Development and Validation of a Multivariable Prediction Model for Postoperative Intensive Care Unit Stay in a Broad Surgical Population. Rozeboom PD, Henderson WG, Dyas AR, Bronsert MR, Colborn KL, Lambert-Kerzner A, Hammermeister KE, McIntyre RC Jr, Meguid RA. JAMA Surg. 2022 Apr 1;157(4):344-352.
The cost of intensive care represents an unbalanced quantity of US health care expenditure. COVID-19 Pandemic highlighted the price and limited amounts of ICU beds, putting stress on the system. The demand for critical care beds can be highly variable, and it can represent a challenge to distribution of resources. Authors have looked to predict postoperative ICU use. The Surgical Risk Preoperative Assessment System (SURPAS) was developed with the goal to estimate the risk of 12 postoperative adverse outcomes. Rozeboom et al used SURSPAS to estimate ICU postoperative admission.
The authors performed a retrospective observational analysis of the ACS NSQIP database, which they merged with individual patients’ electronic health record data. Postoperative ICU use was captured. Multivariable logistic regression modeling was used to determine how the 8 preoperative variables of the SURPAS model predicted ICU use compared with a model inputting all 28 preoperatively available NSQIP variables. The authors identified correlation between the SURSPAS prediction model and actual ICU use. The application of this tool is specifically important given the diversity of the surgical patients included in the study. The biggest limitation of this study is the inability to account for local variations in practices, and other drivers of ICU admission different from the physiologic parameters included in the model, such as surgeon's preference. The authors developed an online tool for predicting ICU admission postoperatively, easy to use that can help institutions where ICU bed resources are limited.
Presymptomatic diagnosis of postoperative infection and sepsis using gene expression signatures. Lukaszewski RA, Jones HE, Gersuk VH, Russell P, Simpson A, Brealey D, Walker J, Thomas M, Whitehouse T, Ostermann M, Koch A, Zacharowski K, Kruhoffer M, Chaussabel D, Singer M. Intensive Care Med. 2022 Sep;48(9):1133-1143.
Early diagnosis and timely treatment implementation of sepsis remains a challenge. Surgical patients present clinical signs of inflammation in response to surgery, making the diagnosis of sepsis uncertain in many opportunities. Clinicians are faced with the diagnostic challenge and the consequences of treating noninfectious causes with antibiotics leading to increased costs, toxicity, and the risk of development of pathogen resistance. Early identification of sepsis biomarkers would allow earlier investigation and intervention.
This trial enrolled 4385 patients undergoing elective surgery, clinical/laboratory data and blood samples were collected. Patients with confirmed postoperative infection were identified through an advisory panel, 154 patients with postoperative infection, of whom 98 progressed to sepsis. Transcriptomics analyses were performed on sequential postoperative samples taken from these patients. These patients were subsequently compared with matched patients who had uncomplicated recovery (151) or postoperative inflammation without infection (148). They were matched on postoperative day-, age-, sex- and procedure. Patients were subsequently divided in an initial discovery cohort and a training/validation cohort. The groups were compared in the three days preceding the symptom onset, using microarray transcriptomic profiling. This led to the identification of specific gene signatures to predict infection or sepsis. Using a machine learning approach, the authors constructed predictive models, obtaining very high sensitivity across all comparisons. Infection from uncomplicated recovery (AUC 0.871), infectious from non-infectious systemic inflammation (0.897), sepsis from other postoperative presentations (0.843), and sepsis from uncomplicated infection (0.703). Showing that biomarker signatures may be able to identify postoperative infection or sepsis up to three days in advance of clinical recognition. Limitations to this study include small cohorts, lack of diversity on the patient sample and no independent validation cohort for the signatures. Overall, this is an important step towards the development and application of this technology. Developing a test with the power to predict postoperative infection up to three days pre-onset of clinical presentation, is possible. Working to validate this as a clinical tool would be one of the next steps.
Aggressive or Moderate Fluid Resuscitation in Acute Pancreatitis. De-Madaria, E. et al. N Engl J Med. 2022 Sep 15;387(11):989-1000.
The WATERFALL multicenter, open-label, superiority RCT compared aggressive versus moderate crystalloid resuscitation in 249 adult patients with acute pancreatitis. The primary outcome was development of moderate or severe pancreatitis. Although the study was likely underpowered due to enrollment, it was stopped at the first safety checkpoint due to the aggressive fluid arm being associated with significantly more fluid overload (20.5% vs 6.3% CI 1.36-5.94) without any corresponding obvious benefit in preventing moderate-severe pancreatitis. In short, a moderate strategy should be preferred over aggressive fluid resuscitation, and we are unlikely to get better comparator studies in the future. Rather, we should probably focus on other interventions mediating the severity of pancreatitis.
Operative vs Nonoperative Treatment of Acute Unstable Chest Wall Injuries: A Randomized Clinical Trial. Dehghan N, Nauth A, Schemitsch E, Vicente M, Jenkinson R, Kreder H, McKee M. JAMA Surg. 2022 Sep 21.
The authors compared non-operative vs operative fixation of acute unstable chest wall injuries defined as displaced rib fractures or flail chest. A total of 207 patients aged 16-85 in 15 sites across Canada were randomized prospectively, but only a pre-specified subgroup analysis of ventilated patients showed more days free from ventilation (not significant) and shorter LOS (30d operative vs 32 nonoperative (1.4 (0.9-2.1) p=0.02). It is unclear why there was a significant difference in mortality of all nonventilated and ventilated patients as the secondary outcome, as the patients in both arms had similar complications of pneumonia and sepsis. In short, this is the largest RCT to date of nonoperative vs operative management of chest wall injury showing possible benefit in ventilated patients.
Early Neuromuscular Electrical Stimulation in Addition to Early Mobilization Improves Functional Status and Decreases Hospitalization Days of Critically Ill Patients. Campos DR, et al. Crit Care Med. 2022 Jul 1;50(7):1116-1126.
The PROSEVA trial demonstrated improved mortality in ARDS with neuromuscular blockade, but at great cost to the survivor’s functional status later. In complete contrast, this study asked whether neuromuscular stimulation would affect functional status and LOS in ICU patients in the setting of a standardized early mobilization protocol. More than 400 patients were screened resulting in a fairly small sample size of ~20 patients in each arm. Using multiple assessments of previously validated scores of functional status, days to stand up, ICU-acquired weakness, and global muscle strength, the authors demonstrated significant improvement with neuromuscular stimulation. This is an interesting pilot study that should be replicated in a larger patient population, as neuromuscular stimulation does not require patient participation.