Mean platelet volume, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio and early post-operative anesthesia complications

Introduction

Adenotonsillectomy is one of the most frequently performed surgeries during childhood. Adenoid hypertrophy and recurrent tonsillitis are commonly seen in children that cause sleep apnea disorder resulting in hypoxia. Chronic hypoxia may also lead to cardiovascular failure in children as in adults. Surgery decision is made for these medical issues in children. These patients are usually allergic children and often get sick, especially after school age. It is known that peri-operative respiratory adverse events (PRAE) like bronchospasm and laryngospasm are the most common complications in adenotonsillectomy [1, 2]. In these surgeries, the rate of respiratory complications requiring medical therapy ranges from 21 to 36 % [3]. Identifying the factors that can increase the risk of complications in early post-operative patients undergoing surgery will predict the complication and the appropriate treatment.

Figure 1:

Boxplot showing the MPV (mean platelet volume) values in CBC pre-operatively measured. Groups III and IV show higher MPV values (p=0.001).

Figure 2:

Boxplot showing the NLR (neutrophil to lymphocyte ratio) values in CBC pre-operatively measured. Groups I and II show lower NLR values (p=0.001).

Figure 3:

Boxplot showing the PLR (platelet to lymphocyte ratio) values in CBC pre-operatively measured. Groups III and IV show higher PLR values (p=0.026).

Recent studies have revealed that platelet/lymphocyte ratio (PLR) and neutrophil/lymphocyte ratio (NLR) are important indicators of systemic inflammation. The neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were also found to be an indicator of the prognosis in cardiovascular disease, malignancies, and chronic inflammatory diseases [4, 5].

Mean platelet volume (MPV) indicates platelet activation. In adults, it is shown that increased MPV values are associated with situations like atherosclerosis, cardiac diseases, and obstructive sleep apnea disorder (OSA) [6]. Hypotension as an early post-operative cardiac complication is more common in patients with cardiac co-morbidities. In many studies, it is shown that there is a relationship between cardiovascular complications and high MPV, NLR values [7]. However, although studies are finding a connection between obstructive adenoid hypertrophy and MPV in children, as well as publications finding opposite [8, 9].

Considering these situations, we hypothesized that there could be a relationship between MPV, PLR, and NLR values that were measured before surgery and complications in the early post-operative period. For this purpose, we examined the relationship between pre-operatively measured MPV, NLR, PLR values, and early anesthetic complications in patients undergoing adenotonsillar surgery and non-adenotonsillar surgeries in both pediatric and adult populations. We aimed to analyze whether the pre-operatively measured NLR, PLR, and MPV values could be a marker predicting early anesthetic complications or not.

Materials and methods

This study was a retrospectively designed research. We recorded the data from a preexisting patient database who had been admitted to Giresun Training and Research Hospital for elective surgery under general anesthesia by endotracheal intubation between 01.01.2021 and 01.11.2022 January 2021 and November 2022. All patients were offered enrollment in the study. The Ethics Committee of Ordu University (2022/257) approved the research protocol, and it was carried out in accordance with ethical regulations of the Helsinki declaration, and written informed consent was obtained from the patient or the patient’s surrogate in all cases. Data were collected retrospectively from the hospital records.

Patients from both sexes aged 1–63 years and the American Society of Anesthesiology (ASA) physical status I–II were included in the study with elective adenotonsillectomy and non-adenotonsillar surgeries. Patients who were pregnant, obese, and had body mass index (BMI) lower than 20, a history of malignancy and immunosuppression, major bleeding during surgery, and post-operative mechanical ventilation were excluded from the study. Two hundred fourteen pediatric and 116 adult patients were included in the study.

