GBZ 24-2002 Diagnostic criteria for occupational decompression sickness
Some standard content:
ICS13.100
National Occupational Health Standard of the People's Republic of China GBZ 24—2002
Diagnostic Criteria of Occupational Decompression Sickness2002-04-08 Issuedbzxz.net
2002-06-01 Implementation
Ministry of Health of the People's Republic of China
Article 4.1 of this standard is recommended, and the rest are mandatory. This standard is formulated in accordance with the "Law of the People's Republic of China on the Prevention and Control of Occupational Diseases". From the date of implementation of this standard, if there is any inconsistency between the original standard GB8782-1988 and this standard, this standard shall prevail. Improper decompression after high-pressure operations such as diving can often cause acute decompression sickness or evolve into decompression bone necrosis due to the formation of bubbles inside and outside the blood vessels and tissues. This standard is formulated to protect the health of workers and effectively prevent and treat occupational decompression sickness. Appendix A of this standard is an informative appendix, and Appendix B and C are normative appendices. This standard is proposed and managed by the Ministry of Health of the People's Republic of China. This standard was drafted by Shanghai Yangpu District Central Hospital, Dalian Labor Health Research Institute, Shanghai Maritime Rescue and Salvage Bureau, Navy 401 Hospital, Guangdong Occupational Disease Prevention and Treatment Institute, Qingdao Medical College. This standard is interpreted by the Ministry of Health of the People's Republic of China. Occupational Decompression Sickness Diagnostic Standard
GBZ24-2002
Decompression sickness is a systemic disease caused by improper decompression after high-pressure work, the gas originally dissolved in the body exceeds the supersaturation limit, and bubbles are formed inside and outside the blood vessels and tissues. Those who develop the disease within a short period of time after decompression or during decompression are acute decompression sickness. It mainly occurs in the femur, cranial bone and tibia, and the slowly evolving ischemic bone or bone joint damage is decompression osteonecrosis. 1 Scope
This standard specifies the diagnostic standards and treatment principles for occupational decompression sickness. This standard applies to the diagnosis and treatment of decompression sickness of workers in high-pressure environments. 2 Diagnostic principles
2.1 Acute decompression sickness
Within 36 hours after high-pressure operation, clinical manifestations caused by bubbles in the body can be diagnosed only after comprehensive analysis and exclusion of similar diseases caused by other reasons. For difficult cases, diagnostic compression should be performed to confirm the diagnosis. 2.2 Decompression osteonecrosis
There is a history of high-pressure operation, and most of them also have a history of acute decompression sickness: X-rays show bone or osteoarticular necrosis mainly occurring in the humerus, femur and (or) tibia. After comprehensive analysis and exclusion of normal variations such as bone islands and other bone diseases, it can be diagnosed. 3 Diagnosis and grading and staging standards
3.1 Acute decompression sickness
3.1.1 Mild
Skin manifestations such as itching, papules, marble-like spots, subcutaneous hemorrhage, edema, etc. 3.1.2 Moderate
Mainly occurs in the large joints of the limbs and nearby muscle and bone joint pain. 3.1.3 Severe
Severe cases are defined as those with any of the following conditions:
Nervous system: difficulty in standing or walking, hemiplegia, paraplegia, urinary and bowel disorders, visual disorders, hearing disorders, vestibular dysfunction, coma, etc.;
Circulatory system: collapse, shock, etc.;
Respiratory system: retrosternal inspiratory pain and dyspnea, etc. 3.2 Decompression osteonecrosis
Stages based on bone X-ray changes:
3.2.11 Stage
Femur, humerus and (or) tibia have local bone density areas, dense patches, stripes and (or) small cysts that become translucent areas, the latter of which may have irregular edges or lobes, surrounded by a sclerotic ring. The area of bone changes does not exceed 1/3 of the humeral head in the upper limbs and 1/3 of the femoral head in the lower limbs.
