
==== Front
Intern Med
Intern Med
Internal Medicine
0918-2918
1349-7235
The Japanese Society of Internal Medicine

38220198
10.2169/internalmedicine.2728-23
Case Report
Cure of Fingertip Necrosis after Median Nerve Block Application in Two Cases of Definite and Probable Systemic Sclerosis
Kinoshita Masakatsu 1
Inokuma Shigeko 2
Yamauchi Mao 2
Kamizeki Yuhki 1
Kuwana Koji 1
Watanabe Kouzou 1
1 Department of Anesthesiology, Chiba Central Medical Center, Japan
2 Department of Allergy and Rheumatism, Chiba Central Medical Center, Japan
Correspondence to Dr.　Shigeko Inokuma, ttn7pip27h@mx10.ttcn.ne.jp

13 1 2024
15 8 2024
63 16 23312335
11 8 2023
6 11 2023
Copyright © 2024 by The Japanese Society of Internal Medicine
https://creativecommons.org/licenses/by-nc-nd/4.0/ The Internal Medicine is an Open Access journal distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. To view the details of this license, please visit (https://creativecommons.org/licenses/by-nc-nd/4.0/).
One patient with systemic sclerosis with index fingertip necrosis and another with probable systemic sclerosis with index and middle fingertip impending necrosis were successfully treated with ultrasound-guided median nerve block application on the affected side. The nailfold temperatures of the affected fingers measured using thermography were below 25°C. Immediately after application, the temperature increased substantially. After repeated applications, the mean basal temperature on the affected side increased by 3.6°C in Case 1 and by 5.9°C in Case 2. Peripheral nerve block can be a basic treatment for fingertip necrosis. The thermographical observation of the extent and region in which the temperature increased is novel.

fingertip necrosis
median nerve block
thermography
systemic sclerosis
==== Body
pmcIntroduction

Peripheral vascular impairment frequently develops in connective tissue diseases (CTDs) and sometimes causes intractable fingertip necrosis. Two cases of fingertip necrosis and impending necrosis successfully treated with median nerve block application on the affected side are presented. The nailfold (NF) temperature changes immediately before and after an application and before and after repeated applications were evaluated by thermography. Thermographic observation is novel and includes a comparison of cases with a short disease duration and longstanding ischemia.

The nerve block application was performed in a sitting position. Thermographic measurements were performed in a sitting position at a room temperature of 25°C for 20 min for acclimatization. The medication was administered as usual.

This study was approved by the Ethics Committee of Chiba Central Medical Center (No. 2021-S-20). Written informed consent was obtained from both patients.

Case Reports

Case 1

An 88-year-old woman visited our hospital in January 2017 with complaints of cyanosis in both hands. She had experienced Raynaud's phenomenon once and underwent transcatheter aortic valve implantation for aortic valve stenosis. She tested positive for antinuclear antibody (ANA; 1280x) and anti-centromere antibody (1280x); other autoantibodies, including anti-phospholipid or anti-neutrophil cytoplasmic antibody, rheumatoid factor, and SS-A/SS-B antibodies, were negative. Systemic sclerosis (SSc) was diagnosed based on the American College of Rheumatology (ACR)/the European League Against Rheumatism (EULAR) classification criteria with 9 points, even though her skin showed little sclerosis (1). Her blood count and levels of inflammatory markers, creatinine, liver enzymes, and lung volumes were within normal limits. Echocardiography revealed an estimated systolic pulmonary artery pressure (PAP) of 46 mmHg; however, she had no symptoms of heart failure, so right heart catheterization was not performed.

Beraprost sodium at 80 μg/day and hand bathing in water at 42°C containing 1,000 ppm CO2 were started. Endothelin receptor antagonists and PDE5 inhibitors were not prescribed. In March 2019, the NF temperature of her left index finger, measured by thermography was 21.1°C.

In December 2020, her left index fingertip showed severe cyanosis and pulp necrosis (Fig. 1a i). Ultrasound-guided left median nerve block application with 5 mL of 1% lidocaine mixed with 6.6 mg of dexamethasone was started and performed every 2 weeks. The necrosis soon stopped progressing and was subsequently cured, and block application was ceased after 13 times in total (Fig. 1a iv).