Results

A comparison of categorical and laboratory parameters of the patients is shown in Table 1. The gender and age distribution of patients who met inclusion criteria were considered; 124 patients in group I (pediatric adenotonsillectomy group), 66 (53.2 %) were boys, and 58 (46.8 %) were girls, whereas 54 (60 %) were boys and 36 (40 %) were girls of the 90 patients in group II (pediatric non-adenotonsillar surgery group). Of the 30 adult patients who underwent tonsillectomy in group III, 13 (43.3 %) were boys and 17 (56.7 %) were girls, whereas 37 (43 %) were boys and 49 (57 %) were girls of the 86 patients in group IV (non-adenotonsillar surgery group in adults).

In total, we included 330 patients in our study and the mean age of all patients was 20.21 ± 20.5.48.5 % of the patients were male whereas 51.5 % of them were female. According to the age groups, 64.2 % of them were pediatric and 35.8 % were adults. There was no difference in gender between groups (p=0.11).

There was a negative correlation between patients’ age and WBC values (p=0.001), as age increases WBC decreases. A positive correlation between patients’ age and platelet, lymphocyte, hemoglobin, MPV, NLR and PLR values (p<0.001), as age increases these values increase (Figures 1–3).

The mean WBC, platelet, and lymphocyte values of the patients in pediatric patients (Group I and Group II) were significantly higher than the adult patients (Group III and IV) (p=0.002, p=0.001, and p=0.001, respectively). On the other hand, the mean hemoglobin and MPV values in adult patients were significantly higher than those in pediatric patients. The mean NLR values were significantly lower in the pediatric adenotonsillectomy group (Group I) than the other groups (p=0.001). The mean PLR values were significantly higher in the Group III and IV (p=0.026).

We statistically examined the relationship between pre-operative MPV, NLR, and PLR values and early post-operative complications (Table 2). For this purpose, we conducted regression analyses to evaluate the relationship. It was observed that the MPV values were significantly higher in patients who had hypotension (p=0.01). In addition, in the correlation analysis, a significant relationship was found between MPV and hypotension (p=0.003, r=0.161). We performed receiver operating characteristic (ROC) analysis to detect cut-off value. When the cut-off value was taken 9.65, area under curve (AUC), sensitivity, specificity, accuracy was measured 0.792, 66.67, 77.47, and 77.27, respectively.

When we analyzed the pre-operative markers of pediatric patients who underwent adenotonsillectomy with or without hypoxia. PLR was significantly higher in those who developed hypoxia (Table 3). In connection with this, the need for steroid was also significantly high in this pediatric group (p=0.001). On the other hand, there was no relationship between other complications and the laboratory values of the groups (Table 3). In the ROC analysis, AUC 0.523, sensitivity 51.58, specificity 51.06, and accuracy were found when the cut-off value was taken 07.36.

Discussion

Chronic tonsillitis and adenotonsillar hypertrophy are the most common causes of nocturnal hypoxia during childhood. If chronic tonsillitis/adenoid hypertrophy is not treated, it can cause being sick often, growth retardation, attention deficiency, loss of appetite, orofacial abnormalities, and behavioral disorders [10]. Tonsillectomy is one of the most common surgical procedures in the pediatric population, 289.000 ambulatory procedures performed annually in the United States based on the most recent published data [11]. Acute phase reactants and inflammatory markers were also high in chronic tonsillitis or tonsillar hypertrophy patients. Many studies show that NLR, MPV and PLR values could be used as markers for systemic inflammation [12].

In the study, white blood count and lymphocyte levels were significantly high in pediatric groups, as expected. Contrary to the expectation, in the study, NLR value as an inflammatory marker was statistically significantly lower in pediatric adenotonsillectomy group. Many various factors may have contributed to this result. Among these, the inhomogeneity of the patient groups, the selection of the patients who will undergo surgery for reasons other than chronic tonsillitis and adenoid hypertrophy, and limited studies in pediatric patient groups can be counted. It is known that the most important factors that affect the development of OSA are male gender, tonsillar and adenoid hypertrophy, obesity, and chronic snoring [13]. The mechanisms underlying OSA have not yet been fully understood, but it is known that systemic inflammation is the main factor for cardiovascular complications in OSA patients: chronic hypoxia, endothelial dysfunction, and inflammation cause CVD in patients with OSAS. Therefore, we hypothesized those laboratory parameters indicating systemic inflammation could enable us to predict cardiovascular complications. In the study of Köseoglu et al. it was reported that PLR values were significantly high in OSAS patients and could be a guiding blood count parameter in predicting the development of CVD [14].