3.2.2 Stage I
Bone changes in the upper or lower limbs exceed 1/3 of the bone or femoral head, or large areas of bone marrow calcification appear. 3.2.3 Stage II
The lesion involves the joints, the joint surface is blurred, destroyed, deformed, dead bone is formed, the joint space is irregular or narrowed: the hip white or shoulder joint is destroyed, deformed, bone hyperplasia and bone and joint damage, etc. The affected joint has local pain and movement disorders. 4
Treatment principles
4.1 Treatment principles
4.1.1 Acute decompression sickness
Compression treatment must be carried out as soon as possible, and comprehensive auxiliary treatment should be given in time according to clinical manifestations. If compression treatment is not carried out in time or correctly at that time and symptoms remain, compression treatment should still be actively carried out. 4.1.2 Decompression osteonecrosis
According to the specific situation, hyperbaric oxygen compression and other comprehensive therapies can be carried out. 4.2 Other treatments
4.2.1 Acute decompression sickness
After the symptoms and signs completely disappear, different periods of rest are given. Mild cases require 1 to 3 days of rest, moderate cases require 3 to 5 days of rest, and severe cases require at least 7 days of rest. After the rest period, qualified personnel are allowed to participate in high-pressure operations after examination by a specialist. Those with recurrent illness or severe nervous system lesions are transferred from the operation. 4.2.2 Decompression osteonecrosis
a) Stage I: Under close medical support, divers can only dive within 10m, and caisson workers and tunnel workers can only participate in high-pressure operations below 203kPa (an additional pressure), and strictly abide by the operating regulations. b) Stage II and III: Transfer from high-pressure operations. Work that requires heavy loads and long periods of standing is prohibited, and active treatment is required. Instructions for the correct use of this standard
See Appendix A (Informative Appendix), Appendix B and C (Normative Appendix). A.1 Scope of use
Appendix A
(Informative Appendix)
Instructions for the correct use of this standard
Various workers in high-pressure environments, such as divers, caisson workers, tunnel workers, and medical personnel, scientific and technical personnel and dive escape personnel in compression chambers and hyperbaric oxygen chambers, etc. A.2 Common causes of improper decompression
This disease occurs due to improper decompression after high-pressure operations. Improper decompression refers to failure to decompress according to regulations, and even if decompression is carried out according to regulations, the disease still occurs due to individual differences, high labor intensity or changes in various environmental factors, resulting in insufficient relative decompression. A.3 Diagnosis of acute decompression sickness
The Doppler bubble meter can measure the larger diameter flowing bubbles in the blood flow, but cannot measure the static bubbles that stay in the tissue and cause musculoskeletal pain and paraplegia, so it is only of diagnostic reference value for some positive cases. A.4 Diagnosis of decompression osteonecrosis
There is a special occupational history, no other medical history that can cause ischemic osteonecrosis, and the radiographs show quite specific bone destruction, which mainly occurs in the humeral head and upper part, the upper, middle and lower parts of the femur, and the upper part of the tibia, that is, the specific parts of the long bones of the limbs, and can be limited to a certain part of a bone: in terms of joints, only the shoulder and hip joints are diseased. There are no I and IⅡ stage lesions without articular surface destruction, which do not cause subjective symptoms. Isotope bone scanning can show osteonecrosis lesions at an early stage, but cannot show old lesions that have been calcified or formed cavities, so it is only of diagnostic reference value for some positive cases. A.5 The division and grading method of the area of the cerebral head and femoral head on X-ray films adopts the self-comparison method. The humeral head is connected by a line between the outermost protrusion of the greater tuberosity and the inner depression, and the femoral head is connected by a line between the two depressions at the junction of the femoral head and the femoral neck. The area above the line belongs to the humeral head or femoral head. The cerebral bone, femoral bone and tibia are staged according to the size of the lesion area and the presence or absence of damage to the joint surface. Each patient uses the bone and joint with the most serious lesions as the regular standard.
