#205 Safeguarding Patients: Navigating the Dangers of Prone Positioning
Jun 04, 2024Episode 205
Anesthesia Patient Safety Foundation
Ever wondered about the underappredicated dangers of prone positioning during surgery? Join me, Alli Bechtel, as we navigate the complexities and risks of managing patients in this critical position. From pressure-related injuries to the eyes, nose, and shoulders, to nerve ischemia and shoulder dislocations, we'll cover it all. In this episode, inspired by Taizoon Dhoon and colleagues' article "The Underappreciated Dangers of the Prone Position," we’ll dissect the physiologic changes that can lead to severe complications if not properly managed. This is an essential listen for anyone involved in perioperative care.
Gain practical insights into protecting vulnerable areas and mitigating risks associated with prone positioning. We’ll explore common pitfalls and offer strategies to improve patient safety, including proper limb positioning and adequate padding. Learn about the specific nerves at risk and the physiologic changes affecting ocular health and overall patient well-being. Grab a pen and paper for this detailed discussion on how to safeguard patients and ensure optimal outcomes in the operating room.
Ever wondered about the underappredicated dangers of prone positioning during surgery? Join me, Alli Bechtel, as we navigate the complexities and risks of managing patients in this critical position. From pressure-related injuries to the eyes, nose, and shoulders, to nerve ischemia and shoulder dislocations, we'll cover it all. In this episode, inspired by Taizoon Dhoon and colleagues' article "The Underappreciated Dangers of the Prone Position," we’ll dissect the physiologic changes that can lead to severe complications if not properly managed. This is an essential listen for anyone involved in perioperative care.
Gain practical insights into protecting vulnerable areas and mitigating risks associated with prone positioning. We’ll explore common pitfalls and offer strategies to improve patient safety, including proper limb positioning and adequate padding. Learn about the specific nerves at risk and the physiologic changes affecting ocular health and overall patient well-being. Grab a pen and paper for this detailed discussion on how to safeguard patients and ensure optimal outcomes in the operating room.
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Speaker 2:
Hello and welcome back to the Anesthesia Patient Safety Podcast. My name is Allie Bechtel and I'm your host. Thank you for joining us for another show. When was the last time that you were providing anesthesia care for a patient in the prone position? Perhaps you positioned a patient prone for a surgical procedure earlier today, before listening to this episode. Prone positioning is required for many different surgical procedures and, depending on your practice, may be common in the operating rooms and procedural suites where you work. This is an important time to remain vigilant, since patients are at risk for positioning injuries as well as significant physiologic changes while in the prone position. Stay tuned for an important discussion as we review the potential injuries, highlight the physiologic changes and provide practical considerations when positioning and managing patients in the prone position.
Speaker 2:
Before we dive into the episode today, we'd like to recognize GE Healthcare, a major corporate supporter of APSF. Ge Healthcare has generously provided unrestricted support to further our vision that no one shall be harmed by anesthesia care. Thank you, ge Healthcare. We wouldn't be able to do all that we do without you. Be able to do all that we do without you. Our featured article today is an article between issues. It is the Underappreciated Dangers of the Prone Position published on 30th April 2024, and written by Taizun Dun and colleagues. To follow along with us, head over to apsforg and click on the newsletter heading. The second one down is articles between issues and from here scroll down until you get to our featured article today. I will include a link in the show notes as well.
Speaker 2:
Our case is just about to get underway. The patient is under general anesthesia, the endotracheal tube is in place and we have just positioned our patient prone. What is the patient at risk for due to being in the prone position? Let's start by reviewing pressure-related injuries. These are injuries from direct pressure with excessive strain on areas of the body that are not used to this sustained stress or load.
Speaker 2:
The resulting injury may be from the direct pressure load or indirect damage due to decreased arterial blood flow or obstructed venous outflow, leading to ischemia or edema. Other types of pressure-related injuries occur due to friction from slight body movements, leading to skin damage or blistering on the head and face or extremities. Vulnerable areas include the eyes, nose, cheekbones and cheeks, forehead, chest, arms, breasts, genitalia and pelvis, including the superior iliac spines, knees and feet. Have you ever seen a shoulder dislocation from repositioning prone? This may occur due to pressure in the prone position combined with abduction and external rotation, leading to anterior shoulder dislocation Trauma, and elderly patients are at higher risk. Patients may also develop postoperative shoulder joint pain related to this intraoperative position. It is vital to protect these vulnerable areas to help reduce the risk of developing pressure sores or nerve injuries during longer surgical procedures.
