Digital necrosis: a potential risk of high-dose norepinephrine

Limb Necrosis in the Setting of Vasopressor Use

BACKGROUND

It remains poorly understood why only some hemodynamically unstable patients who receive aggressive treatment with vasopressor medications develop limb necrosis.

OBJECTIVE

To determine the incidence of limb necrosis and the factors associated with it following high-dose vasopressor therapy.

METHODS

A retrospective case-control medical records review was performed of patients aged 18 to 89 years who received vasopressor therapy between 2012 and 2021 in a single academic medical center. The study population was stratified by the development of limb necrosis following vasopressor use. Patients who experienced necrosis were compared with age- and sex-matched controls who did not experience necrosis. Demographic information, comorbidities, and medication details were recorded.

RESULTS

The incidence of limb necrosis following vasopressor administration was 0.25%. Neither baseline demographics nor medical comorbidities differed significantly between groups. Necrosis was present in the same limb as the arterial catheter most often for femoral catheters. The vasopressor dose administered was significantly higher in the necrosis group than in the control group for ephedrine (P = .02) but not for the other agents. The duration of therapy was significantly longer in the necrosis group than in the control group for norepinephrine (P = .001), epinephrine (P = .04), and ephedrine (P = .01). The duration of vasopressin administration did not differ significantly between groups.

CONCLUSION

The findings of this study suggest that medication-specific factors, rather than patient and disease characteristics, should guide clinical management of necrosis in the setting of vasopressor administration.

An Overview of the Treatment Strategies of Extremities Ischemia in the Intensive Care Unit

OBJECTIVES

 To investigate the effect of the peripheral block on peripheral ischemia on the extremities of patients in the intensive care unit (ICU).

MATERIALS AND METHODS

Sixty-two patients with ischemic peripheral vascular disease were divided retrospectively into two groups; Group 1 (patients who underwent USG-guided infraclavicular or femoral block, n=20) and Group 2 (patients who did not experience any block, n=42). The demographic characteristics of the patients, the diagnosis of hospitalization, the day when the circulatory disorder developed, laboratory tests at the time of diagnosis, other medical treatments applied, presence of inotropic support, the response of ischemia on extremities, amputation, duration of hospital stay, discharge and mortality were compared.

RESULTS

The most common reason for hospitalization was cerebrovascular disease. There was no statistical difference between the groups regarding age, gender, height, body weight, and diagnosis. There was no statistical difference between the groups regarding hematocrit, lactate, creatinine, and albumin values, the day when the peripheral ischemia developed in extremities, inotropic and prednisolone use, presence of cannulation, length of hospital stays, and mortality. The number of patients discharged from the intensive care unit in Group 1 was significantly higher than in Group 2 (p=0.048). Amputation was performed on one patient in Group 1 and two patients in Group 2. There was a decrease in peripheral ischemia in 14 (70%) of the patients in Group 1 and 25 (59.5%) of the patients in Group 2.

CONCLUSIONS

Targeted peripheral block techniques for peripheral circulatory disorders for selected ICU patients in conjunction with preventive and medical treatments may decrease peripheral ischemia in extremities and increase ICU discharge.

Arterial site selection for measurement of mean arterial pressure in septic shock patients on high-dose norepinephrine

Background

The guidelines of the Surviving Sepsis Campaign suggest using invasive blood pressure (IBP) measurement in septic shock patients, without specifying for a preferred arterial site for accuracy in relation to the severity of septic shock. The objective of this study was to determine the mean arterial pressure (MAP) gradient between the femoral and radial artery sites in septic shock patients.

Method

This prospective study was carried out at a 20-bed ICU in a university hospital. Simultaneous MAP measurements at femoral and radial arterial sites were obtained in septic shock patients receiving norepinephrine (≥0.1 μg/kg/min), with a pre-planned subgroup analysis for those receiving a high dose of norepinephrine (≥0.3 μg/kg/min).

Results

The median norepinephrine dose across all 80 patients studied, including 59 patients on a high dose, was 0.4 (0.28-0.7) μg/kg/min. Overall, simultaneous measurement of MAP (mmHg) at the femoral and radial arterial sites produced mean (95% CI) MAP values of 81 (79-83) and 78 (76-80), respectively, with a mean difference of 3.3 (2.67-3.93), p < 0.001. In Bland-Altman analysis of MAP measurements, the detected effect sizes were 1.14 and 1.04 for the overall and high-dose cohorts, respectively, which indicates a significant difference between the measurements taken at each of the two arterial sites. The Pearson correlation coefficient indicated a weak but statistically significant correlation between MAP gradient and norepinephrine dose among patients receiving a high dose of norepinephrine (r = 0.289; p = 0.026; 95% CI 0.036-0.508).

