Review of literature is an essential component of the research process. It aids the researcher in the formulation of the research plan or proposal and condition of the study. It aids in relating the outcomes of the study to the findings of other investigations
Review of literature is defined as a critical summary of research on a topic of interest, often prepared to put a research problem in contest (Polit and Beck, 2006).
The current study and review of various associated literature and review study, topics can divide as follows;
Section A: Literature related to comparison of normal saline and heparin flush to maintain the patency of intravenous line.
Section B: Literature related to cost effectiveness of normal saline flush in maintenance of peripheral intravenous catheter.
Section C: Literature related to complications of using heparin solution for maintaining patency.
Section A: Literature Related to Comparison of Normal Saline and Heparin Flush to Maintain the Patency of Intravenous Line.
Elsevier (2009) did a randomized double blind controlled trial to investigate the efficacy of normal saline versus heparin saline in maintaining the patency of intravenous catheter among 150 children of pediatric unit at United States. In that, Group I received normal saline flush (n=77) whereas Group II received heparin saline flush (n=73). The result showed that 72% of children were recovered from blockage during normal saline flush. Thus researcher concluded that the normal saline flush was effective in maintaining the patency of intravenous catheter.
Klieiber (2008) conducted prospective, randomized double blind study to determine the efficacy of saline versus heparin flush to maintain the peripheral intravenous lock in pediatric populations among 140 children. The sample was selected randomly into two groups. Group I received normal saline flush whereas Group II children flushed with heparinized saline. The findings revealed that there was no significant difference between the groups in maintaining the patency of catheter and reduces incidence of complications.
A randomized controlled double-blind trial was conducted by Esther Mok, Tany & KWong (2007) for maintaining peripheral intravenous lock among 123 children of age from one to ten years. The objective of this study was to evaluate the effectiveness and safety of three flush solutions: normal saline, one unit/ml of heparin saline and ten units/ml of heparin saline for maintaining peripheral intravenous locks in children, and to establish a research-based practice in the study hospital. Group I received one unit/ml of heparin saline, Group II received ten units/ml of heparin saline and Group III received normal saline. The group that received one ml of normal saline demonstrated the highest rate of survival and the mean length of catheter showed (49.8 hours) was seventeen hours longer than the group that received one unit/ml of heparin saline (32.5 hours). The result showed that there was no significant difference among the three types of flushing solution in terms of the catheter longevity and incidence of intravenous complications.
A study was conducted by Visanu Thamlikitkul & Artit Indranoi (2006) on switching from heparinized saline flush to normal saline flush for maintaining peripheral venous catheter patency in the patients hospitalized to medical ward at Sir raj Hospital, Thailand. The study sites were ten medical wards containing two hundred and forty beds. Group I received heparinized saline as a flushing agent whereas Group II received normal saline as a flushing agent. The information on using flush fluids was collected from the physicians’ order sheets in the medical records at baseline, every two to four weeks during the intervention periods, and at six months after launching intervention. The results showed that the children received heparinized saline flush in February 2005, switched on to a practice with normal saline flush in June and November 2005. Hence the researcher concluded that normal saline was effective and implemented as evidence based clinical practice.
Janet Pettit (2003) performed a randomized double blind study to identify the efficacy of saline versus heparin flush to maintain the peripheral intravenous lock in pediatric populations among 124 infants over twenty eight days of age in pediatric ICU at Doctor’s Medical Centre, Modeto. The findings revealed that saline flush had longer period of patency. Thus the researcher concluded that saline was efficacious and safest flush in maintaining the peripheral intravenous catheter.
Nelson (2002) conducted a randomized double blind study to assess the use of 0.9% normal saline flush with or without heparin for maintaining peripheral indwelling intermittent infusion devices among fifty eight children up to one year with twenty four gauge needle. Group I received ten units per ml of heparin solution (n=26) and Group II received 0.9% normal saline flush (n=32). The result showed that there was no significance between 0.9% normal saline flush with or without heparin solutions in maintaining patency of twenty four gauge peripheral intermittent intravenous devices in children younger than one year.