A.6 Treatment principles
Treatment principles for acute decompression sickness are formulated according to the working pressure, the time in the high-pressure environment, the condition and the reaction to the treatment pressure. The stay and decompression time under high pressure should not be too short, and the treatment plan can be adjusted according to the changes in symptoms and signs. Oxygen can be inhaled in the later stage of decompression to accelerate the discharge of nitrogen, except for those caused by hyperbaric oxygen. If compression treatment is not carried out in time after acute decompression sickness, or if certain symptoms have not disappeared without correct treatment, no matter how long the onset has been, as long as there are conditions for compression treatment, compression treatment should still be actively carried out to avoid losing the opportunity for possible cure. A.7 Other treatments
After high-pressure work, people who have decompressed according to regulations and have not developed acute decompression sickness may still have bubbles in their bodies: people with decompression bone necrosis in stages I and II have no conscious symptoms. Therefore, high-pressure workers should have a physical examination once a year. If acute decompression sickness has occurred, or there has been long-term pain and movement disorders in the shoulder and hip joints, they can be checked in advance. Decompression bone necrosis may not appear as a shadow on the X-ray film until about 2 years after the diving operation is stopped. Therefore, the period for health examinations for those who are free of occupational diseases when leaving high-pressure work should be extended to 3 years. If a suspicious lesion is found, it should be checked until it is confirmed; if decompression bone necrosis is confirmed, it should be checked every year thereafter. B.1 X-ray manifestations
B.1.1 Cystic translucent area
Appendix B
(Normative Appendix)
X-ray manifestations and differential diagnosis of decompressive osteonecrosis Cystic shadows are usually round, oval, lobed or clustered, sometimes irregular. Single or multiple, with a diameter of about 3 to 20 mm. The cyst wall generally has a clear hardened edge, 0.5 to 1 mm thick. There is no bone structure in the cystic area, which is more obvious in the body layer. There may be obvious hardened cord bone pattern shadows around the cystic shadow. Single or multiple translucent areas can be seen in the bone necrosis area, with different sizes and shapes, and irregular edges. Individual translucent areas are large in range, with a diameter of up to 3 to 4 cm. B.1.2 Dense patchy shadows
Solitary or multiple, with different sizes, ranging from a few millimeters to a few centimeters, and various shapes, sometimes in strings or clusters, with not very sharp edges. The density of the patch shadow varies. Those with low density can see chaotic or fused bone patterns, while those with high density are as white as ivory, so that the bone structure cannot be seen clearly. It can appear in the humerus, femur and tibia. B.1.3 Dense streak shadow
Dense streak shape can be irregular linear, serpentine, whirlpool, fluffy, messy or beard-like. The edge is not very sharp, about 2 to 5 mm wide and up to several centimeters long. Calcification spots and small translucent areas of varying sizes can be mixed between the streak shadows. This change is different from the direction and distribution of the bone patterns of the surrounding normal cancellous bone, and is often seen in the humeral head and neck and between the femoral neck and trochanter.
B.1.4 Crescent-shaped dense shadow
Refers to the crescent-shaped dense shadow that is close to the inner upper edge of the joint surface. The inner upper edge is sharp, and the outer lower edge is clearly demarcated from the normal bone. The edge is irregular and can be seen as lace-like, or partially blurred, and gradually migrates into the normal bone. It is most common in the humeral head and a few in the femoral head. It can account for 1/6 to 1/2 of the area of the humeral head or femoral head. Sometimes there are translucent areas in the lesions. B.1.5 Medullary cavity calcification
Common in the middle and lower femur and the upper tibia, and can also be seen in the upper and middle humerus. It manifests as an irregular calcification shadow formed by the aggregation of sharp-edged strips and spots and patches in the medullary cavity. The shadow density is lighter in the early stage, and it is spotted or short strips (it is easier to find femoral and cavity bone lesions by taking lateral films in the early stage). Later, the density gradually increases, and the range can also gradually expand. It can be up to 20cm long and has a very irregular shape. There may be a calcified ring around the partially calcified medullary cavity, with irregular translucent areas inside. B.1.6 Articular surface destruction and joint damage
In the early stage, the edge of the articular surface of the femoral head or humeral head is slightly blurred and deformed, followed by the cracking of the articular surface, and a linear translucent band appears in the bone cortex, which is connected to the bone necrosis area under the articular surface. As the destruction continues, in addition to the formation of dead bone, part of the force point of the articular surface collapses, and the range may gradually expand, causing the femoral head or humeral head to be irregularly deformed. At the same time, the hip acetabulum or shoulder joint also shows corresponding destruction and deformation.
