In the medical field, laboratory examinations are playing a huge role in the interpretation of the clinical diagnosis of patients. Each test has its repercussions. Some of the samples need special handling depending on their sensitivity, stability, urgency. Its effects interfere with the tests such as arterial blood gas samples.
For a long time, the pneumatic transport system has proved to be of much importance in the transportation of various samples within and out of health care laboratories. Many modern hospitals and healthcare units widely use the pneumatic tube transportation system to move the specimen from the patient care sections to the laboratory premises. One major attribute of any transport facility in the healthcare sector is its ability to retain the integrity of the sample in transit (Harsten et al., 2003).
The pneumatic tube transportation system has been suggested to alter the results of Blood Gas. An arterial blood gas is a test aimed at measuring the partial pressures of oxygen PO2, Carbon dioxide PCO2, pH, and arterial oxyhemoglobin saturation (Nunn, 2004). This information concerning blood gas is very important when dealing with patients suffering from critical respiratory diseases and in the ICUs (Astles et al., 1996).
Blood gas tests must be run immediately after the collection of the blood gas to minimize contamination of the sample especially through the unintended entry of air bubbles into the specimen. This is because it may greatly alter the results of the partial pressures of the blood gases (Riley and Cournand, 1991). Contamination by air significantly raises the partial pressure measurements. For example, research carried out by the Division of Clinical Laboratories, Duke University Medical Center, showed that patients with a baseline partial pressure of oxygen PO2 of less than 85mg reported an increase of up to 10 mm Hg when their samples were transported via the pneumatic transport system (PTS).
It has also been reported that the use of pressurized systems such as the PTS for transportation significantly exaggerates the effect of air bubbles on the partial pressures of oxygen (Nunn, 2004). Patients suffering from critical respiratory diseases should be handled with a lot of care and the tests concerning their arterial blood gas should be as accurate as possible and should be run as soon as possible. The patient’s blood sample can either be transported manually or using the PTS system (Biswas et al., 2001). As most researchers have concluded, transportation of blood specimens manually is less erratic as compared to the use of the pneumatic system (Riley and Cournand, 1991).
This system has been criticized since there have been several reports stating that the pneumatic tube transport system increases the chances for errors in the partial pressure of oxygen PO2 (Biswas et al., 2001). Comparisons between the manual and the pneumatic tube system of transportation have been made based on various research questions to find a lasting solution for the minimization of blood analytical errors (Astles et al., 1996).
Arterial blood gas analyses have previously been reported to be erroneous as a result of various mistakes characteristic to the samples and especially during transportation. This is because blood gases are easily affected by changes in the partial pressures of the blood gases (Riley and Cournand, 1991). This is unfortunate since the pneumatic system, being a technologically improved transportation system, has proved efficient in areas where manual transportation has failed. For example, the manual system easily results in sample contamination by agents other than air bubbles. Contaminants may include impurities introduced due to unclean vessels of carriage and the rapid shaking the samples undergo while being transported by hand (Nanji and Withklow, 2000).
As at present, we cannot easily avoid the use of the pneumatic tube transportation tool but instead, we can look into minimizing the air pressure problems. This research will aim at finding solutions to the air pressure problems as a result of using PTS for transportation.
References
Astles, JR, Lubarsky D & Loun, B 1996, ‘Pneumatic transport exacerbates interference of room air contamination in blood gas samples’, Journal of Arch Pathological Lab Medicine, vol. 120, pp. 642-7.
Biswas, CK, Ramos JM & Agroyannis B 2001, ‘Blood gas analysis: effect of air bubbles in syringe and delay in estimation’, BMJ., vol. 284, pp. 923-927.
Harsten, A, Berg B & Inerot S 2003, ‘Importance of corrected handling of samples for the results of blood gas analyses, Journal of Anaesthesiol Scand, vol. 32, pp. 365-368.
Mahoney, JJ, Harvey JA & Wong RJ 1999, ‘Changes in oxygen measurements when whole blood is stored in iced plastic or glass syringes’, Journal of Clinical Chemistry, vol. 37, pp. 1244-1248.
Nanji, AA & Withlow, KJ 2000, ‘Is it necessary to transport arterial blood samples on ice for pH and gas analysis’? Journal of Clinical work, 31,568-571.
Nunn, JF 2004, ‘Measurement of blood oxygen tension’ Journal of handling of samples, vol. 34, pp. 621-30.
Riley RL & Cournand, A 1991, ‘Analysis of Factors Affecting Partial Pressures of Oxygen and Carbon Dioxide and Blood of Lungs: Theory1’, Journal of Applied Physiology, vol. 4, no. 2, pp. 77-101.