Preoperative Breathing Exercise Training and Postoperative Delirium After Robotic Radical Prostatectomy

Robot-assisted radical prostatectomy (RARP) is a commonly performed minimally invasive surgical procedure for the treatment of prostate cancer. In this population, perioperative factors including advanced age, comorbidities, general anesthesia, pneumoperitoneum, prolonged surgical and anesthetic duration, and steep Trendelenburg positioning may contribute to postoperative respiratory changes and postoperative delirium. Postoperative delirium is characterized by an acute and fluctuating disturbance in attention, awareness, and cognitive function and may be associated with increased complications, prolonged hospitalization, and greater care requirements.

Preoperative breathing exercise training is a noninvasive, nonpharmacological, and low-cost intervention intended to encourage slow, controlled, and deep breathing. Improving patients' familiarity and adherence to breathing exercises before surgery may facilitate postoperative respiratory exercises and may contribute to preservation of oxygenation and reduction of postoperative respiratory complications. These effects may also influence clinical factors associated with postoperative delirium. Evidence regarding the relationship between preoperative breathing exercise training and postoperative delirium specifically in patients undergoing RARP remains limited.

This study is designed as a single-center, prospective, two-arm controlled pilot study and will include 50 male patients aged 40 years or older who are scheduled for elective RARP. Twenty-five patients will be included in the preoperative breathing exercise training group and 25 patients in the control group.

Patients in the intervention group will receive standardized deep breathing exercise training during the preoperative outpatient evaluation, generally approximately one week before surgery. Patients will be instructed to sit in an upright or semi-upright position, relax their shoulders, inhale slowly and deeply through the nose, hold their breath for approximately 2-3 seconds, and then exhale slowly through the mouth. Each session will consist of 10 deep breaths. Patients will be asked to perform the exercises three times daily until the day of surgery. Adherence will be recorded using a home breathing exercise follow-up form and reviewed on the morning of surgery. Patients in the control group will receive routine preoperative information without additional structured breathing exercise training.

Routine perioperative anesthesia and surgical management will not be modified because of study participation. Intraoperative variables including anesthesia and surgical duration, pneumoperitoneum duration, Trendelenburg duration when available, oxygen saturation, end-tidal carbon dioxide, intraoperative hypotension, vasopressor or inotrope requirement, estimated blood loss, fluid administration, transfusion, and perioperative complications will be recorded from routine clinical and anesthesia records.

Postoperative delirium will be evaluated during the first 48 hours after surgery. The 4AT will be administered at approximately 24 and 48 hours after surgery, and the Nursing Delirium Screening Scale (Nu-DESC) will be used during the first 12 postoperative hours and again during the 24-48-hour postoperative period. A 4AT score of 4 or greater and/or a Nu-DESC score of 2 or greater will be considered indicative of delirium for the purposes of the study.

Secondary clinical assessments will include 4AT and Nu-DESC scores, postoperative peripheral oxygen saturation, supplemental oxygen requirement, postoperative hypoxemia, clinically documented pulmonary complications or atelectasis, postoperative pain, nausea and vomiting, additional analgesic requirement, intensive care requirement, and length of hospital stay.

No additional medication, invasive procedure, blood sampling, laboratory testing, imaging, or medical device assessment will be performed solely for research purposes. All anesthesia, surgery, treatment, and postoperative care will follow routine clinical practice.

• Preoperative Deep Breathing Exercise Training (Behavioral): Participants will receive standardized, device-free deep breathing exercise training during the preoperative period. In an upright or semi-upright position, participants will be instructed to relax their shoulders, inhale slowly and deeply through the nose, hold their breath for approximately 2-3 seconds, and then exhale slowly through the mouth. Each session will consist of 10 deep breaths. Participants will be asked to perform three sessions per day from the time of training until surgery. Exercise adherence will be documented using a home follow-up form and reviewed on the morning of surgery.

Primary outcomes

• Number of Participants With Postoperative Delirium Within 48 Hours After Surgery [From the end of surgery through 48 hours postoperatively]: Postoperative delirium will be defined as a 4AT score ≥4 and/or a Nursing Delirium Screening Scale (Nu-DESC) score ≥2 at any prespecified assessment during the first 48 hours after surgery. The 4AT will be assessed at 24 and 48 hours postoperatively, and the Nu-DESC will be assessed during the first 12 postoperative hours and again during the 24-48-hour postoperative period. The outcome will be reported as the number and proportion of participants who develop postoperative delirium.