Schultz, Drew & Hewitt (2002) investigated a randomized double blind study on comparison of normal saline and heparinized saline flushes for patency of intravenous locks among forty nine neonates at Maine Medical Center, Portland. The objective of the study was to determine the efficacy of patency of intravenous locks maintained with normal saline solution compared with heparinized saline solution. Group I received 0.5 ml of heparinized saline flush containing two units/ml of heparin (n=20) whereas Group II received 0.5 ml of normal saline flush (n=29). There were no significant difference (p =0.841) between mean scores for heparin flushed catheters (M = 41.5 hours, SD = 44.0) and saline-flushed catheters (M = 30.4 hours, SD = 20.8). The researcher concluded that catheter failure was significantly longer for catheters flushed with heparinized saline compared with those flushed with normal saline.
A study was conducted by Harahan & Berends (2000) to evaluate the efficacy of saline versus ten units/ml heparin for peripheral intravenous flushes among 240 neonates of Special Care Nurseries at a Level III Large Mid Western University Teaching Hospital. Here an experimental group design was used to compare the longevity of heparin and saline intravenous locks. Data were collected from a convenient sampling technique. Group I received ten units per ml of heparin (n=123) whereas Group II received preservative-free normal saline solution (n=117). The result showed that there was no significant statistical difference in intravenous catheter longevity between intravenous locks flushed with ten units/ml heparin and those flushed with normal saline.
Krista Brown, Tay-Uyboco & Douglas McMillan (1999) did a randomized controlled trial to determine the relative efficacy and safety of peripheral intravenous locks maintained with heparin saline solutions compared with those maintained with normal saline among 186 neonates at Foot Hills Hospital, Calgary, Alberta. Group I received normal saline (n=93) whereas Group II received heparin saline (n=93). Patients were chosen to receive either heparinized saline with five units/ml or 0.3 ml of normal saline, in the intravenous catheter every six hourly, administered by nursing staff in a blinded manner. The result showed that there was no difference in catheter lifespan (39A±24 hour for the heparinized saline group; 34A±22 hour for the normal saline group) and no difference in the number of intravenous catheters per patient (1.9 heparinized group, 1.6 normal saline group). The researcher concluded that there was no difference between heparinized normal saline and normal saline flush in neonates in maintaining the patency of twenty four gauge peripheral intravenous locks.
Heilskov, Kleiber & Johnson (1998) did a randomized double – blind controlled 3-arm trial of heparin and saline for maintaining intravenous locks among ninety neonates at University of Iowa Hospitals and Clinics, USA. The purpose of this study was to determine the effects of saline, heparin two units (U) per ml saline, and heparin ten units per ml saline flush solutions on the duration of intravenous locks and the incidence of intravenous infiltration in neonates. Group I received heparin two units/ml saline (n=27), Group II received heparin ten units/ml saline flush (n=28) and Group III received normal saline (n=25). Catheter flushed at least every six hourly. The outcome measures total hours from the time the intravenous was inserted to the time the intravenous was removed; hours from the time the intravenous was first flushed to the time the intravenous was removed; number of intravenous removed because of infiltration. The result showed that there was no statistical or clinical difference between the three groups for duration of intravenous therapy or for incidence of complications.
Bridget Mudge, Dion Forcsier & Mary Jo Slattery (1998) conducted a comparative study on heparin and saline flush solutions regarding patency of 24-gauge peripheral intermittent infusion devices. A prospective, non-randomized, sequential, blinded study design was conducted on a pediatric and a neonatal were similar for age, peripheral intermittent intravenous devices (PIID) placement site, irritating substances infused, and initial IV function. The median duration of catheters flushed with normal saline was 42 hours and with heparin was 35.3 hours. Kaplan-Meier Survival Analysis indicated that the duration of catheters flushed with saline was significantly longer than those flushed with heparin (p = .02). More catheters flushed with heparin were removed because of problems (p = .027). Results of this study suggested that normal saline was more effective than heparin in maintaining the patency of small, 24-gauge catheter.
Kotter (1996) conducted a randomized double blind study on heparin versus saline to maintain the patency of intermittent intravenous device maintenance among fifty one neonates including premature neonates, less than one month of age admitted to a Level II Neonatal Intensive Care Unit. Group I received ten units/ml heparin (n=27), whereas Group II received normal saline flush (n=24). Catheter was flushed every fourth hourly with heparin or normal saline solutions. The researcher concluded that there was no statistically significant difference in average duration of patency between normal saline-flushed catheters and heparinized saline-flushed catheters. Phlebitis, occlusion, infiltration, and leaking occurred with equal frequency for both solutions.
