David Lee Skinner

The incidence and outcomes of acute kidney injury amongst patients admitted to a level I trauma unit

PURPOSE This study aimed to identify the incidence and outcomes of patients with trauma related acute kidney injury (AKI), as defined by RIFLE criteria, at a single level I trauma centre and trauma ICU. METHODS We performed a retrospective observational study of 666 patients admitted to a trauma ICU from a level I trauma unit from March 2008 to March 2011. We conducted multivariable logistic regression to identify independent predictors for AKI and mortality. RESULTS The overall incidence of AKI was 15% (n=102). Median injury severity score (ISS) was 25 (inter quartile range [IQR] 16-34) and mean age was 39 (SD 16.3) in the AKI group. Thirteen patients (13%) were referred with rhabdomyolysis associated renal Failure. Overall mortality in the AKI group was 57% (n=58) but was significantly lower in the rhabdomyolysis Failure group (23% versus 64%; p=0.012). AKI was independently associated with older age, base excess (BE)<-12 (odd ratio [OR] 22.9, 95% confidence interval [CI] 1.89-276.16), IV contrast administration (OR 2.7 95% CI 1.39-5.11) and blunt trauma (OR 2.2 95% CI 1.04-4.71). AKI was an independent predictor of mortality (OR 8.5, 95% CI 4.51-15.95). Thirty-nine (38%) patients required renal replacement therapy. CONCLUSIONS AKI in critically ill trauma patients is an independent risk factor for mortality and is independently associated with increasing age and low BE. Renal replacement therapy utilisation is high in this group and represents a significant health care cost burden.

Blunt cardiac injury in critically ill trauma patients: A single centre experience

PURPOSE This study describes the incidence and outcomes of blunt cardiac injury (BCI) in a single trauma intensive care unit (TICU), together with the spectrum of thoracic injuries and cardiac abnormalities seen in BCI. METHODS We performed a retrospective observational study of 169 patients with blunt thoracic trauma admitted from January 2010 to April 2013. BCI was diagnosed using an elevated serum troponin in the presence of either clinical, ECG or transthoracic echocardiography (TTE) abnormalities in keeping with BCI. The mechanism of injury, associated thoracic injuries and TTE findings in these patients are reported. RESULTS The incidence of BCI among patients with blunt thoracic trauma was 50% (n=84). BCI patients had higher injury severity scores (ISS) (median 37 [IQR 29-47]; p=0.001) and higher admission serum lactate levels (median 3.55 [IQR 2.4-6.2], p=0.008). In patients with BCI, the median serum TnI level was 2823ng/L (IQR 1353-6833), with the highest measurement of 64950ng/L. TTEs were performed on 38 (45%) patients with BCI, of whom 30 (79%) had abnormalities. Patients with BCI had a higher mortality (32% vs. 16%; p=0.028) and trended towards a longer length of stay (17.0 days [standard deviation (SD) 13.5] vs. 13.6 days [SD 12.0]; p=0.084). CONCLUSIONS BCI was associated with an increased mortality and a trend towards a longer length of stay in this study. It is a clinically relevant diagnosis which requires a high index of suspicion. Screening of high risk patients with significant blunt thoracic trauma for BCI with serum troponins should be routine practise. Patients diagnosed with BCI should undergo more advanced imaging such as TTE or TOE to exclude significant cardiac structural injury.

Ventricular septal defect following blunt chest trauma

We present a 32-year-old male with ventricular septal defect (VSD) following blunt chest trauma. Traumatic VSD is a rare but potentially life-threatening injury, the severity, course and presentation of which are variable. While the diagnosis of myocardial injury may be challenging, cardiac troponins are useful as a screening and diagnostic test. The proposed pathophysiological mechanisms in the development of traumatic VSD are early mechanical rupture and delayed inflammatory rupture. We conducted a literature review to investigate the pathogenesis, distribution of patterns of presentation, and the associated prognoses in patients with VSD following blunt chest trauma. We found that traumatic VSDs diagnosed within 48 hours were more likely to be severe, require emergency surgery and were associated with a higher mortality. Children with traumatic VSDs had an increased mortality risk. Smaller lesions may be managed conservatively but should be followed up to detect late complications. In both groups elective repair was associated with a good outcome.

