Introduction
Approximately 75% of all trauma deaths now occur out-of-hospital. Reference Bakke and Wisborg1,Reference Beck, Smith and Mercier2 Of these deaths, it is estimated that 20% can be potentially prevented, and thoracic injuries remain one of the leading causes of early preventable trauma-related mortality. Reference Beck, Smith and Mercier2,Reference Pfeifer, Halvachizadeh and Schick3 Pneumothoraxes are potentially life-threatening injuries that require prompt identification and treatment, but they can be highly challenging to diagnose and address during prehospital care. Reference Leigh-Smith and Harris4
Health care professionals can use different strategies to decompress a proven or suspected pneumothorax. Reference Waydhas and Sauerland5 Historically, in the out-of-hospital setting, needle chest decompression (NCD) at the second intercostal space (ICS) at the midclavicular line (MCL) has been the initial temporizing approach recommended by well-established associations such as Prehospital Trauma Life Support (PHTLS) and International Trauma Life Support (ITLS). 6,Reference Campbell7 However, there has been a growing number of studies highlighting some limitations relative to the efficacy and safety of this approach. Reference Leigh-Smith and Harris4,Reference Waydhas and Sauerland5,Reference Wernick, Hon and Mubang8 The inability to reach the pleural space and the risk of catheter obstruction or dislodgment preventing the continuous decompression effect have been described, along with the risk of iatrogenic injuries by a misplaced needle. Reference Leigh-Smith and Harris4,Reference Ferrie, Collum and McGovern9–Reference Leech, Porter and Steyn11 Furthermore, it is practically impossible for the prehospital provider to know if the absence of a response to NCD is because the technique has failed or due to the absence of pneumothorax. Following traumatic cardiac arrest, this confusion can theoretically lead to inadequate termination of resuscitation and preventable mortality. Reference Mistry, Bleetman and Roberts12 In recent years, alternative needle size, gauge, and insertion sites have been proposed and implemented around the world, along with different chest decompression techniques such as finger thoracostomy (FT) and chest tube placement (CTP), but there is a lack of consensus on the efficacy and safety profile of these different approaches, particularly in the prehospital setting. Reference Leech, Porter and Steyn11–Reference Massarutti, Trillò and Berlot13
The aim of this systematic review is to synthesize the recent evidence on the efficacy, patient outcomes, and adverse events of different chest decompression approaches relevant to the out-of-hospital setting.
Methods
Data Source
A literature search strategy using a Boolean approach was developed and applied to PubMed (National Center for Biotechnology Information, National Institutes of Health; Bethesda, Maryland USA), Medline Ovid (US National Library of Medicine, National Institutes of Health; Bethesda, Maryland USA), Web of Science (Thomson Reuters; New York, New York USA), Cochrane (The Cochrane Collaboration; London, United Kingdom), and CINAHL (EBSCO Information Services; Ipswich, Massachusetts USA). MeSH and Entree terms were used for their respective databases (last updated June 15, 2020). Two relevant systematic reviews Reference Clemency, Tanski, Rosenberg, May, Consiglio and Lindstrom14,Reference Laan, Vu and Thiels15 on the topic were published, but they have limited their search to studies published prior to 2015. To review the newest evidence, the search strategy was limited to studies published after January 1, 2014. The search strategy terms included: (1) Catheter OR Needle OR Finger OR Simple or Novel Device OR (Modified Veress) OR (Colorimetric Capnography) OR Trocar; (2) Thoracostomy OR Decompression OR Thoracentesis; (3) Pneumothor* OR (Tension AND Pneumothor*) OR Complication* OR Adverse Event* OR Success*; (4) Pre-Hospital OR Out of Hospital OR Emergency Medical Service* OR EMS OR Paramedic Emergency Medical Technician* OR EMT; (5) (Tube AND Thoracostomy) OR (Chest AND Tube). The first search combined one and two and three, and the second search combined three and four and five. The search strategy was limited to human studies published in English or French. Google Scholar (Google Inc.; Mountain View, California USA; first 100 results) was also scrutinized for additional potentially eligible studies. Finally, references from included studies and previous narrative reviews were scrutinized looking for potential additional studies as well as abstract from relevant conferences.
