Dietary nitrates from spinach and other leafy vegetables, beets and berries help the blood vessels relax and improve the flow of blood and oxygen in the body, says Dr Anam Golandaz.

Last year’s COVID-19 wave focused on roti, kapda, makaan (food, clothing, shelter) – the basics, we thought then. This year’s second intense wave makes us gasp for breath with a shortage of medical oxygen to treat critical COVID-19 infections. Doctors tell us everything we need to know about oxygen – the pranavaayu, which keeps us awake and roughly from baby’s breath (the first breath of a newborn within 10 seconds of birth) to agonal gasping (the last breath before death).

Our body under oxygen

“Oxygen fuels our life processes. It contracts our muscles, helps our cells to function, grow and regenerate, nourishes our brains, calms our nerves, helps the heart to pump, cleanses the body of toxins, fights infections and boosts immunity, “says Dr Narendra Nath Jena, Director, Institute of Emergency Medicine, Meenakshi Mission Hospital & Research Center, Madurai.


Once the air enters the nose or mouth, it is moistened and reaches the alveoli, tiny air sacs that help draw oxygen and transfer it into the bloodstream, as well as extract oxygen from the body. carbon and push it out of the lungs and back. until expire. COVID-19 destroys these alveoli by thickening the walls, which makes gas exchange difficult. Fluid (mostly inflamed cells and proteins) then fills between the alveoli, further hindering breathing.

O2 Basics (Dr Sundeep Salvi, Director Pulmocare Research & Education Foundation, Pune)

  • 21% The amount of oxygen in the atmosphere
  • 2,000 liters The amount of oxygen that enters a healthy person’s body every 24 hours.
  • 90% The percentage of energy our body gets from oxygen; only 10% comes from food and liquids

Some blood

Oxygen straddles red blood cells (RBCs) by binding to hemoglobin (Hb), the protein in each cell, and travels through the body to reach vital organs, brain, tissues, and cells. If you are anemic – that is, you have low Hb levels – it is likely that your organs are receiving less oxygen due to the decreased affinity of hemoglobin for oxygen.


The left side of your heart receives oxygen-rich blood from your lungs and pumps it through your arteries to the rest of your body. The right side of your heart receives oxygen-poor blood from your veins and pumps it to your lungs, where it gets rid of carbon dioxide and takes in oxygen. In COVID-19, an increased demand for oxygen occurs due to weakness in the lungs and fear (which turns the body on). This can lead to heart damage, especially if the arteries were already blocked.

The ideal diet

A diet rich in iron and vitamins helps keep our immune system strong. Foods such as broccoli, soy beans, kidney beans, chicken, nuts, citrus fruits, green beans, carrots help to increase the iron content and our hemoglobin levels and in turn the oxygen absorption. Dietary nitrates from spinach and other leafy vegetables, beets and berries help the blood vessels relax and improve the flow of blood and oxygen in the body, says dietitian Dr Anam Golandaz clinic and consultant at Masina hospital.

What is that?


The level of oxygen saturation (also called SPO2) corresponds to serum pressure (S) (P) and oxygen (O2). In most people, the body needs at least 95% oxygen in the blood to function properly. When deprived of oxygen, it goes into an emergency: the heart rate increases, increasing the risk of acute pulmonary cardiac arrest, there is brain-to-body dysfunction causing restlessness, disorientation, confusion and dizziness . A doctor should take a call to find out if you should start supplemental oxygen, how long it should be given, and at what saturation level.

Happy hypoxemia

A healthy body is naturally able to adapt to varying levels of saturation. For example, when mountaineers climb peaks, their bodies acclimatize to the low level of oxygen at high altitudes. The threshold is different for each person. A person with SPO2 between 88 and 94 may not have breathing problems while someone with a reading of 93 may be short of breath. Low oxygen saturation in the blood without any visible manifestation of distress is called happy hypoxemia.

Respiratory distress

When there is physiological stress ranging from short-term infection (like the flu) or long-term illness (like diabetes), or changes in life like menopause or a poor diet, the demand for Oxygen in the body increases due to a decrease in the number of red blood cells which are otherwise needed to carry enough oxygen to different organs.

With COVID being a disease of the lungs, things are complicated. The coronavirus invades the body when we inhale it (from another infected person nearby) and infects the cells that line the throat, airways and lungs. So if your lungs are not in great shape, let’s say if you smoke you are standing on the edge.

Even like our internal warriors, white blood cells naturally try to fight infections of the respiratory tract, the disease manifests as swelling and inflammation of the lungs and constriction of the airways. The air sacs fill with mucus and make it harder for the body to absorb oxygen. This leads to an abnormal breathing rate – too fast or too slow, shortness of breath or difficulty breathing.

– Dr Lancelot Pinto, consultant pulmonologist, PD Hinduja Hospital, Mumbai

Devices to remember

Pulse oximeter

The non-invasive device allows easy reading of SPO2. Previously used only in health centers, COVID has made it a household item. Lay your hand on a flat surface and attach the stapler-shaped gadget to the right middle finger (or index or thumb in that order). Using light sensors, the device records the percentage of oxygen in the blood flowing through the body. The percentage is displayed on the screen and a reading between 94% and 100% for all age groups is safe.

The reading can be taken at any time of the day. Even a low reading below 94% requires medical attention. Just to be sure to rub and warm your hands before the second reading, or to measure your SPO2 level with two different pulse oximeters in succession. Always check that the nail bed is clean. Readings with artificial nails or any nail paint or color on the surface may show error readings.

Smart wearable devices like the Fitbit or the Apple Watch, doctors say, are fitness devices and the readings recorded by these devices may not be reliable.

Oxygen tank

These contain very pure oxygen without contamination and require refilling because a finite amount of oxygen is compressed in the bottle and is inhaled by the user as long as it lasts. The bottles come in different sizes and can be purchased against a doctor’s prescription only and are used as emergency first aid and life support resuscitation for those who have difficulty breathing.

Doctor’s approval is required because caregivers need to know how much oxygen flow is needed per minute, based on 02 levels drop, type of infection, extent of lung damage, and ‘other comorbidities such as hypertension, diabetes.

Remember: supplemental oxygen is medicine

Oxygen concentrator

Everything you need to know about oxygen

A device that captures and filters ambient air and instantly generates medical grade oxygen at infinite power as long as the battery that powers it is charged. So, although the concentrator does not require any refilling, it does require a continuous supply of electricity.

Concentrators can only be used with approval and are suitable for moderately affected individuals with 85% O2 saturation levels. These handy devices are available in sizes to deliver one to 10 liters of oxygen per minute and are not recommended for intensive care patients who need more oxygen.

Medical advice is needed to know if oxygen should be administered 24 hours or only during exercise, as there is a risk of hypoxemia (oxygen level too low – below 90% on a pulse oximeter ) causing further damage to already incapacitated lungs. In addition, any overdose of self-administered oxygen can cause harm (even death) to people with chronic obstructive pulmonary disease (COPD).


Used for intensive care, they are computerized, microprocessor-controlled machines, which come in invasive and non-invasive variants. Used primarily in intensive care units and emergency departments, non-invasive ventilation is required when a patient is sleeping. It uses a simple, manually operated pocket valve nasal mask.

Invasive methods are needed for long-term addiction, with nasal or tracheal intubation (insertion of a tube through the nose or mouth to the airways). The machine pumps air containing supplemental oxygen into the patient’s airways when they are unable to breathe on their own. Except when lung function is severely impaired due to injury or illness such as COVID, ventilators are also used to support breathing during any surgery.

– Dr Sundeep Salvi