Conclusion

In septic shock patients, MAP readings were higher at the femoral site than at the radial site, particularly in those receiving a high dose of norepinephrine.

Clinical trial registration

[ClinicalTrials.gov], identifier [NCT03475667].

Achieving Functional Outcomes after Surgical Management of Catastrophic Vasopressor-induced Limb Ischemia

Vasopressor-induced limb ischemia is an unfortunate complication that can occur in patients treated for septic shock. Current literature lacks surgical treatment recommendations for this condition, besides amputation. We describe various reconstructive surgeries and functional outcomes in patients treated surgically for vasopressor-induced limb ischemia.

Non-invasive detection of a femoral-to-radial arterial pressure gradient in intensive care patients with vasoactive agents

BACKGROUND

In patient requiring vasopressors, the radial artery pressure may underestimate the true central aortic pressure leading to unnecessary interventions. When using a femoral and a radial arterial line, this femoral-to-radial arterial pressure gradient (FR-APG) can be detected. Our main objective was to assess the accuracy of non-invasive blood pressure (NIBP) measures; specifically, measuring the gradient between the NIBP obtained at the brachial artery and the radial artery pressure and calculating the non-invasive brachial-to-radial arterial pressure gradient (NIBR-APG) to detect an FR-APG. The secondary objective was to assess the prevalence of the FR-APG in a targeted sample of critically ill patients.

METHODS

Adult patients in an intensive care unit requiring vasopressors and instrumented with a femoral and a radial artery line were selected. We recorded invasive radial and femoral arterial pressure, and brachial NIBP. Measurements were repeated each hour for 2 h. A significant FR-APG (our reference standard) was defined by either a mean arterial pressure (MAP) difference of more than 10 mmHg or a systolic arterial pressure (SAP) difference of more than 25 mmHg. The diagnostic accuracy of the NIBR-APG (our index test) to detect a significant FR-APG was estimated and the prevalence of an FR-APG was measured and correlated with the NIBR-APG.

RESULTS

Eighty-one patients aged 68 [IQR 58-75] years and an SAPS2 score of 35 (SD 7) were included from which 228 measurements were obtained. A significant FR-APG occurred in 15 patients with a prevalence of 18.5% [95%CI 10.8-28.7%]. Diabetes was significantly associated with a significant FR-APG. The use of a 11 mmHg difference in MAP between the NIBP at the brachial artery and the MAP of the radial artery led to a specificity of 92% [67; 100], a sensitivity of 100% [95%CI 83; 100] and an AUC ROC of 0.93 [95%CI 0.81-0.99] to detect a significant FR-APG. SAP and MAP FR-APG correlated with SAP (r2 = 0.36; p < 0.001) and MAP (r2 = 0.34; p < 0.001) NIBR-APG.

CONCLUSION

NIBR-APG assessment can be used to detect a significant FR-APG which occur in one in every five critically ill patients requiring vasoactive agents.

Norepinephrine-Induced Peripheral Ischemia Leading to Gangrene: A Case Series

ABSTRACT

Norepinephrine is used in the acute care setting to establish and maintain hemodynamic stability in patients with hypotension. Although it is often a lifesaving medication, norepinephrine may lead to profound vascular insufficiency in the extremities, resulting in dry gangrene and skin necrosis. The purpose of this article is to present a case series of skin complications related to treatment with norepinephrine and review the pathophysiology behind these complications. The authors also explore risk stratification as it relates to history and clinical presentation with subsequent focus on contingencies to mitigate the adverse effects of vasoconstriction on peripheral tissues.

Pedal gangrene in a patient with COVID-19 treated with prone positioning and extracorporeal membrane oxygenation

Many patients hospitalized with coronavirus disease 2019 are treated with venovenous extracorporeal membrane oxygenation and prone positioning to optimize oxygenation. However, this combination can result in lower extremity tissue necrosis, especially without adequate offloading. We report the case of a 31-year-old man who required mechanical ventilation and venovenous extracorporeal membrane oxygenation secondary to complications from coronavirus disease 2019, and subsequently developed pedal dry gangrene. The patient was discharged and healed without requiring an amputation. Our institution has since revised the prone positioning protocol to address offloading the lower extremities and feet.