Eligibility Criteria
To be considered eligible, studies required to report original data on decompression of suspected or proven traumatic pneumothorax and to be considered relevant to the prehospital context. They were also required to be conducted mostly on an adult population (expected more than ≥ 80% of the population ≥ 16 years and older) of patients. Animal or cadaver studies, case reports, as well as opinion piece, letter, comment, or abstract only available data were excluded.
Study Selection and Data Extraction
One researcher (MRF) reviewed sequentially all the titles and abstracts of the retrieved citations. Manuscripts of potentially relevant studies were thereafter fully reviewed, screening for eligibility based on the inclusion and exclusion criteria. Other authors (TA or SN) confirmed the eligibility of the included studies. Relevant data were extracted using a pre-piloted Word (Microsoft Corp.; Redmond, Washington USA) form. Extracted data included variables relative to the study design, country of origin, setting, and relevant results.
Reporting
This review is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement (Appendix 1; available online only). Reference Moher, Liberati, Tetzlaff and Altman16 Given the anticipated clinical heterogeneity relative to the population included, chest decompression approaches, and outcomes, no meta-analytic approach was considered appropriate when the study protocol was developed.
To report the results, included studies were divided into two pre-determined categories. First, studies performed in a clinical setting and reporting on the efficacity, patient outcomes, and/or adverse events were grouped and synthesized. Then, studies limited to anatomical measures and their associated success and failure rates, using radiological data (for instance, studies limited to chest wall thickness [CWT] measures), were grouped and synthesized.
Grade of Evidence
Every retained article was appraised using the Critical Appraisal Skills Program (CASP) 17 and a level of evidence was subsequently assigned to each study by the author using the Harbour and Miller system, which aims to determine the level of evidence. Reference Harbour and Miller18
Results
Characteristics of Included Studies
A total of 1,420 unique citations were obtained by the literature search strategy, of which 20 original studies (two prospective cohort or case series and 18 retrospective cohort or cases series) fulfilled the inclusion criteria. Reference Aho, Thiels and El Khatib19–Reference Sirikun and Wasinrat38 Each study included between 24 and 2,574 patients and most studies (n = 9) were conducted in the United States of America. The main mechanism was blunt trauma. Twelve studies presented data on efficacy, patient outcomes, and/or adverse events, Reference Aho, Thiels and El Khatib19–Reference Weichenthal, Owen, Stroh and Ramos29,Reference Lesperance, Carroll, Aden, Young and Nunez36 while ten studies presented findings limited to anatomical measures and predicted success rate and outcomes (two studies presented results relevant to both categories). Reference Aho, Thiels and El Khatib19,Reference Blenkinsop, Mossadegh, Ballard and Parker30–Reference Sirikun and Wasinrat38 Characteristics of the included studies are presented in Table 1 and Table 2.
Flow Diagram.
Characteristics of Studies on Efficacy, Patient Outcome, and Safety of Chest Decompression
Abbreviations: ICS, intercostal space; MCL, mid-clavicular line; AAL, anterior axillary line; MAL, mid-axillary line; CD, chest decompression; CPR, cardiopulmonary resuscitation; ED, emergency department; AE, adverse event; CTP, chest tube placement; CT, computed tomography; FT, finger thoracostomy; PTx, pneumothorax; NCD, needle chest decompression; NR, not reported; SPO2, peripheral capillary oxygen saturation; TCA, traumatic cardiac arrest; ROSC, return of spontaneous circulation; EMS, Emergency Medical Services; HEMS, helicopter Emergency Medical Services.
Characteristics of Studies on Anatomical Measures
Abbreviations: ICS, intercostal space; MCL, mid-clavicular line; AAL, anterior axillary line; MAL, mid-axillary line; AAL, anterior axillary line; ED, emergency department; BMI, body mass index; CT, computed tomography; CWT, chest wall thickness; PTx, pneumothorax; MRI, medical resonance imaging; NCD, needle chest decompression.