Severe blunt thoracic trauma: Differences between adults and children in a level I trauma centre

BACKGROUND Trauma is a leading cause of death in the developing world. Blunt thoracic trauma represents a major burden of disease in both adults and children. Few studies have investigated the differences between these two patient groups. OBJECTIVE To compare mechanism of injury, presentation, management and outcome in children and adults with blunt thoracic trauma. METHODS Patients were identified from the database of the trauma intensive care unit at Inkosi Albert Luthuli Central Hospital, Durban, South Africa. Demographics and relevant data were extracted from a pre-existing database. RESULTS Of 415 patients admitted to the unit, 331 (79.7%) were adults and 84 (20.2%) children aged < 18 years. The median injury severity score (ISS) was similar for both age groups (32 v. 34; p = 0.812). Adults had a higher lactate level at presentation (3.94 v. 2.60 mmol/L; p = 0.001). Of the children, 96.4% were injured in motor vehicle collisions, 75.0% as pedestrians. Compared with adults, children had significantly fewer rib fractures (20.2% v. 42.0%; p < 0.001), flail chests (2.4% v. 26.3%; p<0.001) and.blunt cardiac injuries (BCIs) (9.5% v. 23.6%; p = 0.004), but sustained more lung contusions (79.8% v. 65.6%; p = 0.013). Mortality in children was significantly lower than in adults (16.7% v. 27.8%; p = 0.037). CONCLUSION Thoracic injuries in children are the result of pedestrian collisions more often than in adults. They suffer fewer rib fractures and BCIs, but more lung contusions. Despite similar ISSs, children have significantly lower mortality than adults. More effort needs to be concentrated on child safety and preventing pedestrian injury.

A multi faceted quality improvement programme results in improved outcomes for the selective non-operative management of penetrating abdominal trauma in a developing world trauma centre.

INTRODUCTION The selective non-operative management (SNOM) of penetrating abdominal trauma (PAT) is well established in our environment. As a quality-improvement initiative, we aimed to re-evaluate patient outcomes with PAT. This follows the application of new imaging and diagnostic modalities using protocolised management algorithms. METHODOLOGY A prospectively maintained digital registry was retrospectively interrogated and all patients with PAT treated by our service from January 2012 to March 2013 were included in this study. RESULTS A total of 325 patients sustained PAT during the fourteen-month study period. This included 238 SWs, 80 GSWs and 7 impalement injuries. 11 patients had eviscerated bowel, and 12 had eviscerated omentum. A total of 123 patients (38%) were selected for a trial of SNOM. This included 103 SWs, 15 GSWs and 5 impalement injuries. Emergency laparotomy was performed on 182 patients (115 SWs, 65 GSWs and 2 impalement injuries) and 21 patients with left sided thoraco-abdominal SWs underwent definitive diagnostic laparoscopy (DL). SNOM was successful in 122 cases (99%) and unsuccessful in one case (1%). In the laparotomy group 161 (88%) patients underwent a therapeutic procedure, in 12 cases (7%) the laparotomy was non-therapeutic and in 9 cases (5%) the laparotomy was negative. In the laparoscopy group (24), two patients required conversion for colonic injuries and one for equipment failure. Seven (33.3%) laparoscopies were therapeutic with the identification and intra-corporeal repair of seven left hemi-diaphragm injuries. CONCLUSION We have improved our results with the SNOM of PAT and have also managed to safely and successfully extend the role of SNOM to abdominal GSWs. We have selectively adopted newer modalities such as laparoscopy to assess stable patients with left thoraco-abdominal SWs and abdominal CT scan for the SNOM of abdominal GSWs.

A meta-analysis of intraoperative factors associated with postoperative cardiac complications

Abstract Background: Preoperative cardiac risk is commonly determined with the help of risk scores and risk stratification tools. This predetermined cardiac risk may be profoundly changed by intraoperative surgical events. This meta-analysis aimed to identify intraoperative factors that independently predict postoperative cardiac complications in the presence of preoperative cardiac risk factors. Method: A PubMed Central search was conducted from January 1966 to June 2010, to identify independent intraoperative predictors of postoperative cardiac complications in observational perioperative studies and randomised controlled trials which controlled for preoperative cardiac risk factors. Results: Eleven studies were identified for inclusion in this meta-analysis. Intraoperative blood transfusion [odds ratio (OR) 2.6, 95% confidence interval (CI) 1.8–3.4] was the only independent intraoperative risk predictor identified in more than one study. Other identified independent intraoperative factors included a > 20 mmHg fall in mean arterial blood pressure for > 60 minutes (OR 3.0, 95% CI 1.8–4.9), > 30% increase in baseline systolic pressure (OR 8.0, 95% CI 1.3–50), tachycardia in the recovery room (> 30 beats per minute from baseline for > 5 minutes) (OR 7, 95% 1.9–26), new onset atrial fibrillation (OR 6.6, 95% CI 2.5–20), hypothermia (OR 2.2, 95% CI 1.1–5) and remote ischaemic preconditioning (OR 0.22, 95% CI 0.070–0.67). None of these studies controlled for blood transfusion. Conclusion: Both surgical and haemodynamic intraoperative events significantly increased the risk of postoperative cardiac complications. Intraoperative blood transfusion has the strongest evidence that supports this finding. It is possible that modification of these intraoperative risk factors by anaesthetists and surgeons might reduce postoperative cardiac events.

