My Personal Experiece Warded in Hospital for Surgery Two Days Ago!

 

At 10:05 am on Wednesday 18, 2023, I underwent a VenaSeal endo-venous surgery for my chronic venous stasis right leg ulcer. 

I was operated on by two vascular surgeons, one was from Malaysia, the other was a Singaporean surgeon who was on assignment from Singapore General Hospital to the Kuala Lumpur Hospital. The Singapore surgeon is a colleague of my niece who is a Clinical Assoc Professor, Professor Anne Hsu Ann Ling, and a Senior Consultant at the Singapore General Hospital.

The surgery was completed at 11:10 am, precisely 40 minutes later. My blood pressure then was between 92 /59 and 112 /66 mm Hg which is quite normal for me. The last surgery done on me was in September 2023 using radio frequency ablation (RFA).

The last surgery was not successful because out of three areas that were patent, the last surgeon could only close two areas. The third one he was unable to close because RFA depends on heat, and the third area was too near a nerve. As a result, he could not close it as the heat may damage the leg nerve. So, this time, a year later they decided to use the glue (cyanoacrylate glue) method.

However, during the surgery and long after that, my blood pressures were only slightly low. It hovered around 108 / 70, which to me has always been like that for me.

At home my blood pressure can drop to an unbelievable 78 /60 mmHg without me having synoptic attacks (fainting).

But during surgery, my heart rate was between 98 - 105 beats per minute (tachycardia) and has remained at around 90 beats per minute even  at  1:00 pm, 2 hours after surgery was completed.

I was given spinal anesthesia. Less than two minutes later, both my legs were numbed and paralyzed. 

My legs could move sideways a little, but not lift up at 1:46 pm

Both legs could be lifted  up at 2:10 pm. I was out of surgical recovery hall at 2:46 pm, and was able to walk in the ward at 5 pm.  

But I was fully conscious and was able to see the data on the monitor in the operation theatre, memorize them, then write them down in the post-surgical recovery hall, and in the ward over a period of 7 hours.  

Below is a small statistical analysis from the raw data I managed to collect on my own in the operation theatre, in the post-surgical recovery hall to the ward as I was fully alert and concious all the way.   

Mean systolic blood pressure = 109 mm Hg, SD = + / - 4.8, variance (s²) = 22.9, n = 18

Mean diastolic blood pressure: 63.5 mm Hg, SD = +/ - 2.4, variance (s²) = 5.6, n = 18  

Mean heart rate: 93.8 beats per minute, SD = 3.6, variance (s²) = 13.5, n = 18

Mean respiratory rate: 17.6 per minute, SD = 4.2, variance (s²) = 17.7, n = 8 

Mean pO_{2 :}97.3 %, SD = 1.34, variance (s²) = 1.79, n = 10 

 

Due to my slightly low blood pressure during surgery, they tried giving me a pint of normal saline, I suppose as a volume expander, plus  phenylephrine, both  given intravenously to increase my blood pressure, but unfortunately my blood pressure remained on the low side.

So they pushed me into the third class ward after 2 hours of monitoring me in the post-surgical recovery room. In the third-class ward they have a surgical high-dependency unit where there are more nurses and doctors. There they could continue to monitor me, rather than pushing me back to my room in the 1st class ward where I was admitted the day before.  In the single room first-class ward there was no nurse in the room to monitor me for my vital signs.  

 But the anaesthetic doctor told me I could go back to the first-class (Ward 14 in Kuala Lumpur Hospital) at 5 pm after surgery, but this was not possible because my resting heartbeat was near 90 beats per minute, and my blood oxygen saturation level were 92 % when the normal should be 95 or 96 %.

When I was given pure oxygen in the surgical theatre at a rate of 5 litres per minute, and even many hours after that, my pSO2 saturation measured by the oximeter was 98 to 100 %. But when oxygen was taken off, my pSO2 dropped to 92 %.

Due to the slightly lower blood oxygen levels measured by the ward oximeter, they decided to take my arterial blood for the actual oxygen content using gas analysis, and the next morning send me for CXR (chest x rays) to see if my lungs are clear.  

An arterial blood gas test is a blood test taken from the artery. It measures the levels of oxygen and carbon dioxide, as well as the pH in the blood. Normally the arterial blood for oxygen level is used in emergency medicine and in critical care. This is more accurate than using the fingertip pulse oximeter that uses light to shine through the fingertip, making the tip appear to be red. By analysing the light that passes through the finger, the device can determine the percentage of oxygen in the red blood cell.

In fact, it merely measures the peripheral sub-cutaneous oxygen saturation after some of the oxygen has already been used up by the deeper underlying tissues. Hence, it will register slightly less than the actual arterial oxygen level. In other words, it measures the colour of the blood, not the actual oxygen content.

But then a question I would like to challenge is, what happens in case of carbon monoxide poisoning?  In the event of carbon monoxide poisoning the colour of blood is light reddish or pink, or “cherry-red,” due to carboxyhemoglobin formation. This would be very misleading if a fingertip oximeter were to be used.

However, the oxygen saturation in my arterial blood measured twice at an interval of about 3 hours both showed it was at 98 %, but the Kuala Lumpur Hospital electronic monitors that has an oximeter attached consistently showed between 92 or 93 % saturation.   

I thought to myself it was unnecessary to keep me there longer in the crowded and less comfortable 3^rd class ward just because they have a surgical high-dependency unit where they could continue to monitor me for my slightly low blood pressure and slightly low oxygen saturation level. The acceptable oxygen saturation level is taken as 95 percent for most healthy people. A level of 92 percent or lower can indicate potential hypoxemia.

