Creatine Phosphokinase (CPK) and Myoglobin Levels in Burn Patients

Creatine phosphokinase (CPK) is an enzyme that can be found in the heart, brain and skeletal muscles. The level of CPK increases with the degree of tissue injury in burn patients. Subsequently, with the rising CPK levels, the risk of acute renal injury also increases. As the patients suffering from burn injuries are already compromised on fluid and are more prone to septicemia, the patients enter a vicious circle of events that ultimately prove to be fatal in severely burnt individuals. Hence the CPK levels, especially with deep thermal and electrical burns, are sensitive tests in evaluating the degree of burn injury so that an appropriate pre-operative strategy for debriding and grafting can be adapted.⁽¹⁾

In contrast to its relation with acute renal injury, according to a study conducted in Germany, a strong relation was noted between increased CPK levels and the risk of limb amputation of the patients and their mortality. The data suggested that the percentage of burned body surface area did not directly correlate with the true extent of tissue damage caused by high tension injuries. It was rather, the degree of muscle tissue violation that corresponded with the initial excess of CPK levels in blood serum. This was therefore suggested to be taken as a strong factor supporting the decisions of immediate surgical management of such patients.⁽²⁾

Another study revealed that the patients whose percentage TBSA burns were 25 ± 13% had a mortality of 4(50%) out of 8. The peak-mean CPK-levels were more than twice and MB-levels were more than four times higher in non-survivors than in survivors. It was therefore suggested that burns associated with rhabdomyolysis resulted in poor survival. ⁽³⁾

  

A study also highlighted the effects of burn injury in victims who used electrocution as method to commit suicide in France. It was revealed that in all three cases whose blood samples were taken, high levels of muscular enzymes such as (CPK, LDH) correlated to the mechanism of electric death, which in this case, was local muscular paralysis and heart fibrillation. ⁽⁴⁾

Correlation between muscle necrosis, elevated CPK levels and myoglobinuria, was noted in a study assessing high voltage electric injury victims. A total of 56 out of 187 patients underwent fasciotomy within 24 hours of injury. This was predicted by presence of myoglobinuria with an overall accuracy of 72.8%. It was hence concluded that patients with gross myoglobinuria were at a higher risk of requiring fasciotomy and/or amputation. ⁽⁵⁾

Another study conducted in Pakistan stated that a statistically significant association was found between the level of serum CPK and burn patients’ morbidity and mortality. It was also found that serial monitoring of this enzyme could be used as an indicator in the management of electrical burns injury. ⁽⁶⁾

Keeping most of these evidences in mind, it can be drawn that the CPK and myoglobin levels in burn patients are increasingly becoming one of the few major factors for the analysis of patient morbidity and mortality.

Acute renal failure complicates about 22.5% of burn patients, and is also related to the size and depth of burn. Urinary malondialdehyde and microalbuminuria were useful tools for prediction of renal outcome in such group of patients, even though the septicemia and burn size proved to be the only clinical parameters that can predict renal outcome in this study. ⁽⁷⁾

The study, which covered Acute Renal Failure in ICU burn patients, concluded that one in every three ICU patients whose S-Cr levels were 1.4mg/dl required renal replacement therapy. The renal function was mostly recovered in all the patients who survived. The patients who did not survive had a larger burned total body surface area, an increased abbreviated burn severity index, were older and had inhalation injuries. The mortality of ICU patients with acute renal failure (ARF) was noted to be 44.1% as opposed to that of patients without ARF (6.9%). ⁽⁸⁾

High mortality was associated with Rhabdomyolysis caused by flame injury. It was further noted that ARF was associated with increased mortality even in minor burns when compared with patients without ARF. Hence concluding that flame burns with ARF and Rhabdomyolysis predict very poor outcomes.

Yet another study highlighted that Acute Kidney Injury, after burn injury was a common observation, with almost one fourth of the patients developing early AKI and about half of them developing it after hospitalization. ^[9] Also highlighted was the fact that early AKI was more serious and progressive and was more likely with larger TBSA burns. Rhabdomyolysis due to increased myoglobinuria and compromised kidney function in flame burn patients indicated a poor prognosis. ⁽¹⁰⁾

The serum CK and myoglobin levels were significantly higher in patients who had third-degree burns, whereas the pro-BNP levels were statistically in significantly higher numbers in patients who had arrhythmia than in those without arrhythmia and higher still in patients who died than in those who healed, following an electric burn. ⁽¹¹⁾ Hence suggesting an emerging trend for assessing pro-BNP levels along with CPK and myoglobin levels as prognostic factors in burn patients.

Serum CPK and myoglobin levels in flame or electric burn patients not only predict the survival of these patients but also predict the treatment modalities that doctors must adapt in order to treat them. Weather in the form of limb amputation or early management, these figures are very important and must never be ignored.

  

References:

1.      Rosen CL, Adler JN, Rabban JT, Sethi RK, Arkoff L, Blair JA, Sheridan R. (1999) Early Predictors of Myoglobinuria and Acute Renal Failure Following Electrical Injury. Journal of Emergency Medicine. 17 (5), 783-9.

2.      Kopp J, Loos B, Spilker G, Horch RE.. (2004). Correlation between serum creatinine kinase levels and extent of muscle damage in electrical burns.. Burns. 30 (7), 680-3.

3.      Stollwerck PL, Namdar T, Stang FH, Lange T, Mailänder P, Siemers F. (2011). Rhabdomyolysis and acute renal failure in severely burned patients. Burns. 37 (2), 240-8.

4.      Marc B, Baudry F, Douceron H, Ghaith A, Wepierre JL, Garnier M.. (2000). Suicide by electrocution with low-voltage current.. Journal of Forensic Science. 45 (1), 216-22.

5.      Cancio LC, Jimenez-Reyna JF, Barillo DJ, Walker SC, McManus AT, Vaughan GM. (2005). One hundred ninety-five cases of high-voltage electric injury. Journal of Burn Care Rehabilitation. 26 (4), 331-40. 

6.      Memon AR, Tahir SM, Memon FM, Hashmi F, Shaikh BF. (2008). Serum creatine phosphokinase as prognostic indicator in the management of electrical burn. J Coll Physicians Surg Pak. 18 (4), 201-4.

7.      Sabry A, El-Din AB, El-Hadidy AM, Hassan M. (2009). Markers of tubular and glomerular injury in predicting acute renal injury outcome in thermal burn patients: a prospective study. Renal Failure. 31 (6), 457-63.

8.      Mustonen KM, Vuola J. (2008). Acute renal failure in intensive care burn patients (ARF in burn patients). Journal of Burn Care Res. 29 (1), 227-37. 

9.      Mosier MJ, Pham TN, Klein MB, Gibran NS, Arnoldo BD, Gamelli RL, Tompkins RG, Herndon DN. (2010). Early acute kidney injury predicts progressive renal dysfunction and higher mortality in severely burned adults. Journal of Burn Care Res. 31 (1), 83-92.

10.  Lazarus, D., and D. A. Hudson. "Fatal rhabdomyolysis in a flame burn patient." Burns 23, no. 5 (1997): 446-450.

11.  Orak, Murat, Mehmet Üstündag, Cahfer Güloglu, Servan Gökhan, and Ömer Alyan. "Relation between Serum Pro-Brain Natriuretic Peptide, Myoglobin, CK Levels and Morbidity and Mortality in High Voltage Electrical Injuries." Internal Medicine 49, no. 22 (2010): 2439-2443.

Thanks to Aiman Awaiz, M4 for this post