Mean platelet volume is one of the most important parameters indicating platelet activity. Larger platelets contain larger granules and are metabolically more active, and so these platelets cause complications due to hypercoagulability. In many studies, OSA patients have higher MPV values than control groups. In the study of Varol et al. it has been shown that there is a significant decrease in MPV values of OSA patients with CPAP treatment [15]. Assuming that children with adenoid hypertrophy may also have signs of OSA, we examined the association between groups and MPV. The study showed that MPV values were statistically significantly higher in adult patients than pediatric groups. But there was no significant difference between adenotonsillectomy groups and others. So we couldn’t indicate the association between obstructive sleep apnea symptoms and MPV values. Because we recorded the data retrospectively, we only asked obstructive sleep apnea syndrome diagnosed before surgery. Especially in pediatric patients should be examined with a scoring system. A prospective randomized-controlled study can examine the association between the reduction in OSA findings after adenoidectomy and MPV.

In our study, although we found that PLR values were higher in the patients having bradycardia in post-operative period, there was no statistically different finding. When we compared early post-anesthetic cardiovascular complications like hypotension and PLR, NLR, and MPV values, MPV values were significantly high in patients who developed hypotension. The result in the study supports the relationship between cardiovascular complications and MPV values shown in many studies.

Also, in many studies, PLR values have been investigated whether if may be a guide in the indication of surgery in adenotonsillectomy who have sleep apnea symptoms and different results [15, 16]. In the study, like MPV values, the PLR values were also found to be statistically significantly higher in adult patient groups. However, we couldn’t find any significant difference between adenotonsillectomy groups that could have sleep apnea symptoms and others in our study.

Respiratory complications like bronchospasm are the most common post-operative complications in pediatric patients. Prediction of post-operative bronchospasm and laryngospasm is an important issue, especially for children undergoing adenotonsillar surgery [17]. In the study, having hypoxia as an early post-operative complication was high in the pediatric adenotonsillectomy group. When we examined pediatric patients (Group I and II) as those who developed hypoxia after bronchospasm and laryngospasm and those who did not develop, we found that the PLR value was higher in those who developed hypoxia. In addition, PLR values were significantly high in the pediatric patients having hypoxia who underwent adenotonsillectomy.

Nevertheless, this result made us think that the inflammation process in adenotonsillectomy pediatric patients may contribute to early post-operative complications. So we think that the PLR value can be a guide in predicting post-operative bronchospasm and laryngospasm. However, with a larger population, age range can be standardized, and PLR values can be examined as a predictor in predicting early post-operative bronchospasm and laryngospasm. Therefore, it would be appropriate to evaluate the relationship between adenotonsillar hypertrophy and inflammation markers and so early post-operative anesthesia complications in a prospective-randomized study.

Routine single-dose dexamethasone therapy was strongly recommended in Clinical Practice Guideline: Tonsillectomy in Children (Update)—Executive Summary subscribed by American Academy of Otolaryngology-Head and Neck Surgery Foundation [10]. In our clinic, we apply steroid treatment to patients considered at risk or who develop laryngospasm or bronchospasm clinically. In the study, most of the patients who needed steroid therapy were in pediatric adenotonsillectomy patients. However, we found no association between steroid need and pre-operatively measured MPV, NLR, or PLR values.

Conclusions

According to the findings of the study, it was found that pre-operative MPV, NLR, and PLR values increased with increasing age. However; PLR values were significantly high in the pediatric patients having hypoxia who underwent adenotonsillectomy. Based on this finding, it has been suggested that pre-operative PLR values can be used as a guide in terms of predicting hypoxia. Also, we can say that high MPV values are guiding for the risk of developing post-operative hypotension.