Kulkarni, Elsner, Ouellet & Zeldin (1994) investigated a randomized double blind study on heparinized saline versus normal saline in maintaining patency of the radial artery catheter among seventy eight adults in the surgical intensive care unit of Toronto East General & Orthopedic Hospital. The objective of the study was to compare the ability of normal saline versus heparinized saline infusion to maintain patency of the radial artery catheter used for monitoring blood pressure or multiple blood sampling. Group I (n=40) patients those who were admitted on odd numbered dates received heparinized saline two units per ml and Group II (n=38) admitted on even dates received normal saline, both as continuous flush solutions. At 96 hours of cannulation, 92% of the catheters in the heparinized saline group were patent compared with 74% in the normal saline group. The result showed that there was no significant difference between flushing with normal saline and heparinized saline in the maintenance of radial arterial line patency.
A comparative randomized controlled trial was conducted by Robertson (1994) on the intermittent intravenous therapy to determine whether heparinized saline solution was a superior flushing agent to normal saline among152 children between the ages of two months to eighteen years. Group I were allocated with heparinized saline as a flushing agent, and Group II were allocated with normal saline as a flushing agent. Each day intravenous sites were examined for signs of phlebitis and on removal of each cannula was flushed to check for fibrin. On Chi-square testing, highly significant associations emerged between the incidence of phlebitis and the use of the intravenous antibiotics such as Tobramycin (p=0.05) andor Timentin (p=0.008). Young children were found to have a significantly higher incidence of blocked cannulae regardless of the flushing solution used. The researcher concluded that there was no significant difference detected in either the duration of intravenous therapy, the patency of the intravenous line or the incidence of phlebitis when normal saline was used to flush the intravenous cannula.
Kleiber, Harahan, Fagan & Zittergruen (1993) conducted a double-blind study to determine the efficacy of saline versus heparin flush solution to maintain peripheral intravenous locks in a pediatric population among 124 infants over twenty eight days of age. Group I received normal saline as a flushing agent, whereas Group II received normal saline with heparin as a flushing agent. The result revealed that the heparin and saline groups were comparable for total hour duration of the intravenous and for incidence of complications. Hence the researcher concluded that saline was efficacious in maintaining patency of intermittent intravenous peripheral intravenous locks in children.
A comparative study was conducted by Rob, Kelly & Trish (1992) on normal saline or heparinized saline flushing on function of arterial lines among sixty-five patients in most New Zealand intensive care units. Group I received normal saline (n=35) where as Group II received three ml/hour as a continuous flush. The scores for the intravascular line for each patient were summed, and the percentage of the total possible score was calculated. Mean study duration was 5.8 and 6.6 days for the normal saline and heparinized saline groups, respectively. Mean percentage scores were 83% with normal saline group and 82% with heparinized saline group. The statistical findings showed that there was no difference between the groups at 95% confidence interval. Thus researcher concluded that heparin as a continuous flush at three units/hour does not improve the function of arterial lines compared with a continuous normal-saline flush.
A quasi-experimental study was conducted by Tuten & Gueldner (1991) on the efficacy of normal saline versus diluted heparin for maintaining the patency of peripheral intermittent intravenous devices in hospitalized medical-surgical patients among seventy seven children. Group I received normal saline solution, whereas Group II received diluted heparin. The statistical findings revealed that there were no incidence of site loss due to coagulation in either group, moreover no significant difference in the incidence of site loss associated with phlebitis (p=0.708) or infiltration (p=0.910). The researcher concluded that normal saline may be an effective alternative to heparin, for maintaining the patency of peripheral intermittent intravenous devices.
Ashton, Gibson & Summers (1990) conducted a randomized double-blind study on the effects of heparin versus saline solution on intermittent infusion device irrigation at Shawnee Mission Medical Center among thirty two patients. The purpose of this study was to compare the effectiveness of one ml of 0.9% normal saline with ten units of heparin in one ml normal saline solution, in maintaining patency and reducing the incidence of phlebitis in patients with intermittent infusion devices. The statistical findings revealed that there was no significant difference between the groups in phlebitis or patency variables. The researcher suggested that 0.9% normal saline was as effective as ten units per ml of heparin in normal saline solution in maintaining intermittent infusion device patency and preventing phlebitis.
