{"uid":"cap_JGNUczM5Xy4hvPUdWwAkI","slug":"possum-surgical-risk-calculator-copeland-1991-329253dd","name":"POSSUM Surgical Risk Calculator (Copeland 1991)","description":"Copeland 1991 POSSUM surgical audit: 12 physiologic and 6 operative 1/2/4/8 items (age has no 8; ECG has no 2). Returns physiologic_score, operative_score, and estimated morbidity and mortality percents from the unrounded Copeland logits. Not P-POSSUM (Whiteley), not a diagnosis, not operative consent. magent does not examine the patient.","url":"https://api.magentlab.com/api/calc/possum","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["age_years","cardiac","respiratory","systolic_bp_mm_hg","pulse","gcs","hemoglobin_g_dl","wbc_k_ul","urea_mmol_l","sodium_mmol_l","potassium_mmol_l","ecg","operative_severity","multiple_procedures","blood_loss_ml","peritoneal_soiling","malignancy","mode_of_surgery"],"properties":{"ecg":{"enum":["normal","atrial_fibrillation_60_90","other_abnormal_or_ectopics_or_q_st_t"],"type":"string","description":"Copeland 1991 electrocardiogram as assigned by the caller: normal (1); atrial_fibrillation_60_90 (4); other_abnormal_or_ectopics_or_q_st_t (8). No 2-point cell. magent does not interpret a tracing."},"gcs":{"type":"integer","description":"Glasgow Coma Scale total as assigned by the caller, integer 3-15. 15 → 1; 12-14 → 2; 9-11 → 4; ≤8 → 8. magent does not examine the patient."},"pulse":{"type":"integer","description":"Pulse in beats/min, integer 20-250. 50-80 → 1; 81-100 → 2; 40-49 or 101-120 → 4; ≤39 or ≥121 → 8. magent does not measure pulse."},"cardiac":{"enum":["no_failure","diuretic_digoxin_antianginal_or_hypertensive","peripheral_edema_warfarin_or_borderline_cardiomegaly","raised_jvp_or_cardiomegaly"],"type":"string","description":"Copeland 1991 cardiac signs as assigned by the caller: no_failure (1); diuretic_digoxin_antianginal_or_hypertensive (2); peripheral_edema_warfarin_or_borderline_cardiomegaly (4); raised_jvp_or_cardiomegaly (8). magent does not examine the patient."},"wbc_k_ul":{"type":"number","description":"White cell count in ×10^9/L (0.1-100). 4.0-10.0 → 1; 10.1-20.0 or 3.1-3.9 → 2; ≥20.1 → 4; ≤3.0 → 8. Table 1 lists 3.1-4.0 on the 2-point cell; 4.0 is scored in the 1-point band."},"age_years":{"type":"integer","description":"Age in years, integer 16-120 (Copeland 1991 Table 1). ≤60 → 1; 61-70 → 2; ≥71 → 4. No 8-point cell."},"malignancy":{"enum":["none","primary_only","nodal_metastases","distant_metastases"],"type":"string","description":"Copeland 1991 presence of malignancy as assigned by the caller: none (1); primary_only (2); nodal_metastases (4); distant_metastases (8). magent does not diagnose."},"respiratory":{"enum":["no_dyspnea","exertional_or_mild_coad","limiting_or_moderate_coad","rest_or_fibrosis_consolidation"],"type":"string","description":"Copeland 1991 respiratory history as assigned by the caller: no_dyspnea (1); exertional_or_mild_coad (2); limiting_or_moderate_coad (4); rest_or_fibrosis_consolidation (8). magent does not examine the patient."},"urea_mmol_l":{"type":"number","description":"Serum urea in mmol/L (0.5-80). ≤7.5 → 1; 7.6-10.0 → 2; 10.1-15.0 → 4; ≥15.1 → 8."},"blood_loss_ml":{"type":"number","description":"Total blood loss in mL (0-20000). ≤100 → 1; 101-500 → 2; 501-999 → 4; ≥1000 → 8. Table 2 writes <100 then 101-500; 100 mL is scored with the lowest band."},"sodium_mmol_l":{"type":"number","description":"Serum sodium in mmol/L (90-200). ≥136 → 1; 131-135 → 2; 126-130 → 4; ≤125 → 8."},"hemoglobin_g_dl":{"type":"number","description":"Haemoglobin in g/dL (3-25). 13-16 → 1; 11.5-12.9 or 16.1-17.0 → 2; 10.0-11.4 or 17.1-18.0 → 4; ≤9.9 or ≥18.1 → 8."},"mode_of_surgery":{"enum":["elective","emergency_resuscitation_gt_2h_or_lt_24h","immediate_lt_2h"],"type":"string","description":"Copeland 1991 mode of surgery as assigned by the caller: elective (1); emergency_resuscitation_gt_2h_or_lt_24h (4); immediate_lt_2h (8). No 2-point cell."},"potassium_mmol_l":{"type":"number","description":"Serum potassium in mmol/L (1-12). 3.5-5.0 → 1; 3.2-3.4 or 5.1-5.3 → 2; 2.9-3.1 or 5.4-5.9 → 4; ≤2.8 or ≥6.0 → 8."},"systolic_bp_mm_hg":{"type":"number","description":"Systolic blood pressure in mm Hg (20-300). 110-130 → 1; 100-109 or 131-170 → 2; 90-99 or ≥171 → 4; ≤89 → 8. magent does not measure blood pressure."},"operative_severity":{"enum":["minor","moderate","major","major_plus"],"type":"string","description":"Copeland 1991 Table 2 operative severity as assigned by the caller: minor (1); moderate (2); major (4); major_plus (8). magent does not classify an operative note."