The Epidemiology of Extremity Threat and Amputation after Vasopressor-Dependent Sepsis

The effect of Montreal's supervised consumption sites on injection-related infections among people who inject drugs: An interrupted time series

BACKGROUND

Between June and November 2017, four supervised consumption sites (SCS) began operating in Montreal, Quebec. Earlier studies on SCS focused on examining their effects on blood-borne viral infections and overdose mortality. Our objective was to examine the effect of Montreal's SCS on the incidence, health service use and outcomes of injection-related infections (IRI) in people who inject drugs.

METHODS

We used Quebec's provincial administrative health data to identify people who inject drugs in Montreal and calculated the incidence of IRI in this population between December 2014 and December 2019. We conducted a retrospective, population-based interrupted time series to estimate the effect of Montreal's four SCS on the monthly incidence rates of IRI-related hospitalizations, emergency department (ED) visits, physician visits, and mortality. We also examined the effects of SCS on average length of IRI-related hospitalizations and incidence of hospitalizations involving surgery.

RESULTS

The average age of Montreal's people who inject drugs was 41.84 years, and 66.41% were male. After the implementation of SCS, there was a positive level change in the incidence of hospitalizations (0.97; 95% confidence interval [CI]: 0.26, 1.68) for IRI. There was also a significant post-intervention decline in hospitalization trends (-0.05; 95% CI: -0.08, -0.02), with modest trend changes in ED visits (-0.02; 95% CI: -0.05, 0.02). However, post-intervention changes in level (0.72; 95% CI: -3.85, 5.29) and trend (0.06; 95% CI: -0.23, 0.34) for physician visits remained limited. SCS had no effect on the average length of hospitalizations, but there was a decreasing post-intervention trend in hospitalizations involving surgery (-0.03; 95% CI: -0.06, 0.00).

CONCLUSION

Following the opening of the SCS, there was a moderate decline in the rate of hospitalizations to treat IRI, but the impact of the sites on the rate of physician visits remained limited. These findings suggest that SCS may mitigate the incidence of more serious and complicated IRI over time.

Use of blood parameters for the prediction of mortality in patients with below‑knee amputation

The present retrospective study aimed to investigate the value of blood parameters in predicting mortality in patients with below-knee amputation (BKA). A total of 178 patients with BKA were included in the present study. The patients were divided into two groups, namely the exitus group (n=136; 76.4%) and the survivors group (n=42; 23.6%). Patients in the exitus group were further divided into three subgroups: i) Those who experienced mortality in <1 month (n=55; 40.4%); ii) those who experienced mortality between 1-12 months (n=48; 35.3%); and iii) those who experienced mortality in >12 months after surgery (n=33; 24.3%). Binary logistic regression and a generalized linear model were used for relational analysis, and a receiver operator characteristic curve was used for diagnostic tests. It was found that the parameters of age (B=0.061; P=0.01), eosinophil-to-lymphocyte ratio (ELR) (B=-2.861; P<0.05), C-reactive protein (CRP)/albumin ratio (B=0.027; P<0.01) and mean platelet volume (MPV)/lymphocyte ratio (B=0.310; P<0.01) had a significant effect on mortality at the multivariate level. Moreover, regression coefficients showed that the effect of age, CRP/albumin and MPV/lymphocyte ratios on mortality were positive, whereas the effect of the ELR was negative. The mortality predictive values of age [area under the curve (AUC)=0.681; P=0.01], ELR (AUC=0.630; P=0.01), CRP/albumin ratio (AUC=0.746; P=0.01) and MPV/lymphocyte ratio (AUC=0.676; P<0.01) were also found to be statistically significant. For the 27.51 CRP/albumin cut-off value, the sensitivity was found to be 80.1%, whereas the specificity was 54.8%. For the 36.93 CRP/albumin cut-off value, the sensitivity was 71.3%, and the specificity was 73.8%. Furthermore, MPV (B=-0.37; P<0.01) and hemoglobin/red-blood-cell distribution width (RDW) ratio (B=5.20; P<0.01) were found to have a significant effect on the time to death at the multivariate level. The parameters MPV (AUC=0.648; P<0.01) and hemoglobin/RDW (AUC=0.673; P=0.01) had predictive value in terms of the time to death. The predictive value for MPV was found to be 64.8%, whereas that for the hemoglobin/RDW ratio was 67.3%. For the 0.54 cut-off value for hemoglobin/RDW, the sensitivity was 74.5%, and the specificity was 11.1%. By contrast, for the 0.84 cut-off value for the hemoglobin/RDW ratio, the sensitivity was 10.9% and the specificity was 81.5%. In conclusion, the CRP/albumin ratio was identified as a significant mortality parameter, whereas the hemoglobin/RDW ratio was a significant time to death predictor, according to the results of the present analysis. These results may guide clinical practices and further research in terms of predicting mortality in patients with BKA.

