RESQDOC
12-04-01, 09:23
Lets think out loud here for a bit on lab medicine under remote and/or disaster conditions. There is quite a thread going about various tests, methods, and equipment, yet no one has really discussed the far more important questions, such as:
- Should lab studies be a part of your mission planning at all?
- What is the purpose of laboratory medicine in the care of the ill and injured?
- What are the conditions that can reasonably be investigated by laboratory methods under remote/disaster conditions?
- What are the highest priority tests? Next priority, etc?
- What are the easiest, cheapest, most feasible means to perform these tests?
Only after these questions are discussed can we really be prepared to debate the merits of the various methods of urine acetone testing, as an example.
These questions of course do not have a single answer, as each individual or group has their own set of potential problems, capabilities, and resources to deal with. My experience over the years providing medical care in diverse environments and teaching diverse groups strongly supports this conclusion. We can however answer these questions in a general way that will provide guidance to developing a lab medicine capability.
Should lab medicine be a part of your mission planning at all? Well, what is lab medicine? For our purposes I would suggest that it consists of tests or studies of body fluids, tissue, or other biological samples for the purpose of detecting or measuring some particular parameter or item of data. For example the evaluation of a sputum sample for bacteria, or urine for glucose. Lab medicine however is not the ultimate source of medical information, but one of many tools that are needed to fit into a unified system of medical care. I would suggest that lab medicine should be a part of your medical planning, in that context. It should not take priority over learning the basics of medical care, or establishment of appropriate ongoing training-supplies-practice. Lab medicine is a rather specialized area of study, can be expensive and time intensive to set up, and can detract from laying the foundation of a good medical care program if it becomes the primary goal. Thus, I would recommend that you focus on the basics first. When your fundamental program is in place, that is the time to expand into a lab medicine capability. It is a worthy goal to work towards, as even a basic lab capability will dramatically improve the quality of care you can provide. But basics first!
Laboratory medicine plays an important part in the process of management of the ill or injured. That process consists of a) recognition that a problem exists, b) determining the nature of the problem and perhaps the cause or source, c) determining the most appropriate treatment or response, and d) monitoring therapy for success or failure. You will be confronted with four specific situations: 1) when you have no idea what is wrong with the patient, 2) when you do not have a specific diagnosis but have things narrowed down to a group of problems or organ systems 3) when you have a diagnosis but need confirmation to choose specific therapy, or 4) when you are certain of the diagnosis and do not need lab studies to manage the patient.
Under remote/disaster medical conditions laboratory medicine will be of the most use under conditions 2 & 3. The resources will generally not be available to “shotgun” a bunch of tests in order to try and get a diagnosis going. Nothing replaces a proper history and physical examination backed up by as much knowledge as possible, but if confronted with a patient that is urinating 15 times a day, the ability to look for infection vs. blood vs. glucose in the urine is very helpful in pinning down a diagnosis or suggesting an area for further investigation.
To properly make use of a laboratory capability you must understand what you are testing, the limits and sources of error in the test, possible other causes of your findings, and how to apply that information to your patient care. For example, glucose in the urine may be a sign of diabetes. But there are at least a dozen other conditions that can lead to sugar in the urine, several different methods of testing with different sensitivities and reliabilities under various conditions, drugs that can lead to falsely positive tests (aspirin being one), and any results generated must be taken in the context of the patient’s symptoms and your other data. Do I want to know if there is glucose in the urine? You bet I do. Can I conclude automatically that it is diabetes? No.
Thus to properly use lab data, you must consider several sources of potential problems. Was the sample collected, stored, processed correctly? Are the tests you are using reliable and repeatable? Do you know what is normal? Do you know the different human physiology and disease mechanisms that can give you the same results? Do you understand what false positives, false negatives, and their sources are?
In that context, what then can reasonably be investigated via lab methods under remote/disaster medical conditions, and what should be your priority?
