AN oxygen concentrator is a medical device that filters out the nitrogen in air, delivering purified oxygen to patients.
For malnourished children with severe anaemia, injured people with severe blood loss and newborns with breathing difficulties, this device can be the difference between life and death.
But despite being essential to our patients' survival, we have no idea if or when an oxygen concentrator will reach a hospital in Gaza.
As Israeli authorities are maintaining full control of the entry and exit points into Gaza,
they have repeatedly refused Doctors Without Borders' (MSF) requests to bring biomedical equipment such as an oxygen concentrator.
When a request has been approved, interminable inspection processes at the border have had the same result in the six months since the war started.
Without this device, our medical teams in Gaza are forced to witness their patients die from preventable causes.
Let's take a look at how the process of getting aid into Gaza actually works.
On arrival at Egypt's Al-Arish airport, humanitarian supplies are loaded onto trucks and taken to Egyptian Red Crescent warehouses, where they are inspected by Egyptian authorities.
After inspection, they are reloaded onto trucks and driven to the Rafah border crossing. This first stage takes five to 10 days.
At Rafah, the trucks are scanned, then driven to an Israeli checkpoint some 50km south in Nitzana, where the supplies are unpacked, loaded onto special pallets to fit into the scanner, and scanned again.
The convoy returns to Rafah, where supplies approved by Israeli authorities are unloaded from Egyptian trucks onto Palestinian trucks to enter Gaza. This stage can take weeks.
It takes four to five weeks, on average, from the moment a shipment arrives on Egyptian territory to the moment it enters Gaza.
If a single item in a shipment is rejected in Nitzana, the entire shipment is rejected and returned to Rafah, where the lengthy process begins again.
In early November 2023, we made a request to Israel to
bring fridges and freezers into Gaza.
These are essential for storing medicines and vaccines that require low temperatures, such as insulin for diabetes, oxytocin to reduce post-partum haemorrhaging, and suxamethonium, used in anaesthesia to induce muscle paralysis.
It was not until April, five months later, that the request was approved. If all goes well, the fridges and freezers will arrive in Gaza this month.
These are not the only essential items in the queue.
We are still waiting for approval to bring in generators, oxygen cylinders, ultrasound scanners, external defibrillators, intravenous sodium chloride solutions, essential for rehydrating patients and diluting drugs.
The list is as long as it is alarming.
We have had no response from Israel to a request made months ago for the shipment of essential solar-powered equipment, including electrical systems for medical facilities, water pumps and water desalination systems.
Satellite telecommunications systems and MSF vehicles, vital for keeping our teams safe and enabling them to get to where they are needed, have also been refused, restricted or seriously delayed.
There is no clarity or consistency to what is allowed into Gaza.
Sometimes aid organisations can bring in certain items, sometimes not, but the reasons are not communicated to us, making it impossible to adapt future shipments accordingly.
Before the war, about 500 truckloads of supplies entered Gaza every day, but by February, the number had dropped to below 100 truckloads per day.
The shortages of essentials across Gaza is compounded by the fact that just two border crossings are open: Rafah and Kerem Shalom, both in southern Gaza.
Few trucks entering the south can pass through the numerous checkpoints further north, due to insecurity or a lack of authorisation from Israeli authorities.
As a result, very little aid and few basic supplies are reaching northern Gaza. With no access to the area, we can only guess at the humanitarian crisis unfolding there.
Blocking aid from reaching Gaza is destroying its health system, which cannot meet people's needs.
The entire Gazan population is paying the price, not only the tens of thousands injured in the war, but also all those with other medical needs: people with chronic illnesses, pregnant women with complications, children falling sick from infectious diseases linked to the deplorable conditions in which they are forced to live.
Without access to medical care, thousands of lives have been lost, and will continue to be lost. These are Gaza's "silent killings", the result of deliberate deprivation.
* The writer is head of emergency programmes for Médecins Sans Frontières/Doctors Without Borders (MSF)