Speaker 2:
And speaking of nerve, injuries this is definitely something that we want to avoid to help keep our patients safe during anesthesia care in the prone position. Nerve ischemia may occur from excessive stretching or direct pressure leading to microvascular compression. Risk factors for nerve injuries include improper positioning of limbs, long cases, inadequate padding, anatomic variations, hypotension, anatomic variations, hypotension, diabetes, hypothermia, malnutrition. Nerves that are at high risk in the prone position include the following the superior orbital nerves, lingual and buccal nerves, often strained due to unintentional jaw retraction caused by tension between master muscles. The phrenic nerve and recurrent laryngeal nerve, potentially impacted by overextension or rotation of the neck, the brachial plexus, the ulnar nerve and the lateral cutaneous nerve of the thigh Next up. Let's review the physiologic changes that occur in the prone position. Go ahead and refresh your cup of coffee and grab a pen and paper. Here we go. Let's start with changes that can impact the eyes. Patients in the prone position are at risk for ocular injuries due to direct or indirect pressure. Direct pressure on the eye may be due to improper positioning and this can cause ischemia. In addition, prone positioning may lead to decreased venous outflow and increased intraocular pressure, with the resultant decreased intraocular perfusion. Intraocular perfusion may be further compromised in the prone position by increased intra-abdominal pressure, decreased preload and decreased mean arterial blood pressure, putting patients at increased risk for optic nerve ischemia, ischemic optic neuropathy and central retinal artery occlusion. Risk factors for postoperative visual loss following prone position include increased surgical duration, large blood loss and administration of large volumes of crystalloid IV fluid. Patients with closed-angle glaucoma are at risk for blindness from prone positioning, even during short procedures if there is reduced aqueous humor outflow, leading to increased intraocular pressure, reduced blood flow and optic nerve injury. Finally, it is important to remain vigilant for complete eye closure, since there is decreased tear production under general anesthesia and patients are at risk for corneal injury and irritation.
Speaker 2:
We are going to stay at the patient's head and review head and neck changes in the prone position. This position may increase intracranial pressure, combined with decreased cerebral blood flow, leading to intracranial vessel distension. You must remain vigilant, especially for patients with intracranial space-occupying lesions. Careful attention to neutral neck positioning is vital, since patients are at risk for vascular injury in the head, neck and chest. Over-rotation of the neck may decrease carotid or vertebral artery blood flow and decrease venous drainage, while in the prone position, hydrostatic pressure increases, which may lead to dependent edema. This combination puts patients at risk for stroke, tongue swelling, tracheal compression and oropharyngeal and glottic edema. You may notice that after repositioning from prone to supine, your patients developed facial, scleral and lingual edema. These patients may require a delayed extubation to allow time for the edema to resolve. This is not the time to let down your guard, since patients who used to have a normal airway and were straightforward to intubate with a good view prior to prone positioning may become impossible to re-intubate or ventilate.
Speaker 2:
Moving down the body, we made it to the lungs and the pulmonary system. So go ahead and take a deep breath. There is some good news here, since pulmonary function may improve in the prone position due to the following Improvement in functional residual capacity, improved ventilation, perfusion matching and increased arterial oxygen tension. Chest wall and lung compliance are not affected in this position, but you may see increases in intrathoracic pressure and peak airway pressure. There is a risk for increased pulmonary vascular resistance in the prone position. It is important to identify patients with obesity and sleep-related breathing disorders who may not tolerate prone positioning. Consider obtaining a preoperative echocardiogram to evaluate systolic and diastolic function and identify patients with decreased heart function who may be at high risk for perioperative cardiac complications. And this brings us nicely to the next category cardiovascular system.
