Plaster cast burns: the reality

Biomechanical properties of splint materials while curing

Many studies have evaluated splint strength at maturity with multiple splint materials, methods, and configurations but none have analyzed splints as they cure. The purpose of this study is to evaluate the properties of different splint materials immediately following activation and as they mature. Splints were dipped for three seconds in two temperatures of water and an additional group of fiberglass with no water was tested as well. Splint weight was taken as an additional measurement to assure homogenous groups. All splints were tested in three-point bending at a constant displacement. The generalized linear model (GLM) including all time frames showed differences in yield load and ultimate loads after three minutes. All ultimate loads occurred at greater than 20° of angulation. Plaster had a much lower displacement at its yield load at all times after 3 min. Plaster had a higher stiffness at 1° of angulation at all time points after six minutes. The GLM that excluded the three-day time showed that the higher temperature increased initial stiffness in the splints at three and six minutes. Fiberglass has a higher yield point and ultimate load when compared to plaster. However, these loads were measured at significant splint angulation for the fiberglass, suggesting that plaster is acting as a true splint. Fiberglass is stronger and faster to cure than plaster. In situations where the surgeon desires the strongest splint, fiberglass may be preferable. However, the initial stiffness of plaster is superior to fiberglass.

Revolution in orthopedic immobilization materials: A comprehensive review

Immobilization material has slowly revolutionized since 3000 BCE from traditional plaster to modern day synthetic casting tape, including other sustainable immobilization material. This revolution is driven by the search for superior casting material that possesses excellent mechanical and load-bearing properties, non-toxicity, excellent healing rates, patient satisfaction and eco friendliness. Even though the new materials have been evolved, the traditional plaster still remains a material of choice owing to its excellent skin conformability, low cost and availability. This paper aims to present a comprehensive review on the technique of immobilization, existing orthopedic immobilization (casting and splinting) materials and complications associated with immobilization (mainly casting) which aimed to assist the medical practitioners and researchers in casting material improvements and selection. Nine immobilization materials are comprehensively discussed for their desirable properties, drawbacks and the required improvements to the composition, along with the most common cast complications ranging from superficial pressure sores to compartment syndrome and Deep Vein Thrombosis. . This paper identifies that among the existing material, plaster casts are still highly used due to their cost benefit and the ability to fit patients into full body casts, while synthetic material is too rigid and has a higher probability of causing complications such as compartment syndrome and deep vein thrombosis. Patients show a higher preference in using synthetic casts for short term and body extremity casting as they are comparatively more comfortable. New materials such as Woodcast shows good promise but their mechanical characteristics and comfort are yet to be critically analyzed. However, there exists an imminent requirement to upgrade existing material as well as to introduce novel promising sustainable material for long term immobilization.

Cast Saw Burn Prevention: An Evidence-Based Review

Cast saw burns are an avoidable complication of cast removal and cast splitting. These iatrogenic injuries often lead to unacceptable clinical sequalae with significant financial and legal consequences. Therefore, a considerable body of research has been directed toward cast saw burn prevention. This review of currently published data provides clinicians with a summary of the literature to guide practice based on the best available evidence, with the goal of preventing iatrogenic cast saw burns. The PubMed database was queried for articles published from 1980 until present with the following key words: cast saw burns, cast saw blades, cast saws, orthopaedic education or surgical simulation. Relevant articles were reviewed and summarized. The prevention of cast saw burns involves awareness of clinical risk factors, maintenance of equipment, use of the proper technique, and the education of novice providers. By implementing evidence-based methods, orthopaedic surgeons and associated healthcare providers can aim to eliminate these preventable complications from their practice.

A simple technique to prolong molding time during application of a fiberglass cast: An in vitro study