Reconstruction of Basic Hand Function by a Free Osteocutaneous Spare-Part Flap From the Lower Leg After Septicemia: A Case Report

Background: Spare-part surgery is widely accepted and offers an option in extremely traumatized patients for reconstructive maneuvers. Standardized techniques are lacking, and the therapy needs to fit the patient's clinic. Materials and Methods: In a woman with necrosis of almost all extremities due to septic infection, we used the lower leg as a free osteocutaneous flap to reconstruct a basic hand function after amputation. The fibula segment was buried alongside the remaining first metacarpal bone. On the hand stump, 2 short metacarpals were lengthened using the remaining 2 metacarpals as osteovascular on-top plasties. The flap was microsurgically anastomosed end-to-side to the ulnar artery. After 3 months, the buried fibula was trimmed to the necessary thumb length and fixed to the local metacarpal I stump. Secondary procedures were performed to deepen the first web space. Results: The patient is now able to manage her daily life. Also, she is able to put on her prosthesis on both legs and walk without aids. Conclusions: To our knowledge, this is the first description of successful microvascular transfer of an osteocutaneous free flap from an amputated lower leg of this size and could present a valuable technique for other cases.

Mean arterial pressure maintenance following spinal cord injury: Does meeting the target matter?

INTRODUCTION

Neurosurgical guidelines recommend maintaining mean arterial pressure (MAP) between 85 and 90 mm Hg following acute spinal cord injury (SCI). In our hospital, SCI patients receive orders for MAP targeting for 72 hours following admission, but it is unclear how often the patient's MAP meets the target and whether or not this affects outcome. We hypothesized that the proportion of MAP measurements ≥85 mm Hg would be associated with neurologic recovery.

METHODS

Spinal cord injury patients with blunt mechanism of injury admitted between 2014 and 2019 were identified from the registry of a level 1 trauma center. Proportion of MAP values ≥85 mm Hg was calculated for each patient. Neurologic improvement, as measured by positive change in American Spinal Injury Association (ASIA) impairment scale by ≥1 level from admission to discharge was evaluated with respect to proportion of elevated MAP values.

RESULTS

A total of 136 SCI patients were evaluated. Average proportion of elevated MAP values was 75%. Admission ASIA grades were as follows: A, 30 (22.1%); B, 20 (14.7%); C, 28 (20.6%); and D, 58 (42.6%). One hundred six patients (77.9%) required vasopressors to elevate MAP (ASIA A, 86.7%; B, 95.0%; C, 92.9%; D, 60.3%). Forty patients (29.4%) were observed to have improvement in ASIA grade by discharge (admission ASIA A, 15%; B, 33%; C, 40%; D, 13%). The proportion of elevated MAP values was higher for patients with neurologic improvement (0.81 ± 0.15 vs. 0.72 ± 0.25, p = 0.014). Multivariate modeling demonstrated a significant association between proportion of elevated MAP values and neurologic improvement (p = 0.028). An interaction revealed this association to be moderated by vasopressor dose (p = 0.032).

CONCLUSION

The proportion of MAP measurements ≥85 mm Hg was determined to be an independent predictor of neurologic improvement. Increased vigilance regarding MAP maintenance above 85 mm Hg is warranted to optimize neurologic recovery following SCI.

LEVEL OF EVIDENCE

Therapeutic/care management, level IV.

Acrocyanosis and digital necrosis are associated with poor prognosis in COVID-19

Acrocyanosis and digital necrosis, which caused by microangiopathic and immunothrombosis phenomenon, may accompanied by microvascular involvement of other organs. Therefore, this finding can play a prognostic role in covid-19 outcome.

Management of vasopressor induced ischemia

Purpose

We evaluated a cohort of patients who developed vasopressor-induced limb ischemia and the management options to prevent progression or minimize morbidity of digital necrosis.

Methods

We reviewed all current literature on pressor-induced limb ischemia and report options for the management of patients requiring vasopressors who developed limb ischemia. We then retrospectively reviewed presentation, treatment, and short-term outcomes for patients at our tertiary referral academic medical center that developed this complication. Finally, we recommend guidelines for the tiered management of these complex patients.

