Regional Anesthesia Facilitating Surgical and Medical Management of a Patient with Necrotizing Fasciitis and Diabetic Ketoacidosis.

Emergent surgery in the setting of a concomitant medical (nonsurgical) emergency challenges the anesthesiology team with multiple and often conflicting concerns. During these rare situations, general anesthesia is often employed. This case report demonstrates a safe and effective regional anesthetic technique utilized as the primary anesthetic during emergent surgery in the setting of a medical emergency. In this particular case, the medical emergency was profound diabetic ketoacidosis and the surgical emergency was life-threatening necrotizing fasciitis of the left upper extremity. An ever-increasing body of literature supports that anesthetic technique has an impact on morbidity and mortality outcomes in specific patient populations. The aim of this case report is to describe the successful use of regional anesthesia to facilitate emergent surgery in a patient who also has a concurrent emergent medical condition. In addition, we review the literature describing the utility of regional anesthesia in such patients. Copyright:

INTRODUCTION

Anesthetic management of patients presenting for emergent surgeries that are complicated by concurrent medical emergencies can be particularly arduous. In rare cases such as these, general anesthesia is often employed.[1] While prioritizing good clinical outcomes, the anesthesia team must also maximize patient safety and facilitate optimal surgical conditions. Recently, a growing body of literature promotes the benefits of regional anesthesia and suggests that the choice of anesthetic technique has implications on morbidity and mortality outcomes in specific patient populations.[234]

This case report and literature review support how regional anesthesia may be utilized in the management of a patient who requires emergent surgical debridement for necrotizing fasciitis with concurrent treatment of diabetic ketoacidosis (DKA), a medical emergency.

METHODS

PubMed literature search was restricted to the English language, included articles up to November 2020, with keywords: “emergency,” “surgery,” “anesthetic considerations,” “plexus,” and “nerve block.” Consistent with the American Society of Anesthesiology Physical Classification System, a condition was deemed emergent if it, when left untreated, poses a “threat to life or body part.”[5] After an independent review and collaborative discussion, the authors agreed that none of the results included such cases. However, one case series described the use of regional anesthesia to facilitate urgent procedures.[6] Concurrent emergent conditions were reported and managed in 4 of the 9 cases described in the article. Our case report was granted a Not Research Determination by the Brooke Army Medical Center Human Research Protections Office, denoting that institutional review board approval was waived/deferred after intention to publish was declared. A health insurance portability and accountability act authorization form was completed for the patient involved in this report. All personal health information was removed from the text and images.

CASE REPORT

We describe a 61-year-old male, with a history of poorly controlled Type 2 diabetes mellitus (Hb A1c > 13%) presenting to the emergency department with severe pain after sustaining thermal injury to his left hand. On examination, there was limited range of motion of all digits, and the left hand was found to be grossly erythematous, edematous, and tender to palpation. Working diagnosis of necrotizing fasciitis was confirmed by computed tomography imaging of the left upper extremity [Figure 1], which demonstrated subcutaneous gas of the dorsal and palmar surfaces of the left hand and wrist, extending to the 1st, 2nd, 3rd, and 4th digits. Further laboratory workup included serum glucose concentration >700 mg/dL, anion gap metabolic acidosis, and positive Acetest, consistent with the diagnosis of DKA. The surgical team planned to address the infected tissue by performing emergent irrigation and surgical debridement of the wound, with possible amputation. The anesthesia team decided to use a regional anesthetic as the primary anesthetic since this would facilitate the surgery, avoid the hemodynamic instability often seen with general anesthesia, reduce the risk of systemic polypharmacy, and allow for prompt neurologic assessment of mental status throughout the perioperative period. After obtaining written informed consent, the anesthesia team immediately initiated treatment of DKA with intravenous (i.v.) fluid resuscitation, insulin administration, and appropriate electrolyte replacement. Concurrently, the team performed a single injection axillary brachial plexus block, including the musculocutaneous nerve, with 18 mL 0.5% ropivacaine. During this period, the operating room equipment was being prepared for the surgical intervention. Immediately after performing the regional anesthetic, the patient was moved to the operating room, prepped, and draped as the anesthesia team uneventfully placed a right radial arterial catheter and initiated sedation with an i.v. propofol infusion at 50 μg.kg − 1.min − 1, which was titrated to sedation effect of Richmond Agitation–Sedation Scale of 2–3. Due to extensive necrotic tissue [Figure 2], transradial amputation was required. The patient tolerated the procedure well. The intraoperative resuscitation included the i.v. administration of 1 L plasmalyte, 250 mL 5% albumin, 38.8 units regular insulin, and 24.4 mEq potassium chloride. This resuscitation resulted in improvements in both hyperglycemia and lactic acidosis [Table 1]. Following the procedure, the patient was safely transferred to the intensive care unit. After 24 days of inpatient care and two further surgeries to close the wound, the patient was discharged home.