},"peritoneal_soiling":{"enum":["none","minor_serous","local_pus","free_bowel_pus_blood"],"type":"string","description":"Copeland 1991 peritoneal soiling as assigned by the caller: none (1); minor_serous (2); local_pus (4); free_bowel_pus_blood (8). magent does not examine the patient."},"multiple_procedures":{"enum":["one","two","more_than_two"],"type":"string","description":"Number of procedures as assigned by the caller: one (1); two (4); more_than_two (8). No 2-point cell."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_D84XQby9yMb8OXLMPzF08","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes Copeland 1991 POSSUM physiologic and operative scores, then returns estimated morbidity and mortality percentages from the unrounded logit equations.","exampleAgentPrompt":"Run a POSSUM surgical risk calculation for a 72-year-old patient with no cardiac failure, mild COPD, systolic BP 130, pulse 88, GCS 15, hemoglobin 11.2 g/dL, WBC 9.4, urea 7.1 mmol/L, sodium 138, potassium 4.1, ECG normal, major operative severity, no multiple procedures, blood loss under 100 mL, no peritoneal soiling, benign malignancy status, and elective surgery — what are the physiologic score, operative score, and estimated morbidity and mortality?","exampleUseCases":[{"title":"Preoperative audit for elective bowel resection","prompt":"I need a POSSUM score for a 65-year-old patient going for elective colonic resection — GCS 15, pulse 75, systolic BP 145, hemoglobin 12.8, WBC 8.2, urea 5.9 mmol/L, sodium 140, potassium 3.9, no cardiac failure, mild respiratory limitation, normal ECG, major severity operation, single procedure, blood loss under 100 mL, no peritoneal soiling, malignant pathology, elective mode. What are the physiologic and operative scores and the predicted morbidity and mortality?"},{"title":"Emergency laparotomy risk estimation","prompt":"Calculate the Copeland POSSUM risk for an 80-year-old emergency laparotomy patient: pulse 124, systolic BP 90, GCS 13, hemoglobin 9.1 g/dL, WBC 21.5, urea 14 mmol/L, sodium 132, potassium 5.2, raised JVP with cardiomegaly, severe respiratory disease on home oxygen, atrial fibrillation ECG 60-90, major-plus operative severity, multiple procedures, blood loss 500-999 mL, free bowel content soiling, node-positive malignancy, emergency surgery."},{"title":"Surgical audit data entry for quality review","prompt":"For our surgical audit, compute the POSSUM score for a 58-year-old who had an urgent cholecystectomy: GCS 15, pulse 95, systolic BP 160, hemoglobin 13.5, WBC 14.3, urea 8.8 mmol/L, sodium 136, potassium 4.0, on diuretics for hypertension, mild COPD on inhaler, normal ECG, moderate operative severity, single procedure, blood loss under 100 mL, local peritoneal soiling, benign disease, urgent surgery."}],"resultDescription":"Returns a JSON object with physiologic_score (integer sum of 12 physiologic items, each 1/2/4/8), operative_score (integer sum of 6 operative items), estimated_morbidity_percent (floating-point percent derived from the unrounded Copeland logit), and estimated_mortality_percent (floating-point percent from the Copeland logit). These are statistical estimates from the 1991 Copeland derivation dataset, not clinical diagnoses or consent documents.","failureModes":["Missing required query parameters returns a 400 error","Out-of-range numeric values (e.g. GCS outside 3-15, pulse outside 20-250) may return validation errors","Invalid enum strings for categorical fields (cardiac, ecg, operative_severity, etc.) cause request rejection","Payment failure or insufficient USDC balance results in 402 response","Extreme physiologic values may produce logit-derived probabilities approaching 0% or 100% but remain mathematically valid"],"whenToPreferThis":"Use this endpoint when you need the original Copeland 1991 POSSUM formulation — specifically when the caller has already assigned the discretized physiologic and operative item values and wants the unrounded logit-based morbidity and mortality estimates. Prefer this over P-POSSUM (Whiteley) when the standard POSSUM mortality equation (not the Portsmouth modification) is required for audit benchmarking or research replication against the original 1991 paper. Do not use for pediatric patients, purely diagnostic questions, or as a substitute for clinical evaluation.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:21:31.920Z","isFirstParty":false}