[Thoughts on the rescue process of a patient with septic shock].

Abstract

Septic shock is a common acute and critical illness in intensive care medicine. It can lead to multiple organ failure, of which the heart is one of the target organs. Fluid resuscitation plays an important role in the treatment of septic shock, but when a patient develops septic-induced cardiomyopathy, the circulation is often not improved by fluid resuscitation, and may even lead to deterioration of circulation. On October 2, 2023, a 52-year-old female patient with septic shock was admitted to the department of intensive care medicine of Civil Aviation General Hospital, whose circulation deteriorated during fluid resuscitation. The main complaint of the patient was left face numbness for more than 20 days, aggravated with unconsciousness for 5 days. Upon admission, the patient was in a coma and intubated by oral tube. The blood pressure was 128/82 mmHg (1 mmHg ≈ 0.133 kPa; intravenous pump of norepinephrine 0.2 μg×kg^-1×min^-1). Chest CT indicated lung infection, and infection markers were elevated. The main diagnoses were septic shock, pneumonia, acute cerebral infarction of left pontine arm and etc. At 12 hours after admission, according to arterial and central vein blood gas analyses, the oxygen uptake rate was 31% (> 30%), and the veno-arterial blood partial pressure of carbon dioxide (Pv-aCO₂) was 7 mmHg (> 6 mmHg), blood lactic acid (Lac) increased, combined with the width of the inferior vena cava of 1.0-1.6 cm, also indicated a relative insufficiency of effective circulating blood volume, so appropriate fluid resuscitation was given. After fluid resuscitation, the urine volume of the patient increased from 40 mL/h to 100 mL/h, but the blood pressure did not increase significantly, indicating that there was no volume responsiveness, so dobutamine 3 μg×kg^-1×min^-1 was added to enhance myocardial contractility. The heart rate did not increase significantly, and the blood pressure was relatively stable. At 21 hours after admission, the patient's systolic blood pressure (SBP) suddenly dropped from 110-120 mmHg to 60-70 mmHg, while heart rate dropped from 100-110 bpm to 80-90 bpm. Therefore, the dosage of norepinephrine was increased to 2 μg×kg^-1×min^-1, and the dosage of dobutamine was increased to 10 μg×kg^-1×min^-1, but the circulation could not be maintained. In addition, no tension pneumothorax was found in the chest radiography, and blood routine did not indicate the possibility of acute blood loss. Troponin I (TnI) decreased from 3 778.8 ng/L to 2 025.9 ng/L, brain natriuretic peptide (BNP) increased from 15 ng/L to 1 638 ng/L. Myocardial enzymology changes were not consistent with acute myocardial infarction, and pulmonary hypertension was not found in cardiac color ultrasound. Therefore, it is considered that the decrease of blood pressure was caused by the decrease of cardiac function, which was combined with septic cardiomyopathy. After increasing the dobutamine pump dose to 20 μg×kg^-1×min^-1, lowering the infusion speed, reducing the cardiac preload, and continuing to use vasoactive drugs to boost blood pressure for about 1 hour, the patient's blood pressure increased, circulation became stable, and the rescue was successful. After 60 days of treatment, the pneumonia of the patient was effectively controlled, vasoactive drugs and dobutamine were successfully stopped, the patient was extubated, and was able to walk short distances with assistance when discharged. When the circulation of septic shock patients cannot be maintained, the three elements of maintaining blood pressure are effective circulating blood volume, cardiac function and peripheral vascular resistance. The three elements interact with each other and are affected by various factors. The difficulty of maintaining circulation in septic shock is to find out which is the main problem correctly. Individualized volume management, correct recognition and treatment of cardiac dysfunction, and rational use of vasoactive drugs are the keys to maintain circulation in septic shock patients.