Efficacy, Clinical Outcomes, and Adverse Events
The most clinically studied chest decompression technique was NCD (n = 7), Reference Aho, Thiels and El Khatib19–Reference Chen, Nadler, Schwartz, Tien, Cap and Glassberg21,Reference Dickson, Gleisberg and Aiken23,Reference Kaserer, Stein, Simmen, Spahn and Neuhaus26,Reference Weichenthal, Crane and Rond28,Reference Weichenthal, Owen, Stroh and Ramos29 followed by FT (n = 5) Reference Chesters, Davies and Wilson22–Reference High, Brywczynski and Guillamondegui25,Reference Peters, Ketelaars, van Wageningen, Biert and Hoogerwerf27 and CTP (n = 3). Reference Chen, Nadler, Schwartz, Tien, Cap and Glassberg21,Reference High, Brywczynski and Guillamondegui25,Reference Kaserer, Stein, Simmen, Spahn and Neuhaus26 Overall, the success rate of NCD ranged between 18% and 86%. Reference Aho, Thiels and El Khatib19,Reference Chen, Nadler, Schwartz, Tien, Cap and Glassberg21,Reference Kaserer, Stein, Simmen, Spahn and Neuhaus26 In general, criteria used to define a successful NCD were heterogeneous as studies included variables such as improvement in vital signs, improvement in oxygenation, a gush of air during the procedure, improved lung compliance, or improved air entry on chest auscultation.
Using a comparison of two needle lengths, Aho, et al reported a non-significant improved success rate using an 8cm (83%) versus a 5cm (62%) needle in the prehospital field (P <.28). Reference Aho, Thiels and El Khatib19 Using CWT measures of patients whose imaging data were available and who underwent chest decompression in the prehospital or hospital setting (n = 49), success rates of 80% and 100% were predicted using respectively the 5cm and 8cm needles compared to the 41% and 83% real-time clinical performance. This illustrates the discordance between the radiographical prediction of success and actual clinical improvement. Reference Aho, Thiels and El Khatib19 Following the prehospital implementation of NCD in a study including mostly hemodynamically stable patients (92%), no modifications of vital signs following the procedure were reported except for an increased oxygen saturation (P = .002). Reference Axtman, Stewart and Robbins20 Three studies found a statistically significant mortality decrease when NCD was reported successful by the prehospital clinician. Reference Aho, Thiels and El Khatib19,Reference Weichenthal, Crane and Rond28,Reference Weichenthal, Owen, Stroh and Ramos29 The mortality was not associated with the needle length. Reference Aho, Thiels and El Khatib19,Reference Weichenthal, Crane and Rond28
Using FT, the decompression success rate ranged between 9.7% to 32.0%. Reference Chesters, Davies and Wilson22–Reference High, Brywczynski and Guillamondegui25,Reference Peters, Ketelaars, van Wageningen, Biert and Hoogerwerf27 In a case series of 250 patients following FT or CTP, the reported improvement rate was 30%. Reference High, Brywczynski and Guillamondegui25 One study found an improved oxygen saturation at hospital arrival compared to the on-field oxygen saturation prior to FT (P = .003). Reference Axtman, Stewart and Robbins20,Reference Chesters, Davies and Wilson22 In a case series of six patients, CTP was reported successful during 83% of prehospital interventions for patients with a tension pneumothorax. Reference Kaserer, Stein, Simmen, Spahn and Neuhaus26 Four studies reported a return of spontaneous circulation (ROSC) rate between 15.7% and 25.0% with associated survival from 0.6% to 9.4% for traumatic cardiac arrest following prehospital FT. Reference Dickson, Gleisberg and Aiken23–Reference High, Brywczynski and Guillamondegui25,Reference Peters, Ketelaars, van Wageningen, Biert and Hoogerwerf27 A single study reporting on six patients following the prehospital use of a 10 French Vygon thoracic trocar and drain catheter did not present data on patient outcomes. Reference Chen, Nadler, Schwartz, Tien, Cap and Glassberg21