Casting is routinely used for acute and post-operative immobilization and remains a cornerstone in the non-operative management of fractures and deformities. The application of a properly fitted and wellmolded cast, especially for a trainee, can be challenging. We present a simple method of prolonging cure time of fiberglass cast — placing ice in the dip water. Eight-ply, fiveinch fiberglass cast was circumferentially applied to an aluminum-wrapped cardboard cylinder. An electronic, 2-channel temperature sensor (TR-71wf Temp Logger, T&D Corporation, Matsumoto, Japan), accurate to 0.1ºC and accurate to ±0.3ºC, was placed between the fourth and fifth layers of fiberglass. Thirty total casts were tested using 9±1ºC (cold), 22±1ºC (ambient), and 36±1ºC (warm) dip water. Room temperature was maintained at 24±1ºC. Cast temperatures were measured during the exothermic reaction generated by the cast curing. Peak temperatures and cure times were recorded. Cure time was defined as the point of downward deflection on the timetemperature curve immediately after peak. Cure and peak temperatures were compared among groups using analysis of variance. Mean cure time was 3.5±0.1 minutes for warm water, 5.0±0.4 minutes for ambient water and 7.0±0.5 minutes for cold water. Peak temperature, measured between layers 4 and 5 of the cast material, was 36.6±0.8ºC for warm water, 31.1±1.4ºC for ambient water and 25.2±0.5ºC for cold water. Cold afforded, on average, an additional 2 minutes (40% increase) in cure time compared to ambient water and an additional 3.5 minutes (100% increase) compared to warm water. Cure time differences were significant (P<0.001) for all groups, as were peak temperature differences (P<0.001). Temperatures concerning for development of burns were never reached. Utilizing iced dip water when casting is a simple and effective method to prolong the time available for cast application. Orthopedic residents and trainees may find this useful in learning to fabricate a high quality cast. For the experienced orthopedic surgeon, this method eliminates the need to bridge longlimb casts and facilitates the application of complex casts.

A Quality Improvement Initiative Reduces Cast Complications in a Pediatric Hospital

BACKGROUND

Casts, while frequently used as routine treatment in pediatric orthopaedic practice, are not without complications. At our large tertiary care pediatric hospital, the baseline rate of all casting complications was 5.6 complications per 1000 casts applied (0.56%). We tested the hypothesis that we could use quality improvement (QI) methodology to decrease the overall cast complication rate and improve patient care.

METHODS

We initiated a QI program implementing concepts derived from the Institute for Healthcare Improvement models, including Plan-Do-Study-Act cycles, to decrease our cast complication rate. A resident casting education program was developed with a competency "checklist" to ensure that casts are applied, bivalved, and removed in a safe and standardized manner to prevent patient harm. AquaCast Saw Stop Protective Strips were required to be applied with every cast application. A review of our facility's processes and procedures determined adequate measures were in place to effectively manage inventory and maintenance of cast-saw blades.

RESULTS

With the multimodal QI intervention, our cast complication rate was reduced to 1.61 complications per 1000 applications, a >90% improvement.

CONCLUSIONS

Implementation of QI concepts to perform a QI initiative resulted in a shift toward fewer cast complications, leading to overall improved patient care at a large tertiary pediatric hospital.

LEVEL OF EVIDENCE

Level II-prospective cohort study.

Exothermic properties of plaster-synthetic composite casts

PURPOSE

Plaster casts can cause burns. Synthetic casts do not. Composite plaster-synthetic casts have not been thoroughly evaluated. This study analyzed the temperature from plaster casts compared with composite casts in a variety of in vitro conditions that would simulate clinical practice.

METHODS

A Pyrex cylinder filled with constant body temperature circulating water simulated a human extremity. Circumferential casts, of either plaster or composite construction (plaster inner layer with outer synthetic layer), were applied to the model. Peak temperatures generated by the exothermic reactions were studied relative to the following variables: dip water temperature (24 °C versus 40 °C), cast thickness (16, 30, and 34 ply), and delayed (5-min) versus immediate application of the synthetic outer layers. Peak temperatures from the all-plaster casts were compared with the composite casts of the same thickness. Finally, the relative cast strength was determined.

RESULTS

Potentially dangerous high temperatures were measured only when 40 °C dip water was used or when thick (30- or 34-ply) casts were made. Cast strength increased with increasing cast thickness. However, the presence of synthetics in the composite casts layers did not increase cast strength in every case.

CONCLUSION

When applying composite casts, the outer synthetic layers should be applied several minutes after the plaster to minimize temperature rise. Composite casts do not routinely generate peak temperatures higher than plaster casts of similar thickness. Because the skin of children and the elderly is more temperature-sensitive than average adult skin, extra care should be taken to limit the exothermic reaction when casting children and the elderly: clean, room temperature dip water, minimal required cast thickness, avoidance of insulating pillows/blankets while the cast is drying.

Epidemiology and prevention of cast saw injuries: results of a quality improvement program at a single institution

BACKGROUND

An investigation was conducted to establish the hospital-wide prevalence of cast saw injuries and to identify variables that put patients at increased risk, with the goal of reducing the injury rate.

METHODS

Information was collected from January 2010 through December 2012 on all patients who had a cast removed or cut at our institution. Locations included the operating suites, emergency department, ambulatory clinics, and hospital floors. A cast cutting log was used to capture the total number of casts cut. An adverse event form was used to document each injury. A continuous quality improvement approach was used throughout the study period to implement incremental improvements to our program. Changes included an education and certification program on cast saw use for all providers, a protocol for a plastic surgery consultation, and a cast saw blade inspection protocol with maintenance logs.

