Evaluation of the relationship between pelvic fracture and abdominal compartment syndrome in traumatic patients.

INTRODUCTION: An increase in abdominal pressure can lead to so-called intra-abdominal compartment syndrome (ACS). Multiple factors such as an increase in retroperitoneal volume due to pancreatitis, bleeding and edema as a result of pelvic fracture can lead to compartment syndrome. Prevention is better than cure in compartment syndrome. By measuring the intra-abdominal pressure (IAP) through the bladder, a quick and accurate assessment of abdominal pressure is achieved. Therefore, this study aimed to evaluate the relationship between pelvic fracture and ACS in traumatic patients.
MATERIALS AND METHODS: This research was a descriptive-analytical study conducted on 100 patients referring to the Shiraz Nemazee Hospital in 2010. IAP was monitored every 4 h in patients suspected to be at high risk for ACS, e.g., those undergoing severe abdominal trauma and pelvic fracture. The IAP was measured via the urinary bladder using the procedure described by Kron et al. Data collected were analyzed using SPSS software.
RESULTS: The findings showed that ACS occurred in 28 of 100 patients. With regard to the associated injuries with abdominal trauma, 19% of all patients and 46/42% of the patients with ACS had pelvic fracture. Chi-square test revealed a significant relationship between pelvic fracture and incidence rate of ACS (P < 0.001).
CONCLUSIONS: According to the collected data, pelvic fracture due to a trauma can be one of the important causes of an increase in IAP and ACS. In this lethal condition, prevention is better than cure. Therefore, serial measurement of IAP through the bladder in high-risk patients (those with pelvic fracture by trauma) is recommended to the nurses to diagnose this condition and to decrease the incidence of mortality.

INTRODUCTION

Abdominal compartment syndrome (ACS) is a life-threatening syndrome with an increase in incidence among critically ill patients. Primary ACS results from a direct injury within the abdomen and pelvic region (e.g., a blunt or penetrating trauma, ruptured abdominal aortic aneurysm or laparotomy).[1234] A direct injury to the abdomen creates an opportunity for hemorrhage and tissue injury.[12] The initial bleeding causes hypoperfusion to the tissues and the accumulating of blood clots within the abdomen initiates intra-abdominal hypertension (IAH).[2] ACS is most commonly diagnosed in patients with sustaining abdominal or pelvic traumas or in those suffering from some other intra-abdominal hemorrhagic catastrophes. Less common etiologic factors are space-occupying lesions (e.g., tumors, obstructed bowel) and bowel/retroperitoneal edema or ascites as well as accompanying mesenteric ischemia or severe pancreatitis.[5678] The incidence of ACS is reported to be up to 35% in the intensive care population, with reduced survival when compared with other intensive care patients.[1] Mortality and morbidity rates are extremely high when patients develop ACS, and recognition and treatment are time critical.[9] Although the cause of IAH can vary, and the degree of organ dysfunction can differ from patient to patient, the reason for this is the effect of decreasing blood flow and increasing pressure on abdominal organs and surrounding organs that creates the end organ dysfunction that defines ACS. ACS is characterized by a silent physiological derangement and can easily be overlooked or misinterpreted.[51011]

Normal values of intra-abdominal pressure (IAP) are considered to be close to atmospheric pressure, represented as 0-5 mmHg. Consensus definitions propose IAH as an IAP greater than 12 mmHg.[1710]

As the pressure rises in the abdomen, the cardiovascular system is affected early. The pressure on the inferior vena cava results in impedance of the venous return. Pooling of blood in the peripheral circulation occurs as congestion is made in the large veins due to the impeded pathway through the abdomen. As the diaphragm is pushed up by the expanding volume of the abdomen, the heart and the pulmonary veins are compressed, causing increased pulmonary vascular resistance and impaired right ventricular systolic function. The congested heart often produces an elevated central venous pressure and pulmonary capillary wedge pressure. This is not a reflection of the patient's fluid status but rather an indicator of the rising intra-thoracic pressure and systemic vascular resistance.[27111213] The increase of thoracic pressures is also manifested by increasing peak airway and plateau pressures that can be measured in a mechanically ventilated patient. These pressures are seen to rise early in the process of ACS (IAP 15 mmHg), and continue to rise as the IAP increases.[14] A decline in cardiac output is an early characteristic of ACS as well as an escalating heart rate, which occur in an attempt to compensate for the reduced stroke volume.[711] Eventually, cardiac contractility decreases and hypotension becomes apparent after the compensatory mechanisms begin to fail.[41516] Hypotension is considered as a late sign.[11] Increasing thoracic pressures are representative of the imposing abdominal compartment pressure. This impairs the lungs’ oxygen exchange as the compressed lung is unable to expand. Alveoli continue to collapse as the pressure increases, resulting in decreased oxygen uptake within the blood.[141718] A strategy to control abdominal hemorrhage is damage control laparatomy. Patients who develop ACS must be decompressed as soon as possible.[1719]

