Key findings:
Key findings of the abstract include the division of phlebitis risk factors into patient characteristics, therapy, healthcare practices, and cannula attributes. The study, conducted at Indira Gandhi Medical College, identifies diabetes, infectious diseases, and gender as significant factors and suggests interventions such as shorter catheter replacement intervals and improved supervision to reduce phlebitis rates.

What is known and what is new?
Prior studies have categorized phlebitis risk factors into patient characteristics, therapy, healthcare practices, and cannula attributes. New: This study investigates thrombophlebitis risk factors among adult patients in a specific hospital setting, employing observational methods and statistical analysis to identify associations between drug usage and phlebitis occurrence, suggesting targeted interventions for risk reduction.

What is the implication, and what should change now?
The study highlights the multifactorial nature of thrombophlebitis risk, emphasizing patient characteristics, therapy, healthcare practices, and cannula properties. It identifies diabetes, infectious diseases, and gender as significant factors and proposes interventions like shortened catheter replacement intervals, improved supervision during insertion and maintenance, gentler intravenous drugs, and better disease control to reduce phlebitis rates in high-risk groups, implying a need for tailored preventive strategies and enhanced clinical protocols.
 

Studies over the past two decades have shown that 27% to 70% of patients receiving peripheral intravenous therapy  develop phlebitis that requires the removal of the cannula, the insertion of a new cannula in a different site, and, often,  local treatment and analgesic drugs [1].Guidelines for the management of intravenous therapy have recommended daily  surveillance of cannula sites and, to reduce the risk for phlebitis and infection, the rotation of cannula sites every 24 to 48  hours.[2].This practice adds considerably to the costs of intravenous therapy. 

Over the last two decades, studies about phlebitis have divided the risk factors into four main groups: patient  characteristics, therapy administered, health professional practices and cannula characteristics. The condition may resolve  easily or proceed to complications like DVT, pulmonary embolism, septicaemia, cellulitis, nodule formation or hyper  pigmentation of skin. Moreover, it causes patient discomfort and insertion of a new catheter at a different site is required. [3]

The complications associated with peripheral IV cannula and IV therapy can have a devastating effect on a patient's  health and quality of life and also increase the costs of health care through prolonged hospital stay and treatment [4]. Given  thrombophlebitis can put patient’s safety at risk, this study is aimed to identify its incidence and associated risk factors in  our local community. 
 

All adult patients admitted in Medicine wards and requiring intravenous cannulation over a period of one year were  included in this observational study conducted in the Department of Medicine, Indira Gandhi Medical College (IGMC),  Shimla, Himachal Pradesh. 

 
The patients were excluded if already suffering from thrombophlebitis at the time of admission, unconscious patients, patients with pre-existing septicaemia, patients who were hemodynamically unstable, patients who were cannulated in  casualty, and/or patients who had already been cannulated at periphery. The study was initiated following approval from institute ethics committee at IGMC Shimla. All the study participants were included after they agreed to participate in the study.  

Data was entered in Microsoft Excel spreadsheet and analysed using Epi Info software version 7.2.2. Categorical data were presented as the number of patients, their percentage and 95% Confidence Intervals. For quantitative variables, means and standard deviations were calculated. Chi square test was applied to determine the association between the use of  different drugs and the occurrence of thrombophlebitis. A p-value of less than 0.05 was considered to be statistically significant. 
 

Catheters were inserted for reasons such as administration of fluids, intravenous drugs and blood products. Catheter  gauge size was 20 in 236(87.73%) patients and 18 in 33(12.27%) patients. 119(44.24%) catheters were inserted in the  hand, 48(55.02%) in the forearm and 2 were inserted at the other sites.153(56.88%)cannula were inserted by staff nurse  and 116(43.12%)cannula were inserted by Junior resident. 

Cannula size and cannula site were also studied as risk factors for thrombophlebitis. 23(69.70%) patients with 18 G  cannula and 122(51.69%) patients with 20 G cannula developed thrombophlebitis with p value of 0.052. 

Cannula inserted on hand developed thrombophlebitis in 68(57.14%) patients compared to 77(51.33%) patients who  had cannula inserted at other sites with P value of 0.342. Cannula were inserted either by staff nurses or Junior Resident  and these were also studied as a risk factor for the development of thrombophlebitis. 85(55.56%) patients with cannula  inserted by staff nurse and 60(51.72%) patients with cannula inserted by junior residents developed thrombophlebitis  with P value of 0.532. 