But in my case, I was very alert. I did not suffer from any signs or symptoms of cyanosis on my face, lips, fingertips. Neither did I have dyspnoea (short of breath), restlessness, discomfort, chest pain, except slightly fast heart rate. In fact, I was quite stable, and they could wheel me back to my first-class ward that was more comfortable. But they decided to keep me overnight in the third-class ward for monitoring till I was discharged the next day.  

There is always a difference between the oximetry and the arterial gas analysis. The arterial oxygen level is always slightly higher than the oximetry reading.

What they could do was to take as many readings as possible from as many patients as possible, both by oximetry and arterial blood analysis. The many readings are to prevent a statistical risk of being biased, or ‘by chance’. We can then look at the difference between the arterial and superficial skin oximetry readings after many studies.

 Let us say the higher arterial reading is x, and the lower oximetry reading is y. The difference consistently after several studies is x – y = c.

We can then use ‘c’ as the correction factor to add it on to y to get the actual arterial reading x each time oximetry reading is taken. This would have avoided the trauma of taking arterial blood which can be very painful than the normal venous blood draw. But this correction factor was not used.

Fortunately, the doctor whom my surgeon selected, and trusted more than the rest of the other Medical Officers took my arterial blood.  He told me he trusted only a certain doctor in front of dozens of his other doctors under him. I don’t know how the rest of the doctors felt. The selected lady doctor drew my brachial artery blood twice almost painlessly. It was less painful than even the usual venous blood done on me by numerous doctors and phlebotomists in the past.

Following this letter I wrote in my WhatsApp chat, a friend of mine, Dato Dr Ong Eng Leong asked me this  question in pink below:

“Dear Prof JB Lim, glad to know that you are progressing well and wishing you complete recovery from your surgery. With the discrepancy you described, should not a correlation be being done between oximeter readings and chemical results before the oximeter is commercialised? Now, many are relying on portable oximeters available in the market”.

Here’s my reply to Dr Ong in dark green:

I agree with you Dr Ong that there must be some correlation studies that need to be done between chemical analysis and oximetry readings before commercializing of all these products

As I am also a qualified analytical food quality control chemist, besides being a clinician and nutritionist among others,  sometimes in chemical analysis, we can go down to  levels of just a few parts per million (ppm) or even to the tune of a few parts per billion (ppb) depending on the analytical instruments we use, especially the wide range of spectrophotometers, from infra-red and far infra-red spectrometers to Nuclear Magnetic Resonance (NMR) spectroscopy available to us, and also the analytical procedures we chose to adopt.

Analytical results even if repeated should not be more than 1 %, at most 2 % error even if we use a recovery method to get back a known weight of a sample we added into the original analytical sample

But the error of the oximetry method varies as large as 5 % which is a huge difference between just a few parts per million within the same series of measurements.. For us as analytical chemists and quality controllers, how do they expect us to accept such large variations?

What these medical doctors, nurses and laboratory technicians can do is to do a series of measurements using their oximeters and match them with the far more accurate chemical  analysis done in the laboratory to calculate out  the correction factor as I have already explained in my original letter above to be added  to all oximetry readings. But this was not done.

The advantage with oximeters even those match box size ones sold in the pharmacy, is that, they are so extremely easy and fast to use by anyone, and they are not wet and messy at all so unlike in wet analytical chemistry where the analyst must also be trained and qualified under the Chemist Act  1975 before he can sign the analytical lab report, not to say chemical analytical  procedures are far more time consuming and far, far more expensive to conduct.

So which one do we want? the Devil or the Deep Blue Sea?

But I think clinicians should not be too fussy about objective measurements but they should also look subjectively and clinically at the patients. In other words, they must have good clinical judgement instead of relying on all these lab tests all the time!

For instance they kept me a day  longer than necessary just because the hospital's large ward vital signs monitors with oximeters showed my pSO2 level was consistently "only" 92 %  when my arterial blood oxygen content was 98 %  taken twice within 3 hours.

Furthermore, I was fully alert, not cyanotic, dyspnoea (SOB) or short of breath, hypoxic, dizzy and so on. These are clinical judgments I would use and as a clinician myself..

But they insisted on the arterial blood analysis that took some hours instead of seconds with an easy to use oximeter

My feeling is, a good clinician is a good diagnostician, and a good clinical observer of the patient's conditions, and his wellbeing

He should not rely  solely on lab tests alone unless the case is complicated by other underlying morbidities where the presentations (signs and symptoms) are not so clear cut.

In that case we need lab support to differential diagnose with medical history being one of the first and most important diagnostic tools.

Maybe this is why doctors here in KL Hospital and in all government hospitals big or small, doctors  spend most of their time writing and clerking tons and tons of clinical notes on medical history and other findings leaving the nurses to do most of the basic clinical work such as taking blood pressure, body temperature, do the pO2 readings, do the dressing, set up the IV drips and monitor them, give injections, give medicine regularly, cleanse the patient, do the bedding, attend to patients’ needs, measure and monitor the fluid input and output.

Nurses do all this clinical work far more than doctors do. So, I always wonder why medical doctors and not the nurses called clinicians? In some countries nurses are appropriately called ‘nurse clinicians’

Of course there are other doctors such as anaesthesiologists, surgeons, obstetricians, and gynaecologists who do a lot of hand-on clinical work, while I think physicians do the least.

So we leave them as they are. That's why clinicians hardly win the Nobel Prize in medicine which is the world's most glamorous and prestigious Prize in health care that I wrote here:

“Nobel Prizes in Medicine: Are Clinicians out of Fashion?”

https://scientificlogic.blogspot.com/2023/

Thank you, Dr Ong, for your comment and question.

Kind regards,

Lim ju boo