Results

Thirty-six patients were included. Twenty-six patients (72%) required resuscitation with more than one vasopressor. Vasopressors were initiated for septic-shock (52.7%), cardiogenic-shock (16.7%), hypovolemic-shock (13.9%), acute transplant rejection (13.9%), and neurogenic-shock (2.8%). According to the tiered management recommendations, patients were managed with phase 1 care (19%), phase 2 care (8.3%), phase 3 care (50%) or phase 4 care (5.6%). The patient expired in the acute setting in 13.9% of cases.

Conclusion

Life-saving vasopressors risk digital ischemia and necrosis. Early recognition, reporting, and treatment of this complication are important in minimizing morbidity. Using a tiered approach helps organize the healthcare team's management of this iatrogenic complication while respecting the treatment paradigm of "life over limb," and may be safely performed with acceptable outcomes.

Utilization of bone scan and single photon emission computed tomography on amputation planning in acute microvascular injury: Two cases

The use of single photon emission computer tomography (SPECT/CT) in acute vascular injury is not well documented. SPECT/CT combines the anatomic detail of computer tomography with the functional vascular perfusion of photon emission to determine the viability of osseous structures and surrounding soft tissue. The superimposed imaging provides the practitioner with a reliable anatomic image of viability of a specific anatomic area following insult or injury. We present two cases, bilateral lower extremity frostbite, and symmetric peripheral gangrene in which this imaging modality provided guidance for surgical intervention with adequate predictability and results.

Causes and outcomes of finger ischemia in hospitalized patients in the intensive care unit

OBJECTIVE

Vascular surgeons may be consulted to evaluate hospitalized patients with finger ischemia. We sought to characterize causes and outcomes of finger ischemia in intensive care unit (ICU) patients.

METHODS

All ICU patients who underwent evaluation for finger ischemia from 2008 to 2015 were reviewed. All were evaluated with finger photoplethysmography. The patients' demographics, comorbidities, ICU care (ventilator status, arterial lines, use of vasoactive medications), finger amputations, and survival were also recorded. ICU patients were compared with concurrently evaluated non-ICU inpatients with finger ischemia.

RESULTS

There were 98 ICU patients (55 male, 43 female) identified. The mean age was 57.1 ± 16.8 years. Of these patients, 42 (43%) were in the surgical ICU and 56 (57%) in the medical ICU. Seventy (72%) had abnormal findings on finger photoplethysmography, 40 (69%) unilateral and 30 (31%) bilateral. Thirty-six (37%) had ischemia associated with an arterial line. Twelve (13%) had concomitant toe ischemia. Eighty (82%) were receiving vasoactive medications at the time of diagnosis, with the most frequent being phenylephrine (55%), norepinephrine (47%), ephedrine (31%), epinephrine (26%), and vasopressin (24%). Treatment was with anticoagulation in 88 (90%; therapeutic, 48%; prophylactic, 42%) and antiplatelet agents in 59 (60%; aspirin, 51%; clopidogrel, 15%). Other frequently associated conditions included mechanical ventilation at time of diagnosis (37%), diabetes (34%), peripheral arterial disease (32%), dialysis dependence (31%), cancer (24%), and sepsis (20%). Only five patients (5%) ultimately required finger amputation. The 30-day, 1-year, and 3-year survival was 84%, 69%, and 59%. By Cox proportional hazards modeling, cancer (hazard ratio, 2.4; 95% confidence interval, 1.1-5.6; P = .035) was an independent predictor of mortality. There were 50 concurrent non-ICU patients with finger ischemia. Non-ICU patients were more likely to have connective tissue disorders (26% vs 13%; P = .05) and hyperlipidemia (42% vs 24%; P = .03) and to undergo finger amputations (16% vs 5%; P = .03).

CONCLUSIONS

Finger ischemia in the ICU is frequently associated with the presence of arterial lines and the use of vasopressor medications, of which phenylephrine and norepinephrine are most frequent. Anticoagulation or antiplatelet therapy is appropriate treatment. Whereas progression to amputation is rare, patients with finger ischemia in the ICU have a high rate of mortality, particularly in the presence of cancer. Non-ICU patients hospitalized with finger ischemia more frequently require finger amputations, probably because of more frequent connective tissue disorders.