Most studies (n = 6) Reference Aho, Thiels and El Khatib19,Reference Chen, Nadler, Schwartz, Tien, Cap and Glassberg21,Reference Chesters, Davies and Wilson22,Reference Peters, Ketelaars, van Wageningen, Biert and Hoogerwerf27–Reference Weichenthal, Owen, Stroh and Ramos29 did not report any adverse events or complications relative to chest decompression. One study reported three significant iatrogenic events, including one iatrogenic pneumothorax, one hematoma, and one vessel injury causing a hemothorax following NCD at 2ICS-MCL. Reference Axtman, Stewart and Robbins20 In the same study, patients who had a computed tomography (CT) scan with the catheter still in place on hospital arrival, 94% (48/51) of the catheter’s tips were hanging outside of the pleura. Similarly, Lesperance, et al reported that 76% of the NCD catheters were more than 5mm away from the pleura on the imaging performed in the emergency department (ED). Reference Lesperance, Carroll, Aden, Young and Nunez36 Four studies reported that between 18% and 42% of patients did not have any evidence of pneumothorax on ED admission imaging following prehospital chest decompression attempt. Reference Axtman, Stewart and Robbins20,Reference Hannon, St Clair and Smith24,Reference Kaserer, Stein, Simmen, Spahn and Neuhaus26,Reference Lesperance, Carroll, Aden, Young and Nunez36 High, et al reported nine complications (3.6%), including eight chest tube misplacements and one empyema, in their cohort of 250 patients. Reference High, Brywczynski and Guillamondegui25 In a cohort of 57 patients with prehospital FT, three complications (5.2%) were reported, including two failures to reach the pleura and one concomitant laceration of the diaphragm and liver. Reference Dickson, Gleisberg and Aiken23 Kaserer, et al found three chest tube misplacements or dislodgments which represent 50% of their cohort. Hannon, et al reported three adverse events (4.8%), including one cellulitis, one vessel injury with arterial bleed, and one diaphragmatic and a liver laceration in their cohort of FT. Finally, Dickson, et al and Peters, et al specified that no procedural injuries to the clinicians were reported with the use of a scalpel for FT in their case series.
Anatomical Measures and Predicted Success Rate
Ten studies presented data on anatomical measures predicting the association between chances of success or failure and different chest decompression approaches (Table 2). Reference Aho, Thiels and El Khatib19,Reference Blenkinsop, Mossadegh, Ballard and Parker30–Reference Sirikun and Wasinrat38 These studies mostly included civilians (n = 4,304) and military personnel (n = 185). Measurements in all studies were performed using CT, except for Lamblin, et al Reference Lamblin, Turc and Bylicki35 who used ultrasound and Hecker, et al who used magnetic resonance imaging (MRI). Reference Hecker, Hegenscheid and Völzke34
All ten studies reported the mean CWT at various anatomical sites and the associated potential success or failure rates using NCD. To determine the potential success rate associated with a puncture site, studies compared the measured CWT to a pre-determined needle size (usually 5cm or 8cm). If the needle was long enough to theoretically penetrate the CWT, the procedure was considered as a potentially successful procedure, and if not, the procedure was considered as a potential failure. Four studies also determined the risk of iatrogenic injury by calculating the distance to the nearest critical organ from the needle penetration point with 90 degrees penetration angle (n = 2) Reference Blenkinsop, Mossadegh, Ballard and Parker30,Reference Chang, Ross and Kiefer31 and/or without restricting the angle of penetration (n = 4). Reference Blenkinsop, Mossadegh, Ballard and Parker30,Reference Chang, Ross and Kiefer31,Reference Lesperance, Carroll, Aden, Young and Nunez36,Reference Sirikun and Wasinrat38