Identification of risk factors and clinical outcomes for symmetric peripheral gangrene: A new scoring system using a common data model database

Background: Symmetrical peripheral gangrene (SPG) is a destructive clinical condition where amputation is often the final treatment option. We aimed to identify the predictors of SPG using the common data model (CDM) and propose a new scoring system for predicting hospitalized patients at risk of developing SPG. Methods: A cohort of patients treated with intravenous noradrenaline, epinephrine, and vasopressin between 2011 and 2020 was retrospectively analyzed using the CDM database. The main outcome was amputation performed as a resuscitation measure. We investigated risk factors including demographic characteristics, comorbidities, and preoperative laboratory values. Based on demographic variables such as age and sex, a 1:10 propensity score matching (PSM) was performed. The odds ratio (OR) was calculated using logistic regression analysis. Results: Amputation was performed in 308 (0.4%) patients out of a cohort of 73,902 patients. Age, sex, hypertension, diabetes mellitus (DM), renal disease (RD), heart failure, anemia, hypercholesterolemia, peripheral vascular disease (PVD), and laboratory markers such as albumin, eosinophils, hematocrit, lymphocytes, monocytes, neutrophils, ESR, aPTT, creatinine, and BUN were statistically significant. Logistic regression analysis revealed statistically significant differences in DM (OR 5.51), RD (OR 2.90), PVD (OR 9.67), and cerebrovascular disease (CVD) (OR 0.49). Compared to the group without amputation, logistic regression analysis after matching the age and sex group with 1:10 PSM showed statistically significant results in DM (OR 3.59), RD (OR 2.59), PVD (OR 7.76), and CVD (OR 0.40). Conclusion: Early recognition of high-risk patients may help medical providers prevent severe outcomes, including amputation surgery.

Managing sepsis and septic shock in an endothelial glycocalyx-friendly way: from the viewpoint of surviving sepsis campaign guidelines

Maintaining tissue perfusion in sepsis depends on vascular integrity provided by the endothelial glycocalyx, the critical layer covering the luminal surface of blood vessels. The glycocalyx is composed of proteoglycans, glycosaminoglycans, and functional plasma proteins that are critical for antithrombogenicity, regulating tone, controlling permeability, and reducing endothelial interactions with leukocytes and platelets. Degradation of the glycocalyx in sepsis is substantial due to thromboinflammation, and treatments for sepsis and septic shock may exacerbate endotheliopathy via additional glycocalyx injury. As a result, therapeutic strategies aimed at preserving glycocalyx integrity should be considered, including modifications in fluid volume resuscitation, minimizing catecholamine use, controlling hyperglycemia, and potential use of corticosteroids and anticoagulants. In this review, we explore treatment strategies aligned with the recommendations outlined in the Surviving Sepsis Campaign Guidelines 2021 with a special emphasis on evidence regarding glycocalyx protection.

The Nuances of Hand Transplantation After Sepsis

Vascularized composite allotransplantation (VCA) of the upper extremity is an established restorative procedure for selected patients with acquired upper limb loss. The majority of upper limb VCAs performed worldwide have been for victims of various forms of trauma. However, in the developed world, amputation following severe sepsis seems to be an increasingly common indication for referral to hand transplant programs. Unlike trauma patients with isolated limb injuries, patients with amputations as a complication of sepsis have survived through a state of global tissue hypoperfusion and multisystem organ failure with severe, enduring effects on the entire body's physiology. This article reviews the unique considerations for VCA candidacy in postsepsis patients with upper limb amputation. These insights may also be relevant to postsepsis patients undergoing other forms of transplantation or to VCA patients requiring additional future solid organ transplants.

