Patient and case characteristics with results of samples taken*
| ID no. | Age range,† yr | Sex | No. of days from first SARS-CoV-2 positive test to surgery (repeat test) | Procedure performed | VOC | Ct value of NP swab‡§ | Positive¶ samples obtained (Ct value) | Negative** samples |
|---|---|---|---|---|---|---|---|---|
| 1 | 30–39 | F | 3 | Cesarean delivery (spinal anesthesia) | Not tested | NA | None |
|
| 2 | 30–39 | F | 4 | Cesarean delivery (spinal anesthesia) | Not tested | NA | None |
|
| 3 | 40–49 | F | 3 | Cesarean delivery (spinal anesthesia) | Not tested | 30.89 | Placenta (25.9) |
|
| 4 | 20–29 | F | 30 (24) | Cesarean delivery (intubation and extubation) | Alpha | 18.69 | ETT (25.66) |
|
| 5 | 20–29 | F | 14 (0) | Cesarean delivery (spinal anesthesia) | No VOC | 34.29 | None |
|
| 6 | 30–39 | F | 3 | Cesarean delivery | Alpha | 24.41 |
|
|
| 7 | 30–39 | F | 1 | Vaginal delivery | Not tested | 31.31 | None |
|
| 8 | 30–39 | F | 0 | Vaginal delivery | Not tested | 18.87 | None |
|
| 9 | 30–39 | F | 14 (0) | Vaginal (vacuum) delivery | Alpha | 14.81 | None |
|
| 10 | 50–59 | F | 1 | TAHBSO, node dissection (intubation and extubation) | Not tested | 32.17 | None |
|
| 11 | 40–49 | F | 16 | TAHBSO, omentectomy (intubation and extubation) | Alpha | 11.86 |
|
|
| 12 | 80–89 | F | 4 | Left hip hemiarthroplasty (spinal anesthesia) | Not tested | 21.44 | None |
|
| 13 | 30–39 | F | 2 | Bilateral tibial fracture (spinal anesthesia) | Not tested | NA | None |
|
| 14 | 50–59 | M | 22 (3) | T10–T12 spinal decompression (arrived in OR intubated and left intubated) | Not tested | 29.17 | ETT (22.27) |
|
| 15 | 70–79 | M | 2 (0) | ORIF cervical spine fracture (arrived in OR intubated and left intubated) | Not tested | NA | None |
|
| 16 | 60–69 | F | 4(2) | ORIF ankle, fibula (arrived in OR intubated and left intubated) | Alpha | 32.35 | None |
|
| 17 | 50–59 | M | 2 | Humerus fracture (came to OR intubated and left OR intubated) | No VOC | 13.45 | Floor (21.97) |
|
| 18 | 70–79 | M | 26 (5) | Superficial and deep compartment irrigation of leg and débridement (arrived in OR intubated and left OR intubated) | Alpha | 37.25 | None |
|
| 19 | 50–59 | M | 1 | Laparotomy (came to OR intubated and left intubated) | Not tested | 32.7 | None |
|
| 20 | 50–59 | F | 15 | Bilateral mastectomy (intubation and extubation) | Not tested | NA | None |
|
| 21 | 70–79 | M | 70 (3) | Tracheostomy | Not tested | NA | ETT (21.74) |
|
| 22 | 60–69 | M | 50 (5) | Tracheostomy | Alpha | NA | None |
|
| 23 | 60–69 | M | 54 (16) | Tracheostomy | No VOC | NA |
|
|
| 24 | 70–79 | F | 62 (2) | Tracheostomy, gastroscopy, insertion of gastrostomy tube | No VOC | 32.94 |
|
|
| 25 | 70–79 | M | 4 | Gastroduodenoscopy | Alpha | 18.62 | Gastroscope (30.56) |
|
| 26 | 60–69 | F | 2 | Burn reconstruction (intubation and extubation) | Not tested | NA | ETT (24.88) |
|
| 27 | 70–79 | M | 2 | Débridement, graft lower abdomen, thighs (intubation and extubation) | Beta/ Gamma | 26.69 |
|
|
| 28 | 20–29 | M | 2 | Hand surgery (regional block) | Not tested | 35.29 | None |
|
| 29 | 60–69 | F | 1 | Débridement and graft (arrived in OR intubated and left intubated) | Alpha | 36.01 | None |
|
| 30 | 60–69 | M | 14 | Aortic valve replacement (intubated in OR and left OR intubated) | No VOC | 32.98 | None |
|
| 31 | 70–79 | M | 2 | Carotid endarterectomy (intubation and extubation) | Not tested | NA | None |
|
| 32 | 40–49 | M | 0 | Decompressive craniotomy (arrived in OR intubated and left intubated) | Not tested | NA | None |
|
Note: Alpha = Alpha variant (United Kingdom, B.1.1.7); Beta/Gamma = Beta or Gamma variant (South African, B.1.351; or Brazilian, P.1); CI = confidence interval; Ct = cycle threshold: the number of cycles required for the fluorescent signal to cross the threshold in RT-PCR (a lower Ct would indicate a higher viral load); ETT = endotracheal tube; F = female; GI = gastrointestinal; HCW = health care worker; M = male; NA = not available; NP = nasopharyngeal; OB = obstetrics; OR = operating room; ORIF = open reduction internal fixation; RT-PCR = reverse transcription polymerase chain reaction; TAHBSO = total abdominal hysterectomy bilateral salpingo-oophorectomy; UTM = universal transport medium; VOC = variant of concern.
↵* See Appendix 4 (available at www.cmajopen.ca/content/10/2/E450/suppl/DC1) for more detail including active air sampling times.
↵† Age range used to preserve anonymity.
↵‡ The mean Ct value of the initial patient NP swab was 21.72 (95% CI 16.90–27.29) and 29.96 (95% CI 27.07–33.43), respectively, in the group of patients that had positive samples (evidence of SARS-CoV-2 RNA) and the group that had all samples negative (Mann–Whitney U test, p = 0.007).
↵§ The mean Ct value of the initial patient NP swab was 24.52 (95% CI 18.72–30.99) and 28.41 (95% CI 25.35–30.33), respectively, in the group of patients that had known VOC and the group that included known non-VOC and unknown or untested status (Mann–Whitney U test, p = 0.5).
↵¶ Positive samples refer to the samples collected (patient, instrument, equipment, surface, air and mask) that had the presence of SARS-CoV-2 RNA detected on real-time RT-PCR.
↵** Negative samples refer to the samples collected (patient, instrument, equipment, surface, air and mask) that did not have the presence of SARS-CoV-2 RNA detected on real-time RT-PCR.
↵†† A variety of masks were used by health care workers in our cohort, including American Society for Testing and Materials (ASTM) level 3 masks, N95 masks, double masks (inner mask sampled) or masks worn under face shields. Of 143 masks: 51 from nurses, 31 from anesthetists, 32 from surgeons and 29 from surgical house staff.