Eight studies made statistical comparisons between the anterior and lateral sites. Reference Aho, Thiels and El Khatib19,Reference Blenkinsop, Mossadegh, Ballard and Parker30–Reference Goh, Xu and Teo33,Reference Lesperance, Carroll, Aden, Young and Nunez36,Reference Sirikun and Wasinrat38 All reported a thinner CWT for lateral sites except for Aho, et al and Chanthawatthanarak, et al who found the opposite. Reference Aho, Thiels and El Khatib19,Reference Chanthawatthanarak, Munkong, Apiratwarakul, Ienghong and Bhudhisawasdi32 When comparing the predicted failure rate, most of the studies found a predicted higher failure rate at 2ICS-MCL compared to lateral sites when using a 5cm needle, but none reported a statistically significant higher failure rate when using needle >7cm. Specifically, for decompressions performed at the 2ICS-MCL, the failure rate ranged between 2.6% and 93.0% with a 5cm needle. Reference Blenkinsop, Mossadegh, Ballard and Parker30,Reference Chanthawatthanarak, Munkong, Apiratwarakul, Ienghong and Bhudhisawasdi32,Reference Goh, Xu and Teo33,Reference Lamblin, Turc and Bylicki35,Reference Lesperance, Carroll, Aden, Young and Nunez36,Reference Sirikun and Wasinrat38 The highest failure rate was reported for a cohort of American patients with a body mass index (BMI) >3037 while the lowest rate was for a cohort of Thai patients. Reference Chanthawatthanarak, Munkong, Apiratwarakul, Ienghong and Bhudhisawasdi32 Using lateral decompression sites, the predicted failure rate ranged between 0% to 47%. Reference Blenkinsop, Mossadegh, Ballard and Parker30,Reference Chanthawatthanarak, Munkong, Apiratwarakul, Ienghong and Bhudhisawasdi32,Reference Goh, Xu and Teo33,Reference Lamblin, Turc and Bylicki35,Reference Lesperance, Carroll, Aden, Young and Nunez36,Reference Sirikun and Wasinrat38 When using needles >7cm, the predicted failure rate ranged between 0% and 5% for anterior decompression sites Reference Blenkinsop, Mossadegh, Ballard and Parker30,Reference Chang, Ross and Kiefer31,Reference Goh, Xu and Teo33,Reference Hecker, Hegenscheid and Völzke34,Reference Lesperance, Carroll, Aden, Young and Nunez36 and between 0% and 10% for the lateral decompression sites. Reference Blenkinsop, Mossadegh, Ballard and Parker30,Reference Chang, Ross and Kiefer31,Reference Lesperance, Carroll, Aden, Young and Nunez36
Only four studies reported on the potential risk of adverse events. Reference Blenkinsop, Mossadegh, Ballard and Parker30,Reference Chang, Ross and Kiefer31,Reference Lesperance, Carroll, Aden, Young and Nunez36,Reference Sirikun and Wasinrat38 The highest risk was always for the left puncture sites. Sirikun, et al report a 2.9% risk of injury to the mediastinum with a 5cm needle at 2ICS-MCL. Reference Sirikun and Wasinrat38 Chang, et al reported a risk of organ injury of 0% with a 5cm needle and up to 9% with an 8cm needle at 2ICS-MCL (P >.05). Reference Chang, Ross and Kiefer31 For the lateral approach, the risk of iatrogenic injury ranged between 0% and 1% with a 5cm needle and between 9.0% and 48.1% with an 8cm needle on the left side. Reference Blenkinsop, Mossadegh, Ballard and Parker30,Reference Chang, Ross and Kiefer31,Reference Lesperance, Carroll, Aden, Young and Nunez36,Reference Sirikun and Wasinrat38 The heart was the organ at highest risk for left lateral NCD. Reference Chang, Ross and Kiefer31,Reference Lesperance, Carroll, Aden, Young and Nunez36 The predicted risk of serious adverse events was statistically higher using lateral decompression sites compared to anterior sites in one study (P <.05). Reference Chang, Ross and Kiefer31
Level of Evidence
Overall, using the Harbour and Miller appraisal tool, the level of evidence assessment showed that most included studies were considered Grade 3 (Table 3).
Level of Evidence of Included Studies
Discussion
This systematic review of the recent literature relative to chest decompression in the out-of-hospital field highlights the low-grade evidence relative to different approaches such as NCD and FT to decompress a potential pneumothorax despite their wide-spread use. When NCD is the chosen approach, recent evidence showed that the failure rate can be as high as 93% with 5cm needle compared to 10% with longer needles (>7cm). While FT is a promising technique, data are limited at the moment, particularly relative to its success, impact on patient-important outcomes, and complication rates.