Modifications of peripheral perfusion in patients with vasopressor-dependent septic shock treated with polymyxin B-direct hemoperfusion

Abnormal peripheral perfusion (PP) worsens the prognosis of patients with septic shock. Polymyxin B-direct hemoperfusion (PMX-DHP) increases blood pressure and reduces vasopressor doses. However, the modification of PP following administration of PMX-DHP in patients with vasopressor-dependent septic shock have not yet been elucidated. A retrospective exploratory observational study was conducted in patients with septic shock treated with PMX-DHP. Pulse-amplitude index (PAI), vasoactive inotropic score (VIS), and cumulative fluid balance data were extracted at PMX-DHP initiation (T0) and after 24 (T24) and 48 (T48) h. Changes in these data were analyzed in all patients and two subgroups (abnormal PP [PAI < 1] and normal PP [PAI ≥ 1]) based on the PAI at PMX-DHP initiation. Overall, 122 patients (abnormal PP group, n = 67; normal PP group, n = 55) were evaluated. Overall and in the abnormal PP group, PAI increased significantly at T24 and T48 compared with that at T0, with a significant decrease in VIS. Cumulative 24-h fluid balance after PMX-DHP initiation was significantly higher in the abnormal PP group. PMX-DHP may be an effective intervention to improve PP in patients with abnormal PP; however, caution should be exercised as fluid requirements may differ from that of patients with normal PP.

Differentiation of Lower Extremity Skin Changes in the Intensive Care Setting

Digital and lower extremity skin changes often signify critical underlying disorders. Patients in the intensive care unit also frequently have hemodynamic instability requiring the use of vasoactive medications, which may lead to various presentations of limb ischemia; preexisting conditions increase these patients' risk for arterial embolization. Most arterial emboli are clots that originate in the heart and travel to distant vascular beds, where they cause arterial occlusion, ischemia, and, potentially, infarction; the 2 most common sequelae are stroke and lower limb ischemia. Emboli also arise from atherosclerotic plaques. Other conditions can also cause skin color changes in this vulnerable population. Prompt recognition and differentiation of lower extremity skin changes can result in improved patient outcomes. A thorough literature search was conducted to differentiate the primary causes of lower extremity and digital skin changes in the critically ill patient and outline diagnostic and management techniques.

Hirudotherapy for limb ischemia in the pediatric intensive care unit: A retrospective observational cohort

BACKGROUND

Acute limb ischemia due to microvascular malperfusion may be refractory to initial therapies. Medicinal leech therapy (hirudotherapy) has been attempted in plastic and reconstructive surgery to improve venous congestion in ischemic flaps; however, there are minimal reports related to ischemia secondary to arterial malperfusion. We evaluated a pediatric cohort from an academic intensive care unit with refractory limb ischemia in whom hirudotherapy was attempted to elucidate its use and outcomes.

METHOD

Institutional patient database was queried to identify pediatric patients (<18 years) who received hirudotherapy in the pediatric critical care unit and met inclusion/exclusion criteria. Patient charts were evaluated for indices including demographics, primary disease, coagulative status, vascular access, vasoactive medication dosing, bleeding, leech use, limb and mortality outcomes. Data was evaluated to identify trends or suspected impact on outcomes.

RESULTS

Hirudotherapy was used in 7 patients for limb ischemia, 5 with congenital heart disease, and 2 others with viremic shock. Time to leech application following recognition of ischemia averaged 3 days, with duration of use averaging 3.9 days. Five patients discontinued therapy due to bleeding. Mortality rate was 57%, all secondary to multiorgan failure. In 3 surviving patients, 4 of 5 treated limbs resulted in at minimum partial amputation. Vasoactive-inotropic score tended higher prior to leech application, suggesting a vasoconstrictive pathway for arterial malperfusion. No identifiable trends appeared associated with salvaged limb or adverse effects. Blood loss predictably increased with leech application, as did total transfusion requirement.

CONCLUSION

This case series establishes baseline data for use of hirudotherapy in critically ill children with acute limb ischemia caused by arterial malperfusion. Based on this retrospective cohort, we cannot recommend routine use of hirudotherapy for acute limb ischemia from arterial malperfusion in the pediatric intensive care unit. Application of leeches should be aligned with a protocol defining start and stop parameters, standardized leech utilization, and monitoring for adverse outcomes. Future study would benefit from consensus definitions of study outcomes, including perfusion recovery, tissue/limb salvage and bleeding manifestations. Additional prospective studies are needed prior to any standard or systematic recommendations for use.