Figure 1. (a) Pulp of the left index finger of Case 1. i, At the seventh left median nerve block application; ii, at the 13th application; iii and iv, four months after the last application. (b) Nailfold (NF) temperatures just before and immediately after the sixth left median nerve block application in Case 1. (c) Basal NF temperatures during the course of repeated left median nerve block application in Case 1.

In February 2021, the NF temperatures before and immediately after the sixth left median nerve block application were measured and showed increases (left index finger, 22.1 to 24.5°C; left five fingers, 25.2±2.0 to 27.1±2.0°C) (Fig. 1b); the increase was even more prominent on the contralateral side of the application (right five fingers, 24.7±2.9°C to 29.2±1.0°C) (Fig. 1b). The thermal dispersion among the fingers, evaluated as the coefficient of variation (CV; standard deviation/mean), decreased to a greater extent on the contralateral right side than on the left (left, 0.08 to 0.07; right, 0.12 to 0.03) (2,8). After repeated block applications, the basal NF temperatures increased (left five fingers, 21.6±1.0 to 25.2±2.1°C; right five fingers, 21.4±0.8 to 24.7±2.9°C) (Fig. 1c), but the CV did not decrease (left, 0.04 to 0.08; right, 0.04 to 0.12). Her PAP was 39 mmHg. No recurrence of necrosis was observed at the latest follow-up in July 2023.

Case 2

A 32-year-old woman visited our hospital in December 2020 with a complaint of cyanosis in her fingers. She showed sustained deep cyanosis and impending necrosis in the fingertips of her right index and middle fingers and punctate infarctions and hemorrhaging around the nails (Fig. 2a, left). She was positive for ANA (320x) and anti-Scl-70 antibody (2x), while other autoantibodies, as confirmed in case 1, were negative. The skin did not show any thickening. The patient did not fully meet the SSc criteria at 8 points, and undifferentiated connective tissue disease was diagnosed (2). Routine tests, as in Case 1, yielded normal results. Echocardiography revealed a PAP of 28 mmHg. In January 2021, the NF temperatures of her right index and middle fingers were 22.9°C and 23.3°C, respectively.

Figure 2. (a) Palms of Case 2. Left, at the first visit. Right, 11 months after introduction of right median nerve block application. (b) NF temperatures just before and immediately after the sixth left median nerve block application in Case 2. (c) Basal NF temperatures during the course of repeated right median nerve block application in Case 2.

In addition to 60 μg/day oral beraprost sodium and hand bathing, similar to Case 1, ultrasound-guided right median nerve block application was started. Her subjective symptoms improved soon after the start of treatment. Impending necrosis was cured until August 2021 (Fig. 2a, right).

The NF temperatures measured at the time of the 10th application increased immediately after the application on both sides. The increases were much greater on the affected side where the block was applied than on the contralateral side, where the temperatures had not been very low from the start (right, 25.8±1.6 to 32.1±0.8°C; left, 29.5±0.8 to 30.4±0.5°C) (Fig. 2b). After repeated nerve block applications every 2 weeks for 10 months, the basal NF temperatures increased on both sides (right, 25.8±3.3°C to 31.7±0.9°C; left, 27.4±2.2°C to 32.0±0.8°C), and the CVs decreased (right, 0.13 to 0.03; left, 0.08 to 0.02) (Fig. 2c). No recurrence was observed as of the latest follow-up in July 2023.

In both patients, after block application, short-lasting numbness and warm feeling in the fingertips developed within 3-5 min, with the latter lasting for approximately 90 min. A block application once every two weeks was set to suit the patients' scheduled visits. No apparent involvement of motor function or adverse events were observed.

Discussion

Fingertip necrosis, which may result in amputation, may be caused by peripheral vascular impairment in CTDs. Vascular wall remodeling and vasoconstriction via excessive autonomic nervous reactions to stimuli, including cold, are related to fingertip necrosis. These pathogeneses might progress most frequently in SSc and could develop in cases that do not meet the 2013 ACR/EULAR classification criteria for SSc. Applying these criteria, Case 1 was barely diagnosed as having SSc, although she had no skin thickening, and Case 2 did not fully satisfy these criteria.