Hamilton, Plis, Clay & Sylvan (1988) conducted a randomized double-blind study on heparin saline versus 0.9% normal saline injection for maintaining patency of indwelling intermittent infusion devices in the Department of Pharmacy practice, Albany College among 307 adult patients. Group I received one ml of heparin saline as a flushing solution (n=170), whereas Group II received 0.9% normal saline flush solution (n=137). The result revealed that heparin offers no advantage over 0.9% normal saline injection in maintaining the patency of intermittent intravenous devices. The researcher concluded that there was no significant difference in the duration of catheter patency or incidence of phlebitis was observed between the groups.
Epperson (1984) did a randomized study on the efficacy of 0.9% normal saline with and without heparin for maintaining indwelling intermittent injection sites in the medical and surgical units of an acute-care hospital among 412 patients. Three different solutions were used to flush intravenous catheters. Group I were flushed with 0.9% normal saline alone, Group II were flushed with heparin 10 units/ml in 0.9% normal saline and group III were flushed with heparin 100 units/ml in 0.9% normal saline. Heparin locks were flushed after each medication administration and every eight hours when medications were not being given. Using a standardized evaluation form, one of five intravenous therapists evaluated each site daily for the presence of phlebitis and loss of patency. Length of catheter placement and the percentage of patient days during which patients received cephalosporin and penicillin antibiotics were examined for each group. Rates of site loss caused by phlebitis or loss of patency were compared in each group. The result showed that there was no significant differences were found among the three groups in the mean duration of heparin-lock placement, the percentage of patient days during which antibiotics were prescribed, or the rate of site loss caused by phlebitis or loss of patency.
Section B: Literature Related to Cost Effectiveness of Normal Saline in Maintenance of Peripheral Intravenous Catheter.
Hephzibah Alexander (International Journal for the Advancement of Science & Arts, 2010) conducted a systematic review of the study on heparin versus normal saline as a flush solution. The electronic database of Ovid, Pub-Med, the Cochrane Library and the Cochrane Database of Systematic Reviews (CDSR) was searched for heparin or normal saline (either singly or in combinations). Relevant studies were critically appraised and evidence obtained was graded according to the modified Catalan Agency for Health Technology Assessment scale (CAHTA). In terms of safety, the findings indicate that it might be safer to use normal saline as it does not have the risks associated with heparin. Cost analysis studies proved that without any doubt the use of normal saline flush results in a significant amount of cost savings. For arterial catheters, majority of the available data suggest that heparin saline given as a continuous flush at low doses improved catheter patency. The result of the study revealed that normal saline should be used as an alternative to heparin in intravenous catheters. Low-dose heparin with 0.25 units per ml normal saline should be added to the infuscate to maintain patency of arterial catheters. The researcher concluded that heparin as an intermittent flush was ineffective and normal saline was just as effective as and more efficacious than heparin.
Karen Le Duce (1997) investigated a prospective, randomized, double blind controlled trial on the efficacy of normal saline solution versus heparin solution for maintaining patency of peripheral intravenous catheters in children at the emergency department of children’s hospital, USA among 150 children. The purpose of this study was to establish the effects of heparin flush and saline solution flush solutions in maintaining patency of infusion devices in the pediatric population, and to establish cost-saving implications related to normal saline solution versus heparin flush for PIIDs in terms of pharmacy costs and costs related to nursing time to both procedures. Group I (n = 77) received 3 ml of a ten units heparin/ml normal saline solution intravenous flush whereas Group II (n = 73) received three ml of normal saline solution for the intravenous flush. Descriptive and correlation statistics were used to analyze the data. The result showed that there were no significant differences between the two groups for demographics or complications. Annual cost savings were computed with an estimated annual savings of nursing time and unit cost of solutions equaling $27,594. The researcher concluded that the normal saline solution should be used as an alternative to heparin solutions for the maintenance of peripheral intravenous devices.