RESULTS

Twenty-nine injuries occurred in 23,615 cast cuttings over the three years, for an overall rate of 1.23 (95% confidence interval [CI], 0.86 to 1.76) per 1000. A minor decrease in cast saw injuries was recorded over the course of the study (eleven of 8043 [1.37 per 1000] in 2010, ten of 7885 [1.27 per 1000] in 2011, and eight of 7687 [1.04 per 1000] in 2012), but the decrease was not significant (p = 0.87). The emergency department had the highest rate of cast saw injuries (p &lt; 0.0001), with a significantly greater rate during the night compared with the day (eleven of 1293 [8.51 per 1000] compared with fifteen of 19,419 [0.77 per 1000], respectively; p &lt; 0.0001). The injuries were all minor. Key risk factors for a cast saw injury included provider inexperience, patient sedation, and poor cast saw blade condition.

CONCLUSIONS

The rate of cast saw injuries in a busy pediatric orthopaedic department was small, but a considerably increased risk existed for those patients cared for in the emergency department by orthopaedic residents. Improving education and training in cast saw use has the potential to decrease the prevalence of cast saw injuries over time.

Effect of pressure applied during casting on temperatures beneath casts

BACKGROUND

Burns and pressure sores are common injuries during cast application. Various factors such as water temperature, padding, and cast material layers may play a role in these injuries; however, the effect of cast molding on temperatures and pressures has not been investigated. This raises the following questions, does the application of molding during cast application: (1) alter skin level temperatures in a variety of cast materials? and (2) risk inducing either thermal injury or pressure necrosis?

METHODS

An upper extremity model was created to measure pressure and temperature underneath casting materials. Cast padding, water bath temperature, and cast thickness were standardized. A 3-point mold was simulated using 3 casting materials-Fiberglass only, Plaster Only splint, and Plaster splint overwrapped with Fiberglass-while pressure and temperature were recorded.

RESULTS

: Pressure application led to a statistically significant (P<0.0001) increase in temperature at the sites where the mold was applied although absolute temperature did not reach the theoretical burn threshold of 49 to 50°C for the casting materials studied. With pressure applied, the Plaster/Fiberglass combination reached an average peak temperature of 47.9°C, which was maintained for up to 6 minutes. Neither Fiberglass nor Plaster Only reached peak temperatures of this magnitude (average of 42.7 and 43.6°C, respectively). Peak (369 mm Hg) and highest residual (21 mm Hg) pressures were below harmful levels.

CONCLUSIONS

Pressure application during casting is a risk factor for burn injuries. Care should be taken when molding a plaster splint overwrapped in fiberglass by waiting until the plaster has fully cooled.

CLINICAL RELEVANCE

Combined with other known risk factors, the pressure from molding a cast could increase the likelihood of causing cutaneous burns.

Plaster and synthetic cast temperatures in a clinical setting: an in vivo study

Previous studies have reported thermal injuries with thick cast materials and warm dip water temperatures, often much higher than is clinically applicable. The goal of this study was to assess the temperature produced in vivo by current casting techniques and materials. The study was done using clinically applicable materials and water temperatures. A single volunteer was used to test skin temperatures produced with various casting techniques. We tested several types of fiberglass and plaster of 5 or 10 layers, used soft roll of 1 or 3 layers, and used dip water temperatures of 30 °C and 40 °C. We tested 2 plaster types: Johnson & Johnson Specialist Fast Set and Specialist Extra Fast Set (New Brunswick, New Jersey). Fiberglass tested included 3M Scotchcast Poly Casting Tape and Scotchcast Plus (St Paul, Minnesota), Royce Medical Techform (Camarrillo, California), and DeBusk Classic Synthetic Tape (Powell, Tennessee). The highest temperature reached using 30 °C water temperature was 39 °C with 10 layers of 3M Scotchcast fiberglass and 1 layer of soft roll. The highest temperature reached with 40 °C water was 39.5 °C, which was reached twice: once with Johnson & Johnson Fast Set Plaster with 5 layers of plaster and 3 layers of soft roll, and once with DeBusk Classic Synthetic Casting Tape of 10 layers with 1 layer of soft roll. Under the clinically applicable conditions described in this study, using the materials we tested and with a normal vascular supply, it is unlikely that temperatures high enough to cause a burn will be produced. We caution that good clinical judgment is advised if a patient reports a cast is too hot.