How to choose antibiotics for severely ill patients

Since antibiotics are used in clinics, bacterial infectious diseases have been relieved to a certain extent, and the lives of countless patients have been saved. Due to the continuous development of science and technology, the types of antibiotics are increasing day by day, and the clinical problem of bacterial resistance is becoming more and more serious. Therefore, how to use antibiotics correctly has become a very important topic. Improper use of antibiotics will not only cause drug waste, but also increase the mortality and hospitalization rate of patients. Antibacterial drugs are needed after severe infections, but the use of ineffective antibiotics and high-dose antibiotics has led to the emergence of more and more resistant strains, so the use of antibiotics for severe infections needs to be optimized. The strategy of using antibiotics for severe infections is a heavy-hammer strategy, a step-down strategy, and a sequential strategy at the end, as well as a strategy to prevent double infections.

Severe infections refer to primary infections focusing on pathogen infections, causing systemic inflammation and multiple organ dysfunction in the body. Due to the use of ineffective antibiotics and high-dose antibiotics, there are more and more resistant strains, so it is necessary to optimize the use of antibiotics in severe infections. In the early stage of infection, antibiotics should be used appropriately. Later, with the control of infection, pathogenic bacteria and drug susceptibility tests, drugs are usually used based on drug experience and drug sensitivity results. To avoid double infection and drug resistance, two or more antibiotics can be used in combination. Pregnant women, infants, children, the elderly and other special populations have specific contraindications to the use of antibiotics, and it is advisable to choose other metabolic antibiotics or reduce treatment. According to the pharmacokinetic effects of antibiotics, antibiotics are divided into two types: time-dependent and concentration-dependent. The former is based on the antibiotic maintenance concentration greater than the ratio of the interval between administrations to determine the dosage and frequency of the medication; the latter is based on the ratio of the administration concentration time greater than the minimum inhibitory concentration to determine the dosage.

Application of antibiotics in severely infected patients

1. Grasp the symptoms. Severe infections need to choose antibiotics based on the infection site and its pathogens and drug sensitivity experiments. Glycopeptide antibiotics are common, which are mostly used for sensitive methicillin-resistant Staphylococcus aureus, Enterococcus and anaerobic bacteria; if resistance to vancomycin and other glycopeptides appears, you can choose linezolid. Linezolid can also be used for methicillin-resistant Staphylococcus aureus and streptococcal infections that are not sensitive to vancomycin. It can also be used for skin and soft tissue infections including diabetic feet without osteomyelitis. If there is a complicated abdominal cavity infection, you can consider using tigecycline. For common pathogens in the hospital, such as Pseudomonas aeruginosa, Klebsiella, Acinetobacter, enzyme inhibitors such as piperacillin, sulbactam, ceftazidime, cefoperazone, and fourth-generation cephalosporin can be selected based on the drug sensitivity results , Can also be combined with sensitive quinolone or aminoglycoside antibiotics.

2. Understand the method of administration of the drugs used to avoid overdose or under-dose. Each antibiotic has its own characteristics, and it is necessary to understand these characteristics when using drugs and not to use drugs blindly. It is necessary to understand the usage and dosage of drugs. Excessive drugs not only waste drugs, increase medical costs, and side effects will increase; too low doses will have no effect. Therefore, antibiotics with strong antibacterial effect and sufficient dosage must be selected, the dosage is appropriate, and the combination medication must be used.

3. Make a reasonable choice of antibiotics. First, it is necessary to judge whether it is a hospital infection or a community infection based on the condition and characteristics of the disease. Community infections are mostly gram-positive cocci, streptococcus pneumoniae, followed by Staphylococcus aureus, Legionella pneumophila, Haemophilus influenzae and so on. For Mycoplasma pneumoniae infection, penicillin or a first-generation cephalosporin can be used. In severe cases, ampicillin or aminoglycosides can be added. Nosocomial infections are mainly caused by Gram-negative bacteria, mainly Escherichia coli, Klebsiella pneumoniae, Proteus and Acinetobacter. Can choose broad-spectrum semi-synthetic penicillin or cephalosporin and aminoglycosides. The possible pathogenic bacteria of mild infections include Streptococcus pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila. The first choice for treatment is oral or intravenous infusion. In addition to the above three drugs for moderate and severe infections, erythromycin and third-generation cephalosporins can also be used in combination. In the selection of antibiotics for severe infections, sensitive antibiotics are mostly selected based on pathogens and drug sensitivity results; if drug sensitivity tests have not been done, broad-spectrum antibiotics can be combined according to experience to observe the treatment effects, and improve pathogen and drug sensitivity tests as soon as possible.


1. The use of antibiotics is an important part of the treatment of infectious diseases. The final control of infection and the elimination of pathogenic bacteria are closely related to the body’s defense and immune functions. It cannot replace surgical treatment principles such as incision and drainage. Therefore, the patient must take strong care measures to achieve a balanced nutrition.

2. The dosage should be appropriate and the course of treatment should be sufficient. For acute infections that are not easy to prolong, and acute infections with good resistance to the disease, the drug can be stopped within 13 days after the disease is completely controlled.

3. Prevent the abuse of antibiotics. For symptoms such as shock and heart failure caused by viral diseases and non-infectious diseases, the use of antibiotics will not have a practical effect, but will increase the financial pressure of patients.