Secondary outcomes

• 4AT Delirium Screening Score [At 24 and 48 hours postoperatively]: The 4AT will be used to assess postoperative delirium-related symptoms. The total score ranges from 0 to 12, with higher scores indicating greater likelihood of delirium. A score ≥4 indicates a high likelihood of delirium. Scores will be recorded at 24 and 48 hours after surgery.
• Nursing Delirium Screening Scale (Nu-DESC) Score [During the first 12 postoperative hours and during the 24-48-hour postoperative period]: The Nu-DESC will be used to assess postoperative delirium-related symptoms. The total score ranges from 0 to 10, with higher scores indicating more delirium-related symptoms. A score ≥2 indicates a high likelihood of delirium.
• Peripheral Oxygen Saturation (SpO₂) at Predefined Postoperative Time Points [PACU/early postoperative period and at 6, 24, and 48 hours postoperatively]: Peripheral oxygen saturation (SpO₂), expressed as a percentage, will be recorded from routine clinical monitoring at predefined postoperative time points.
• Number of Participants Requiring Supplemental Oxygen Postoperatively [From the PACU/early postoperative period through 48 hours postoperatively]: The need for supplemental oxygen will be recorded at predefined postoperative assessments. The number and proportion of participants requiring supplemental oxygen will be compared between study groups.
• Postoperative Pain Score on the NRS/VAS [PACU/early postoperative period and at 6, 24, and 48 hours postoperatively]: Postoperative pain intensity will be assessed using a 0-10 Numerical Rating Scale/Visual Analog Scale (NRS/VAS), where 0 indicates no pain and 10 indicates the worst imaginable pain. Higher scores indicate greater pain intensity.

Sex: Male, ages: 40 Years to any

Inclusion Criteria:

* Male patients aged 40 years or older.
* Scheduled to undergo elective robot-assisted radical prostatectomy (RARP) at -Akdeniz University Hospital.
* Able to communicate and suitable for preoperative and postoperative -cognitive/delirium assessment using the 4AT and Nu-DESC.
* Able and willing to provide written informed consent.
* Availability of clinical follow-up data during the first 48 postoperative hours.

Exclusion Criteria:

* Refusal to participate or withdrawal of informed consent.
* History of delirium, severe dementia, severe cognitive impairment, or an active neurological disorder that would interfere with delirium assessment.
* Active psychosis, severe psychiatric disease, or use of psychoactive medication that could substantially affect cognitive assessment.
* Level of consciousness not allowing assessment, or severe hearing or speech impairment preventing adequate communication.
* Emergency surgery or failure to complete the planned procedure as robot-assisted radical prostatectomy.
* Inability to complete the postoperative 4AT and/or Nu-DESC assessments or substantial missing data affecting the primary analysis.
* Inability to tolerate the breathing exercises or insufficient home exercise adherence/follow-up data for the planned analysis.

• Gaudreau JD, Gagnon P, Harel F, Tremblay A, Roy MA. Fast, systematic, and continuous delirium assessment in hospitalized patients: the nursing delirium screening scale. J Pain Symptom Manage. 2005 Apr;29(4):368-75. doi: 10.1016/j.jpainsymman.2004.07.009. PMID 15857740
• Bellelli G, Morandi A, Davis DH, Mazzola P, Turco R, Gentile S, Ryan T, Cash H, Guerini F, Torpilliesi T, Del Santo F, Trabucchi M, Annoni G, MacLullich AM. Validation of the 4AT, a new instrument for rapid delirium screening: a study in 234 hospitalised older people. Age Ageing. 2014 Jul;43(4):496-502. doi: 10.1093/ageing/afu021. Epub 2014 Mar 2. PMID 24590568
• Inouye SK, Westendorp RG, Saczynski JS. Delirium in elderly people. Lancet. 2014 Mar 8;383(9920):911-22. doi: 10.1016/S0140-6736(13)60688-1. Epub 2013 Aug 28. PMID 23992774