Space Surgery: Challenges

The following post references this article: 

• Burke, T.F., Suarez, S., Sessler, D.I., Senay, A., Yusufali, T., Masaki, C., Guha, M., Rogo, D., Jani, P., Nelson, B.D. and Rogo, K. (2017), Safety and Feasibility of a Ketamine Package to Support Emergency and Essential Surgery in Kenya when No Anesthetist is Available: An Analysis of 1216 Consecutive Operative Procedures. World J Surg, 41: 2990-2997 1. 

Who gives the anesthetic on Mars?

Most discussion of space surgery revolves around the surgeon. Robotic platforms, microgravity fluid containment, restraint systems, and instrument miniaturization dominate the literature, and a recent review in the British Journal of Surgery lays out a nice architecture for a compact, multifunctional, AI-supported surgical robot for exploration missions.[1] But the same review flags a quieter constraint that no amount of robotics will engineer away: provision of anesthesia. A crew of four to six on a three-year Mars transit will likely not include both a board-certified surgeon AND anesthesiologist. It might not include either. This is not a new problem, and we can learn a lot from existing literature.

The Kenya experience

Burke and colleagues published an analysis of 1216 consecutive operative procedures across fifteen Kenyan facilities in which anesthesia was delivered by non-anesthetist mid-level providers. This included clinical officers, medical officers, and nurses who were trained to use a standardized package called Every Second Matters for Emergency and Essential Surgery-Ketamine (ESM-Ketamine).

• A 5-day hands-on training course

• A physical kit containing ketamine, pulse oximeter, blood pressure device, oxygen source and facemask, suction, bag-valve mask, and a short list of rescue drugs

• Wall charts in the operating theater

• A pocket-sized checklist modeled on the WHO Safe Surgery Checklist, specifying confirmation of ketamine concentration, equipment function check, IV placement, pre-oxygenation, monitor placement, and titrated dosing

  • Dosing was fixed and simple: 2 mg/kg IV over 30–60 seconds for induction in emergency/essential surgery, then 1–2 mg/kg every 10–15 minutes; 1 mg/kg for procedural sedation with 0.25–1 mg/kg as needed. The rescue formulary was limited and consisted of four drugs: diazepam for agitation or hallucinations, promethazine or prochlorperazine for nausea, atropine for hypersalivation, and hydralazine for severe hypertension of pregnancy. The card carried an explicit instruction that no other medications were permitted in the pathway.

The results: 

• The median Ketamine dose was 2.1 mg/kg

• Brief (<30 s) desaturation below 92% in 3%

• Prolonged (>30 s) desaturation in 0.6%

• Hallucinations or agitation requiring diazepam in 13%

• Hypersalivation requiring atropine in 9%. 

• No ketamine-related deaths or disabilities. 

Importantly, 22% of cases were Lancet Commission "bellwether" procedures that included 150 emergency cesarean sections, 112 emergency laparotomies, and 7 open fracture repairs.

Why this maps onto exploration-class spaceflight

1. No expert is available, and none is coming. ESM-Ketamine was activated when no anesthetist was available and transfer was impossible or dangerous. On a Mars transit, communications delay reaches up to 40 minutes round-trip and evacuation to Earth is not an option.[2] Both settings share the same operational logic: the choice is not between a protocolized non-expert and an expert; it is between a protocolized non-expert and nothing.

2. Short, high-stakes, physically simple procedures dominate. The Kenyan caseload was cesarean sections, laparotomies, abscess drainage, wound debridement, fracture and dislocation reduction, foreign body removal. Space medicine risk modeling identifies a comparable slate of survivable, mission-critical events that include trauma, penetrating injury, and surgical emergencies that cannot be temporized for a prolonged trip home.[3]

3. Ketamine is nearly ideal for a spacecraft. Ketamine is cheap, thermally robust, available in concentrated small-volume vials, effective by IV, IM, intranasal, oral, sublingual, and rectal routes, and preserves spontaneous ventilation and airway reflexes at titrated doses.[4][5] Cardiovascular function is generally maintained, which matters when hemorrhage is on the differential. Militaries reached the same conclusion independently: ketamine became a first-line battlefield analgesic under Tactical Combat Casualty Care guidelines, with use rising from 0.4% to 11.3% of combat casualties over five years of Operation Enduring Freedom.[6] Furthermore, there is a second indication for the same molecule in the same kit: a 2025 review in Aerospace Medicine and Human Performance argues for stocking ketamine on exploration missions for acute suicidality, a genuinely plausible behavioral emergency on a multi-year isolated mission.[7] Mass and volume are the hardest currency in spaceflight; a single vial that covers procedural anesthesia, severe pain, and a psychiatric emergency is exactly the kind of multi-use payload exploration medicine needs.