Speaker 2:
This review is sure to get your heart pumping, because we will be talking about changes in preload, afterload and contractility. The prone position can cause the cardiac index to decrease by 24% on average, and this is mostly from a decrease in stroke volume. Tachycardia and increased peripheral vascular resistance may also occur following repositioning prone. In addition, patients with a history of heart failure, pulmonary hypertension or restrictive or obstructive lung disease who become acidotic may develop increased pulmonary vascular resistance and right ventricular strain, leading to significant hemodynamic instability. Constant vigilance is required. Hemodynamic instability Constant vigilance is required.
Speaker 2:
Here are some other changes in the cardiovascular system while patients are in the prone position Increased risk for mediastinal compression, with the right ventricle compressed against the sternum. Increased intrathoracic pressure, combined with decreases in IVC filling, atrial compliance and left ventricular compliance, leading to decreased cardiac output. Local compression of the anterior chest wall or abdomen, leading to decreased right ventricular function or IVC preload. And we can't forget about the effects of volatile anesthetics and propofol on the cardiovascular system as well, since the combination can lead to hemodynamic instability. These effects include decreased systemic vascular resistance, changes in heart rate and decreased cardiac contractility from myocardial suppression. Specially designed bolsters to provide support and padding for chest and abdominal positioning can help to minimize the physiologic changes.
Speaker 2:
Patients at higher risk from prone positioning include those with scoliosis, pectus excavatum or recent cardiothoracic surgery. Who is at risk for cardiovascular collapse in the prone position? Risk factors include the following Massive blood loss, hypothermia, fluid shifts, cardiac comorbidities, venous air embolism, anatomic deformity such as thoracic lordosis or pectus excavatum. The authors remind us that patients with right ventricular dysfunction, pulmonary hypertension, patients who are preload dependent and patients who are sensitive to increases in pulmonary vascular resistance are at risk for cardiovascular collapse in the prone position. It may be necessary to have a conversation with the surgeon and patient to discuss the risks from prolonged prone positioning, which may include myocardial infarction and cardiac arrest, and determine how to proceed safely.
Speaker 2:
Once again, we cannot let down our guard. There are additional physiologic changes that occur in the prone position, especially in obese patients, due to abdominal compression, leading to decreased arterial inflow and venous outflow to the visceral organs. There are reports of postoperative pancreatitis and hepatic ischemia following surgery in the prone position. Other complications from increased intra-abdominal venous compression include increased venous fleeting and increased risk for postoperative thrombotic complications. It is important to minimize direct pressure on the abdomen and specially designed bolsters or beds can help. We also need to pay careful attention to the extremities in the prone position, especially for longer procedures and, depending on the patient's position, bending the hips and knees can decrease arterial blood flow and put patients at risk for limb compartment syndrome, rhabdomyolysis and the resultant renal failure.
Speaker 2:
The authors have highlighted quite a few threats to patient safety during anesthesia care in the prone position. We hope that you tune in next week because we are going to review some important clinical recommendations to help keep your patients safe. In the meantime, we hope that you will check out episode number 16 of this podcast, all about postoperative vision loss from ischemic optic neuropathy, which is a complication following spine fusion surgery in the prone position. You can also check out the October 2020 APSF newsletter article Postoperative Vision Loss by Lori Lee. I will include a link in the show notes as well. If you have any questions or comments from today's show, please email us at podcast at APSForg. Please keep in mind that the information in this show is provided for informational purposes only and does not constitute medical or legal advice. We hope that you will visit APSForg for detailed information and check out the show notes to links to all the topics we discussed today.
Speaker 2:
The APSF newsletter is the official journal of the Anesthesia Patient Safety Foundation. Readers include anesthesia professionals, perioperative providers, key industry representatives and risk managers. It is free of charge and available in a digital format, with a focus on anesthesia-related perioperative patient safety issues. The June newsletter has just been published, but the deadline for the October 2024 APSF newsletter is right around the corner, on July 10th. Check out the guide for authors over at APSForg for more information, and I will include a link in the show notes as well. Who knows, you could be the next APSF newsletter author and we might be featuring your article on a future anesthesia patient safety podcast. So what are you waiting for? Go ahead and submit your article today. Until next time, stay vigilant so that no one shall be harmed by anesthesia care.