It's 5am, the sky is light, but the city is sleeping. Brenda had gone to bed the night before feeling fine, but has woken in a panic. She is not untypical of a lady her age: 76 years old, with diet-controlled diabetes, angina, high blood pressure, and heart failure. When she feels well, she is able to get her messages from her local shops, but occasionally she suffers shortness of breath as her heart struggles to pump her blood round her system. Despite this, she rarely fails to get through her 10 cigarettes a day.
Today is different. Today, she has been woken with a feeling that someone has poured a bucket of water into her lungs. She thinks she is dying and is terrified. She is breathing so fast she can barely get a word out between breaths. She has to sit upright with her arms propped on her knees to get as much air as she can into her lungs. The gaps between her ribs are being indrawn with every breath, such is the effort of her breathing. Her chest is heaving and rattling, and she coughs up a light pink froth every minute or so. Instinctively, she struggles over to her bedroom window and puts her head out to try and relieve this appalling sensation.
Cameron, her husband, has woken up with the commotion, and having seen his wife's distress, has called an ambulance straight away. The ambulance arrives within a few minutes, and they administer some oxygen and take some vital signs to assess the situation. They note that Brenda's oxygen levels are very low, her pulse and breathing rate are rapid, and her blood pressure reads very high. They transfer her to the ambulance and transport her to the Emergency Department.
When she arrives, Brenda's breathing has settled a little on the oxygen treatment, but she is still struggling to get any string of words out, and looks like she might be tiring with all the effort of breathing. Her pulse is still very fast, and now bounding when you feel it at the wrist. Her blood pressure is sky high. We take a handover of information from the ambulance crew and then set about examining Brenda. Her chest is full of crackles, her veins are distended in her neck and her ankles are swollen.
We do a heart tracing, get a drip in her arm, take some blood tests from the vein and also one from the artery on the inside of the wrist. This tells us specifically how well the lungs are able to transfer oxygen and carbon dioxide, and how affected the body is by any lack of oxygen supply to the tissues. We order a chest Xray as we explain to Brenda what the likely explanation is.
Brenda's alarming symptoms are caused by a rapid inability of the heart to pump all the blood it receives from the venous system out into the arterial system. This causes a build up of pressure in the lungs and backwards into the veins, and a leakage of fluid into the lungs' airspaces. The sensation of drowning for patients is very real, and caused by this fluid being pushed out of the circulation into your lungs.
Fortunately, we in the Emergency Department can administer some treatments to help quickly reverse this problematic pressure differential in the majority of cases. Our aim in the first hour or two is to offload the pressure on the heart, so that it firstly receives less blood to it, as well as making it easier to pump the blood forward out into the arteries.
We do this by using a nitrate compound that acts on the venous and arterial blood vessels, relaxing the muscle layers within them and making them open up. This reduces the resistance that the heart has to pump blood against, as well as reducing the amount of blood that returns to it. This starts to reverse the pressure build-up in the lungs that enables the fluid that is in there to be squeezed back into the circulation.
We also use a form of ventilation support that increases the oxygen and air pressure within the lungs. This is delivered through a tight-fitting mask, through which gas is pushed and timed with Brenda's breaths, so that it pushes air and oxygen into the lungs, as well as improving the ability of Brenda's lungs to inflate. It is a bit like enabling the patient to breathe whilst having their head out of a fast-moving car window, (but with a little more control).
Once we have resolved some of the problems with the pressures in arterial and venous systems, and are seeing improvements in how blood is being pumped round the body and Brenda's ability to breathe, we then start to remove any excess fluid in the circulation with diuretics, so that the body can re-balance itself. After 90 minutes of intensive treatment and monitoring, Brenda's breath returns, and she surfaces from her self-immersion.
These episodes are incredibly frightening for patients, and often happen in the early hours of the day (for a variety of reasons). Taking care of your heart is the key to avoiding them