Arterial cannulation can hasten the onset of symmetrical peripheral gangrene

Abstract

Symmetrical peripheral gangrene (SPG) is a devastating complication seen in critical care settings due to several contributory factors like low perfusion, high dose of vasopressors, disseminated intravascular coagulation, etc. Arterial cannulation is commonly done in critical patients for monitoring. We report a case of patient who developed early features of SPG which recovered in one hand, although it progressed in the hand which had the arterial cannula.

INTRODUCTION

Symmetrical peripheral gangrene (SPG) is a rare but devastating complication involving distal portions of two or more extremities simultaneously. Disseminated intravascular thrombosis and hemorrhagic infarction of skin with uninvolved proximal arteries are hallmark of this condition.[1] Low-flow circulation and septicemia play an important role in the development of SPG.[2] SPG can also occur as a complication of measles,[3] chickenpox,[4] malignancy, and ergotism. Aggravating factors are increased sympathetic tone,[2] diabetes mellitus,[2] immunosuppression,[5] cold injury to extremities,[6] use of vasopressors,[6] and renal failure.[7]

Cause of vascular occlusion is not exactly defined, but disseminated intravascular coagulation is present in up to 85% patients with SPG.[5] Low-flow state and septicemic conditions are almost invariably present. Fever followed by marked coldness, pallor, cyanosis, pain, and restricted mobility of extremity should always raise suspicion of SPG. If aggressive and prompt intervention is delayed, frank gangrene may develop. Ischemia starts and manifests from distal extremity and proximal parts are unaffected invariably. Vascular compromise in SPG results in erythematous cold extremities and dusky discoloration of skin. Acral cynosis and hemorrhagic bulla are followed by development of dry gangrene within 24 hours. Despite therapeutic interventions, different studies report amputation rate of 30 to 50%.[8,9]

In critical care settings, percutaneous radial artery catheterization for continuous arterial pressure monitoring has become a common procedure. This group of patients are also at increased risk for SPG because of several underlying comorbidities. We describe a case of atypical presentation of SPG involving the digits of the left hand alone which had the radial artery cannula in place. SPG complicated by arterial cannulation has not been reported in the literature so far.

CASE REPORT

A 47-year-old female patient was referred to our hospital for the management of postoperative bleeding following vaginal hysterectomy done elsewhere for third-degree uterovaginal prolapse. She was conscious but drowsy on examination and tachypneic. Heart rate was 120 beats per minute and blood pressure (BP) of 90/60 mm Hg in supine position. Peripheries were cold and clammy. Laboratory investigations were normal except for low hemoglobin (6.2 g/dl.). She was posted for emergency laparotomy and re-exploration. In view of low blood pressure and the need for inotropic support, a triple lumen central venous access was secured through right subclavian vein. Fluid resuscitation was done with one liter of colloid and two units of packed red blood cells. Exploration was planned under general anesthesia. Before induction, left radial artery was cannulated with 20 ga PVC Jelco^® cannula and invasive hemodynamic monitoring was instituted. Surgery involved ligation of bilateral internal iliac arteries because of continuous ooze. Intraoperatively, she received four units of fresh frozen plasma and three more units of packed red blood cells. Inotropic support with dopamine 10 to 15 μg/kg/min was required to maintain a mean BP of 65 mm Hg. Patient was admitted in intensive care unit (ICU) for monitoring and elective ventilation after the procedure. In the ICU, she developed disseminated intravascular coagulopathy on the second day which was managed with blood products and cryoprecipitate. Inotropic support with dopamine up to 20 μg/kg/min was continued. On the third day, there were features of acute respiratory distress syndrome and she required increasing ventilatory support to maintain acceptable oxygenation. Tracheostomy was done on the seventh day and ventilatory support was continued for the next 15 days and gradually weaned off successfully.

On the third postoperative day, dusky discoloration of the digits involving both hands were noted. The extremities were cold to feel. In view of unstable hemodynamic status and due to technical difficulties in securing arterial cannulation at alternate site, we deferred decannulation immediately. On the fifth day, the left thumb, index and middle finger showed worsening of discoloration. The left radial artery cannula was removed and vascular surgery opinion was sought then. Doppler ultrasound of the radial artery showed partial thrombosis at the cannulation site, even though the arterial pulsation was well felt. Injection Clexane (enoxaparin), a low molecular weight heparin, was started in a dose of 0.4 ml subcutaneously for seven days and IV low molecular weight Dextran was also started at 40 ml/hr for the next two days. Stellate ganglion block was also attempted on the same side using bupivacaine 0.25% 20 ml. Nitroglycerine ointment was applied for the dusky discoloration in both hands from the time it was noted.

The discoloration of the digits involving the right hand improved but the left hand digits, especially the left thumb, index and middle finger, did not improve with the conservative management and was slowly turning dark. Over the next three days, the digits had become blackish in color with clear line of demarcation suggesting dry gangrene [Figure 1]. Patient required pulmonary and psychiatric rehabilitation after recovering from the acute event. After adequate counseling, she underwent amputation of the gangrenous digits under brachial plexus block four weeks later.

Figure 1.

Dry Gangrene with clear demarcation of the thumb, index and middle finger in left hand

DISCUSSION

Despite the apparent safety of radial artery cannulation, the reported catastrophic events requiring digit or even forearm amputation following radial artery cannulation are extremely rare.[10] Some of the alleged contributory causes in these reports include emboli originating in the heart, excessive trauma from very large or long catheters, and prolonged circulatory failure with vasoconstrictor administration.[6]

Several factors overlap in the causation of SPG and ischemic damage due to radial artery cannulation. So far, there are no case reports where arterial cannulation can hasten the progress of SPG. In our case, patient showed features of SPG involving both hands. Because of delay in decannulating the radial artery, the digits in the hand which had the cannula in place progressed to gangrene, whereas the other hand recovered completely.

Early diagnosis followed by discontinuation and reduction of vasopressor therapy and proper intervention for sepsis and disseminated intravascular coagulation is needed for successful treatment of peripheral symmetrical gangrene. In our patient, possibly the disseminated intravascular coagulation along with vasopressor therapy with hypoperfusion would have triggered SPG. As the patient improved with treatment, the dusky discoloration disappeared in the right hand without progressing to gangrene, whereas the left hand which had the cannula in situ had progressed to gangrene in our case. In conclusion, early decannulation of the artery and aggressive management for dusky discoloration of extremities in critically ill patients might prevent the progression of SPG.