Out-of-hours maxillofacial trauma surgery: a risk factor for complications?


Recent literature from general and orthopaedic surgery as well as anaesthetic viewpoints has identified that operations performed outside normal work hours pose potential risks for both patients and healthcare workers. This is in contrast to the increasing pressure for 24 h surgical availability for the public and the desire to reduce waiting times for patients. Further, there is evidence of the effects of fatigue on reducing performance. The authors aim to compare outcomes of maxillofacial trauma surgery performed in and out of normal work hours. Retrospective analysis was carried out on all maxillofacial trauma surgery under general anaesthesia at a tertiary referral hospital over a 14-month period. Outcomes of patient mortality, injury severity, patient demographics and operation duration were analysed with reference to two groups: in-hours (0800–1700 Monday to Friday) and out-of-hours (1700–0800 Monday to Friday as well as all operations performed Saturday and Sunday). 134 patients/procedures met the inclusion criteria, 53 out-of-hours and 81 in-hours. A statistically significant ( p = 0.05) higher complication rate (13%) was found in the out-of-hours cases compared to the in-hours cases (4%). The potential implications for this result on the need for increased availability of dedicated in-hours maxillofacial trauma operating lists at major hospitals are discussed.

Recent literature from general and orthopaedic surgery as well as anaesthetic viewpoints has identified that operations performed outside normal work hours pose potential risks for patients and healthcare workers . This is in contrast to the growing demand for emergency theatre time out of normal working hours to limit waiting times for the public. In New South Wales, Australia, recent guidelines are available that assist in scheduling of emergency surgery . The overall aim of such guidelines is to limit adverse events for patients and healthcare workers, and decrease the economic burden that is associated with performing non-elective surgery after hours. Much evidence exists detailing the effects of fatigue on reducing performance . There is suggestion that the most effective method of reducing this risk in surgery is to eliminate surgery performed after hours unless absolutely necessary .

The majority of maxillofacial trauma surgery seen at the authors’ institution is non-urgent, yet a large proportion is performed out of normal work hours due to the limited availability of in-hour theatre time. Theoretically, operating on these cases out-of-hours could have implications on treatment outcomes. The authors aim to compare outcomes of maxillofacial trauma surgery performed in- and out-of-normal work hours with particular emphasis on postoperative complications.

Materials and Methods

After receiving hospital approval to access electronic records, a 14-month (January 2009–March 2010) retrospective analysis of all maxillofacial trauma surgery under general anaesthesia at a tertiary referral trauma centre in the Australian Capital Territory, Australia was carried out. Data collected included: age; gender; medical co-morbidities; mechanism of injury; a severity score of injury; time from injury to operation; type of operation; preoperative complications; intra-operative complications; postoperative complications; indigenous status; presence or absence of consultant; operation duration; operation start time and finish; date of operation. The Maxillofacial Injury Severity Score (MFISS) as described by Zhang et al. , was available for all but three of the patients from a pre-existing audit of all maxillofacial trauma patients from this hospital. Registrars, in addition to one of two consultants, performed operations and this was recorded as Consultant A present, Consultant B present or registrar only. Where patients had multiple procedures, their definitive, corrective, maxillofacial trauma surgery was used for data collection. For example, some patients had a tracheotomy performed as a stabilising procedure and an open reduction, internal fixation (ORIF) of facial fractures at a later date. In such a scenario, the ORIF surgery data were used for the analysis. Operations were classified as within normal working hours (in-hours) between 0800 and 1700 Monday to Friday and as out-of-hours between 1700 and 0800 Monday to Friday as well as all times Saturday and Sunday. Complications were recorded as pre-, intra- or postoperative. Complications were for a period up to 6 weeks postoperatively from clinical records of follow-up appointments.

Complications were recorded as documented in clinical notes and later classified as minor or major. Minor complications included paraesthesia, persistent diplopia not requiring further surgery, pain not requiring further surgery, non-specific headaches, and other minor issues not requiring any additional medical or surgical management. Major complications were all those requiring another admission, or corrective treatment, including under local anaesthetic, general anaesthetic or by another specialist such as an orthodontist in the case of malocclusion. Data were entered into SPSS (SPSS Inc., Chicago, IL, USA) for statistical analysis. In addition to descriptive statistics, logistic regression was used to examine correlates with major complications. Odds ratios and 95% confidence intervals, along with p values are presented. A two-block method of entry was used. The first block included potential confounding factors: age; gender; indigenous status; severity; duration; consultant; intra-operative complication; age of injury. The second block examined the contribution of in- or out-hours of surgery time. The probability of inclusion was 0.05 a probability of 0.1 was used for removal. A forward likelihood ratio method was used.


138 patients were identified in the search. Of these, 134 were used in the statistical analysis. Those for whom MFISS was not available were excluded. There was one death in the in-hours group that was excluded. This patient was a multi-trauma case from a motor vehicle accident. He underwent ORIF of a mandible fracture at an early stage in his overall management but succumbed to brain injury sustained during his accident and life-support was stopped at 1 month post-injury. He had no identifiable complications related to his maxillofacial surgery procedure up until the time of death. The overall cohort showed a male predominance and age pattern consistent with other maxillofacial trauma epidemiological studies . Table 1 demonstrates the similarities between the two groups. Descriptive statistics further demonstrate the similarities in demographics between the in- and out-of-hours groups ( Tables 2 and 3 ). Table 4 highlights location of injuries for the entire patient cohort. Registrar-only was present for 11 cases, of which none had any reported intra- or postoperative complications. In the out-of-hours group there were 7 (13%) major complications and 18 (34%) minor complications. Comparatively, in the in-hours group there were 3 (4%) major complications and 24 (30%) minor complications. The specific detail of each patient assigned as having a major complication is listed in Table 5 . There was a statistically significant increase in major complications in the out-of-hours group compared to the in-hours group (OR 4.2 CI 1–18, p = 0.05) after adjusting for age, gender, duration, consultant, MFISS, intra-operative complications, age of injury and indigenous status. There was no significant difference in minor complications between the in- and out-of-hours groups.

Table 1
Comparison of in- and out-of-hours groups.
In-hours Out-of-hours
Number 81 53
Males 72 (89%) 44 (83%)
Females 10 (12%) 9 (17%)
Existing co-morbidities 38 (47%) 25 (47%)
Indigenous 3 (4%) 3 (6%)
Consultant A 49 (63%) 29 (37%)
Consultant B 26 (59%) 18 (41%)
Consultant A and B percentages represent the proportion of their cases for each group. Means were calculated using SPSS (SPPS Software Inc., Chicago, IL).

Table 2
Descriptive statistics (in-hours).
Minimum Maximum Mean Std deviation
Age 1 71 27.23 13.214
MFISS 1 45 9.93 7.914
Duration (min) 1 361 69.26 58.318
Age of injury (days) 0 20 5.96 4.462

Table 3
Descriptive statistics (out-of-hours).
Minimum Maximum Mean Std deviation
Age 4 69 27.64 12.660
MFISS 1 42 11.85 8.422
Duration (min) 16 185 77.51 44.912
Age of injury (days) 0 35 5.06 6.701

Jan 24, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Out-of-hours maxillofacial trauma surgery: a risk factor for complications?
Premium Wordpress Themes by UFO Themes