The single most instructive finding in the Kenyan data is the failure analysis. Of the seven prolonged desaturations, two were airway obstruction and four were protocol violations (e.g., omitted pre-oxygenation, double the permitted diazepam dose, ketamine pushed too fast). After an audit of the first 72 cases and a mandatory in-service review of checklist adherence, desaturations became less common. The adverse events were not really drug events. They were process events, and they were fixable by feedback. This is congruent with what space medicine simulation research already shows. In a study of 16 three-person crews managing medical emergencies in a spacecraft simulator, crews with real-time flight surgeon support performed better clinically and technically, completed more checklist tasks, and reported lower cognitive load. This lead the authors to conclude that medical checklists are necessary but not sufficient for autonomous crew performance.[8] Kenya experience and simulations demonstrate the same lesson: the protocol is the foundation, but audit, feedback, and some form of expert backstop are what keep it safe.

Where the analogy breaks down

• Microgravity and partial gravity physiology are not modeled. Cephalad fluid shifts, cardiovascular deconditioning, and spaceflight-associated neuro-ocular syndrome mean an astronaut is not a physiologically normal 28-year-old Kenyan patient. Ketamine's sympathomimetic profile and its effects on intracranial and intraocular pressure in microgravity or lowered gravity (e.g., Moon, Mars) deserve specific scrutiny in a population with suspected elevated intracranial pressure.[2]

• Airway rescue is the rate-limiter. Both the Wilderness Medical Society and the Kenyan authors emphasize that ketamine at dissociative doses demands a provider equipped and able to manage airway obstruction, laryngospasm, and hypersalivation. Two of the seven Kenyan serious adverse events were airway events relieved by repositioning and bag-mask ventilation. In microgravity, bag-mask ventilation, suctioning secretions, and positioning a head all become non-trivial mechanical problems requiring restraint systems.[4][1]

• Ketamine does not relax the abdominal wall. Kenyan surgeons explicitly did not recommend it for long or complex abdominal cases. Any prolonged or complex intraperitoneal emergency on Mars will need more than ketamine alone.

• Skill decay is real. Kenyan program leaders' top-cited barrier was provider turnover, leaving facilities with no trained provider. The erosion of emergency skills in the crew medical officer over a multi-year mission could be substantial, and regular just-in-time refresher training is a proposed countermeasure.

The transferable lesson

The most valuable export from rural Kenya to the lunar surface is not ketamine. It is the package: a single well-characterized and shelf stable drug, a fixed dosing algorithm, a bounded rescue formulary with an explicit prohibition on improvisation, a defined minimum equipment set, a short intensive competency-based training program, a pocket checklist, and a continuous audit loop that feeds adverse events back into retraining.

That architecture is directly portable to an exploration medical system. It is compact, low-mass, cognitively offloaded, deliverable by a non-expert under stress, and it degrades gracefully. Space surgery research is rightly investing in robotics and AI-assisted decision support.[1][9] But, the Kenyan data make a case that the highest-yield near-term work may be far less exotic: define the smallest possible anesthesia protocol that a trained non-anesthetist can execute alone, validate it in analogue environments, and build the audit system before the first crew launches.

Two-thirds of the world already lives without access to timely emergency surgery. The engineering problem of anesthesia without an anesthetist has been under active field study for a decade. Exploration medicine should not solve it from scratch.

References

1. Surgery for Interplanetary Space Missions. Khanna R, Li Y, Cook M, et al. The British Journal of Surgery. 2026;113(3):znag005. doi:10.1093/bjs/znag005.

2. Space Medicine in the Era of Civilian Spaceflight. Stepanek J, Blue RS, Parazynski S. The New England Journal of Medicine. 2019;380(11):1053-1060. doi:10.1056/NEJMra1609012.

3. Medical Event Management for Future Deep Space Exploration Missions to Mars. Robertson JM, Dias RD, Gupta A, et al. The Journal of Surgical Research. 2020;246:305-314. doi:10.1016/j.jss.2019.09.065.