The highest priority is clearly that test or tests that has bearing on any chronic medical problems that you currently are faced with. Diabetes would be an example. The ability to do blood sugar testing is critical. Supplementation with urine sugar, pH, ketones, and protein would dramatically improve your ability to care for this problem.
Your next highest priority is testing to aid in the diagnosis and treatment of the most common survivable/treatable conditions.
This would include, in rough order:
- Infections of skin, respiratory tract, and digestive system
- Anemias and malnutrition
- Pregnancy
- Metabolic disease
Clearly then the ability to collect blood, urine, sputum, or stool and examine it under a microscope, with appropriate processing, is the most important capability.
This will allow you to:
- Determine the presence of bacterial, fungi, ova, parasites, crystals, etc.
- Possibly identify at least the class of these organisms to guide therapy selection
- Repeat the testing to gauge therapeutic success
- Determine white cell status
- Determine red cell status
- Infer a great deal about the patients condition
Determination of a patient’s hemoglobin or hematocrit level is important in acute blood loss, chronic blood loss, malnutrition, chronic disease, etc.
Pregnancy may seem unlikely, but “where there’s a will, there’s a way.” The diagnosis of abdominal pain and many other conditions in women always starts with this question. All other decisions follow from this answer.
Metabolic disease, dehydration, etc., can also be monitored via appropriate testing. In remote/disaster conditions this is most easily done, or only done, via urine testing.
There are many other test of course that can be done, but should they be done? For example cheap easy rapid tests are available that screen blood for evidence of cardiac muscle injury such as that seen in a heart attack. But under remote/disaster conditions will a positive test change how you manage this patient?
In summary then, here are some thoughts & suggestions for an initial focus in developing a lab medical capability:
- Whatever you need to deal with known problems
- Low power microscopy with the ability to perform Giemsa (or Fields), Gram, and Wright stains as well as general examination and ova/parasite work on any sort of sample
- White cell counts, and if possible a “guess” differential
- Hemoglobin level
- Pregnancy testing
- Urine testing for infection & metabolic changes
- More advanced procedures as indicated or desired
We can cuss and discuss this, then deal with specific methods of accomplishing these tests.
Hope this helps,
Keith
- Should lab studies be a part of your mission planning at all?
- What is the purpose of laboratory medicine in the care of the ill and injured?
- What are the conditions that can reasonably be investigated by laboratory methods under remote/disaster conditions?
- What are the highest priority tests? Next priority, etc?
- What are the easiest, cheapest, most feasible means to perform these tests?
Only after these questions are discussed can we really be prepared to debate the merits of the various methods of urine acetone testing, as an example.
These questions of course do not have a single answer, as each individual or group has their own set of potential problems, capabilities, and resources to deal with. My experience over the years providing medical care in diverse environments and teaching diverse groups strongly supports this conclusion. We can however answer these questions in a general way that will provide guidance to developing a lab medicine capability.
Should lab medicine be a part of your mission planning at all? Well, what is lab medicine? For our purposes I would suggest that it consists of tests or studies of body fluids, tissue, or other biological samples for the purpose of detecting or measuring some particular parameter or item of data. For example the evaluation of a sputum sample for bacteria, or urine for glucose. Lab medicine however is not the ultimate source of medical information, but one of many tools that are needed to fit into a unified system of medical care. I would suggest that lab medicine should be a part of your medical planning, in that context. It should not take priority over learning the basics of medical care, or establishment of appropriate ongoing training-supplies-practice. Lab medicine is a rather specialized area of study, can be expensive and time intensive to set up, and can detract from laying the foundation of a good medical care program if it becomes the primary goal. Thus, I would recommend that you focus on the basics first. When your fundamental program is in place, that is the time to expand into a lab medicine capability. It is a worthy goal to work towards, as even a basic lab capability will dramatically improve the quality of care you can provide. But basics first!