The two cases reported here were cured with median nerve block. The major mechanism of cure is predicted to involve reduction of vasoconstriction and possible vasodilation; reverse remodeling can be expected as a long-term effect, as re-worsening was not observed after the arrest of progression in either case.

One noteworthy aspect of this report is the thermographic observation during the course of block applications. To our knowledge, the temperature in the affected, with necrosis/impending necrosis, fingertip area has never been reported, nor temperatures either before or after nerve block application. Reports on peripheral nerve blocks in patients with CTDs are very few (3). A study of the thermographic response after a specific nerve block application in patients undergoing hand surgery showed an increase of 8.4°C from 27.4°C in the second finger 22 min after median nerve block application (4).

In Case 1, longstanding ischemia resulted in an NF temperature of the affected index finger as low as 21.1°C, which remained below 25°C even immediately after median nerve block application (Fig. 1b). The temperature increase immediately after an application was greater on the side contralateral to the application than on the treated side (Fig. 1b). In contrast, in Case 2, which had a shorter history of CTD and fingertip ischemia, the NF temperatures prominently increased on the affected and treated side, whereas the temperatures on the contralateral side, having been higher, did not change much (Fig. 2b). Although longstanding ischemia may be related to both hyperspasm and remodeling of vessels, vasoconstriction might be rather conspicuous in patients with a shorter disease duration. The NF temperature increased after an application in regions other than the innervated ones as well, including the ring and little fingers, and even on the side contralateral to the application, possibly due to the autonomic reflex rather than absorption of analgesics. Repeated applications increased the basal temperatures overall in both patients.

The NF temperatures varied notably among the fingers, possibly due to dispersed peripheral blood flow (5,6). Blood flow dispersion can occur via irregular vascular wall remodeling and different vasospasms, with different autonomic nerve reactions (7-9). A block application may relieve dispersed vasospasm and even induce vasodilatation. However, after repeated applications, while the basal temperature increased as a whole in both Cases, the CV was high on the most severely affected side in Case 1, who had had longstanding ischemia for a number of years (Fig. 1b, c). Case 2, conversely, had a shorter disease duration, and the CV decreased. This disparity might reflect an early and not easily resolved pathology of peripheral vascular impairment in CTDs.

Controlling vascular flow in CTDs is a major concern. Small vasculatures, not only in the peripheral limbs but also in the internal organs, may be involved in causing disorders, including pulmonary hypertension. Indeed, Case 1 showed an elevated PAP, which decreased after treatment. Therapies for small vasculature involvement include those for underlying diseases, vasodilators, warm CO2 bathing (10), and sympathetic ganglion block applications (11,12). Regarding vasodilators, continuous intravenous prostacyclin (PGI2) may increase blood flow (13). Warm CO2 water bathing has been shown to ameliorate the thermal dispersion among fingers (6). In Case 1, oral PGI2 prescription and hand bathing in warm CO2 water had been adopted beforehand, but their effects were limited, ultimately resulting in the introduction of block application.

Stellate ganglion block may be invasive. On the other hand, as no large arteries or other major tissues are around a median nerve, median nerve block application has fewer risks such as accidental administration of an anesthetic into the blood flow, than stellate ganglion block. The fingertips of the patients who were already undergoing PGI2 and CO2 bathing were successfully treated with additional block application. Repeated applications increased the basal temperatures in both patients and improved the thermal dispersion in Case 2, who had less severe ischemia and a shorter CTD history than Case 1.

The drugs and their doses administered for block application were commonly used for pain relief. Co-administration with a steroid is considered to prolong the anesthetic effect (14). Even if 6.6 mg of dexamethasone could have helped treat some tissue damage, it might not have been the major pathway for healing impending necrosis. Steroids are not considered to cure such vascular involvement, as in the case of scleroderma, nor to induce rapid vasodilatation. Lidocaine may contribute to the resolution of vasoconstriction through two mechanisms: sodium channel blockade, which leads to sympathetic nerve blockade (15); or the activation of vascular endothelial cells and the promotion of NO production (16). Although the subjective warm feeling in their hands was sustained for only one to two hours after an application, repeated applications ultimately led to a cure.