Jerri Shoaf & Sandra Oliver (1997) did a study on the efficacy of normal saline with and without heparin for maintaining intermittent intravenous site in the coronary care unit of Scott and White Memorial Hospital among two hundred and sixty surgical patients. Group I received normal saline with heparin as a flushing agent, whereas Group II received normal saline without heparin as a flushing agent. The researcher concluded that heparinized saline was not needed to maintain the patency of an intermittent intravenous site, and the use of saline solution alone was less irritating, causes less occurrence of phlebitis, less expensive to patients, and saves nursing time.
A randomized comparative study conducted by Paisley et al (1997) on the use of heparin and normal saline flushes in neonatal intravenous catheters among eighty seven preterm and term infants ranging from 33 weeks to 44 weeks of gestation in the University of Missouri-Columbia Children’s Hospital. Data were collected between February 1994 and March 1995. The majority of infants were thirty eight to forty weeks gestation (M = 38.46 weeks, S.D. = 2.48). Group I (n=33) infants received 0.6 ml of heparin solution containing 10 units/ml of heparin and Group II (n=54) received 0.6 ml of normal saline as flushing agent. The frequency of flush was 0.6 ml flush every fourth hourly. The researcher concluded that the normal saline was much cheaper than heparin. Nursing time was saved using a single solution and physician spends time in writing order was saved by standing orders. If only normal saline was used, the chance for error, over dosage, heparin-associated drug incompatibilities and heparin induced thrombocytopenia would be eliminated.
Section C: Literature Related To Complications Of Using Heparin Solution For Maintaining Patency.
Mitchell et al (2009) conducted a study on a systematic review of heparin flushing and other interventions to maintain patency of central venous catheters. The objective of this study was to assess clinical studies comparing the effectiveness of different means of maintaining central venous catheter patency. A search was conducted using the MEDLINE, CINAHL, EMBASE, Cochrane, National Guideline Clearinghouse and University Health System Consortium databases. The method was a systematic review of effectiveness using grade criteria to assess the strength of evidence for each intervention. Flushing with heparin was a routine part of central venous catheter maintenance, but it presents risk, including heparin-induced thrombocytopenia. Other techniques used to prevent occlusion of catheters include saline flushes, heparin-bonded catheters and pressure caps. The result showed that flushing catheters with saline solution was more effective than flushing with heparin.
A study was conducted by Stephens et al (1997) on normal saline versus heparin flush for maintaining central venous catheter patency during aphaeresis collection of peripheral blood stem cells (PBSCS) among seventy eight cancer patients. The purpose of this study was to examine the incidence of thrombotic occlusions in central venous catheters using heparin compared to saline flushing. Group I (n=29) received saline flushes and Group II (n=49) received heparin with 100 units per ml of saline flushes. Numerous studies comparing heparin to saline flushing in peripheral devices suggested equal rates of thrombotic occlusions. The outcome of the study suggested that serious complications including drug interactions and heparin induced thrombocytopenia and thrombosis syndrome in association with heparin flushing. The researcher concluded that saline was as effective as heparin for maintaining patency of central venous catheters.
Triolo, Pamela & Goode (1991) conducted a study on meta-analysis to estimate the effects of heparin flush and saline flush solutions on maintaining patency, preventing phlebitis, and increasing duration in peripheral heparin locks. The researcher concluded that saline was as effective as heparin in maintaining patency, preventing phlebitis, and increasing duration in peripheral intravenous locks. Quality of care can be enhanced by using saline as the flush solution, thereby eliminating problems associated with anticoagulant effects and drug incompatibilities. In addition, an estimated yearly savings of $109,100,000 to $218,200,000 U.S. health care dollars could be attained.
Barrett & Lester (1990) did a double-blinded, cross-over study on heparin versus saline flushing solutions for a period of two months in a small community hospital at Aroostook Medical Centre, Presque Isle. Floor nurses were used as observers and observe catheter failures, as either loss of patency or phlebitis. Data revealed a statistically significant advantage to using saline flushes when both loss of patency and phlebitis were combined (p < 0.05). The researcher concluded that heparin was shown to cause more phlebitis than saline (p < 0.025), but no difference was found between the two flushing solutions in loss of patency.