4. Wilderness Medical Society Clinical Practice Guidelines for the Treatment of Acute Pain in Austere Environments: 2024 Update. Fink PB, Wheeler AR, Smith WR, et al. Wilderness & Environmental Medicine. 2024;35(2):198-218. doi:10.1177/10806032241248422.

5. Wilderness Medical Society Practice Guidelines for the Treatment of Acute Pain in Remote Environments: 2014 Update. Russell KW, Scaife CL, Weber DC, et al. Wilderness & Environmental Medicine. 2014;25(4 Suppl):S96-104. doi:10.1016/j.wem.2014.07.016.

6. Ketamine Use in Operation Enduring Freedom. Leslie E, Pittman E, Drew B, Walrath B. Military Medicine. 2021;186(7-8):e720-e725. doi:10.1093/milmed/usab117.

7. Expanding Ketamine Application for Treatment of Acute Suicidality in Long-Duration Spaceflight. Kutz CJ, Mistry AM, Dukes CH. Aerospace Medicine and Human Performance. 2025;96(6):509-519. doi:10.3357/AMHP.6619.2025.

8. Crew Autonomy During Simulated Medical Event Management on Long Duration Space Exploration Missions. Yule S, Robertson JM, Mormann B, et al. Human Factors. 2023;65(6):1221-1234. doi:10.1177/00187208211067575.

9. Artificial Intelligence Applications in Space Medicine. Cheung HC, De Louche C, Komorowski M. Aerospace Medicine and Human Performance. 2023;94(8):610-622. doi:10.3357/AMHP.6178.2023.

As humanity looks toward interplanetary colonization, medical autonomy becomes a critical challenge. While robotic surgery is commonplace in modern hospitals, tele-surgery over vast distances introduces a formidable adversary: the speed of light. While there is a lot of interest in remote robotic surgery in space flight, the barrier imposed by communications delays remains an impediment to implementation. 

On Earth, a surgeon using a da Vinci robot experiences negligible delay. The movement of the hand translates instantly to the movement of the instrument. However, a signal sent from Earth to Mars takes an average of 20 minutes to arrive, depending on orbital alignment. Even a short delay of 3 seconds renders direct manual control impossible. If a surgeon sees a bleed and moves to clamp it, the patient has already been bleeding for 3 seconds before the doctor even saw the image, and the command takes another 3 seconds to reach the robot. 

The following tele-surgery simulator is a browser-based educational tool designed to demonstrate why traditional manual control fails in deep space environments and how advances in Supervisory Control and Edge Computing may provide the solution. The APEX Simulator gamifies this engineering challenge. It tasks users with neutralizing moving biological targets under varying latency conditions (0ms to 3000ms+). To succeed, the user must abandon the mouse and embrace automation. The simulator guides users through four distinct control protocols:

1. Manual Control (Direct Tele-operation)

• The Mechanic: The robot mimics the user's mouse position exactly.

• The Lesson: At 0ms (Earth), this is intuitive and precise. At 400ms (Low Earth Orbit), it feels spongy. At 3000ms (Mars), it is uncontrollable. This demonstrates the hard limit of human reaction time in feedback loops.

2. Ghost Assist (Visualized Latency)

• The Mechanic: An AI overlay shows a Ghost Cursor representing the user's real-time hand position, while the robot lags behind.

• The Lesson: Visualization helps the user lead the target, but it doesn't solve the physical delay. It highlights the disconnect between intent and execution. It can help with moderate latency but is still insufficient with more prolonged delays.

3. Predictive Command (Open Loop)

• The Mechanic: The user selects a target (by typing the number of the desired target into the keyboard), and the Earth computer calculates where that target will be when the signal arrives.

• The Lesson: This reduces user error and improves accuracy, until the target moves unexpectedly. This protocol demonstrates the fragility of "Open Loop" control. Math alone cannot account for the chaos of a biological environment (simulated here via Brownian motion).

4. Autonomous Agent (Supervisory Control)

• The Mechanic: The user sends a high-level intent: "Treat Target 1." (Again, this is done by typing into the keyboard the desired target's number.) The robot receives the command seconds later, uses its own local sensors and knowledge to locate Target 1 in real-time, and executes the task instantly.

• The Lesson: This is Edge Computing. By moving the brain to the robot (the edge), we close the feedback loop locally. The latency becomes irrelevant to the precision of the cut; it only affects the initiation of the task.

The APEX simulator helps show that the future of remote surgery isn't about better bandwidth, but that it's about smarter robots. Go ahead and give it a try!