In conclusion, repeated median nerve block applications cured necrosis of the index fingertip in an SSc patient and impending necrosis of the index and middle fingertips in a probable SSc patient. Peripheral nerve block application could be a major, possibly the initial, choice for preventing necrosis of the tips of extremities complicating CTDs.

The authors state that they have no Conflict of Interest (COI).

Acknowledgement

The authors would like to thank Ms. Yuka Tanaka for her assistance.
==== Refs
1. van den Hoogen F , Khanna D , Fransen J , et al . 2013 classification criteria for systemic sclerosis: an American College of Rheumatology/European League Against Rheumatism Collaborative Initiative. Arthritis Rheum 65 : 2737-2747, 2013.24122180
2. Alarcón GS . Unclassified or undifferentiated connective tissue disease. Baillieres Best Pract Res Clin Rheumatol 14 : 125-137, 2000.10882218
3. Saito H , Takei Y , Murakami T , et al . Effect of bilateral brachial plexus block on finger involvement in a case of mixed connective tissue disease. Nihon Pain Clinic Gakkaishi (J Jpn Soc Pain Clin) 24 : 68-71, 2017 (in Japanese).
4. Lange KHW , Jansen T , Asghar S , Kristensen PL , Skjønnemand M , Nørgaard P . Skin temperature measured by infrared thermography after specific ultrasound-guided blocking of the musculocutaneous, radial, ulnar, and median nerves in the upper extremity. Br J Anaesth 106 : 887-895, 2011.21474476
5. Horikoshi M , Inokuma S , Kijima Y , et al . Thermal disparity between fingers after cold-water immersion of hands: a useful indicator of disturbed peripheral circulation in Raynaud phenomenon patients. Intern Med 55 : 461-466, 2016.26935364
6. Inokuma S , Kijima Y . Thermal disparity among fingers and its amelioration by CO2-water bathing in connective tissue disease patients. Int J Vasc Med 2021 : 1-5, 2021.
7. Emad MR , Farpour HR , Ahmed F , et al . Is there any sympathetic skin response abnormality in Raynaud phenomenon? Sultan Qaboos Univ Med J 22 : 274-279, 2022.35673285
8. Nawaz I , Nawaz Y , Nawaz E , Manan MR , Mahmood A . Raynaud's phenomenon: reviewing the pathophysiology and management strategies. Cureus 14 : e21681, 2022.35242466
9. Gosk-Bierska I , Misterska-Skóra M , Wasilewska M , et al . Analysis of peripheral nerve and autonomic nervous system function and the stage of microangiopathy in patients with secondary Raynaud's phenomenon in the course of connective tissue diseases. Adv Clin Exp Med 27 : 1587-1592, 2018.29558039
10. Ohshige T , Ohwatashi A , Kiyama R , Nishi H , Takamori A . Hyperthermic effects of hand bathing: benefits of incorporating finger flexion-extension exercise. J Phys Ther Sci 27 : 3779-3782, 2015.26834351
11. Umemoto K , Ohmichi M , Ohmichi Y , et al . Vascular branches from cutaneous nerve of the forearm and hand: application to better understanding raynaud's disease. Clin Anat 31 : 734-741, 2018.28960445
12. Stephas SA , Hertel P , Bennetts P . Peripheral nerve blockade for patients with Raynaud phenomenon and other causes of digital ischemia: a case report and practice implications. AANA J 89 : 391-395, 2021.34586992
13. Cruz JE , Ward A , Anthony S , Chang S , Bae HB , Hermes-DeSantis ER . Evidence for the use of epoprostenol to treat Raynaud's phenomenon with or without digital ulcers. Ann Pharmacother 50 : 1060-1067, 2016.27465880
14. Movafegh A , Razazian M , Hajimaohamadi F , Meysamie A . Dexamethasone added to lidocaine prolongs axillary brachial plexus blockade. Anesth Analg 102 : 263-267, 2006.16368840
15. Newton DI , Mcleod GA , Khan F , Belch JIF . Mechanisms influencing the vasoactive effects of lidocaine in human skin. Anaesthesia 62 : 146-150, 2007.17223807
16. Cooke JP , Marshall JM . Mechanisms of Raynaud's disease. Vasc Med 10 : 293-307, 2005.16444858