Laboratory medicine plays an important part in the process of management of the ill or injured. That process consists of a) recognition that a problem exists, b) determining the nature of the problem and perhaps the cause or source, c) determining the most appropriate treatment or response, and d) monitoring therapy for success or failure. You will be confronted with four specific situations: 1) when you have no idea what is wrong with the patient, 2) when you do not have a specific diagnosis but have things narrowed down to a group of problems or organ systems 3) when you have a diagnosis but need confirmation to choose specific therapy, or 4) when you are certain of the diagnosis and do not need lab studies to manage the patient.
Under remote/disaster medical conditions laboratory medicine will be of the most use under conditions 2 & 3. The resources will generally not be available to “shotgun” a bunch of tests in order to try and get a diagnosis going. Nothing replaces a proper history and physical examination backed up by as much knowledge as possible, but if confronted with a patient that is urinating 15 times a day, the ability to look for infection vs. blood vs. glucose in the urine is very helpful in pinning down a diagnosis or suggesting an area for further investigation.
To properly make use of a laboratory capability you must understand what you are testing, the limits and sources of error in the test, possible other causes of your findings, and how to apply that information to your patient care. For example, glucose in the urine may be a sign of diabetes. But there are at least a dozen other conditions that can lead to sugar in the urine, several different methods of testing with different sensitivities and reliabilities under various conditions, drugs that can lead to falsely positive tests (aspirin being one), and any results generated must be taken in the context of the patient’s symptoms and your other data. Do I want to know if there is glucose in the urine? You bet I do. Can I conclude automatically that it is diabetes? No.
Thus to properly use lab data, you must consider several sources of potential problems. Was the sample collected, stored, processed correctly? Are the tests you are using reliable and repeatable? Do you know what is normal? Do you know the different human physiology and disease mechanisms that can give you the same results? Do you understand what false positives, false negatives, and their sources are?
In that context, what then can reasonably be investigated via lab methods under remote/disaster medical conditions, and what should be your priority?
The highest priority is clearly that test or tests that has bearing on any chronic medical problems that you currently are faced with. Diabetes would be an example. The ability to do blood sugar testing is critical. Supplementation with urine sugar, pH, ketones, and protein would dramatically improve your ability to care for this problem.
Your next highest priority is testing to aid in the diagnosis and treatment of the most common survivable/treatable conditions.
This would include, in rough order:
- Infections of skin, respiratory tract, and digestive system
- Anemias and malnutrition
- Pregnancy
- Metabolic disease
Clearly then the ability to collect blood, urine, sputum, or stool and examine it under a microscope, with appropriate processing, is the most important capability.
This will allow you to:
- Determine the presence of bacterial, fungi, ova, parasites, crystals, etc.
- Possibly identify at least the class of these organisms to guide therapy selection
- Repeat the testing to gauge therapeutic success
- Determine white cell status
- Determine red cell status
- Infer a great deal about the patients condition
Determination of a patient’s hemoglobin or hematocrit level is important in acute blood loss, chronic blood loss, malnutrition, chronic disease, etc.
Pregnancy may seem unlikely, but “where there’s a will, there’s a way.” The diagnosis of abdominal pain and many other conditions in women always starts with this question. All other decisions follow from this answer.
Metabolic disease, dehydration, etc., can also be monitored via appropriate testing. In remote/disaster conditions this is most easily done, or only done, via urine testing.
There are many other test of course that can be done, but should they be done? For example cheap easy rapid tests are available that screen blood for evidence of cardiac muscle injury such as that seen in a heart attack. But under remote/disaster conditions will a positive test change how you manage this patient?
In summary then, here are some thoughts & suggestions for an initial focus in developing a lab medical capability:
- Whatever you need to deal with known problems
- Low power microscopy with the ability to perform Giemsa (or Fields), Gram, and Wright stains as well as general examination and ova/parasite work on any sort of sample
- White cell counts, and if possible a “guess” differential
- Hemoglobin level
- Pregnancy testing
- Urine testing for infection & metabolic changes
- More advanced procedures as indicated or desired
We can cuss and discuss this, then deal with specific methods of accomplishing these tests.
Hope this helps,
Keith