Doctors and nurses in Syria's beleaguered Eastern Ghouta enclave have run out of several life-saving items and a massive medical re-supply is critically urgent, a charity said on Friday.
Doctors Without Borders (MSF) also called for medical teams to be allowed into the besieged rebel enclave east of Damascus.
"The need for a massive medical resupply, without life-saving items being removed, is increasingly urgent with each passing hour," MSF said.
A humanitarian convoy entered Eastern Ghouta on Friday, carrying food that aid workers were not able to distribute from a first convoy earlier this week.
It did not contain some life-saving medical items, such as trauma kits, that were removed from the dozens of trucks sent in on Monday.
A spokesperson for the International Committee of the Red Cross, however, said there were "some positive indications that a bigger convoy with additional supplies, including medical items, might happen next week."
MSF said there was an acute emergency in Eastern Ghouta, where almost 400,000 civilians have endured a blistering military assault by the Syrian government and its allies since February 18.
"The numbers reveal a relentless barrage of mass casualty influxes at a time when medical supplies are extremely limited, medical facilities have been hit by bombs or shells, and the medics are completely exhausted.
"Daily, we hear of an increasing sense of hopelessness and despair, as our medical colleagues reach the limits of what a person can be expected to do," MSF Director General Meinie Nicolai said.
The Paris-based medical charity said 15 of the 20 medical facilities it supports in Eastern Ghouta were hit by air strikes or shelling.
According to the Syrian Observatory for Human Rights, a Britain-based war monitor, more than 930 civilians have been killed since the assault began.
MSF urged the warring parties to pause the bombing and shelling to allow for the evacuation of critically sick or wounded patients.
More than a week ago, the United Nations said those already numbered more than 700.