The most studied chest decompression technique remains NCD, Reference Aho, Thiels and El Khatib19–Reference Chen, Nadler, Schwartz, Tien, Cap and Glassberg21,Reference Dickson, Gleisberg and Aiken23,Reference Kaserer, Stein, Simmen, Spahn and Neuhaus26,Reference Weichenthal, Crane and Rond28,Reference Weichenthal, Owen, Stroh and Ramos29 while five studies reported on FT Reference Chesters, Davies and Wilson22–Reference High, Brywczynski and Guillamondegui25,Reference Peters, Ketelaars, van Wageningen, Biert and Hoogerwerf27 and three reported some data on CTP. Reference Chen, Nadler, Schwartz, Tien, Cap and Glassberg21,Reference High, Brywczynski and Guillamondegui25,Reference Kaserer, Stein, Simmen, Spahn and Neuhaus26 Both FT and CTP require a higher level of training and are more invasive than NCD, especially for alert and spontaneously breathing patients. On the other hand, FT is interesting because it is diagnostic as well as therapeutic. Reference Heavyside39 Establishing the diagnosis and monitoring its cardiovascular and respiratory impacts after chest decompression is critical when trying to stabilize a critically ill trauma patient. 40 The reported success rate of FT ranged between 9.7% to 32.0% but with heterogeneous definitions of success and a large number of patients in traumatic cardiac arrest. The success rate was associated with the patient’s clinical improvement following the procedure and not the capacity to access the pleural space. The most significant reported adverse event was a liver injury. Reference Hannon, St Clair and Smith24 Studies published before this systematic review have reported a rate of clinical improvement as high as 100% Reference Deakin, Davies and Wilson41 following the procedure and a relatively low rate of complications Reference Mistry, Bleetman and Roberts12,Reference Massarutti, Trillò and Berlot13,Reference Deakin, Davies and Wilson41,Reference Aylwin, Brohi, Davies and Walsh42 in studies with small sample sizes and high risk of bias.
When NCD is used, the risk of severe adverse events seemed higher for lateral decompression sites, particularly for the left lateral approach with the proximity of the heart, Reference Blenkinsop, Mossadegh, Ballard and Parker30,Reference Chang, Ross and Kiefer31,Reference Lesperance, Carroll, Aden, Young and Nunez36,Reference Sirikun and Wasinrat38 but only one study reported a statistically significant predicted increase risk of iatrogenic injuries compared to the standard anterior approach. Reference Chang, Ross and Kiefer31 The risk of adverse events is an important consideration to choose the optimal decompression technique. However, as highlighted by two included studies, the predicted success and complication rates based on anatomic measures are different from those obtained on the field. Reference Chang, Ross and Kiefer31,Reference Lesperance, Carroll, Aden, Young and Nunez36 Therefore, the risk of serious adverse event might be over-estimated for imaging studies. Reference Chang, Ross and Kiefer31,Reference Lesperance, Carroll, Aden, Young and Nunez36 Two studies showed that a large proportion of the needle tips on arrival to the hospital were outside the pleura, reflecting either a high placement failure or a high catheter displacement rate after NCD. Reference Axtman, Stewart and Robbins20,Reference Lesperance, Carroll, Aden, Young and Nunez36 No included study was powered to detect a statistically significant difference in complication rates between the interventions and no studies used a standardized and systematic approach to look for immediate complications of chest decompression. Therefore, the exact safety profile of NCD remains unclear. Furthermore, four studies reported that between 18% and 42% of the patients did not present any signs of pneumothorax on the imaging performed in the ED. Establishing the correct diagnosis is critical and the lack of strong diagnostic tool has an impact on the perceived efficacy and safety of the different chest decompression techniques. Accurate diagnosis is also important to avoid harm associated with unnecessary procedures such as chest decompression. These data raise doubts regarding the historical teaching that tension pneumothorax should be diagnosed clinically. Implementation of prehospital ultrasound can be an interesting diagnostic area to assist clinician decision making. Reference Hew and Tay43,Reference Ketelaars, Reijnders, van Geffen, Scheffer and Hoogerwerf44