Indications for IAP monitoring include abdominal surgery, traumatic injuries, distended abdomen with ACS signs and symptoms such as oliguria, hypoxia, hypotension, unexplained acidosis, mesenteric ischemia and/or elevated intra-cranial pressure.[19] Monitoring of IAP should be considered for the patients having temporary closure with abdominal packs and receiving large volumes of resuscitation fluids for septic or hypovolemic shock.[20] There needs to be vigilance in assessment of the patient's IAP and organ function to optimize early recognition.[1] Every clinician, especially nurses, should remember the risk factors for intra-abdomen hypertension and be vigilant to avoid the progression to ACS. By measuring the IAP through the bladder, a quick and accurate assessment of abdominal pressure is achieved, and this can be performed by emergency or critical care nurses without a specific medical order or sophisticated invasive monitoring equipments.[21] With regard to the fact that ACS is a very lethal condition, the researcher intended to recognize patients affected by ACS via IAP measurement in patients with severe abdominal and pelvic trauma and then investigate the relationship between pelvic fracture and this hazardous syndrome [Figure 1].

Figure 1

Pressure increase inside the abdomen may cause what is named abdominal compartment syndrome. Increase Intra abdominal pressure may cause changes in all organs. The clinical presentation of compartment syndrome is also related to heart system, respiratory system and kidney. Death rate is high for compartment syndrome. And, the diagnosis of patients in danger, and monitoring them for the symptoms of the syndrome and precocious treatment could help decrease death rate for this syndrome

MATERIALS AND METHODS

This research was a descriptive–analytical study that was performed to characterize patients who develop primary ACS and to investigate the relationship between pelvic fracture and ACS in abdominal trauma patients (n = 100) referring to the Nemazee Hospital in 2010. IAP was firstly monitored at the time of patient's entrance to the emergency room and then every 4 h in patients suspected to be at high risk for ACS, e.g., those undergoing severe abdominal trauma and pelvic fracture. The IAP is measured via the urinary bladder using a procedure described by Kron.[1] The bladder pressure method is described as the gold standard and is the most reliable measurement of IAP via indirect means.[41214172223] The bladder is considered an excellent vehicle for reflecting the IAP as it acts as a passive reservoir when its volume is less than 100 mL.[1] With the patient in supine position, the drainage tube, connected to the foley catheter, is clamped; 60 mL sterile saline is instilled into the bladder via the aspiration port using an 18-gauge needle and the needle is then attached to a three-way stopcock and water manometer. The manometer is filled with sterile saline and then opened to the patient. The zero mark of the manometer is placed at the level of the pubic symphysis and the pressure is read at the meniscus. The IAP is measured in cm H2O and converted to mmHg by the formula: mmHg = cm H2O divided by 1.36. A supine and horizontal position during measurement is most likely to provide reproducible and comparable readings.[111] ACS is diagnosed when there is a sustained IAH of > 20 mmHg with single or multiple organ dysfunctions such as hypoxia, oliguria or anuria and hypotension, which were not previously present.[1] The data were analyzed using SPSS.

If the critical care nurse is aware of the high-risk patient groups, suspicion and vigilance may be pivotal in the recognition of the clinical manifestations and early intervention. This highlights the importance of establishing and tracking the IAP at an early stage in patients considered to be at risk of ACS.

RESULTS

During a 12-month period (since November 2010), we measured the IAP in 100 patients afflicted with severe abdominal and pelvic trauma, and diagnosed primary ACS in 28 of them. About 82.14% (n = 23) of the patients with ACS were male and 17.86% (n = 5) were female, and their mean age was 27 years (5-50 years). Frequency and percent of participants’ demographic characteristics have been presented in Table 1.