Hyperlipidemia was also studied as a risk factor. 32(78.05%) patients with hyperlipidemia developed  thrombophlebitis with P value of 0.001. (Table 1) 

Table 1: Determining risk factors for thrombophlebitis (N=269) 

The most common infection encountered in the patients suffering from  thrombophlebitis was Tropical Infections, followed by Pneumonia, and Urinary tract infection. Among patients with infectious diseases, 32(78.05%) patients developed thrombophlebitis with a P value of 0.844. (Figure 1) 

Figure 1: Description of Infections suffering from thrombophlebitis among the study participants
 

Large bore catheters generally cause more phlebitis due to greater mechanical irritation. However, in contrast to most  studies, [5,6]. Our findings did not show catheter bore as a risk factor for phlebitis. One of the possible reasons may be that  very large bore catheters (16G) were not used in our patients.  

 
A study conducted by Abhijit Mandal & Raghu, showed that the incidence of phlebitis was higher when a larger  caliber catheter like 18 G (37.97% OR 1.94, 95% CI 0.95‑3.85) was used and it was less in 20 G catheter [7].These  findings also coincide with the study conducted by Magerotel et al.,[8]. 

In our study, there was no relationship between thrombophlebitis and site of insertion of cannula and  whether the cannula was inserted by a junior resident or staff nurse. 

Hyperlipidemia was also found as a risk factor for thrombophlebitis in our study. Thrombophlebitis developed in  32(78.05%) patients with hyperlipidemia compared to 113(49.56%) patients without hyperlipidemia. This is similar to  the result found in the study done by Salma U et al.,[9] . In this study, the thrombophlebitis rate was significantly higher in the hyperlipidemia group (17.11%) compared to the group without hyperlipidemia. 

 
Our study found no significant difference in the incidence of thrombophlebitis in patients with or without infection.  Most of the patients were suffering from UTI, Pneumonia, enteric fever, tropical infections like scrub typhus or  leptospirosis and other non- specified infections. This is in contrast to the results of the studies conducted by Maki et  al.[10], Barbut F, Pistone T, Guiguet M, et al.,[11] and Ena J, Cercenado E, Martinez D, Bouza E [12] in that infectious diseases  increase risks of phlebitis (OR 6.21, 95% CI 4.27-9.03). One of the reasons may be related to the fact that the intravenous antibiotics used in these patients cause chemical irritation of the endothelium, with resultant phlebitis. 
 

Based on our findings, we believe that if certain variables influencing the risk of phlebitis (especially diabetes  mellitus, infectious diseases and gender) are taken into consideration, the rate of phlebitis can be reduced in high risk  groups by: shortening the intervals between catheter replacements, better supervision during insertion and maintenance of  catheters, use of milder irritant intravenous drugs, especially with respect to antibiotics, and better control of underlying  diseases. 

Funding: No funding sources.

Conflict of interest: None declared.

Ethical approval: The study was approved by the Institutional Ethics Committee of Indira Gandhi Medical College
 

1. Maki, Dennis G., et al. "Infection control in intravenous therapy." Annals of Internal Medicine 78.5 (1973): 825-825. https://www.acpjournals.org/doi/abs/10.7326/0003-4819-78-5-825_2 
2. Turnidge, John. "Hazards of peripheral intravenous lines." Medical Journal of Australia 141.1 (1984): 37-40. https://onlinelibrary.wiley.com/doi/abs/10.5694/j.1326-5377.1984.tb132666.x 
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6. Tan, R. H. H., A. J. Dart, and B. A. Dowling. "Catheters: a review of the selection, utilisation and complications of catheters for peripheral venous access." Australian veterinary journal 81.3 (2003): 136-139. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1751-0813.2003.tb11074.x 
7. Mandal, Abhijit, and K. Raghu. "Study on incidence of phlebitis following the use of pherpheral intravenous catheter." Journal of family medicine and primary care 8.9 (2019): 2827-2831. https://journals.lww.com/jfmpc/fulltext/2019/08090/Study_on_incidence_of_phlebitis_following_the_use.14.aspx 
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