Differential diagnosis
In X-ray differential diagnosis, attention should be paid to the following items. B.2.1 Bone island
It is a calcified spot left behind by local ossification variation during the ossification process. Most of them are round, oval or irregular in shape, with a diameter ranging from 3 to 10 cm. The bone island has clear and sharp edges, sometimes with thorn-like protrusions, and is surrounded by cancellous bone structures. It is often found in the cancellous bones at both ends of the femur and tibia. B.2.2 Cartilage islands are cartilage tissues that remain due to localized ossification disorders during the ossification of long bones or flat bones. They are often found in the femoral neck, with clear boundaries and usually single, and can be up to 10 cm long. Most of them are round translucent shadows, and adjacent overlapping or crossing bone lines can be seen. B.2.3 Pseudocystic changes in the humeral head are cystic osteoporotic areas near the greater tuberosity on the outside of the humeral head of normal people, often bilaterally. Its inner edge is the dry boat part of the humeral head with rich trabeculae, which is often convex in arc shape. The upper end is connected to the remains of the physiological healing part of the bone boat, and the outer edge is the shadow of the greater tuberosity. The upper edge is generally not very clear and gradually migrates into the cancellous bone of the humeral head; the outer end of the lower edge is often at right angles to the shadow of the greater tuberosity. Sometimes, several round translucent areas with a diameter of about 5 mm can be seen in the middle of the humeral head, with unclear edges. B.2.4 Long bone marrow calcification
Can be seen in rare diseases such as hyperphosphataseemia, and it is not difficult to identify after comprehensive analysis. B.2.5 Hip osteoarthrosis
Can be seen in adult femoral head avascular necrosis and degenerative osteoarthritis caused by various reasons. C.1 Radiographic requirements and quality assessment
Appendix C
(Normative Appendix)
Precautions for X-ray examination
C.1.1 The shoulder, hip, and knee joints on both sides should be projected separately. The shoulder joint should be separated from the humeral head. The radiographic range should include the joint and its nearby bone shaft, and generally include 1/3 of the bone shaft. The radiographic quality requirements are clear image, good contrast, clear trabeculae without artifacts, and no abrasions.
C.1.2 Radiographic quality assessment standards
Excellent: The photo fully meets the quality requirements of bone films. Good: It does not fully meet the quality standard requirements, but it does not affect the diagnosis. Poor: There are technical defects, but it can still be used for diagnosis. Waste: It cannot be used for diagnosis.
Radiographic technology
When taking a radiograph, refer to the past bone films to determine the exposure site and conditions. Take an anteroposterior film, and if necessary, take a lateral film or a body layer film. Before taking a radiograph, the examinee must be trained several times and get full cooperation before exposure. When projecting the lower limbs, the reproductive organs must be protected with a lead plate. The distance between the target piece and the target piece is 80 to 90 cm, and the exposure is expressed in milliampere-seconds. Adjust the exposure according to the contrast of the film. The kilovolt value should be increased for films with large contrast. Reduce milliampere-seconds; if the contrast is small, increase milliampere-seconds appropriately. C.3 Projection mechanical equipment
X-ray machine uses more than 200mA, full-wave rectification, rotating anode tube, focal point 1~2mm, power string greater than 20~40kW, medium-speed calcium tungstate intensifying screen, and its resolution is not less than 7 line pairs/mm. X-ray film uses blue negative film, medium speed I~II, contrast greater than 2.5, gray fog less than 0.2, and the power supply voltage must be stable. C.4 Darkroom technology
The developer uses the formula specified by the film factory, and the liquid temperature is controlled at 18~20℃. Fixing should be sufficient and rinsing should be thorough.2 Cartilage islands
are cartilage tissues that remain due to localized ossification disorders during the ossification of long bones or flat bones. They are more common in the femoral neck, with clear boundaries and usually single, and can be up to 10 cm long. Most of them are round translucent shadows, and adjacent overlapping or crossing bone lines can be seen. B.2.3 Pseudocystic changes in the humeral head
are cystic osteoporotic areas on the outside of the humeral head adjacent to the greater tuberosity in normal people, and often occur bilaterally. Its inner edge is the dry boat part of the humeral head with rich trabeculae, which is often convex in arc shape. The upper end is connected to the remains of the physiological healing part of the bone boat, and the outer edge is the shadow of the greater tuberosity. The upper edge is generally not very clear and gradually migrates into the cancellous bone of the humeral head; the outer end of the lower edge is often at right angles to the shadow of the greater tuberosity. Sometimes several round translucent areas with a diameter of about 5 mm can be seen in the middle of the humeral head, and the edges are not clear. B.2.4 Long bone marrow calcification
Can be seen in rare diseases such as hyperphosphataseemia, and it is not difficult to identify after comprehensive analysis. B.2.5 Hip osteoarthritis
Can be seen in adult femoral head avascular necrosis and degenerative osteoarthritis caused by various reasons. C.1 Radiographic requirements and quality assessment
Appendix C
(Normative Appendix)
Precautions for X-ray examination
C.1.1 Shoulder, hip and knee joints on both sides should be projected separately. The shoulder joint should be separated from the humeral head. The radiographic range should include the joint and its adjacent bone shaft, generally including 1/3 of the bone shaft. The radiographic quality requirements are clear image, good contrast, clear bone trabeculae without artifacts, and no abrasions.
C.1.2 Radiographic quality assessment standards
Excellent: The photo fully meets the quality requirements of bone slices. Good: It does not fully meet the quality standard requirements, but does not affect the diagnosis. Poor: There are technical defects, but it can still be used for diagnosis. Useless: It cannot be used for diagnosis.