Table 1

Demographics of patient groups by age, sex, mechanism of trauma, associated injury and refer or not refer to operation room

About 75% (n = 21) of the patients with ACS were referred to the operating room, and underwent laparatomy. Among the patients being referred to the operating room, 76.2% (n = 16) expired and 23.8% (n = 5) survived the operation. Among the patients not being referred to the operating room, 100% (n = 7) expired. About 46.42% (n = 13) of the patients with ACS had pelvic fracture, and the Chi-square test showed a significant relationship between pelvic fracture and the percent of ACS.

DISCUSSION

ACS has been indicated as a complication in serious abdominal trauma for more than 50 years. It develops as a consequence of increased IAP not only in abdominal trauma but also in intestinal obstructions, with serous edema of the bowels or a chronically growing ascites, in acute hemorrhagic necrotic pancreatitis and septic peritonitis. In recent years, its occurrence has been reported following acute resuscitation with crystalloid or blood.[1823]

One clinical picture of ACS is characterized by abdominal distension, hypoxia and hypercapnia with oliguria up to anuria, when organ dysfunction improves after abdominal decompression.

In this research, IAP was measured in 100 patients afflicted with abdominal and pelvic trauma. Of these 100 patients, 28 patients with primary ACS were identified. Among the patients with ACS, 82.15% (n = 23) expired and 17.85% (n = 5) survived.

Malbrain (2005) showed that the incidences of IAH and detected patients with ACS were 32.1% (n = 85) and 12.9% (n = 11), respectively. Patients with IAH (IAP > 12 mmHg) on admission had a 30-day decrease in survival time compared with those with no IAH (62% vs. 79%), but the difference was not statistically significant.[11]

Regarding age and gender, 82.14% (n = 23) of the patients with ACS were male, and their mean age was 27 years (5-50 years) in the present study, which is in accordance with Walter et al.'s study. They reported that 13 males, aged 45 ± 5 years, developed ACS 11.6 ± 2.2 h following resuscitation from a shock.

Regarding the type of trauma in the present study, 57.14% (n = 16) of the patients with ACS had car accidents, 35.71% (n = 10) had motorcycle accidents and 7.14% (n = 2) had suffered from a fall. About 46.42% (n = 13) of the patients with ACS had pelvic fracture; Chi-square showed a significant relationship between pelvic fracture and the percent of ACS.

About 75% (n = 21) of the patients with ACS were referred to the operating room and underwent laparatomy, of whom 76.1% expired, but 100% of the patients who were not referred to the operating room expired. Among all the patients with ACS, 82.15% (n = 23) expired.

In a research by Pleva et al., traffic accident trauma together with sporting and leisure time injuries prevailed in 73% of the subjects, and there were 87 abdominal cavity traumas: 31 injuries of the liver, 35 injuries of the spleen, four injuries of the pancreas, 12 injuries of the bowels and five injuries of the retroperitoneum. In the present study, ACS occurred in eight patients, of whom six had liver injury. From those six patients, four cases were treated by suture and drainage and two cases and by tamponade in the area of traumatized liver segments seven and eight. In another patient, ACS developed as a result of a blunt abdominal trauma associated with pelvic fracture, where decompression laparotomy found no surgical source of bleeding and there was only 500 mL of blood in the Douglas space, but extensive distension of thin loops was found together with edema, which was consistent with the findings of our study. Immediately after decompression of the abdominal cavity, diuresis was restored and ventilation parameters of the injured improved significantly. In the last patient, ACS developed due to extensive retroperitoneal hematoma with injury of soft retroperitoneal tissues and pelvic fracture, where progressive bleeding into the abdominal cavity occurred with developed coagulopathy.

Prevention in compartment syndrome is better than cure. Every clinician, especially the nurses, should remember the risk factors for IAH and be vigilant to prevent its progression to ACS.

CONCLUSION

Technology and diagnostic capabilities have been developed and refined to optimize the care and treatment of critically ill patients. This has bought a new set of challenges as critically ill patients survive longer and new complications unfold. ACS is considered a potentially reversible complication. In pelvic fractures, ACS can develop due to extensive retroperitoneal hematoma with injury of soft retroperitoneal tissues. Early intervention and diagnosis is essential among these patients as delayed intervention enhances the risk of death extremely. A critical care nurse is well situated to detect subtle signs or changes in the patients’ clinical condition that may prompt early investigation into the IAP. ACS is a clinical syndrome that can easily be misinterpreted and a high index of suspicion to IAH may be attributed to improved survival from ACS.