Pertussis syndrome is also known as day-cough syndrome, and is very difficult to distinguish from pertussis. The typical clinical manifestations of pertussis syndrome are characterized by paroxysmal cough, cough with choking echo and peripheral blood lymphocytosis. However, the clinical performance of infants less than 6 months is not typical. Most of them have suffocation with slow heartbeat, difficult breathing while coughing, as the main symptoms (1,2) due to blockage of organ secretions caused by hypoxia and suffocation. This disease has a long course of illness with a complicated medical history, and severe life-threatening illness (3). It has been reported that paroxysmal cough in pertussis children within 6 months only accounted for 10%, and respiration stopped after coughing accounted for 18% (4). Findings have shown that pertussis syndrome is associated with adenovirus (5). According to the statistics of the World Health Organization in recent years, even under the high coverage of diphtheria-pertussis-tetanus combined vaccine, the incidence of pertussis is still on the increase with a small margin (6). According to reports of the American Prevention Center, in 2012, the incidence of pertussis has reached its 50-year highest level (7). The current equipment used to identify the two diseases is expensive and many hospitals have not yet been popularized (8).

Vitamin K is a fat-soluble vitamin, used for unique post-translational chemical modification of proteins with calcium-binding properties. These proteins are collectively referred to as vitamin K-dependent proteins (VKDPs) or Gla proteins. Vitamin K is mainly used for coagulation, but it is also involved in the metabolic pathways of bones and other tissues (9,10). Vitamin K contains vitamin K1 and vitamin K2 (11). Previous findings have shown that vitamin K1 has a contractile effect against acetylcholine and smooth muscle, and has a sedative effect on central nervous organs (12,13). In addition, vitamin K1 exerts an antitussive effect on bronchiolitis and bronchial asthma (14). In the 1930s, Per et al reported that the extract of alfalfa ether can be used for hemostasis, separate the yellow oil from the alfalfa, and named it as vitamin K1 (15). Meropenem is a second-generation carbapenem antibiotic. Compared to the first-generation, the second-generation has a higher safety and a stronger antibacterial effect on Gram-negative bacteria (16,17). The current study focused on the clinical analysis of meropenem in the treatment of pertussis syndrome with vitamin K1.

Pertussis syndrome is a common lower respiratory tract infectious disease in infants. According to statistics, approximately 300,000 children die each year due to pertussis syndrome. Particularly, the disease condition had become more severe in small infants (18,19). The disease progressed rapidly in the absence of protective antibodies in 3 months old infants. If combined with cardiovascular dysfunction, the difficulty of treatment will increase (20). Due to the slender trachea in children lung secretions cannot be effectively discharged, this leads to intracellular bacterial growth in the tracheal ciliated skin, blocked cilia movement and affects excretion discharge. Large accumulation of inflammatory secretions in the trachea stimulate the nerve endings and cause severe paralysis (21,22). Some reports indicate that respiratory syncytial virus and bordetella parapertussis were the main causes of pediatric pertussis syndrome (23,24). In this investigation, depending on the treatment method, patients were divided into two different groups. Among them, 87 patients in the experiment group were treated with vitamin K1 combined with meropenem. A total of 83 patients in the control group were treated with meropenem alone. The general information between the groups was compared, the results showed that the general information difference was not statistically significant (P>0.05), suggesting that the groups of patients had comparability. First, we compared the duration of spasmodic cough and the length of hospitalization between the groups, the results showed that the duration of spasmodic cough in the experiment group was significantly lower than the control group, and the difference between the groups was statistically significant (P<0.05). The length of hospitalization in the experiment group was significantly shorter than the control group, the difference between the groups was statistically significant (P<0.05). This suggested that vitamin K1 combined with meropenem can shorten the duration of spasmodic cough and length of hospitalization. Recent research has shown that vitamin K1 can relieve spasmodic cough in patients as well as reduce the cough duration and length of hospitalization (25). This is consistent with our results. Clinically, vitamin K1, as an effective drug for the treatment of pertussis, can alleviate spasmodic cough. It is speculated that vitamin K1 promoted the synthesis of prothrombin in the liver to achieve the effect of hemostasis, and reduced the number of complications caused by spasmodic cough in order to shorten the disease duration. Then, the clinical efficacy was compared between the groups of patients. The results showed that, the experiment group, included 45 cases of significantly-effective patients, 39 cases of effective patients and 3 cases of non-effective patients, and the total effective rate was 96.55%. The control group, included 30 cases of significantly-effective patients, 35 cases of effective patients and 18 cases of non-effective patients, with a total effective rate of 78.31%. The total effective rate in the experiment group (96.55%) was significantly higher than the control group (78.31%), the difference was statistically significant (P<0.05). It is suggested that the clinical efficacy of vitamin K1 combined with meropenem in the treatment of spasmodic cough is better than the clinical efficacy of meropenem alone. Currently, there is no relevant report on the efficacy between the groups. Meropenem, a type of carbapenem antibiotic, has broad-spectrum activity and is widely used for antibacterial treatment of infections in the respiratory tract, urinary tract and digestive tract (26). Our results suggested that, meropenem during the period of antibacterial and anti-infection, adding appropriate amount of vitamin K1 can supplement the body's vitamin K1 deficiency to prevent respiratory hemorrhage, so that combining both drugs can achieve a better efficacy. Next, the antipyretic time, duration of voice disappearance and healing time were compared. The results showed that the duration of voice disappearance and healing time in the experiment group were significantly lower than the control group, the difference between the groups was statistically significant (P<0.05). The antipyretic time in the experiment group was lower than the control group, the difference between both groups was not statistically significant (P<0.05). It is suggested that vitamin K1 combined with meropenem can help to shorten the duration of voice disappearance and healing time, which is more conducive to the rehabilitation of spasmodic cough. Currently, no relevant reports exist. From the pathological point of view, there may be respiratory secretion elimination disorder caused by respiratory inflammation, however, meropenem has an excellent antibacterial and anti-inflammatory effect and vitamin K1 has a good hepatic coagulation function. The drugs combined achieve the best possible effect.

There are only a small number of patients in this study, which is not a sufficiently adequate data analysis, therefore, certain limitations may exist. There is currently very little scientific research on the drugs between the groups, so we will continue to conduct relative research and improve the accuracy of the results.

In summary, treatment of meropenem combined with vitamin K1 has a significant effect on relieving children with spasmodic cough syndrome. It can shorten the duration of spasmodic cough, length of hospitalization antipyretic time and duration of voice disappearance as well as improve the clinical efficacy. We also emphasize that timely vaccination is the key to preventing spasmodic cough, even if the patient suffers from spasmodic cough, the disease condition would be much milder.