Figure 1

Computed tomography scan of the left hand. Extensive soft tissue edema, erosive changes, and subcutaneous gas visible

Figure 2

Photograph of the left hand. Tissue discoloration consistent with necrotizing soft tissue infection

Table 1

Laboratory analysis of arterial blood samples for the patient described in the case report

Lab	0055 h	0125 h	0200 h	0234 h	0407 h
pH	7.29	7.38	7.31	7.38	7.38
PaCO2 (mmHg)	33	26.3	35	31.2	34.1
PaO2 (mmHg)	250.1	188.3	205.2	176.9	147.6
HCO3− (mmol/L)	15.5	15.3	17.1	18	19.7
Na+ (mmol/L)	129	129	130	130	131
K+ (mmol/L)	3.49	4.1	4.13	4.25	3.82
Cl− (mmol/L)	96	98	99	99	102
Glucose (mg/dL)	>600	563	504	468	383
Lactate (mmol/L)	2.79	3.07	3.31	3.16	1.82
Anion gapa	17.5	15.7	13.9	13	9.3

The anion gap was calculated with the following commonly used formula: Anion gap=Na+- (Cl−+HCO3 −)

DISCUSSION

Currently, the guidelines suggest that providers consider cancellation or postponement of nonemergent surgery in the cases of medical emergencies, such as DKA or acute coronary syndrome.[7] However, the existence of such a medical emergency with a concurrent surgical emergency often requires that the medical comorbidities be managed simultaneously or after surgical intervention. The gold standard is to optimize medical management without delaying surgical management. While the impact of various anesthetic techniques on specific patient outcomes is now being identified, there is currently a paucity of evidence to address the effect of anesthetic technique selection in patients with both surgical and medical emergencies.

To gain additional understanding of the utilization of peripheral nerve or plexus regional anesthesia to facilitate emergent surgeries in patients with concurrent emergent conditions, we conducted a literature review. In our search, we found no such cases had been reported. However, we did find a case series that described the use of supraclavicular brachial plexus block as the primary anesthetic in the management of nine patients undergoing urgent surgeries.[6] In this case series, 4 of the 9 included patients had emergent comorbid conditions that required perioperative management. These conditions included hypoxemia, pneumothorax, severe mitral stenosis, and cardiac dysrhythmias. These cases are described in Table 2. In the 2 cases involving concurrent pneumothoraces with hypoxemia, the author cites how a regional anesthetic negated the need for general anesthesia and positive pressure ventilation (PPV). In the face of such pulmonary pathology, PPV can often be detrimental, resulting in cardiopulmonary embarrassment or even collapse. Regarding the other 2 patients listed in Table 2, the author simply expresses the desire to avoid general anesthesia as it may be associated with greater morbidity and mortality risks.

Table 2

Data from case series by Tantry et al. in which regional anesthesia facilitated emergency surgery in the setting of urgent comorbidities

Case	Age	Sex	Comorbid condition, requiring perioperative intervention	Emergent/urgent surgical procedure	Additional perioperative interventions	Author’s concern with general anesthesia
1	43	Male	Complete heart block, asystole	“Skeletal fixation” and soft tissue debridement	Cardiopulmonary resuscitation and transvenous pacing	Aspiration risk (“full stomach”)
2	65	Male	Fractured ribs (3-6) with pneumothorax	“Skeletal fixation” and soft tissue debridement	Chest tube placement	Worsening of subcutaneous emphysema by positive pressure ventilation
3		Female	Severe mitral stenosis and atrial fibrillation	Brachial artery embolectomy	Perioperative anticoagulation and monitoring of hematoma formation at site of regional anesthetic	Increased morbidity associated with general anesthesia in the setting of “cardiac illness”
4	45	Male	Flail chest, pneumothorax, hypoxemia	“Skeletal fixation” and soft tissue debridement	Chest tube placement	Increased “morbidity” with mechanical ventilation

In our particular case, the patient was faced with both a medical emergency and a surgical emergency, DKA, and emergent wound debridement for necrotizing fasciitis. While it has been well established that the stress of surgical stimuli and the use of general anesthetics worsen hyperglycemia in the diabetic patient,[8910] recent literature suggests that regional anesthesia may reduce this insult.[1011] Furthermore, general anesthesia may mask symptoms of DKA (i.e., abdominal discomfort, and agitation),[12] leading to delays in diagnosis and treatment of this medical emergency.

Maintenance of hemodynamic stability was also of great concern to the anesthesia team. The suspected hypovolemia, secondary to osmotic diuresis, combined with the distributive shock resulting from the ongoing infectious process was likely contributing to an ongoing state of hypoperfusion. This state of decompensated shock was reflected by the initially elevated serum lactate levels. Naja et al. described the reduction in the incidence of intraoperative hypotension with regional anesthesia when compared to general anesthesia.[13] For this reason, utilizing a peripheral nerve block as the primary anesthetic and minimizing systemic anesthetics likely reduced further hemodynamic instability in a patient already who was already in a labile state.

Although the combination of DKA with concurrent necrotizing fasciitis is uncommon, the management of these concurrent emergencies in such a patient was described by Leyva et al. in a case report.[1] However, in their case, the concern for airway compromise and anatomic location of pathology prompted the use of general anesthesia with endotracheal intubation as the primary anesthetic. The use of regional anesthesia to facilitate surgery in these rare situations has not yet been well described.

The case described above originated from a contemporary Level I trauma center and a busy academic hospital. As with any anecdotal report, single-center, institutional biases and sample size limitations are inherent to this case report. Additional research is needed to identify best practices and optimal patient care with regard to anesthetic technique selection in challenging patient cohorts. Finally, as the practice of regional anesthesia continues to advance in perioperative management, further investigation into its use in the management of concurrent medical and surgical emergencies is warranted.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.