Risk of Harm in Needle Decompression for Tension Pneumothorax.

INTRODUCTION: Tension pneumothorax (TPX) is the third most common cause of preventable death in trauma. Needle decompression at the fifth intercostal space at anterior axillary line (5th ICS AAL) is recommended by Tactical Combat Casualty Care (TCCC) with an 83-mm needle catheter unit (NCU). We sought to determine the risk of cardiac injury at this site. METHODS: Institutional data sets from two trauma centers were queried for 200 patients with CT chest. Inclusion criteria include body mass index of =30 and age 18-40 years. Measurements were taken at 2nd ICS mid clavicular line (MCL), 5th ICS AAL and distance from the skin to pericardium at 5th ICS AAL. Groups were compared using Mann-Whitney U and chi-squared tests. RESULTS: The median age was 27 years with median BMI of 23.8 kg/m2. The cohort was 69.5% male. Mean chest wall thickness at 2nd ICS MCL was 38-mm (interquartile range (IQR) 32-45). At 5th ICS AAL, the median chest wall thickness was 30-mm (IQR 21-40) and the distance from skin to pericardium was 66-mm (IQR 54-79). CONCLUSION: The distance from skin to pericardium for 75% of patients falls within the length of the recommended needle catheter unit (83-mm). The current TCCC recommendation to "hub" the 83mm needle catheter unit has potential risk of cardiac injury.

Risk of Harm Associated With Using Rapid Sequence Induction Intubation and Positive Pressure Ventilation in Patients With Hemorrhagic Shock.

Based on limited published evidence, physiological principles, clinical experience, and expertise, the author group has developed a consensus statement on the potential for iatrogenic harm with rapid sequence induction (RSI) intubation and positive-pressure ventilation (PPV) on patients in hemorrhagic shock. "In hemorrhagic shock, or any low flow (central hypovolemic) state, it should be noted that RSI and PPV are likely to cause iatrogenic harm by decreasing cardiac output." The use of RSI and PPV leads to an increased burden of shock due to a decreased cardiac output (CO)2 which is one of the primary determinants of oxygen delivery (DO2). The diminishing DO2 creates a state of systemic hypoxia, the severity of which will determine the magnitude of the shock (shock dose) and a growing deficit of oxygen, referred to as oxygen debt. Rapid accumulation of critical levels of oxygen debt results in coagulopathy and organ dysfunction and failure. Spontaneous respiration induced negative intrathoracic pressure (ITP) provides the pressure differential driving venous return. PPV subsequently increases ITP and thus right atrial pressure. The loss in pressure differential directly decreases CO and DO2 with a resultant increase in systemic hypoxia. If RSI and PPV are deemed necessary, prior or parallel resuscitation with blood products is required to mitigate post intervention reduction of DO2 and the potential for inducing cardiac arrest in the critically shocked patient.

Getting "SMART" on Shock Treatment: An Evidence-Based Mnemonic Acronym for the Initial Management of Hemorrhage in Trauma.

Treating hemorrhagic shock is challenging, the pathology is complex, and time is critical. Treatment requires resources in mental bandwidth (i.e., focused attention), drugs and blood products, equipment, and personnel. Providers must focus on treatment options in order of priority while also maintaining a dynamic assessment of the patient's response to treatment and considering potential differential diagnoses. In this process, the cognitive load is substantial. To avoid errors of clinical reasoning and practical errors of commission, omission, or becoming fixated, it is necessary to use evidence-based treatment recommendations that are concise, in priority order, and easily recalled. This is particularly the case in the austere, remote, or tactical environment. A simple mnemonic acronym, SMART, is presented in this article. It is a clinical heuristic that can be used as an aide-mémoire during the initial phases of resuscitation of the trauma patient with hemorrhagic shock: Start the clock and Stop the bleeding; Maintain perfusion; Administer antifibrinolytics; Retain heat; Titrate blood products and calcium; Think of alternative causes of shock.

Airway and ventilation management strategies for hemorrhagic shock. To tube, or not to tube, that is the question!

Many standard trauma management guidelines advocate the early use of endotracheal intubation (ETI) and positive pressure ventilation as key treatment interventions in hemorrhagic shock. The evidence for using these airway and ventilation strategies to manage a circulation problem is unclear. The potentially harmful effects of drug-assisted intubation and positive pressure ventilation include reduced cardiac output, apnea, hypoxia, hypocapnea (due to inadvertent hyperventilation), and unnecessarily prolonged on-scene times. Conversely, the beneficial effects of spontaneous negative pressure ventilation on cardiac output are well described. Few studies, however, have attempted to explore the potential advantages of a strategy of delayed intubation and ventilation (together with a policy of aggressive volume replacement) in shocked trauma patients. Given the lack of evidence, the decision making around how, when, and where to subject shocked trauma patients to intubation and positive pressure ventilation remains complex. If providers choose to delay intubation, they must have the appropriate skills to safely manage the airway and recognize the need for subsequent intervention. If they decide to perform intubation and positive pressure ventilation, they must understand the potential risks and how best to minimize them. We suggest that for patients with hemorrhagic shock who do not have a compromised airway and who are able to maintain adequate oxygen saturation (or mentation if monitoring is unreliable), a strategy of delayed intubation should be strongly encouraged. LEVEL OF EVIDENCE: Review article, level IV.