X-ray technology
Refer to the bone films in the past to determine the exposure site and conditions when taking the film. Take the anteroposterior film, and take the lateral film or body film if necessary. Before taking the film, the examinee must be trained many times to get full cooperation before exposure. When projecting the lower limbs, the reproductive organs must be protected with lead plates. The distance between the target piece is 80 to 90 cm, and the exposure is expressed in milliampere-seconds. Adjust the exposure according to the contrast of the film. For films with large contrast, increase the kilovolt value. Reduce the milliampere-second; for films with small contrast, increase the milliampere-second appropriately. C.3 Mechanical equipment for projection
X-ray machine uses more than 200mA, full-wave rectification, rotating anode tube, focal spot 1 to 2mm, power series greater than 20 to 40kW, and medium-speed calcium tungstate intensifying screen, with a resolution of not less than 7 line pairs/mm. X-ray film uses blue negative film, medium speed I~II, contrast greater than 2.5, fog less than 0.2, and the power supply voltage must be stable. C.4 Darkroom Technology
The developer solution uses the formula specified by the film factory, and the temperature of the solution is controlled at 18~20℃. Fixing should be sufficient and rinsing should be thorough.2 Cartilage islands
are cartilage tissues that remain due to localized ossification disorders during the ossification of long bones or flat bones. They are more common in the femoral neck, with clear boundaries and usually single, and can be up to 10 cm long. Most of them are round translucent shadows, and adjacent overlapping or crossing bone lines can be seen. B.2.3 Pseudocystic changes in the humeral head
are cystic osteoporotic areas on the outside of the humeral head adjacent to the greater tuberosity in normal people, and often occur bilaterally. Its inner edge is the dry boat part of the humeral head with rich trabeculae, which is often convex in arc shape. The upper end is connected to the remains of the physiological healing part of the bone boat, and the outer edge is the shadow of the greater tuberosity. The upper edge is generally not very clear and gradually migrates into the cancellous bone of the humeral head; the outer end of the lower edge is often at right angles to the shadow of the greater tuberosity. Sometimes several round translucent areas with a diameter of about 5 mm can be seen in the middle of the humeral head, and the edges are not clear. B.2.4 Long bone marrow calcification
Can be seen in rare diseases such as hyperphosphataseemia, and it is not difficult to identify after comprehensive analysis. B.2.5 Hip osteoarthritis
Can be seen in adult femoral head avascular necrosis and degenerative osteoarthritis caused by various reasons. C.1 Radiographic requirements and quality assessment
Appendix C
(Normative Appendix)
Precautions for X-ray examination
C.1.1 Shoulder, hip and knee joints on both sides should be projected separately. The shoulder joint should be separated from the humeral head. The radiographic range should include the joint and its adjacent bone shaft, generally including 1/3 of the bone shaft. The radiographic quality requirements are clear image, good contrast, clear bone trabeculae without artifacts, and no abrasions.
C.1.2 Radiographic quality assessment standards
Excellent: The photo fully meets the quality requirements of bone slices. Good: It does not fully meet the quality standard requirements, but does not affect the diagnosis. Poor: There are technical defects, but it can still be used for diagnosis. Useless: It cannot be used for diagnosis.
X-ray technology
Refer to the bone films in the past to determine the exposure site and conditions when taking the film. Take the anteroposterior film, and take the lateral film or body film if necessary. Before taking the film, the examinee must be trained many times to get full cooperation before exposure. When projecting the lower limbs, the reproductive organs must be protected with lead plates. The distance between the target piece is 80 to 90 cm, and the exposure is expressed in milliampere-seconds. Adjust the exposure according to the contrast of the film. For films with large contrast, increase the kilovolt value. Reduce the milliampere-second; for films with small contrast, increase the milliampere-second appropriately. C.3 Mechanical equipment for projection
X-ray machine uses more than 200mA, full-wave rectification, rotating anode tube, focal spot 1 to 2mm, power series greater than 20 to 40kW, and medium-speed calcium tungstate intensifying screen, with a resolution of not less than 7 line pairs/mm. X-ray film uses blue negative film, medium speed I~II, contrast greater than 2.5, fog less than 0.2, and the power supply voltage must be stable. C.4 Darkroom Technology
The developer solution uses the formula specified by the film factory, and the temperature of the solution is controlled at 18~20℃. Fixing should be sufficient and rinsing should be thorough.
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