Serum procalcitonin levels predict acute kidney injury in critically ill patients.

To determine whether admission procalcitonin (PCT) was associated with the subsequent development of acute kidney injury (AKI) in a general population of critically ill patients.

Hyperchloraemia is associated with acute kidney injury and mortality in the critically ill: A retrospective observational study in a multidisciplinary intensive care unit

Purpose: The aim of this study was to determine whether serum chloride and changes in serum chloride over time were associated with acute kidney injury (AKI) or intensive care unit (ICU) mortality in a heterogenous critically ill population. Materials and methods: The study was a retrospective observational study of 250 adult patients admitted to a multidisciplinary academic ICU. Serum chloride within 48h of admission, changes in chloride, and other biochemical and clinical parameters were evaluated as predictors of AKI and mortality. Results: Hyperchloraemia occurred in 143 (57.2%) patients within 48h of ICU admission. Hyperchloraemia at 48h was significantly associated with AKI, OR=6.44 (95% CI 2.95–14.10) and mortality, OR=2.46 (95% CI 1.22–4.94) on univariate analysis, with this association persisting on multivariable analysis. An increase in serum chloride was also associated with a significantly increased risk of AKI and mortality on univariate analysis. Hyperchloraemia on admission was, however, not associated with AKI or death. Of the 150 patients with AKI, 147 (98.0%) had developed AKI by 48h. Conclusions: Hyperchloraemia and increasing serum chloride are associated with adverse outcomes in critically ill patients. There is equipoise as to whether this represents an association, an epiphenomenon or causation. HIGHLIGHTSHyperchloraemia is associated with AKI and death in the critically ill.There is equipoise as to whether this represents an association, an epiphenomenon or causationUnnecessary chloride loads should be avoided in critically ill patients only where circumstances permit.

Hypoxaemia on arrival in a multidisciplinary intensive care unit

BACKGROUND Transport of the critically ill patient poses the risk of numerous complications. Hypoxaemia is one such serious adverse event and is associated with potential morbidity and mortality. It is, however, potentially preventable. OBJECTIVE To determine the incidence of hypoxaemia on arrival in a tertiary multidisciplinary intensive care unit (ICU) and to identify risk factors for this complication. METHOD A retrospective observational study was conducted at King Edward VIII Hospital, Durban, South Africa, from May 2013 to February 2014. RESULTS Hypoxaemia occurred in 15.5% of admissions sampled. Statistically significant risk factors for hypoxaemia on univariate analysis (p<0.05) included lack of peripheral capillary oxygen saturation (SpO2) monitoring, transfer by an intern as opposed to other medical/paramedical staff, and transfer from internal medicine. Use of neuromuscular blockers and transfer from theatre were protective. Binary logistic regression analysis revealed lack of SpO2 monitoring to be the only significant independent predictor of hypoxaemia (odds ratio 6.1; 95% confidence interval 1.5 - 24.5; p=0.02). CONCLUSION Hypoxaemia is common on admission to the ICU and may be prevented by simple interventions such as appropriate transport monitoring.

Procalcitonin kinetics in the first 48 hours of ICU admission is associated with higher mortality in critically ill patients with community-acquired pneumonia in a setting of high HIV prevalence

Background: Severe community acquired pneumonia (CAP) commonly results in ICU admission and is associated with significant morbidity and mortality. Procalcitonin (PCT) may assist risk stratification and prediction of aetiology but is not well studied in critically ill patients with a high HIV prevalence. Methods: A retrospective observational study of patients admitted to ICU with a clinical diagnosis of CAP was undertaken. PCT on admission and at 48 hours was evaluated as a predictor of ICU outcome and pneumonia aetiology. Results: A total of 100 patients were included; 62% were HIV positive. Overall ICU mortality was 61%. PCT at admission and 48 hours was not associated with any outcome variables. A significant association was found between mortality and patients whose PCT levels increased or remained >10 ng/ml at 48 hours, compared with those that remained unchanged or decreased (67% vs. 41% p = 0.018). The commonest aetiology identified was Mycobacterium tuberculosis (n = 18, 21.4%). Patients with admission PCT levels >10 ng/ml were more likely to have positive bacterial cultures (OR = 3.14; 95% CI 1.11–9.73). Conclusions: Increasing or persistently elevated PCT predicts a higher mortality in critically ill patients with CAP. This suggests PCT kinetics may be useful in risk stratifying patients with CAP at 48 hours. While positive bacterial cultures are more likely in patients with high admission PCT, this assay does not allow for decisions to be made on antimicrobial management and is of limited clinical utility in critically ill patients with a high HIV prevalence and CAP.