[Retracted] Efficacy of Cold Atmospheric Plasma Therapy on Chronic Wounds: An Updated Systematic Review and Meta-Analysis of RCTs

Table 1

General characteristics of the included studies.

(a)

Author1 year	Design	Country	Sample size (E/C)	Age (range or )	Type of wound	Intervention group	CAP technical parameters	Control group	Outcomes	Treatment endpoints or treatment duration
Quantitative analysis
Isbary^15; 2010	RCT	Germany	38/38	40–94y	VU, AU, DFU, TU	5 min of CAP every day and ST	Microwave 2.46 GHz,86 W; Ar2.2 slm; distance to torch 2 cm	ST	②	Negative bacterial swabs; or the wound was healed, or the patient decided to stop.
Isbary^16; 2012	RCT	Germany	α: 14/14; β: 10/10	40–85y	AU, VU,; TU	2 min of CAP every day and ST	Microwave 2.46 GHz; voltage 50–100 V; power 86 W; Ar2.2 slm	ST	②	Negative bacterial swabs; or the wound was healed, or the patient decided to stop.
Heinlin^17; 2013	RCT	Germany	34/34		Skin graft donor site healing	2 min of CAP every day and ST	Microwave 2.45 GHz, 86 W; Ar2.2 slm; distance to torch 2 cm	Placebo and ST	④	Complete healing of the donor site or the patient decided to stop.
Mirpour^22; 2020	RCT	Tehran	22/22	E: C:	DFU	CAP (3 times a week for 3 weeks) and ST	Helium gas; voltage 10 kV; frequency 6 kHz	ST	① ③	3 weeks
Moelleken^19; 2020	RCT	Germany	E1: 14; E2: 13; C: 10	E1: avg65.2y; E2: avg66.8y; C: avg73.7y	VU, DFU, pyoderma gangrenosum	E1: CAP (1 time a week for 12 weeks) and ST; E2: CAP (3 times a week for 12 weeks) and ST	Ar	Placebo and ST	① ④	12 weeks
Amini^21; 2020	RCT	Tehran	22/22	18–80y	DFU	CAP(3 times a week for 3 weeks)and ST	Helium gas; voltage 10 kV; Frequency 6 kHz	ST	②⑤	3weeks
Samsavar^23; 2021	RCT	Tehran	10/10	E: C:	DFU	CAP (2 times a week for 6 weeks) and ST	Helium gas; voltage 4.5 Kv; frequency 22 kHz	ST	①	6weeks

(b)

Author1; year	Design	Country	Sample size (E/C)	Age; (range or; )	Type of wound	Intervention group	CAP technical parameters	Control group	Outcomes	Treatment duration
Strohal^24; 2022	RCT	Austria	39/39	E: 42.58–93.91y; C: 42.58–93.91y	VLU, DFU	3 times in the 1st week, twice in the 2nd week, and once per week in the following observation period	CAP-jet treatment (kINPen® med, neoplas med GmbH, Greifswald/Germany)	Best practice wound dressings	①	6 weeks
Quantitative analysis
Brehmer^18; 2014	RCT	Germany	7/7	E: 51–85y; C: 51–83y	VLU	CAP (3 times per week for 8 weeks) and ST	Frequency 50 Hz, maximum power consumption: 8 VA	ST	① ④	8 weeks
Chuangsuwanich^20; 2016	RCT	Thailand	23/19	E: C:	PU	CAP (once per week for 8 weeks) and ST	Ar; frequency 15–20 Hz; peak voltage was around 6 to 7 kV	ST	Wound and bacterial load reduction is assessed by scores	8 weeks
Stratman^12; 2020	RCT	Germany	33/32	E: C:	DFU	CAP (8 times within 2 weeks) and ST	Ar	ST	Wound and bacterial load reduction is assessed by scores	2 weeks
Van Welzen^13; 2021	RCT	Germany	10/10		Skin graft donor site healing	CAP (3 times for 1 week) and ST	CAP was applied using a single dose of 100–240 V and 1.3–8 VA	ST	④	1 week
Hiller^14; 2022	RCT	Germany	14/13	E: C:	DFU	CAP (8 times within 2 weeks) and ST	Ar	Placebo and ST	Inflammatory cytokines

Abbreviations: CAP: cold atmospheric plasma; RCT: randomized clinical trials; E-CAP group; C: control group; y-years; ST: standard treatment; Ar: argon gas; DFU: diabetic foot ulcer; VLU: venous leg ulcer; VU: venous ulcer; AU: arterial ulcer; PU: pressure ulcer; TU: traumatic ulcer. Outcomes: (a) reduction of wound area (cm2); (b) immediate reduction of the bacterial load (log Nfc/Nic, where Nfc/Nic is the number of colonies after (before) each treatment; (c) long-term reduction of the bacterial load (log Nfc/Nic, where Nfc/Nic is the number of colonies after (before) the entire treatment duration); (d) assessment of pain (visual analogue scale (VAS) from 0 (no pain) to 10 (most severe pain)); (e) the level of inflammatory cytokine.