The bleep went off again. It was 11pm and already my night shift covering the surgical wards was busy. I answered. It was a staff nurse from the orthopaedic ward asking me to come and see a lady she was worried about with a low blood pressure. I was just next door to the ward so went along straight away.
Mrs James was an 81 year old lady who had become more confused and unwell over the past few hours. The nurse told me her blood pressure (BP) had been dropping over the last three hours, along with her urine output in the urinary catheter. She had undergone an emergency operation on her left hip, a hemiarthroplasty earlier that morning for a broken neck of femur. I scanned her notes and saw she also had a history of hypertension and heart failure, though it was not clear how severe.
I approached Mrs James who opened her eyes to my voice and asked ‘Can you send me in to hospital’. She was disorientated, thinking she was at home. Her GCS was 13/15 (E=3 V=4 M=6). Her airway seemed clear, with normal respiratory rate 18 breathes per minute, saturations of 98% on room air and clear chest on auscultation. Her mouth mucous membranes looked dry – the nurse told me she didn’t fancy eating or drinking much at dinner as she felt ‘too tired’. Her hands were cool, capillary refill of 4 seconds which I thought seemed a bit long. I couldn’t see her JVP. I repeated her BP – it was 89/66mmHg and pulse rate was 106 which felt regular. Her pupils were normal size and reactive to my pen torch light – I thought this was good: I had once seen an older patient after a hip operation become opiate toxic, where the pupils went pin point after having too much morphine for pain. Jugular Venous Pressure ◦ Cardiovascular Basics ◦ Cardiovascular Reflexes
I was a bit worried. This lady was hypotensive and tachycardic; I could see her urine output was trailing; she was oliguric as only 15mls of dark urine had passed in the last hour. I thought she was probably hypovolaemic following her surgery, i.e. she may not have had much to eat or drink before and after the operation. I thought of whether there may have been some blood loss from the operation or if sepsis could also be making her blood pressure low. However thankfully her temperature was normal there were no obvious symptoms of infection and the leg wound looked clean with no bleeding or large bruising. I asked the nurse to send off a urine sample for culture anyway. Hypovolaemia ◦ Sepsis
I thought the priority was to get her blood pressure up. I inserted a large bore cannula into her antecubital fossa in her arm where I had thankfully found a large vein. My hands were shaking as I really wanted to make sure it went in - hypotensive patients can be difficult to cannulate because their veins aren’t full. I sent off bloods urgently including FBC and U&Es. I wondered how much fluid I should give. With her heart failure history (though I didn’t know how bad this was) I was worried about giving too much to cause fluid overload and pulmonary oedema. I decided to prescribe a fluid challenge of 500ml of 0.9% saline fluid over 15 minutes, as I had been reading about in the recent NICE guidelines on intravenous (IV) fluid therapy and asked the nurse to observe her urine output and the oxygen saturations. N I C E Fluid Management Guidelines ◦ N I C E Fluid Management Algorithms ◦ Fluid Challenge
I contacted the medical SpR on call, explained the patients’ condition and what I had done so far. He suggested I do a few more tests, give another fluid challenge if the BP didn’t improve and said he would come along to review her right away.
I did an arterial blood gas (ABG), which showed: Taking An Arterial Blood Sample ◦ Arterial Blood Gas Basics
She was acidotic but with a low PaCO2 suggesting a metabolic basis. The high lactate reading fitted with the obvious cause: organ hypoperfusion. Her organs were running on anaerobic metabolism. I was a bit alarmed by the potassium level which was very high. When I returned to the ward I asked the nurse to do an urgent ECG, to see if the potassium had affected the heart. Hyperkalaemia And Hypokalaemia
There were classic tented T waves and flattened P waves on the ECG - I needed to urgently treat the hyperkalaemia! The first step was to give her calcium gluconate slowly IV, to protect the heart and prevent dangerous cardiac arrhythmias occurring. Then I prescribed insulin with glucose infusion to shift potassium back in to cells to reduce extracellular potassium levels.
Meanwhile the 500ml of fluid had finished and the BP came up a bit to 100/60 mmg/Hg. I asked for another 250ml fluid challenge to go through – it was important to fill her. The blood test results had also come back:
Hb 129 g/L
Creatinine 120
eGFR 45
Looking through her notes her eGFR and creatinine before the operation were 90 and 60, respectively. I realised this was acute kidney injury (AKI), likely due to hypoperfusion of her kidneys. I remembered that there are some good guidelines available from the London AKI Network. Acute Kidney Injury ◦ A K I Perioperative Guidelines ◦ A K I Care Bundle
I looked at her drug chart to see if there were any medications which were making her blood pressure low and potentially her kidneys worse. She was on an ACE inhibitor called ramipril. I put a hold on this as for the time being as this would likely do more harm. She was also on ibuprofen for a painful knee. I stopped this as NSAIDs can also worsen kidney injury.
I asked the nurse for hourly observations, a strict fluid balance chart and wrote her up for 1 litre of IV fluid to continue over the next six hours. I returned to the ward after half an hour later and thankfully she looked much better and her blood pressure had picked up. By this time the medical SpR arrived on the ward – he went to review Mrs James and seemed happy with my management so far. I repeated a venous blood gas sample which showed her potassium has come down to 4.5 and her acidosis has improved. I ordered repeat U&Es for the morning and planned to make sure that when I handover to her regular ward team to let them know the events of the night.