The lateral CWT at the 4-5ICS-mid-axillary line (MAL) or the 4-5ICS-anterior axillary line (AAL) was often thinner than the anterior 2ICS-MCL. Presented CWT measures of the studies included in this review were similar to those described in the recent systematic review and meta-analysis conducted by Clemency, et al and Laan, et al. Reference Clemency, Tanski, Rosenberg, May, Consiglio and Lindstrom14,Reference Laan, Vu and Thiels15 Using studies published from 2005 through 2014, the two reviews found a mean CWT of 42.50mm (SD = 13.80) and 42.79mm (95% CI, 38.78-46.81) compared to 39.85mm (95% CI, 28.70-51.00) and 34.33mm (95% CI, 28.20-40.47) at the 4-5ICS-MAL or the 4-5ICS-AAL, respectively. Reference Clemency, Tanski, Rosenberg, May, Consiglio and Lindstrom14,Reference Laan, Vu and Thiels15 Those two systematic reviews published in 2015 and 2016 reported that a catheter longer than 6.44cm would be required to decompress 95% of patient’s anterior chest and that lateral NCD have a higher predicted rate of success for decompression with any sort of needle due to the thinner chest wall at this location. Reference Clemency, Tanski, Rosenberg, May, Consiglio and Lindstrom14,Reference Laan, Vu and Thiels15 The clinical significance of a thinner chest wall is limited since the expected failure rate is similar at both sites when using a sufficiently long needle (>7cm). This seems to be the case regardless of patient sex. Reference Hecker, Hegenscheid and Völzke34 The thinner lateral CWT could be meaningful in scenarios such as patients with an unusually large CWT due to a high BMI as there is a correlation between these two variables. Reference Aho, Thiels and El Khatib19,Reference Chang, Ross and Kiefer31,Reference Goh, Xu and Teo33,Reference Powers, Clancy, Adams, West, Kotwall and Hope37,Reference Sirikun and Wasinrat38 Lateral decompression approaches may be clinically useful in situations where anterior placement is impossible due to injuries or physical constraint such as bulletproof vest in an active shooting situation. The optimal needle gauge was not studied explicitly in any of the included studies, so no data are available to support the use of a bigger or smaller gauge than the standard 14-gauge needle. The absence of data is a problem because the needle gauge and length may be directly related to its capacity to decompress a tension pneumothorax. Reference Leatherman, Fluke and McEvoy45
Limitations
The methodological quality of the included studies was limited. No randomized control trial has been recently published on the subject and so, the study designs are weak according to the hierarchy of evidence of Miller and Harbour. Only two of the presented studies carried out a power analysis. Reference Chanthawatthanarak, Munkong, Apiratwarakul, Ienghong and Bhudhisawasdi32,Reference Sirikun and Wasinrat38 Furthermore, the criteria for a successful procedure used were heterogeneous and often subjective. The level of training of the clinicians was also heterogeneous, which can potentially impact the external validity. Additionally, the chest decompression procedures were conducted without formal proof of the presence of the disease, meaning that the absence of treatment effect, in some situations, might have been due to the absence of the disease in the first place. Moreover, some of the cohort studies did not control for confounders, such as associated injuries, and were prone to patient’s selection bias. The patient outcomes and adverse events presented were not standardized and were heterogeneous. Finally, despite the author’s best effort to include all relevant studies on the topic, selection bias cannot be completely excluded.
Conclusions
Based on the recent evidence, for optimal success, prehospital NCD should be performed using a needle >7cm length despite an associated theoretical higher risk of iatrogenic injuries. There is a paucity of evidence to support primarily the lateral approach compared to the anterior approach when an 8cm needle is used as the reported and predicted decompression success rates are similar. While FT is an interesting diagnostic and therapeutic approach with a reported clinically beneficial success rate ranging between 9.7% to 32.0%, results relative to patient-important outcomes and adverse events associated with FT are inconsistently reported in the literature. High-quality studies are required to further inform clinicians about the most beneficial chest decompression technique applicable in the out-of-hospital field.
Conflicts of interest
none
Author Contributions
MRF had the original idea for this study. MRF conceived the study’s design and protocol with support, input, and oversight from SN, TA, and EM. MRF and SN elaborated the original database search strategy. MRF performed the study selection and data extraction with oversight from EM. MRF wrote the manuscript first draft. All authors contributed substantially to the manuscript revision and they all approved the final submitted version. MRF is accountable for all aspects of this study.
Supplementary Materials
To view supplementary material for this article, please visit https://doi.org/10.1017/S1049023X21000509
