9mm pistols. Instead, the wounds are coming from rifles designed to shoot rounds that can pierce walls, and with a range measured in kilometers (miles).
"Before, a shot patient mostly arrived alive. Now, in many cases, they come in dead," said Jose Roberto Figueiredo, the medical chief in the City of God facility.
- 'Fear' among staff -
With an increase in the number of people hit by stray bullets, the clinic is receiving more and more wounded women. Sometimes there is also tension with police who come in looking for suspected wounded dealers or criminals.
"One wanted to leave and disappear. The violence has become too much. It only affects innocent people," said Rogeria Brites, a 57-year-old female cook in the waiting room.
Given the rise in bullet wounds, medical staff in some of the favela clinics have been trained specifically in treating such injuries.
Keeping their emotional balance in order is more difficult.
Many workers in the City of God clinic, most of them young, can't bear the pressure, despite fairly competitive wages.
Three left in June, citing "fear." Each time there are recruitment drives, City of God is one of the last to find takers.
Iara Viana, a 27-year-old doctor, remembers how late last year the staff became trapped in the facility when the major gang in the favela, the Red Command, ordered a lockdown of all the roads as members engaged in an hours-long firefight with police.
The scenes surpassed anything seen in the 2002 "City of God" movie or other works of fiction, she said.
"But, when all's said and done, it's gratifying to be able to help people who really need it," Viana said.
"Here, we really feel like true doctors."